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Patterns of Neotropical Plant Species Diversity
Abstract
Diversity has been given a central role in attempts to develop a general theory of ecology (Johnson and Raven, 1970). Much attention has been focused on large-scale trends, such as the increase in species diversity with decreasing latitude (Pianka, 1966; Mac Arthur, 1965; Fischer, 1960; Tramer, 1974), but there is surprisingly little documentation of the equally striking changes in diversity within the tropics. Moreover, additional information on tropical plant species diversity patterns is critically needed because of their potential importance in resolving some of the fundamental and theoretically significant differences of opinion as to the nature and manner of regulation of species diversity.
... These families are also among the ten most diverse in the flora of Brazil and the Atlantic Forest Biome (BFG 2015). Fabaceae, Rubiaceae, Euphorbiaceae and Bignoniaceae are also among the ten richest families in the Neotropics (Gentry 1982). In addition, Fabaceae and Myrtaceae stand out in terms of species richness for dense rainforests, semideciduous seasonal forests and lowland tropical forests (Gentry 1982(Gentry , 1988(Gentry , 1995. ...
... Fabaceae, Rubiaceae, Euphorbiaceae and Bignoniaceae are also among the ten richest families in the Neotropics (Gentry 1982). In addition, Fabaceae and Myrtaceae stand out in terms of species richness for dense rainforests, semideciduous seasonal forests and lowland tropical forests (Gentry 1982(Gentry , 1988(Gentry , 1995. However, of the ten families with the greatest species richness in the present work (Fabaceae, Euphorbiaceae, Asteraceae, Sapindaceae, Malvaceae, Cyperaceae, Malpighiaceae, Myrtaceae, Bromeliaceae and Rubiaceae, in descending order), with the exception of Malvaceae, the study by Araujo (2000) demonstrates that the others are among the richest in species in the Restinga forests of Rio de Janeiro. ...
The present work describes the phytophysiognomies and inventories the remaining floristic diversity of the Brisas Environmental Protection Area, which is located on the coast of Sepetiba Bay in the state of Rio de Janeiro, Brazil, covering approximately 101 hectares. Three phytophysiognomies were identified and described, namely Restinga, the Lowland Dense Ombrophylous Forest and the Mangrove. Different types of vegetation can be recognized for Restinga, such as beaches and dunes, those located on sandy ridges, in this case represented by Low and High Restinga forests, and the vegetation associated with depressions, such as the Swampy Restinga and Swampy forest. The floristic survey identified 311 species, distributed in 231 genera and 86 families. Herbaceous plants represent 29.26% of the flora, followed by vines (27.75%), trees (27.33%), shrubs (14.46%) and epiphytes (4%). Restinga is home to 81% of the flora, followed by the Lowland Dense Ombrophylous Forest (28.30%) and the Mangrove (2.25%). The most representative families were Fabaceae (38 spp.), Euphorbiaceae (15 spp.), Asteraceae (14 spp.) and Sapindaceae (14 spp.). The area has low floristic similarity with other areas of the state of Rio de Janeiro, but it has a greater grouping with restingas from the state of Rio de Janeiro.
... El muestreo se realizó durante dos campañas de campo: 31 de octubre al 2 de noviembre 2021 y 2 al 3 de marzo 2022. Se evaluó un área total de 1 000 m² (Gentry, 1982) distribuidas en 10 parcelas de 20 x 5 m (Camacho-Rico, Trejo, y Bonfil, 2006) que se establecieron paralelas al cauce del río a no más de 5 m del borde, orientadas río abajo considerando la morfología y accesibilidad del terreno (Lebrija-Trejos, 2001;Alvarado, 2008). Dentro de cada parcela se establecieron dos subparcelas de 4 m 2 para la evaluación del estrato arbustivo. ...
... Entre estas familias, se destacan Fabaceae (siete especies), Piperaceae (cinco), Cyatheaceae (cuatro), Lauraceae (tres) como las más ricas. A excepción de Cyatheaceae, estas familias son ampliamente reconocidas en la literatura por su alta riqueza en los bosques ribereños del Neotrópico (Gentry, 1982;Lebrija-Trejos, 2001; Las familias con mayor riqueza fueron: Piperaceae con cinco especies, seguida de Cyatheaceae y Fabaceae, ambas con tres. Por otro lado, en la zona núcleo de la reserva, se contabilizaron 368 individuos pertenecientes a 26 especies, repartidas en 24 géneros y 20 familias. ...
The riparian forests in the Loma Quita Espuela Scientific Reserve, located in the Dominican Republic, face ecological threats from intensive productive activities. However, research in this area remains limited. In response, a study was conducted to analyze the diversity, structure, and composition of woody species along the Nagua River. Utilizing a 1,000 m² area divided into 10 plots, all woody species were catalogued, and the height and diameter of trees with a diameter ≥ 2.5 cm were measured. The study identified 627 individuals from 53 species, demonstrating diversity levels consistent with regional riparian forests. The forest exhibited low growth, with vegetation in early developmental stages and self-regenerating stable populations. Guarea guidonia emerged as a prominent specie, while Mora abbottii was prevalent in higher, pristine areas. The biodiversity was notably rich, marked by a variety of unique species. This study underscores the critical role of riparian forests in flora conservation, especially in ecosystems dominated by a few species.
... However, considering the spectrum of seed dispersal in the SDTF of the Mexican Pacific, this hypothesis can be discarded (Arredondo-Amezcua et al. 2015). In general, trees in the Neotropical SDTF are more often anemochorous than the (endo) zoochorous (Frankie, 1974;Gentry 1982;Bullock 1995;Greene et al. 2008;Lopezaraiza-Mikel et al. 2014). Both dispersal syndromes disseminate a fraction of their seeds out of the immediate local habitat. ...
... The probability that habitat preference patterns are driven by dispersal limitation may be low considering that most species are dispersed by wind (Gentry 1982;Bullock 1995;Greene et al. 2008). However, it is important to consider some aspects that can restrict dispersal and that could help explain the patterns observed. ...
In this article, we explored how the taxonomic, functional and phylogenetic patterns of woody STDF species in north-western Mexico are correlated with habitat type defined by slope orientation (north-facing vs. south-facing) and topographic position (upslope vs. slope bottom). By studying these patterns in two life-stages (juveniles and adults) of trees and shrubs. Our results showed the segregation of two species groups in both life stages is related to slope orientation, but not to topographic position. We found a strong habitat association for 68% of the species with both juveniles and adults similarly associated with the same habitat. Slope orientation was related to taxonomic, functional and phylogenetic structure, but it differed in the two life stages. The functional and evolutionary segregation of species between north-facing vs. south-facing habitats indicates that species are non-randomly distributed; suggesting that deterministic mechanisms (e.g. topographic habitat specialisation) are operating at a local scale.
... Los bosques tropicales se caracterizan por tener una alta riqueza y diversidad de especies, lo cual ha generado un gran interés por parte de biólogos en determinar los mecanismos que han llevado al origen y mantenimiento de esta alta diversidad (Richards, 1952). La mayor parte de los estudios se han centrado en comparaciones de la composición florística a lo largo de gradientes latitudinales o distintas escalas especiales (Gentry 1982). Solamente en las últimas dos décadas hemos comenzado a comprender la estructura y dinámica de estos bosques, a través del uso de parcelas permanentes de gran escala para estudiar los cambios en poblaciones a lo largo del tiempo (Hubbel & Foster 1986, Losos & Leigh 2004. ...
... Uno de los factores que determinan la composición florística esta relacionada con la historia evolutiva, biogeografía e historia de la región de estudio (Crane et al. 1995, Morley 2000. Dentro de una misma región biogeográfica encontramos diferencias a lo largo de gradientes latitudinales, que se encuentran correlacionados con factores biofísicos como suelos o precipitación (Gentry 1982, Ashton 1997, Condit et al. 2002. Sin embargo, encontramos que existe una gran variación en la diversidad de especies a nivel local, lo cual lleva a preguntarse cuales son los mecanismos que determinan la coexistencia de tantas especies en un espacio reducido. ...
Los bosques tropicales se caracterizan por tener una alta riqueza y diversidad de especies. Existen diversas hipótesis sobre los factores que determinan el origen y mantenimiento de esta riqueza, las cuales han sido estudiadas a través de una red global de parcelas permanentes. Este es el primer estudio de gran escala sobre la estructura y dinámica de poblaciones de plantas en un bosque montano, a través de una parcela permanente establecida en la Reserva Natural La Planada (Nariño, Colombia). La parcela ha permitido el seguimiento de más de 130,000 árboles y arbustos pertenecientes a 240 especies de plantas a lo largo de cinco años. Los resultados revelan una tasa de mortalidad de plantas de 3.65%/año y una tasa de reclutamiento de 3.52% anual, mientras que el área basal y biomasa de la parcela incrementó en cerca del 5% en cinco años. Los bosques montanos de los Andes presentan una dinámica de poblaciones muy alta y tasas de crecimiento bajas comparadas con bosques tropicales en zonas bajas.
... To estimate food availability, we used a food availability index (Chaves & Bicca-Marques, 2016), which integrates both spatial and temporal variation in potential food resources. To determine spatial variation in food availability, following the zoning of the home ranges of the two groups, we identified feeding trees in core, non-core, and overlap areas using the Gentry method (Gentry, 1982). Accordingly, in each area of the home range we plotted 10 randomly distributed transects of 2 Â 50 m (Gentry, 1982). ...
... To determine spatial variation in food availability, following the zoning of the home ranges of the two groups, we identified feeding trees in core, non-core, and overlap areas using the Gentry method (Gentry, 1982). Accordingly, in each area of the home range we plotted 10 randomly distributed transects of 2 Â 50 m (Gentry, 1982). In each transect we identified all trees reported as food sources for howler monkeys to species level (Dias & Rangel-Negrín, 2015). ...
Objectives:
Long-distance vocalizations are used by primates in a variety of contexts and may have different functions. The long-distance vocalizations of howler monkeys (Alouatta spp.) underlie the spatial regulation of neighboring groups and could be associated with the defense of food resources. Here, we test the hypothesis that the behavioral responses of mantled howler monkeys (A. palliata) to neighbor long-distance vocalizations are influenced by the potential for range defensibility while accounting for location within the home range and food availability.
Methods:
We studied two groups for 13 months and a total of 888 h at La Flor de Catemaco (Mexico). Group 1 had a 92-ha home range and Group 2 had a 24-ha home range. We recorded vocalizations (N = 178 calls) and movements (N = 74 movements) of focal groups following long-distance vocalizations produced by their neighbors.
Results:
Movement responses, but not vocal responses, were predicted by range defensibility, location, and food availability. As predicted, the group living in the smaller and more defendable range showed stronger movement responses than the group in the larger home range. These movement responses had a shorter latency and longer duration in more valuable spatial and temporal contexts (i.e., the core area and during periods of low food availability).
Conclusions:
These results suggest that the tradeoff between the costs and benefits of range defense varies according to the interactions between home range size and both the spatial (core areas) and temporal (food availability) abundance of resources. Thus, the responses of mantled howler monkeys to neighbor long-distance vocalizations could be related to home range defensibility.
... Para describir las características florísticas, estructurales y de diversidad de una comunidad vegetal, se sugiere cubrir un área de muestreo de al menos 1 000 m 2 (0.1 ha) (Gentry 1982, Trejo 2005. De este modo, para el muestreo de la vegetación leñosa en el sitio de estudio se utilizaron 10 parcelas cuadradas (10 × 10 m = 100 m 2 ) distribuidas de manera equitativa (Gallardo-Cruz et al. 2009) en línea recta con dirección este-oeste, sobre un lomerío de 10 msnm, cubriendo un área total de 1 000 m 2 (Figura 1). ...
The objective of this study was to describe the diversity, composition, and structure of the woody vegetation in a section of LDF in Lerma, Campeche. Between August and September 2018, 10 plots of 10 × 10 m2 (1 000 m2 in total) were delimited, measuring all woody individuals with diameter at breast height (DBH = 1.30 cm). The structure of the site was described based on the relative values of density, frequency, and dominance (IVI), as well as the distribution of diameter classes. Diversity was estimated with the Shannon-Wiener index (H'), while equity was measured by the Pielou index. 40 woody species were recorded, belonging to 35 genera and 19 families. The H' index had a value of 2.92, and the Pielou index was 0.79, the density was 8 950 ind ha-1. Gymnopodium floribundum (204 individuals) and Lonchocarpus xuul (129) were the most abundant species. Bursera simaruba and Lysiloma latisiliquum showed higher diameter values (36 and 28.6 cm DBH, respectively). The families Rubiaceae (eight species), Fabaceae (five species), Ebenaceae and Polygonaceae (three species each) were the most representative. The species with the highest IVI were Gymnopodium floribundum (48.24%), Lonchocarpus xuul (29.12%), Bursera simaruba (26.11%) and Lysiloma latisiliquum (24.98%), these species being the most important in the structure of the LDF in the site. The distribution of the diameter classes suggests that the section of the LDF in Lerma Campeche is in an adequate state of regeneration.
... Our research reveals a negative correlation between pollen diversity in the A. mellifera diet and latitude ( Figure 6b). Supporting our findings, existing literature suggests a trend where plant diversity tends to rise with decreasing latitude in comparable habitats and elevations (Gentry, 1982). ...
The decline of honey bee populations significantly impacts the human food supply due to poor pollination and yield decreases of essential crop species. Given the reduction of pollinators, research into critical landscape components, such as floral resource availability and land use change, might provide valuable information about the nutritional status and health of honey bee colonies. To address this issue, we examine the effects of landscape factors like agricultural area, urban area, and climatic factors, including maximum temperature, minimum temperature, relative humidity, and precipitation, on honey bee hive populations and nutritional health of 326 honey bee colonies across varying landscapes in Mexico. DNA metabarcoding facilitated the precise identification of pollen from 267 plant species, encompassing 243 genera and 80 families, revealing a primary herb‐based diet. Areas characterized by high landscape diversity exhibited greater pollen diversity within the colony. Conversely, colonies situated in regions with higher proportions of agricultural and urban landscapes demonstrated lower bee density. The maximum ambient temperature outside hives positively correlated with pollen diversity, aligning with a simultaneous decrease in bee density. Conversely, higher relative humidity positively influenced both the bee density of the colony and the diversity of foraged pollen. Our national‐level study investigated pollen dietary availability and colony size in different habitat types, latitudes, climatic conditions, and varied levels and types of disturbances. This effort was taken to gain a better insight into the mechanisms driving declines in honey bee populations. This study illustrates the need for more biodiverse agricultural landscapes, the preservation of diverse habitats, and the conservation of natural and semi‐natural spaces. These measures can help to improve the habitat quality of other bee species, as well as restore essential ecosystem processes, such as pollination and pest control.
... Para describir las características florísticas, estructurales y de diversidad de una comunidad vegetal, se sugiere cubrir un área de muestreo de al menos 1 000 m 2 (0.1 ha) (Gentry 1982, Trejo 2005. De este modo, para el muestreo de la vegetación leñosa en el sitio de estudio se utilizaron 10 parcelas cuadradas (10 × 10 m = 100 m 2 ) distribuidas de manera equitativa (Gallardo-Cruz et al. 2009) en línea recta con dirección este-oeste, sobre un lomerío de 10 msnm, cubriendo un área total de 1 000 m 2 (Figura 1). ...
El objetivo de este estudio fue describir la diversidad, composición y estructura de la vegetación leñosa en una sección de la selva baja caducifolia (SBC) en Lerma, Campeche. Entre agosto y septiembre 2018, se delimitaron 10 parcelas de 10 × 10 m2 (1 000 m2 en total) midiendo todos los individuos de 1 cm de DAP (diámetro a la altura del pecho, 1.30 m). Se describió la estructura del sitio basado en los valores relativos de densidad, frecuencia y dominancia (IVI), así como la distribución de clases diamétricas. La diversidad se estimó con el índice de Shannon-Wiener (H’), mientras que la equidad fue medida por el índice de Pielou. Se registraron 40 especies leñosas, pertenecientes a 35 géneros y 19 familias. El índice H’ tuvo un valor de 2.92, y el índice de Pielou fue de 0.79, la densidad fue de 8 950 ind ha-1. Gymnopodium floribundum (204 individuos) y Lonchocarpus xuul (129 individuos) fueron las especies más abundantes. Bursera simaruba y Lysiloma latisiliquum mostraron valores diamétricos más altos (36 y 28.6 cm de DAP, respectivamente). Las familias Rubiaceae (ocho especies) y Fabaceae (cinco especies), fueron las más representativas. Las especies con mayor IVI fueron Gymnopodium floribundum (48.24%), Lonchocarpus xuul (29.12%), Bursera simaruba (26.11%) y Lysiloma latisiliquum (24.98%), siendo estas especies las más importantes en la estructura de la SBC en el sitio. La distribución de las clases diamétricas sugiere que la sección de la SBC en Lerma Campeche se encuentra en un adecuado estado de regeneración.
... Para describir las características florísticas, estructurales y de diversidad de una comunidad vegetal, se sugiere cubrir un área de muestreo de al menos 1 000 m 2 (0.1 ha) (Gentry 1982, Trejo 2005. De este modo, para el muestreo de la vegetación leñosa en el sitio de estudio se utilizaron 10 parcelas cuadradas (10 × 10 m = 100 m 2 ) distribuidas de manera equitativa (Gallardo-Cruz et al. 2009) en línea recta con dirección este-oeste, sobre un lomerío de 10 msnm, cubriendo un área total de 1 000 m 2 (Figura 1). ...
El objetivo de este estudio fue describir la diversidad, composición y estructura de la vegetación leñosa en una sección de la selva baja caducifolia (SBC) en Lerma, Campeche. Entre agosto y septiembre 2018, se delimitaron 10 parcelas de 10 × 10 m2 (1 000 m2 en total) midiendo todos los individuos de 1 cm de DAP (diámetro a la altura del pecho, 1.30 m). Se describió la estructura del sitio basado en los valores relativos de densidad, frecuencia y dominancia (IVI), así como la distribución de clases diamétricas. La diversidad se estimó con el índice de Shannon-Wiener (H’), mientras que la equidad fue medida por el índice de Pielou. Se registraron 40 especies leñosas, pertenecientes a 35 géneros y 19 familias. El índice H’ tuvo un valor de 2.92, y el índice de Pielou fue de 0.79, la densidad fue de 8 950 ind ha-1. Gymnopodium floribundum (204 individuos) y Lonchocarpus xuul (129 individuos) fueron las especies más abundantes. Bursera simaruba y Lysiloma latisiliquum mostraron valores diamétricos más altos (36 y 28.6 cm de DAP, respectivamente). Las familias Rubiaceae (ocho especies) y Fabaceae (cinco especies), fueron las más representativas. Las especies con mayor IVI fueron Gymnopodium floribundum (48.24%), Lonchocarpus xuul (29.12%), Bursera simaruba (26.11%) y Lysiloma latisiliquum (24.98%), siendo estas especies las más importantes en la estructura de la SBC en el sitio. La distribución de las clases diamétricas sugiere que la sección de la SBC en Lerma Campeche se encuentra en un adecuado estado de regeneración.
... General allometric equations are frequently unsuitable compared to regional or species-specific local equations [16,30]. Allometric models differ with sites and species due to a variety of parameters such as climate fluctuations, tree age, species composition, altitude, soil Ecological Frontiers xxx (xxxx) xxx types, and topographic conditions [2,4,8,25,43,46,68]. Therefore, speciesspecific allometric models are more favourable to avoid errors owing to species since tree species differ in their architectural and wood-specific gravity [41]. ...
... General allometric equations are frequently unsuitable compared to regional or species-specific local equations [16,30]. Allometric models differ with sites and species due to a variety of parameters such as climate fluctuations, tree age, species composition, altitude, soil Ecological Frontiers xxx (xxxx) xxx types, and topographic conditions [2,4,8,25,43,46,68]. Therefore, speciesspecific allometric models are more favourable to avoid errors owing to species since tree species differ in their architectural and wood-specific gravity [41]. ...
Pinus kesiya and Toona ciliata are widely distributed commercially important tree species in Northeast India. However, precise tree volume estimation is absent; therefore, the estimation of biomass and carbon stock of these tree species is difficult. The present study attempted to bridge this gap by developing non-destructive allometric models for estimating the biomass and carbon stock of these trees. Allometric models were developed by selecting 46 trees of P. kesiya and 54 trees of T. ciliata from different diameter classes covering the entire girth range. For developing tree volume and biomass models in this study, total tree height (H), diameter at breast height (DBH) and various tree heights for both species were measured. The performance of these models was assessed based on the coefficient of determination (adjusted R 2) and Akaike's Information Criterion (A.I.C.), besides many other statistics. The best-fit model of P. kesiya was: lnAGB = −3.7268 + 1.5908 (lnD*H) and for T. ciliata was: lnAGB = −2.0311 + 1.4858 (ln D*H*WD). The developed allometric models of P. kesiya and T. ciliata may be suitable for estimating the species-specific biomass and carbon stock of these species. The study will be useful in estimating the carbon stock and sequestration potential of the region, which will help in the assessment of global carbon cycling.
... O estudo foi realizado na estação da seca, em agosto de 2022. Para caracterizar o estrato de regeneração da comunidade arbórea, foi adotado o método adaptado de cobertura proposto por Braun-Blanquet (1979) com um quadrado de 1 m 2 e aleatoriedade, adaptando o método deGentry (1982), que consistiu em distribuir 30 pontos de coletas de 1m² em três pontos distantes um do outro em 12,5m, seguindo o menor lado da parcela 40m, e cada linha equidistante em 25m uma da outra. Os pontos foram enumerados de 1 a 30. ...
A regeneração natural ocorre pela interação de processos naturais de restabelecimento do ecossistema florestal, sendo parte do ciclo de crescimento da floresta, e se refere às fases iniciais de seu estabelecimento e desenvolvimento. Este estudo avaliou a regeneração natural, após incêndios em fragmentos de floresta poliespecífica, na Estação Ecológica de Taiamã, Cáceres-MT. Foram instaladas aleatoriamente 30 subparcelas de 1m2, em duas áreas de 1 ha cada. Todos os indivíduos foram contabilizados, e os diâmetros à altura do solo e a altura foram aferidos. Compuseram a amostra 276 indivíduos, dos quais 125 estão na área 1 e 151, na área 2, pertencentes a 12 famílias botânicas, 16 gêneros e 14 espécies. As espécies com maiores Índices de Valor de Importância na área 1 foram Zygia inaequalis (33,92%), Trichilia catigua (19,14%) e Garcinia brasilensis (15,43%) e, na área, 2, Triplaris americana (36,6%) e Zygia inaequalis (29,1%). Considerando que não haja mais incêndios de grandes proporções nas áreas estudadas, há chances de estabelecimento das plântulas e, consequentemente, a regeneração natural, mas é preciso realizar avaliação, após as plântulas serem submetidas à inundação.
... b) Possible interactions among these factors and their potentially interlinked, temporally staggered direct and indirect effects on diversification, with two multifactor scenarios where iii) occurrence in a different biogeographic area alters climatic niche evolution (ClimR, i.e., rapid adaptation to new environments), which then affects diversification rates, or iv) occurrence in a different biogeographic area directly impacts rates of climatic niche evolution, which is followed by increased trait evolution (i.e., to adapt to changed biotic interactions in new environments) and then affects diversification rates and results in an adaptive radiation. 3 neotropical areas, the uplift of the Andes is commonly detected as major recent driver of neotropical biodiversity (Gentry 1982;Antonelli et al. 2015;Antonelli 2021;Palma-Silva et al. 2022;Pérez-Escobar et al. 2022), given temporal correlations of North Andean uplift during the Mio-Pliocene and radiations of animals (i.e., lizards: Esquerré et al. 2019;amphibians: Santos et al. 2010;moths: Strutzenberger andFiedler 2011, Li et al. 2022) and plants (Lagomarsino et al. 2016;Testo et al. 2019;Meseguer et al. 2022;Vieu et al. 2022). Thus, the question arises whether these North Andean radiations were spurred through colonization by species from the older mountain ranges, preadapted to the newly forming Andean environments (Rull 2011;Ledo and Colli 2017;Tejedor and Calatayud 2022) or through de novo abiotic climatic niche and trait evolution upon North Andean colonization. ...
Why and how organismal lineages radiate is commonly studied through either assessing abiotic factors (biogeography, geomorphological processes, and climate) or biotic factors (traits and interactions). Despite increasing awareness that both abiotic and biotic processes may have important joint effects on diversification dynamics, few attempts have been made to quantify the relative importance and timing of these factors, and their potentially interlinked direct and indirect effects, on lineage diversification. We here combine assessments of historical biogeography, geomorphology, climatic niche, vegetative, and floral trait evolution to test whether these factors jointly, or in isolation, explain diversification dynamics of a Neotropical plant clade (Merianieae, Melastomataceae). After estimating ancestral areas and the changes in niche and trait disparity over time, we employ Phylogenetic Path Analyses as a synthesis tool to test eleven hypotheses on the individual direct and indirect effects of these factors on diversification rates. We find strongest support for interlinked effects of colonization of the uplifting Andes during the mid-Miocene and rapid abiotic climatic niche evolution in explaining a burst in diversification rate in Merianieae. Within Andean habitats, later increases in floral disparity allowed for the exploitation of wider pollination niches (i.e., shifts from bee to vertebrate pollinators), but did not affect diversification rates. Our approach of including both vegetative and floral trait evolution, rare in assessments of plant diversification in general, highlights that the evolution of woody habit and larger flowers preceded the colonization of the Andes, but was likely critical in enabling the rapid radiation in montane environments. Overall, and in concert with the idea that ecological opportunity is a key element of evolutionary radiations, our results suggest that a combination of rapid niche evolution and trait shifts was critical for the exploitation of newly available niche space in the Andes in the mid-Miocene. Further, our results emphasize the importance of incorporating both abiotic and biotic factors into the same analytical framework if we aim to quantify the relative and interlinked effects of these processes on diversification.
... El muestreo se llevó a cabo entre octubre de 2019 y febrero de 2020. Se aplicó la metodología de "inventario rápido" propuesta por Gentry (1982), muestreando un área de 0,1 ha, dividida en diez transectos de 50 × 2 m (100 m²) cada uno. Los transectos se levantaron aleatoriamente separados entre sí por 5 m, buscando zonas sin evidencia de intervención humana. ...
Artículo Estructura y composición florística de un bosque subandino en Togüí (Boyacá, Colombia) Structure and floristic composition of a sub-Andean forest in Togüí (Boyacá, Colombia) Resumen Se caracterizó la estructura y composición florística de un bosque subandino en Togüí (Boyacá, Colombia). Se muestrearon 10 transectos de 50 x 2 m (0,1 ha), registrando individuos con un diámetro a la altura del pecho (DAP) mínimo de 1 cm. El análisis se centró en la composición florística, la importancia ecológica de las familias y las especies, así como en la estructura vertical y horizontal del bosque. Se registró un total de 287 individuos, 68 especies y 34 familias de plantas. Estas cifras indican una menor riqueza de especies e individuos en comparación con otros bosques subandinos. Las familias Clusiaceae, Lauraceae y Rubiaceae resultaron ser las de mayor importancia ecológica. El patrón de distribución diametral siguió una forma de J invertida, y el dosel del bosque alcanzó una altura de 23 metros. Se resalta la importancia ecológica de Alfaroa williamsii Ant. Molina (Juglandaceae), una especie raramente documentada en el país. Palabras clave: Alfaroa williamsii, flora andina, flora de Colombia, registros biológicos.
... La metodología empleada para conformar la base de datos de árboles y arbustos es descrita ampliamente por Santana et al. (2014). Brevemente, se siguió el método Gentry (Gentry, 1982), el cual consistió en muestrear 10 transectos continuos de 50x2 m en cada fragmento (al conjunto se le llamó sitio). ...
La Microcuenca Estero El Salado localizada en la ciudad turística de Puerto Vallarta, Jalisco, alberga el Área Natural Protegida (ANP) homónima. Sin embargo, su alta biodiversidad y servicios ecosistémicos están amenazados por actividades antrópicas que han acelerado el cambio de coberturas y usos de suelo. Este trabajo evaluó la dinámica del paisaje y la fragmentación de esta área en el periodo 2000 2021. Se generaron mapas temáticos de coberturas y usos del suelo con imágenes de satélite Landsat 5 y 8 para los años 2000 y 2021, y se calcularon métricas de composición y configuración del paisaje. La microcuenca evidencia una predominancia de los usos de suelo urbano, pastizal y agrícola, que pasaron de ocupar un 73.56% de la superficie (2000) a un 78.33% (2021). Las coberturas y usos de suelo registraron cambios en el 38.86% de la superficie. Los cuerpos de agua y bosque tropical disminuyeron su superficie un 75% y 23.86% respectivamente, mientras que el uso urbano la incrementó un 82%. La cobertura de vegetación acuática registró cambios en su configuración espacial, caracterizados por la disminución del número de parches (NP= 127 vs 26) y el aumento del área de los mismos (ÁREA= 2.25 vs 15.05 ha), con mayor agregación hacia la parte baja de la microcuenca (IA= 81.91 vs 95.38), evidenciando que el ANP brinda una protección efectiva a este ecosistema. Las coberturas y usos de suelo presentaron una disminución en el número de parches (NP= 942 vs 849) y un aumento en la distancia entre ellos, principalmente en la selva tropical (ENN_MN= 107.60 vs 180.86 m). El paisaje de la microcuenca mantiene una baja conectividad (Connect= 11.52%-48.65% vs .3.57%-18,15%), por lo que es necesario elaborar instrumentos de planeación territorial que regulen los cambios de uso de suelo, particularmente en las partes altas de la microcuenca.
... La metodología empleada para conformar la base de datos de árboles y arbustos es descrita ampliamente por Santana et al. (2014). Brevemente, se siguió el método Gentry (Gentry, 1982), el cual consistió en muestrear 10 transectos continuos de 50x2 m en cada fragmento (al conjunto se le llamó sitio). ...
Dentro de la línea de investigación “ecología del paisaje urbano”, la propuesta aborda la problemática del sprawl y la creciente importancia de las ciudades para la biodiversidad del planeta. En esta dirección, se estudia el rol de la densidad y el papel ecológico de las pequeñas áreas verdes urbanas, como los jardines. La necesidad de compacidad para la preserva�ción del territorio es lugar común en la bibliografía internacional. Por otro lado, Formann (2022) demostró que las grandes áreas verdes públicas, como los parques, contribuyen a la biodiversidad y a la mejora del (micro) clima urbano, pero las áreas verdes más pequeñas contribuyen a la permeabilidad del suelo y, por lo tanto, también al (macro)drenaje. Otros estudios señalan que, vinculados a la introducción y mantenimiento de especies exóticas, los jardines tienen un papel destacado en la polinización, influyendo (in)directamente en la conservación de la biodiversidad, entre otros beneficios para la salud humana. La metodología consiste en, a partir de esta visión, reforzar el papel de la densidad + áreas verdes urbanas en la promoción de la conservación/ conectividad del paisaje, orientando a nuestros estudiantes del Curso de Arquitectura de la Universidad de Santa María, Brasil, a desarrollar proyectos de vivienda social que brinden una concatenación de espacios verdes en varias escalas y alcances –público, privado, etcétera–. Resultados: Algunas tipologías se comportan mejor en términos de densidad o áreas verdes, funcionando los jardines como complemento de los espacios verdes públicos como parques y plazas. Conclusiones: Se trata pues de proponer una “matriz” urbana, o tipologías asociadas a zonas verdes con una morfología característica, que no es solo una cuestión de densidad, ni de metros cuadrados verdes por habitante, sino de la calidad de estos espacios como forma de contribuir a la constitución de una base ecológica para las ciudades.
... La metodología empleada para conformar la base de datos de árboles y arbustos es descrita ampliamente por Santana et al. (2014). Brevemente, se siguió el método Gentry (Gentry, 1982), el cual consistió en muestrear 10 transectos continuos de 50x2 m en cada fragmento (al conjunto se le llamó sitio). ...
El presente libro reúne una serie de trabajos cuidadosamente seleccionados, los cuales fueron presentados por estudiantes e investigadores de México y Latinoamérica dentro del marco del Primer Simposio Nacional sobre Estudios en Conectividad del Paisaje. El Simposio se desarrolló en el Centro de Investigaciones en Geografía Ambiental de la Universidad Nacional Autónoma de México, campus Morelia, del 13 al 15 de septiembre de 2022. La obra está conformada por 14 capítulos que fueron seleccionados después de ser revisados por pares académicos a doble ciego, bajo estrictas normas editoriales y dictaminados por evaluadores expertos en el tema, a los cuales les agradecemos su tiempo y dedicación. Los trabajos abordan temas sobre análisis de la fragmentación, conectividad estructural y funcional del paisaje, además de conectividad hidrológica, y elaboración de propuestas de corredores y sitios prioritarios para la conservación del paisaje.
... La metodología empleada para conformar la base de datos de árboles y arbustos es descrita ampliamente por Santana et al. (2014). Brevemente, se siguió el método Gentry (Gentry, 1982), el cual consistió en muestrear 10 transectos continuos de 50x2 m en cada fragmento (al conjunto se le llamó sitio). ...
Los estudios orientados al análisis de la diversidad alfa y beta, particularmente en el Bosque Mesófilo de Montaña (bmm) han sido descritos de manera limi-tada. Actualmente, este ecosistema ha sido altamente fragmentado, lo que ha generado una disminución en su superficie original y en los cambios estructurales del bosque. Por ello, es necesario describir la importancia de conectividad del bmm a través de diversas métricas del paisaje. El objetivo de este trabajo fue analizar el efecto de la heterogeneidad ambiental sobre la composición de especies arbóreas y arbustivas en las áreas de Zirahuén y Mil Cumbres con un área que contó con seis fragmentos de bmm respec-tivamente en el Sistema Volcánico Transversal de Michoacán (svtMich).
... Las plantas con flores (Angiospermas), exhiben diversas estrategias de sistemas reproductivos, incluyendo mecanismos de autofecundación y sistemas de transporte biótico y abiótico (Proctor, Peter y Lack ,1997). Sin embargo, la mayoría de las especies tropicales aprovechan la polinización zoófila y dispersión de semillas por animales para asegurar una transferencia, intercambio de información genética y supervivencia exitosa de individuos (Gentry, 1982;Vanbergen, 2013 Para ecosistemas tropicales como el bosque seco, la polinización biótica es fundamental, estimándose que alrededor del 85% de sus especies angiospermas dependen de ella para la reproducción (Ollerton et al., 2011). La polinización cruzada resulta casi obligatoria debido al gasto energético que representa la alta exposición a condiciones de estrés (Proctor et al., 1997), dado que estas plantas dedican su energía a la producción de atrayentes para maximizar la dispersión y reproducción exitosa. ...
INTERACCIONES MUTUALISTAS DE FRUGIVORÍA Y POLINIZACIÓN MEDIADAS
POR MURCIÉLAGOS FILOSTÓMIDOS EN UN FRAGMENTO DE BOSQUE SECO
TROPICAL EN VENADILLO, TOLIMA
... To survey saplings, we established 25 circular plots (1.60 m radius each; total sampling area per patch = 200 m 2 ) in a grid of 5 × 5 plots with 30 m separation between plots and counted and identified all tree saplings (excluding palms and lianas) with a height of ≥30 cm and diameter at breast height (DBH) of <1 cm (Arasa-Gisbert et al., 2021). Juvenile and adult trees were sampled using a modification of Gentry's protocol (Gentry, 1982). We recorded all juveniles (i.e., trees 1-10 cm DBH) and adults (DBH >10 cm) in ten 50 × 2-m plots (i.e., 0.1 ha sampled area) within each forest site (Hern andez-Ruedas et al., 2018). ...
Tropical tree species are increasingly being pushed to inhabit deforested landscapes. The habitat amount hypothesis posits that, in remaining forest patches, species diversity in equal‐sized samples decreases with decreasing forest cover in the surrounding landscape. We tested this prediction by taking into account three important factors that can affect species responses to forest loss. First, forest loss effects can be linear (proportional) or nonlinear, as there can be threshold values of forest loss beyond which species extirpation may be accelerated. Second, such effects are usually scale dependent and may go unnoticed if assessed at suboptimal scales. Finally, species extirpation may take decades to become evident, so the effects of forest loss can be undetected when assessing long‐lived organisms, like adult old‐growth forest trees. Here, we evaluated the linear and nonlinear effects of landscape forest loss across different spatial scales on site‐scale abundance and diversity of old‐growth forest trees, separately for four plant‐life stages (seeds, saplings, juveniles, and adults) in two rainforest regions with different levels of deforestation. We expected stronger (and negative) forest loss effects on early plant‐life stages, especially in the region with the highest deforestation. Surprisingly, in 13 of 16 study cases (2 responses × 4 life stages × 2 regions), null models showed higher empirical support than linear and nonlinear models at any scale. Therefore, the species richness and abundance of local tree assemblages seem to be weakly affected by landscape‐scale forest loss independently of the spatial scale, life stage, and region. Yet, as expected, the predictive power of forest cover was relatively lower in the least deforested region. Our findings suggest that landscape‐scale forest loss is poorly related to site‐scale processes, such as seed dispersal and seedling recruitment, or, at least, such effects are too small to shape the abundance and diversity of tree assemblages within forest patches. Therefore, our findings do not support the most important prediction of the habitat amount hypothesis but imply that, on a per‐area basis, a unit of habitat (forest) in a highly deforested landscape has a conservation value similar to that of a more forested one, particularly in moderately deforested rainforests.
... To analyze the diversity patterns of different shrubland communities, species richness and the Shannon-Wiener index were selected as the species diversity indexes in this study [14], and Faith's PD (namely the evolutionary branch length of all species in the community [15]) was selected as an indicator of the phylogenetic diversity. ...
Shrubland is an important type of vegetation in the semi-arid region of the western Loess Plateau, and it is of great value to the maintenance of biodiversity and soil and water conservation. Equally, there may be significant differences in the level of diversity and the community assembly patterns across different types of shrublands (desert, alpine, and secondary shrublands). This study aimed to reveal the diversity and the community assembly patterns of different types of shrublands and the environmental explanations for these by using a taxonomic and phylogenetic analysis approach, as well as by considering soil and climate factors. The diversity level of the desert shrublands was low, and the habitats of the three types of shrubland were significantly different. Precipitation may be the main environmental factor driving the variation in and diversity of these types of shrubland. All three types of shrubland were strongly affected by environmental filtering and competitive exclusion, and their community assembly patterns were similar.
... En la dieta de los grupos familiares fue relevante las familias de plantas Moraceae y Ulmaceae por tiempo de consumo, mientras que Moraceae y Urticaceae por número de especies consumidas. De la familia Moraceae, consumieron principalmente frutos y ocasionalmente hojas y flores, lo cual podría estar relacionado a las características carnosas de los frutos de esta familia, los cuales están adaptados a la atracción de animales que potencialmente dispersan sus semillas (Gentry, 1982). Adicionalmente, estos frutos contienen grandes concentraciones de ácido ascórbico el cual es indispensable en la dieta de los primates (Milton, 1987(Milton, ,1993Serio-Silva, 2002 (Castaño et al. 2010;Guzmán et al., 2016;Helenbrook et al., 2019). ...
Las dinámicas ecológicas asociadas a los comportamientos de selección de recursos han sido uno de los aspectos mejor estudiados en primates neotropicales. Sin embargo, históricamente estas investigaciones se han enfocado en abordar aspectos descriptivos, en los que usualmente se ha ignorado el subyacente componente evolutivo, fundamental para entender plenamente la selección de recursos como proceso. Por su hábito nocturno y rango de distribución en ecosistemas de montaña, los monos nocturnos andinos (Aotus lemurinus) plantean interrogantes singulares sobre los elementos que determinan los patrones conductuales asociados a la selección de recursos. En este estudio describimos la ecología básica de dos grupos familiares de A. lemurinus (PI1 y PI2) de un fragmento de bosque subandino en el municipio de Pijao-Quindío, Colombia. Adicionalmente, evaluamos la preferencia en la selección de frutos, o si su consumo depende de su disponibilidad en el hábitat. Este estudio acumuló 1134 horas de seguimiento, divididas entre los dos grupos familiares en 583 para PI1 y 551 para PI2. Se obtuvieron 1027 registros de actividad, divididos en 460 para PI1 y 567 para PI2. Los dos grupos familiares invirtieron la mayor parte de su tiempo en descanso (PI1 38.1% - PI2 53.1%), seguido por alimentación (PI1 33.2% - PI2 20.8%) y movimiento (PI1 27.5% - PI2 25.7%), las actividades de interacciones sociales y otras estuvieron representadas en menos del 1% del presupuesto de tiempo total. Identificamos 29 especies de plantas con frutos en la dieta de los grupos evaluados, documentando una preferencia de consumo por plantas asociadas filogenéticamente a la subclase Rosidae, reforzando la hipótesis que las especies de plantas filogenéticamente cercanas comparten características funcionales que las hacen predilectas para los dispersores.
... Vegetation and soil sampling was realized from October 2017 to March 2018. We randomly established a total of 36 linear transects (10 × 25 m; modified from Gentry, 1982), with a minimum distance of 40 m between them (Fig. S1). The tree previously named conditions included 14, 10, and 12 transects respectively, which were laid out as parallel as possible and perpendicular to the slope (Fig. S1). ...
... The Neotropical realm hosts the most diverse terrestrial ecosystems on the planet (Jenkins et al., 2013). The role of the formation of the Andean Cordillera and associated landscape modifications throughout the continent have become paradigmatic for explaining the origins of Neotropical biodiversity (Gentry, 1982;Hughes and Eastwood, 2006;Hoorn et al., 2010;Esquerré et al., 2019). These mountains acted both as cradles (promoting in situ speciation) and museums (serving as refugia to isolated relict species from groups that went extinct elsewhere), thereby leading to neo-and paleo-endemisms, respectively (Rangel et al., 2018;Rahbek et al., 2019;Azevedo et al., 2020;Boschman and Condamine, 2022). ...
The iconic mountains of the Pantepui biogeographical region host many early-diverging endemic animal and plant lineages, concurring with Conan Doyle’s novel about an ancient “Lost World”. While this is the case of several frog lineages, others appear to have more recent origins, adding to the controversy around the diversi- fication processes in this region. Due to its remoteness, Pantepui is challenging for biological surveys, and only a glimpse of its biodiversity has been described, which hampers comprehensive evolutionary studies in many groups. During a recent expedition to the Neblina massif on the Brazil-Venezuela border, we sampled two new frog species that could not be assigned to any known genus. Here, we perform phylogenetic analyses of mito- genomic and nuclear loci to infer the evolutionary relationships of the new taxa and support their description. We find that both species represent single lineages deeply nested within Brachycephaloidea, a major Neotropical clade of direct-developing frogs. Both species diverged >45 Ma from their closest relatives: the first is sister to all other Brachycephaloidea except for Ceuthomantis, another Pantepui endemic, and the second is sister to Bra- chycephalidae, endemic to the Brazilian Atlantic Forest. In addition to these considerable phylogenetic and biogeographic divergences, external morphology and osteological features support the proposition of two new family and genus-level taxa to accommodate these new branches of the amphibian tree of life. These findings add to other recently described ancient vertebrate lineages from the Neblina massif, providing a bewildering reminder that our perception of the Pantepui’s biodiversity remains vastly incomplete. It also provides insights into how these mountains acted as “museums” during the diversification of Brachycephaloidea and of Neotropical biotas more broadly, in line with the influential “Plateau theory”. Finally, these discoveries point at the yet unknown branches of the tree of life that may go extinct, due to global climate change and zoonotic diseases, before we even learn about their existence, amphibians living at higher elevations being particularly at risk
... Las parcelas rectangulares son más usadas cuando hay una alta heterogeneidad topográfica y altitudinal, en la cual se establecen transectos que pueden contener varias subparcelas (normalmente cuadradas) hasta completar el área de muestreo. Uno de los métodos más populares de este tipo de muestreo en parcelas rectangulares es el establecido por Alwyn Gentry (Gentry 1982), en el cual se trazan 10 transectos de 2 x 50 m dentro de una localidad, con el fin de tener un área total de 1000 m 2 (0.1 ha). En este procedimiento, se registra el número de individuos de cada especie que cumplan el criterio de tener diámetros mayores a 2.5 cm a la altura del pecho. ...
Presentamos una descripción breve de algunas técnicas más comunes empleadas en los inventarios florísticos y forestales como unidad para describir la vegetación. Haremos énfasis en las principales técnicas de reconocimiento de la vegetación a nivel de comunidades, pues con ellas es posible aproximarse a describir los tipos de vegetación que caracterizan un lugar. Distinguiremos entre evaluaciones únicas como aquellas que se realizan solo una vez con el propósito de describirlos de aquellos muestreos sistemáticos y repetidos en el tiempo que constituyen parte de un esfuerzo de monitoreo a largo plazo. Bajo ambas aproximaciones, están inherentes las preguntas de investigación al igual que los objetivos. Asimismo, presentaremos una breve descripción de los análisis más usados para el estudio de la vegetación, con énfasis en las comunidades presentes en Chiapas pero que son plenamente válidas para cualquier tipo de vegetación. En la parte final, presentaremos también de manera sintética la perspectiva de la restauración ecológica como una de las herramientas para mitigar o compensar algunos de los impactos de las actividades humanas sobre el componente biológico motivos de la investigación, inventario o monitoreo biológico.
... Data was collected by sampling with sample plot sizes following the Gentry (1982) method, namely 2 m x 50 m. Furthermore, using this method, the researcher walked toward the observation path in the middle of the sample plots and recorded all species and individuals for the growth rates of seedlings, saplings, poles, and trees. ...
Supartono T, Adhya I, Kosasih D, Wildani W. 2023. Tree species diversity adapted to Pinus merkusii forests in Gunung Ciremai National Park, West Java, Indonesia. Biodiversitas 24: 4314-4323. One of the challenges faced in rehabilitating pine forests in conservation areas is the limited information on plant species capable of adapting to these ecosystems. This study aimed to analyze the diversity of tree species that grow and adapt to pine forests and the relationship of natural forests with the vegetation characteristics of pine forests. The research was conducted in pine forests bordering natural forests and far from natural forests using the sample plot method. The study recorded 44 species from 27 families of seedlings, 46 species from 21 families of saplings, 25 species from 18 families of poles, and 24 species from 17 families of trees. Accumulation of species from all growth stages recorded 83 species (76 local species and 7 cultivated species) from 39 families. Based on the species accumulation curve, pine forests adjacent to natural forests have more species than those far from natural forests. Individual and family density in pine forests adjacent to natural forests were also higher than the density of these two variables in pine forests far from natural forests. Furthermore, both the pine forest adjacent to the natural forest and that far from the natural forest, each has its own species peculiarities. The results indicate that the existence of natural forests has an important role as a source of biodiversity for the surrounding ecosystem. As an implication of this study, species that can grow to the level of poles and trees can be recommended as rehabilitation plants in the Pinus merkusii Jungh. & de Vriese forests in Gunung Ciremai National Park, Indonesia because pine is not a local species and the allelopathy it releases can reduce plant diversity.
... Además, si estas especies atraen animales frugívoros, suelen actuar como depósitos de semillas, aumentan las interacciones con otras plantas y animales, y con ello se mantiene alta biodiversidad (Camargo et al., 2020). Es probable que lo anterior ocurra en las selvas y bosques con mayor frecuencia, porque hay más especies zoocoras que en otros ecosistemas (Gentry, 1982;Willson et al., 1990), sin embargo, en áreas perturbadas de zonas áridas, la dispersión zoócora y la acumulación de semillas bajo árboles aislados también ocurre (Filazzola et al., 2019) y de su estudio depende si se constituye como una herramienta útil para la recuperación de la vegetación y las interacciones que se pierden con el continuo cambio de uso de suelo. ...
Estudiar el banco de semillas permite interpretar el estado de sitios perturbados, la respuesta a cambios impulsados por disturbios y la consecuente dinámica de una comunidad vegetal. La heterogeneidad en la formación del banco de semillas está influida por la latencia de estas, su tipo de dispersión y componentes del paisaje como topografía o vegetación. El número de semillas en el suelo depende, en parte, de la vegetación presente, sin embargo, en paisajes deforestados y fragmentados, los árboles aislados representan los únicos reservorios potenciales para la regeneración de la vegetación. En este trabajo se exploró, durante dos años, la variación espacial y temporal en la abundancia, densidad y número de especies de semillas germinables en el suelo bajo cinco especies arbóreas aisladas comunes en áreas abiertas del Matorral Espinoso Tamaulipeco. Las características del banco de semillas se calcularon para cada especie de árbol aislado y se compararon entre ellas, estaciones y año de colecta. El banco de semillas bajo las copas de dos árboles zoócoros (Neltuma laevigata y Diospyros texana) fue más rico y denso que bajo otras tres especies (Yucca filifera, zoócora; Parkinsonia aculeata y Vachellia farnesiana dispersión no asistida). También se registraron más especies y semillas germinadas en otoño que en primavera, y más herbáceas que arbóreas.
... The explosive flowering (Gentry, 1982) and fruiting of H. spongiosus Fig. 7. Partial dependence of the generalized additive model (GAM) for the vegetative and reproductive phenophases of H. spongiosus and the abiotic variables of study sites in SDTF, in northeastern Brazil. Partial dependence of the (a) vegetative phenophases on the average monthly temperature, (b) vegetative phenophases on accumulated monthly rainfall, (c) vegetative phenophases on photoperiod, (d) reproductive phenophases on the mean monthly temperature, (e) reproductive phenophases on accumulated monthly rainfall, and (f) reproductive phenophases on photoperiod. ...
The scarcity of phenological studies based on different populations of tropical forest trees limits seed management and collection for reforestation efforts. Precipitation is the primary factor driving tropical plant phenology in seasonal environments, although other environmental variables and plant traits may be associated. We examined the seasonality, synchrony, and intensities of the vegetative and reproductive phenophases of four populations of Handroanthus spongiosus, an endangered species, under similar climate regimes in a seasonally dry tropical forest, in northeastern Brazil. We expected to observe some divergence in the phenologies of the populations related to distinct functional traits selected for by differences in rainfall and soil properties. Mature trees (n = 87) were monitored during a three-year period. Seasonality was examined using circular statistics, and the influences of environmental variables on phenophases were investigated using generalized additive models. Variations in intensities and activity indices were identified among the different populations. Vegetative phenophases were seasonal, driven by precipitation and photoperiod, with leaf longevity of up to 7 months; budding peaked in February-March, while leaf fall peaked in April and October. The reproductive phenophases were found to be seasonal, during the rainy season (November to April), influenced by temperature and photoperiod. The slight divergences noted among the phenological behaviors of the populations were related to distinct functional traits (e.g., tree height, stem diameter) selected for by differences in certain environmental variables (rainfall volumes and soil properties). Given ongoing global climate changes, increases in leaf fall and reductions of flowering intensity, as verified here, will likely be observed.
... En cada sistema o uso del suelo seleccionado en las fincas de estudio, se estableció una parcela de 20 x 50 m (0,1 hectáreas) en la cual se evaluaron la composición de especies de plantas vasculares y la estructura de la vegetación. Se midió la altura (m) y el diámetro a la altura del pecho o DAP (cm) de cada individuo con DAP mayor a 2,5 cm (Gentry 1982). Adicionalmente, se registró el hábito de crecimiento del individuo (arbusto, árbol, epífita, hierba, palmoide, parásita, trepadora herbácea o trepadora leñosa). ...
Los sistemas silvopastoriles han sido promovidos en el valle del río Cesar, Colombia, como estrategia para mejorar la productividad de la ganadería y los servicios ecosistémicos. Entre 2014 y 2017 se estudiaron los patrones de diversidad, estructura y composición de la vegetación (>2,5 cm de DAP) en 35 parcelas de 1000 m2 situadas en sistemas silvopastoriles, potreros convencionales y bosques en fincas ganaderas de la región. Se registraron 1852 individuos, distribuidos en 281 morfoespecies, 109 géneros y 44 familias. Las familias más abundantes fueron Fabaceae (35 %), Bignoniaceae (7,5 %) y Myrtaceae (6,7 %). Leucaena leucocephala (Lam.) de Wit, Eucalyptus cf. Tereticornis Sm. y Roseodendron chryseum (S.F. Blake) Miranda fueron las especies más abundantes. Los fragmentos de bosque y bosques ribereños presentaron los valores más altos de densidad de individuos, cobertura de dosel, índice de densidad foliar, volumen total de vegetación y riqueza de especies, seguidos de los potreros con árboles dispersos y los bancos mixtos de forrajes. Los árboles de mayor porte se encontraron en los relictos de bosque y potreros con árboles dispersos (Peltogyne purpurea Pitter.., Enterolobium cyclocarpum (Jacq.) Griseb., Anacardium excelsum (Bertero & Balb.) Skeels., Ceiba pentandra (L.) Gaertn. y Albizia saman (Jacq.) Merr.). Los arreglos silvopastoriles contribuyen a la conectividad del paisaje y complementan la función de los fragmentos de bosque para conservar el 14,2 % de las especies arbóreas del valle del río Cesar. Sin embargo, la restauración de este paisaje exige conservar y conectar los fragmentos de bosque existentes, ampliar la escala de los sistemas ganaderos con árboles y arbustos e integrar una mayor diversidad de especies nativas en todos los usos de la tierra.
... As florestas tropicais possuem uma grande diversidade de espécies arbóreas quando comparadas com as florestas temperadas (GENTRY, 1982;WHITMORE, 1984). Entretanto, nos trópicos, há a ocorrência de florestas que apresentam um padrão estrutural anômalo, onde o dossel apresenta dominância por uma única espécie arbórea. ...
O objetivo deste trabalho foi avaliar a estrutura do compartimento arbóreo de um fragmento florestal situado no município de Inconfidentes, Minas Gerais e identificar seus agrupamentos florísticos por meio de análise estatística multivariada. Foram alocadas de forma sistemática 29 parcelas de 400 m2 cada, distribuídas em seis transecções transpondo o fragmento em seu sentido de maior declividade. Todos os indivíduos com DAP > 5 cm foram amostrados. Os resultados apontaram 1560 indivíduos distribuídos em 111 espécies, 80 gêneros e 38 famílias para uma área amostral de 1,16 há. As cinco espécies com maior densidade foram: Euterpe edulis (673,28 ind./ha), Rollinia sylvatica e Urera baccifera (46,55 ind./ha), Cryptocarya aschersoniana (38,79 ind./ha), Senegalia polyphylla (35,34 ind./ha) e Geonoma schottiana (28,45 ind./ha) totalizando 64,62% do número total de indivíduos. A elevada densidade da Euterpe edulis (673,28 ind./ha ou 50,06% dos indivíduos)
caracteriza a área estudada como uma floresta monodominante. Os índices de diversidade de Shannon, e equabilidade de Pielou foram H’= 2,69 nats.individuo-1 e J= 0,57 quando se considerou todos indivíduos com DAP > 5 cm. Quando se considerou indivíduos com DAP > 10 cm os mesmos índices foram H’= 2,41 nats.ind.-1 e J’ = 0,53. Os baixos valores observados para estes parâmetros,
particularmente para J’, é resultado da elevada concentração de indivíduos de uma única espécie que domina a comunidade arbórea. A análise de correspondência canônica (CCA) não encontrou nenhuma correlação entre a distribuição da abundancia das espécies e as variáveis ambientais, porém foram encontrada correlações simples entre 7 espécies e algumas variáveis ambientais.
... Temporary transects generally used in rapid exploratory sampling, called Gentry-type sampling [91,92], were installed, modifying the original 500 × 2 m plots to 100 × 10 m plots, where each plot was 0.1 ha. All the species of the Moraceae family were inventoried, marked, measured, and collected. ...
The current study determined the floristic composition, structure, and aboveground biomass (AGB) of the individuals of the Moraceae family. This occurred in order to value them as a source of biomass carbon, which itself is dependent on the altitudinal gradient (601-1000 m.a.s.l.) in the evergreen foothill forest of the Ecuadorian Amazon. The study encountered 117 individuals belonging to the Moraceae family, which was grouped into 32 species. Hereby, the most abundant were the genus Ficus sp., with 9.40% relative abundance, Brosimun alicastrum with 6.84%, and Aucleopsis sp. with 5.98%. Forest structural characteristics, such as the horizontal and vertical structure, diameter at breast height (DBH), and the diameter of the tree crown, were considered for the analysis. The horizontal profile determined that the crowns of the species of the Moraceae family cover approximately 16.43% of the upper canopy within the sampling unit area. The trees of the Moraceae family have a carbon capture capacity in the projected AGB per hectare of 35.09 (Mg ha −1), with the Ficus cuatracasana Dugand species being the species with the highest projected capture per hectare, with 15.737 (Mg ha −1). These results highlight the relevance of similar studies assessing the carbon accumulation capacity of species from other families, emphasizing high commercial value species due to their timber resource.
... La mayoría de las investigaciones referentes a lianas fueron realizadas en las zonas tropicales de África y Asia, mientras que en América los trabajos se localizaron en los bosques de Costa Rica y en la selva Amazónica de Brasil, Ecuador y Bolivia, razón por la que éstos son los países sudamericanos con más antigüedad en la investigación referida a lianas (e.g. Schenck, 1892;Obaton, 1960;Gentry, 1982Gentry, , 1986Gentry, , 1995Putz, 1983Putz, , 1984Putz & Mooney, 1991;Appanah et al., 1993;Caballé, 1993;Araque et al., 2000Araque et al., , 2007Burnham, 2002;Bongers et al., 2005;Dewalt & Chave, 2006;Piovesan et al., 2018). En nuestro país, la Selva Misionera (Paranaense), la Selva Tucumano-Boliviana (Yungas) y el Parque Chaqueño, poseen lianas en abundancia y diversidad, sin embargo existe poca información disponible al respecto (Lorea, 2006, y referencias allí citadas). ...
Debido a su forma de vida, las lianas presentan una gran diversidad de adaptaciones en sus tallos, y, como consecuencia, son fácilmente distinguibles a partir de su morfología caulinar. Generalmente, las hojas y órganos reproductivos de las lianas se localizan por encima de las copas de los árboles, por lo que muchas veces resulta difícil reconocer estas plantas dentro de la selva y por ello los caracteres de los tallos son muy útiles para su identificación taxonómica. Este trabajo tiene como objetivo caracterizar la morfología y anatomía caulinar de las lianas del Parque Provincial Moconá (Misiones, Argentina) para su reconocimiento macroscópico. Se relevaron los senderos de fácil acceso e importancia turística del parque: Sendero de la Gruta, Sendero de los Chachíes, Humedal y Camino al embarcadero "Piedra Bugre". Se determinaron y caracterizaron macroscópicamente 16 especies de lianas, pertenecientes a 8 familias de angiospermas: Apocynaceae (3 spp.), Aristolochiaceae (1 sp.), Bignoniaceae (4 spp.), Cactaceae (1 sp.), Fabaceae (2 spp.), Nyctaginaceae (1 sp.), Sapindaceae (3 spp.), Vitaceae (1 sp.). En las lianas estudiadas se reconocieron diferentes tipos de características adaptativas al hábito trepador, las que pueden agruparse de la siguiente manera: forma de crecimiento del tallo, morfología externa del tallo, superficie del tallo, sección del tallo, estructuras de anclaje, variantes cambiales y características anatómicas del leño. Se elaboraron dos claves dicotómicas para su reconocimiento, una utilizando sólo caracteres externos de los tallos y otra con caracteres externos y anatómicos.
... We sampled 24 farms that produce SC in CAFS in 2021 (January-March). Tree diversity data was collected following the method of Gentry (1982) applied to study American CAFS tree diversity (Méndez et al. 2007;Zapata 2019). This method samples trees in one 20 x 50 m plot (1000m 2 ) per CAFS. ...
Specialty coffee (SC) production enables farmers to earn premium prices for high-quality coffee. In Bolivia, some coffee-based agroforestry systems (CAFS) produce SC. However, while many Bolivian families’ livelihoods depend on coffee, studies on SC-producing CAFS remain scarce. Yet, research on tree diversity, CAFS management and the factors affecting tree diversity can offer novel insights on agroforestry. We sampled 24 farms in three villages located in the Caranavi municipality. We analyzed farms main characteristics, biophysical variables, shade tree diversity, tree uses, management practices and farmers’ socioeconomic background. Additionally, we surveyed 50 coffee farmers to collect information about their preferences for shade tree species and tree characteristics. Then, we investigated if farmers’ socioeconomic and farm biophysical variables affect CAFS tree species richness and tree density using generalized linear models (GLM). Our results showed that studied farms are small and certified properties (average: 2.6 ha) managed by families; we observed that CAFS provide farmers with valuable products besides SC. We identified 85 tree species that provide principally shade for coffee and fruits, timber, lumber and medicines. Moreover, farmers prefer mostly shade tree species that offer them useful and marketable products, while tree characteristics are preferred according to their benefits to coffee and farmers. GLM revealed that socioeconomic and biophysical variables related to management and landscape composition affect: tree species richness and density. These results suggest that management and landscape are influential factors driving CAFS tree diversity. Hence, factors fostering farmers’ ability to manage their CAFS for biodiversity and household wellbeing should be promoted.
Different aspects of plant diversity and productivity were studied in a 40-yr-old rehabilitated forest developed on barren sodic land at Banthra, Lucknow, U.P. It was a dry semi-deciduous forest with both planted as well as invading species. Tree species were grouped in two strata: overstorey and understorey with 44 and 8 species, respectively. Three stands, each of about 1 ha were selected according to gross morphology, population density and different basal area of 21-39 m2 ha-1. Dominant species were established on the basis of in importance value index. Stands were compared for population size, dominance, species richness, heterogeneity and several diversity indices. On average, the forest consisted of a high equitability (0.73) and less redundancy (0.27) with a Shannon Weiner’s general diversity index of 2.45. The forest biomass has been estimated as 329 Mg ha-1 for overstorey and 5 Mg ha-1 for understorey.
Given the current environmental crisis, biodiversity protection is one of the most urgent socio-environmental priorities. However, the effectiveness of protected areas (PAs), the primary strategy for safeguarding ecosystems, is challenged by global climate change (GCC), with evidence showing that species are shifting their distributions into new areas, causing novel species assemblages. Therefore, there is a need to evaluate PAs' present and future effectiveness for biodiversity under the GCC. Here, we analyzed changes in the spatiotemporal patterns of taxonomic and phylogenetic diversity (PD) of plants associated with the Neotropical seasonally dry forest (NSDF) under GCC scenarios. We modeled the climatic niche of over 1000 plant species in five representative families (in terms of abundance, dominance, and endemism) of the NSDF. We predicted their potential distributions in the present and future years (2040, 2060, and 2080) based on an intermediate scenario of shared socio-economic pathways (SSP 3.70), allowing species to disperse to new sites or constrained to the current distribution. Then, we tested if the current PAs network represents the taxonomic and phylogenetic diversities. Our results suggest that GCC could promote novel species assemblages with local responses (communities' modifications) across the biome. In general, models predicted losses in the taxonomic and phylogenetic diversities of all the five plant families analyzed across the distribution of the NSDF. However, in the northern floristic groups (i.e., Antilles and Mesoamerica) of the NSDF, taxonomic and PD will be stable in GCC projections. In contrast, across the NSDF in South America, some cores will lose diversity while others will gain diversity under GCC scenarios. PAs in some NSDF regions appeared insufficient to protect the NSDF diversity. Thus, there is an urgent need to assess how the PA system could be better reconfigured to warrant the protection of the NSDF.
El Instituto de Ciencias Ambientales de la Orinoquia Colombiana (ICAOC) en colaboración con el Centro de Innovación y Tecnología Instituto Colombiano del Petróleo (ICP) aunaron esfuerzos para realizar la caracterización de la flora asociada al morichal de la finca Manacacías (latitud 4.172383 y 4.167133; longitud -72.043167 y -72.060983), como ecosistema estratégico para la captura de CO2 en biomasa, necromasa y suelo. El estudio arrojó como resultado la presencia de 75 familias, 143 géneros y 226 especies, entre árboles, arbustos, palmas, lianas, hierbas, epífitas y hemiparásitas, material biológico que fue depositado en el Herbario LLANOS de la Universidad de los Llanos. Entre las especies encontradas, Xylopia plowmanii se encuentra catalogada como Vulnerable (VU) según la UICN y Cyathea microdonta está incluida en el Apéndice II del CITES. Las especies Clitoria hermannii y Cybianthus llanorum están restringidas a la Orinoquia. Así mismo, Henriettea goudotiana, Ouratea membranacea y Protium macrophyllum tienen distribución solo para Colombia. Los registros presentados permiten aumentar el conocimiento de la flora asociada a los ecosistemas de morichal en la Orinoquia colombiana y resaltar la importancia de su conservación. El listado se encuentra disponible en formato Darwin Core https://doi.org/10.15472/wan8uq vía GBIF y el material biológico está depositado en el Herbario LLANOS de la Universidad de los Llanos.
Monteleón es considerado un relicto de bosque subandino, y su biodiversidad está amenazada por distintos factores antropogénicos, lo que causa su fragmentación y la pérdida del hábitat de las especies que allí habitan. Con el objetivo de conocer su actual composición, estructura y diversidad florística, se establecieron tres parcelas de 0.1 ha en zonas con distintos grados de perturbación. En total se registraron 941 individuos y 116 especies, donde la parcela con perturbación baja presentó la mayor diversidad alfa. Según el análisis de la diversidad beta, entre las comunidades, los individuos de las especies que se pierden son en su mayoría sustituidos por individuos de otras especies, y un pequeño porcentaje se pierde sin sustitución. En conclusión, se registró un estado de afectación en el bosque debido a su heterogeneidad, que aun así se encuentra en un estado natural de recuperación.
Uno de los principales retos de las sociedades del siglo XXI es el denominado cambio climático. La influencia del ser humano y sus actividades cuenta con diferentes manifestaciones entre las que destaca la emisión de Gases de Efecto Invernadero (GEI) que, a su vez, generan este calentamiento global de las temperaturas con múltiples fenómenos adversos asociados. Ante esta realidad es necesario determinar las fuentes de fijación de los mencionados GEI, sobre todo del carbono, de cara a minimizar los efectos adversos o absorber la mayor cantidad posible de emisiones. Se realiza un análisis de la captura de la biomasa aérea (tronco) en los pinares de Chirche (vertiente sur del macizo del Teide) para obtener el almacén aéreo de carbono de esta formación vegetal. Para ello se han tomado los DAP (Diámetro a la altura del Pecho) en una superficie de un décimo de hectárea de todos los ejemplares de Pinus canariensis presentes en esta superficie, para calcular su biomasa, y a partir de ella, la captura potencial de carbono (CO2). Para el modelo de cambio climático se utilizará la base de datos climática de wordclim y el método de regímenes climáticos de Cámara (2020). El resultado alcanzado se compara con otros obtenidos para Pinus canariensis. De esta manera, con estos resultados se tiene un valor de la importancia de la conservación de estos bosques en su contribución a la captura de carbono dentro del paradigma del cambio
climático y se evalúa el impacto del mismo sobre la conservación de estos bosques de pinos a partir de modelos para 2070.
We present a list of bats collected above 2000 meters in Río Abiseo National Park. Sixteen bat species belonging to the Phyllostomidae and Vespertilionidae families were collected during four expeditions between 1987 and 1990. Twelve species were found within expected altitudinal ranges, but four exceeded their previously reported maximum altitudinal ranges. A comparison with other bat lists from other localities at similar altitudes is presented.
We present a list of bats collected above 2000 meters in Río Abiseo National Park. Sixteen bat species belonging to the Phyllostomidae and Vespertilionidae families were collected during four expeditions between 1987 and 1990. Twelve species were found within expected altitudinal ranges, but four exceeded their previously reported maximum altitudinal ranges. A comparison with other bat lists from other localities at similar altitudes is presented.
Citation: Pablo-Rodríguez, J.L.; Bravo-Monzón, Á.E.; Montiel-González, C.; Benítez-Malvido, J.; Álvarez-Betancourt, S.; Ramírez-Sánchez, O.; Oyama, K.; Arena-Ortiz, M.L.; Alvarez-Añorve, M.Y.; Avila-Cabadilla, L.D. Linking Anthropogenic Landscape Perturbation to Herbivory and Pathogen Leaf Damage in Tropical Tree Communities. Plants 2023, 12, 3839. https://doi. Abstract: Anthropogenic disturbance of tropical humid forests leads to habitat loss, biodiversity decline, landscape fragmentation, altered nutrient cycling and carbon sequestration, soil erosion, pest/pathogen outbreaks, among others. Nevertheless, the impact of these alterations in multitrophic interactions, including host-pathogen and vector-pathogen dynamics, is still not well understood in wild plants. This study aimed to provide insights into the main drivers for the incidence of herbivory and plant pathogen damage, specifically, into how vegetation traits at the local and landscape scale modulate such interactions. For this purpose, in the tropical forest of Calakmul (Campeche, Mexico), we characterised the foliar damage caused by herbivores and pathogens in woody vegetation of 13 sampling sites representing a gradient of forest disturbance and fragmentation in an anthropogenic landscape from well preserved to highly disturbed and fragmented areas. We also evaluated how the incidence of such damage was modulated by the vegetation and landscape attributes. We found that the incidence of damage caused by larger, mobile, generalist herbivores, was more sensitive to changes in landscape configuration, while the incidence of damage caused by small and specialised herbivores with low dispersal capacity was more influenced by vegetation and landscape composition. In relation to pathogen symptoms, the herbivore-induced foliar damage seems to be the main factor related to their incidence, indicating the enormous importance of herbivorous insects in the modulation of disease dynamics across tropical vegetation, as they could be acting as vectors and/or facilitating the entry of pathogens by breaking the foliar tissue and the plant defensive barriers. The incidence of pathogen damage also responded to vegetation structure and landscape configuration; the incidence of anthracnose, black spot, and chlorosis, for example, were favoured in sites surrounded by smaller patches and a higher edge density, as well as those with a greater aggregation of semi-evergreen forest patches. Fungal pathogens were shown to be an important cause of foliar damage for many woody species. Our results indicate that an increasing transformation and fragmentation of the tropical forest of southern Mexico could reduce the degree of specialisation in plant-herbivore interactions and enhance the proliferation of generalist herbivores (chewers and scrapers) and of mobile leaf suckers, and consequently, the proliferation of some symptoms associated with fungal pathogens such as fungus black spots and anthracnose. The symptoms associated with viral and bacterial diseases Plants 2023, 12, 3839. https://doi.org/10.3390/plants12223839 https://www.mdpi.com/journal/plants Plants 2023, 12, 3839 2 of 29 and to nutrient deficiency, such as chlorosis, could also increase in the vegetation in fragmented landscapes with important consequences in the health and productivity of wild and cultivated plant species. This is a pioneering study evaluating the effect of disturbances on multitrophic interactions, offering key insights on the main drivers of the changes in herbivory interactions and incidence of plant pathogens in tropical forests.
COMPENDIO La actividad minera tiene como consecuencia la formación de huecos, lagunas de lodo y colas. En este caso, se estudió la composición florística y estructura de comunidades vegetales afectadas por la minería aluvional aurífera en Río Grande, estado Delta Amacuro, Venezuela. La investigación se ejecutó en dos localidades: Puente Roto y Los Arenales, donde se encontraron bosques y zonas intervenidas por la minería. En las areas intervenidas se realizaron caminatas a lo largo de unos 200 m y se tomó nota de las especies presentes en cuatro zonas según el sustrato observado. La mayoría de las especies inventariadas en estas áreas son comunes de sitios que han sido perturbados. En los bosques se establecieron cuatro parcelas de 0,1 ha y se contaron e identificaron los individuos con DAP > 10 cm. Los bosques son siempreverdes y semejantes en altura del dosel (≤25 m). En ambos sitios los bosques variaron en su composición florística de acuerdo a su posición geomorfológica: a) bosque en valle, b) bosque en planicie. Los resultados indicaron rangos entre 13-18 familias, 21-28 especies y 59-84 individuos en 0,1 ha. De las 32 familias
Specialty coffee (SC) production enables farmers to earn premium prices for high-quality coffee. In Bolivia, some coffee-based agroforestry systems (CAFS) produce SC. However, while many Bolivian families’ livelihoods depend on coffee, studies on SC-producing CAFS remain scarce. Yet, research on tree diversity, CAFS management and the factors affecting tree diversity can offer novel insights on agroforestry. We sampled 24 farms in three villages located in the Caranavi municipality. We analyzed farms main characteristics, biophysical variables, shade tree diversity, tree uses, management practices and farmers’ socioeconomic background. Additionally, we surveyed 50 coffee farmers to collect information about preferences for tree species and tree characteristics. Then, we investigated if farmers’ socioeconomic and farm biophysical variables affect CAFS tree species richness and tree density using generalized linear models (GLM). Our results showed that studied farms are small and certified properties (average: 2.6 hectares) managed by families; we observed that CAFS provide farmers with useful products besides SC. 85 tree species, primarily serving as shade providers for coffee, were identified. These species also yield valuable resources like: fruits, timber, lumber, and medicinal products. Accordingly, surveyed farmers exhibit preference for tree species offering useful and marketable products, with tree characteristics selected based on their advantages for coffee and farmers. GLM revealed that socioeconomic and biophysical variables affect species richness and density. Additional research is needed to evaluate the relationship between biodiversity and the social-economic sustainably of Bolivian CAFS. Likewise, is necessary to enhance farmers’ ability to manage their CAFS for biodiversity conservation and household wellbeing.
Se presenta una caracterización ecológica del paisaje terrestre de las islas Múcura y Tintipán del Archipiélago de San Bernardo (Depto. de Bolívar). Mediante fotointerpretación, caracterización de campo e implementación de SIG, se elaboró un mapa en el que se diferencian 11 Unidades de Paisaje (UP). La Isla Tintipán presenta la mayor diversidad de UP (11) entre las que dominan las unidades de manglar (253 ha, 64 %); las unidades restantes corresponden a cimas de terrazas coralinas con vegetación secundaria de Bosque Seco Tropical (BST) y cultivos de coco que muestran diferentes niveles de transformación antrópica. La Isla Múcura, presenta 6 UP dominadas por vegetación secundaria de BST y cultivos de coco sobre suelos de origen calcáreo (31 ha, 82 %). Ambas islas han sido impactadas por la extracción de madera desde hace muchas décadas. Actualmente las actividades humanas incluyen la extracción de leña, agricultura extensiva, asentamientos permanentes e incremento en la presión turística.
Los bosques pre-montanos y montanos son poco estudiados y su composición florística es muy poco conocida, aunque últimamente aquí se han descubierto nuevas especies de árboles. Describimos la diversidad, composición florística y estructura del bosque en 13 parcelas permanentes de 1 ha, evaluadas en el 2018 en el Transecto Yanachaga en el centro del Perú (400 a 3170 msnm). Registramos un total de 6998 árboles, 617 especies, 249 géneros y 82 familias. Existe unas altas correlaciones entre la altitud, la riqueza y diversidad de especies. La mayor riqueza ocurre en la parcela PNY-05 a 470 msnm con 202 especies y la menor con 43 especies en la parcela PNY-01 a 3170 mnsm. La altura promedio del dosel es mayor entre los 400 y 800 msnm, y disminuye progresivamente a medida que se va subiendo, presentando alturas mínimas entre 2800 y 3170 msnm. Este mismo comportamiento ocurre con respecto al área basal y volumen de madera. Los individuos muestreados están representados por especies de árboles (88%), palmeras (4%), helechos arborescentes (6.5%), lianas (1.5%) y hemiepífitos leñosos (0.03%). Las formas de vida varían notablemente en el transecto altitudinal, los árboles y palmeras son más abundantes y diversos en la parte baja, mientras los helechos arborescentes son abundantes por encima de los 1800 m. Existen diferencias en la diversidad, composición y estructura de árboles entre parcelas y también si se compara al llano amazónico. Los bosques del Transecto Yanachaga juegan un papel importante, puesto que conservan una alta diversidad de especies y hábitats.
Estudiar las interacciones frugívoras en un sentido amplio de red es fundamental para conocer y evaluar la respuesta de los ecosistemas frente a diferentes perturbaciones. El presente trabajo tuvo por objetivo conocer las especies de aves que dispersan semillas en el bosque del espinal, identificar que especies de semillas están siendo dispersadas, establecer si las semillas son dispersadas sin daños físicos (dispersión legítima) y describir la red de interacción generada. Para ello se realizaron muestreos mensuales de aves con redes de niebla y se tomaron muestras de fecas las cuales fueron analizadas bajo lupa estereoscópica y separadas para su identificación. A nivel de red se analizaron las interacciones potenciales, reales, el grado de conectividad y el grado de anidamiento. Seis especies de aves presentaron semillas en sus fecas y el 90% de las mismas no presentaron daños físicos. Las semillas observadas fueron de cinco especies autóctonas, cinco exóticas y dos especies no fueron identificadas. A nivel de red se observó que el número de interacciones potenciales fue de 72 y el número de interacciones observada fue de 16 para una conectancia del 22%. La densidad de la red fue estimada en 0,88 vínculos por especie. El grado de anidamiento de la red fue de NODF=28,09, con un mayor grado de anidamiento en las aves NODF=30,3 que en las plantas NODF=18,33. La red de interacción conformada por las aves y las plantas ornitócoras del bosque del espinal presenta una baja conectividad donde se observa que algunas aves son más generalistas e interactúan con un subconjunto de especies de plantas con menos interacciones.
Hygrophilous forests are tree dominated formations in periodically or permanently waterlogged environments. The species composition, phytosociological structure and tree diversity of hygrophilous forest stands located in Puerto Valle, in the northeast of the Iberá wetland (Corrientes, Argentina), are described. The forest of Puerto Valle consists of 24 species with a monodominant formation of the “arary”, Calophyllum brasiliense (Calophyllaceae), as the main component. The floristic similarity between communities indicates complete dissimilarity between forest patches in Puerto Valle sites. Natural recruitment in Puerto Valle also showed a predominance of C. brasiliense, in line with the monodominant character of the species. Our results indicate a great spatial variability of the rain forests in the territorial matrix and reinforce the relict character of the forest with C. brasiliense in Argentina.
El Corredor BiolÛgico (COBIO) Chichinautzin es un ¡rea Natural Protegida ubicada al norte del estado de Morelos, importante por su riqueza de especies, suelo agrÌcola y recarga de acuÌferos, donde sus habitantes originarios y recientemente urbanos manejan la biodiversidad. Sin embargo, el COBIO no escapa al proceso de fragmentaciÛn del paisaje. Una estrategia de resistencia cultural ante la problem·tica mencionada son los cercos vivos (CV), que se encuentran en todo el mosaico antrÛpico dentro de matrices agrÌcolas, cuya estructura dentro del paisaje provee servicios ecosistÈmicos. Se documentÛ el efecto del conocimiento ecolÛgico tradicional (CET) y de la altitud sobre la riqueza, estructura y diversidad de especies en tres tipos de vegetaciÛn: bosque tropical caducifolio (BTC), bosque de pino-encino (BPE) y la ecotonÌa entre Èstos. Para documentar el CET se aplicaron entrevistas semiestructuradas a los manejadores, que son campesinos originarios y recientemente urbanos, con el propÛsito de registrar las pr·cticas culturales para el establecimiento y manejo de los CV, el uso local y el destino de la producciÛn de cada especie. La obtenciÛn de los par·metros ecolÛgicos se generÛ mediante muestreos en cinco municipios del COBIO, en los que se eligieron 10 sitios en un gradiente altitudinal que va de los 1212 a 2561 m, allÌ se establecieron 23 transectos de 100 x 2 m cada uno. Se determinÛ el Ìndice de diversidad de Jaccard, el Ìndice de valor de importancia (IVI) y el Ìndice de valor forestal (IVF). El dendrograma de calor permitiÛ identificar las comunidades con m·s similitud. El An·lisis de Escalamiento Multidimensional No MÈtrico(NMDS) se empleÛ para determinar quÈ variables influyen en la riqueza, estructura y diversidad arbÛrea. Las especies arbÛreas registradas fueron 35, pertenecientes a 30 gÈneros y 21 familias, de las cuales el 71% son nativas de MÈxico y de Èstas el 8% son endÈmicas del paÌs. Estos taxa proveen seis valores de uso. Las pr·cticas de manejo cultural fueron cuatro. Los CV ubicados en la zona de transiciÛn y en el BTC mostraron la mayor riqueza de especies, mientras que en el BPE est· mÈtrica fue menor. Tanto en el IVI como en el IVF las especies jer·rquicamente dominantes fueron Erythrina americana Mill., Ipomoea murucoides Roem. & Schult. y Spondias purpurea L. El dendrograma visualiza la existencia de dos grandes grupos y expresan una baja tasa de recambio de especies a lo largo del gradiente altitudinal. El NMDS muestra que tres pr·cticas culturales asociadas con el CET son estadÌsticamente significativas y que influyen directamente en la riqueza, estructura y diversidad arbÛrea. La presencia de los CV es importante para la conservaciÛn biocultural porque albergan en su mayorÌa especies nativas tanto silvestres como cultivadas, adem·s de que suministran alimento y combustible para cubrir necesidades b·sicas. Contrario a lo esperado, los par·metros ecolÛgicos estructurales no est·n influenciados por el gradiente altitudinal y por los tipos de vegetaciÛn, sino por el tipo de especies cultivadas o favorecidas por los campesinos.
Resumo Foi feita uma mostragem numa área de 1000 m2, na capoeira do INPA (Manaus). Algumas famílias, inclusive as Bignoniaceae, mostram aqui a mesma diversidade e composição de espécies que uma floresta em clímax. Todavia, certas famílias estão sub-representadas (Sapotaceae, Lauraceae, Chrysobalanaceae, entre as árvores, e Apocynaceae, Malpighiaceae e Dilleniaceae, entre os cipós). Sugere-se que as famílias mais bem representadas, como as Bignoniaceae e Lecythidaceae, sejam Intrinsecamente melhores em sua capacidade de regenerar por brotamento dos tocos, do que, por exemplo, as famílias Chrysobalanaceae e Sapotaceae.
Nine hummingbird-pollinated species of Heliconia occur together at Finca La Selva, in the wet Caribbean lowlands of Costa Rica. In forest habitats, Heliconia clumps (clones) are typically small; in more open areas, many clumps attain large size. This probably reflects differences in light intensity and degree of vegetative competition in these habitats. Nine species of hummingbirds regularly visit Heliconia flowers at La Selva. The four hermits are nonterritorial, traplining foragers with long, curved bills. Non-hermits frequently hold territories at Heliconia clumps, and have short, straight bills. Pollination by hermits tends to produce more cross-pollination; territorial hummingbirds increase self-pollination. Different Heliconia species appear to be specialized for pollination by either hermits on non-hermits, largely through components of the caloric phenotype: amount and timing of nectar production, rate of inflorescene and flower production, and morphological paramerters that affect the energetic efficiency of nectar-harvesting hummingbirds. Habitat may influence pollination systems through its effects on clump size and thus on the number of flowers a clump can have at any one time. Ultimately, specialization for hermits or non-hermits may depend on the degree of self-compatibility of the different Heliconia species. Hermit-pollinated Heliconia mostly show sequential and nonoverlapping flowering peaks, probably resulting from competition for pollinators and/or selection against hybridization. Two hermit-pollinated species bloom simultanesoulsy, thereby inducing the birds to utilize an other-wise little-used microhabitat. Heliconia species pollinated by non-hermits bloom in the early to middle rainy season, and are mostly separated by habitat. Isolating mechanisms among sympatric Heliconia species involve both spatial and temporal patterns of partioning available pollinators. Floral parameters include mechanical (different site of pollen deposition on the bird) and ethological (caloric and visual factors affecting flower choice) mechanisms. Selection for pollinator specificity may result in convergence of blooming peaks, provided that other isolating mechanisms are present. Human activity has broken down some habitat barriers by producing large areas of second growth.
This paper seeks to elucidate causal factors in the temporal organization of blooming patterns, both within and between years, of a coadapted group of plants sharing a group of pollinators: the hummingbird flowers of Finca La Selva, Costa Rica. Quantitative data on flowering of 42 species over a four-year period are presented, with supplementary data on an additional 17 species. Peaks of flower availability for hummingbirds occur in the dry and early wet seasons; a severe and predictable flower shortage occurs in November and December, the wettest months of the year. This pattern is repeated in several other tropical areas, among hummingbird foodplants and the plant communities in general. A severe drought in March-April 1973 severely affected flowering of many species for up to four months thereafter; some species were noticeably affected as much as a year later. Hummingbird foodplants of large light gaps and second growth have longer peak blooming periods than do those of forest understory; vines bloom for shorter periods than do other growth forms. Mean year-to-year variation in various temporal parameters of flowering was about two months among La Selva hummingbird flowers, and about one month among those of a California locality. If, as in other groups of organisms, the action of photoperiod is to define the time span within which plants may be stimulated to flower by other factors like rainfall, then La Selva plants respond to a daylength change about half as great as do California plants. Two mechanisms may help maintain a regular sequence of blooming peaks from year to year in the face of annual variations in rainfall: displacement of the entire sequence, and opposite and compensating responses of individual plant species. In California and probably in tropical dry forest, the first mechanism predominates; at La Selva, both mechanisms may be important.
The roughly 300,000 species of green plants and algae provide the means by which the energy of the sun that reaches the earth’s surface is locked up in chemical bonds. By carrying out this process, the plants and algae provide all of the food for from ten to thirty times as many heterotrophic organisms, including all the animals and man himself. Because of the nature of food chains and the degree of specialization in feeding habits of these heterotrophs, we may assume that the extinction of each species of plant is, on the average, accompanied by a ten- to thirty-fold loss amongst other organisms. Therefore, the diversity of plants is the underlying factor controlling the diversity of other organisms and thus the stability of the world ecosystem. On these grounds alone, the conservation of the plant world is ultimately a matter of survival for the human race.
Rarefaction is a statistical technique useful in both pollution and evolutionary ecology. It can be used to infer whether samples are drawn from the same community and also to estimate minimum feasible sample size. Rarefaction is most powerful in pollution ecology when entire curves, and not just single values, are calculated. In evolutionary ecology, species/genus and related ratios have been examined as an indicator of both competition and adaptive radiation, but rarefaction demonstrates that the former, at least, is rarely evidenced by such ratios. The ratios are largely determined by the number of species, and claimed relationships between the ratios and area are primarily artifacts of the high correlation between the ratios and species number. The analytic expressions for expectation and variance in rarefied samples and a FORTRAN IV program for their calculation are given.
Models of optimal foraging often separate the time and energy expended in getting to a feeding area (commuting costs) from the time and energy expended in searching for food (search costs) in animals that are "pure searchers." We predict that under certain circumstances (e.g., a relatively uniform resource distribution) searching and commuting behavior will be synchronous, whereas under other circumstances (e.g., a relatively patchy resource distribution) these two behaviors will be temporally separated. We have tested these predictions by studying the foraging and food location behavior of several species of Costa Rican frugivorous bats using mist-netting programs, radio- telemetry, and fruit relocation experiments. Concurrent observations were made on the phenology and distribution patterns of the six fruit species used in the relocation experiments. The mist-netting program allowed us to determine the food habits of the common frugivorous bats in our study area and to identify the major chiropteran dispersal agents of the six fruit species. The radio-tracking program provided detailed information on the foraging behavior of one of the most important seed dispersal agents, Carollia perspicillata, whose individuals commute up to 2.7 km from a central day roost before beginning to feed. Results of the fruit relocation experiments, in which ripe fruits of the six species were individually placed on "fruit poles" located either close to or at a considerable distance (>0.5 km) away from con- specific plants in areas known to be used by bats, indicated the following: (1) fruits of two species of Piper, which are highly preferred by Carollia and which occur in low nightly densities for extended periods of time, had as high (-.90) a probability of being found away from nonspecific plants as when they were near conspecifics; (2) fruits of two species of Ficus and Muntingia calabura, which are very patchily distributed in time and/or space, had a significantly higher probability (.30-.50 vs. .02-.12) of being found near rather than away from conspecifics; and (3) when placed on poles with Piper fruits, fruits of Ficus ovalis, Chlorophora tinctoria, and Muntingia calabura had a significantly higher proba- bility (.40-.60 vs. .08-.13) of being found than when placed in similar areas without Piper fruits. These results indicate that certain bats (e.g., Carollia perspicillata and Glossophaga soricina) are constantly "on the alert" for ripe Piper fruits while commuting, whereas bats that eat Ficus, Chlorophora, or Muntingia fruits (e.g., G. soricina orArtibeusjamaicensis) are not constantly "on the alert" for these fruits while commuting. Bats feeding on Piper probably search and commute simultaneously, whereas those feeding on Ficus or Muntingia separate commuting and searching behavior. The food location behavior of frugivorous bats appears to be highly responsive to differences in the spatiotemporal distribution patterns of their food resources.
(1) An area of moist subtropical rain forest was completely cleared in November 1957. Ten quadrats were established within the cleared area and, at twelve sampling periods over the following 7 years, the identity, number and size of all plants in the quadrats were recorded; the final data matrix was dimensioned ten sites × twelve periods × 118 species. The area was subsequently inspected after a further 4 years. (2) The data were analysed by five numerical methods: (i) Twelve separate analyses, each of 10 × 118. (ii) Normal and inverse `linked' analyses, of (normal) 10 × 1416, and (inverse) 12 × 1180. (iii) A single analysis regarding sites at different periods as all potentially independent, dimension 120 × 118. (iv) An information statistic classification of the transition-matrices obtained from (iii). (v) Calculation of the Brillouin diversity for each period of individual sites and of the entire area. Of these methods, (iii) proved the single most informative, but (iv) provide valuable ancillary information. Although numbers of seedlings and biomass (estimated from seedling numbers and height) provided assistance in interpretation of minor heterogeneities, the main pattern required only presence-and-absence data. (3) The ecological implications of the results are considered in relation to earlier successional studies.
Twenty-one species of rodents were trapped or observed in two forests in the Panama Canal Zone. Data on the ecology, molt, and food habits of seven species are presented. Among the terrestrial rats and mice, three species (Liomys adspersus, Oryzomys capito, and Proechimys semispinosus) were common in the Pacific slope forest, whereas two (Oryzomys capito and Proechimys semispinosus) were common in the Atlantic slope forest. Year-round breeding occurs in eight of nine species; Liomys adspersus breeds seasonally. Adults of L. adspersus and P. semispinosus molt during restricted portions of the year, but there was no apparent synchrony of molt in adults of Heteromys desmarestianus, Oryzomys capito, Zygodontomys microtinus, and Sigmodon hispidus. Ecological segregation serves to minimize competition among the rodents in both forests.
Three bat communities were studied for 1 year at each of two localities in the Panama Canal Zone and one locality in western Costa Rica. Removal sampling and banding techniques using Japanese mist nets were employed to document community structure, food habits, reproductive cycles, and movement patterns of these bats. Results indicated that 27-31 species occur at or near ground level at each locality. Species diversity, as measured by H', was highest in the Costan Rican community; each community contained 3-4 common species and many uncommon species. Based on body size and general food habits, niche overlap appears to be greatest among small to intermediate-sized insectivores and frugivores, many of which, however, are apparently uncommon. Four basic reproductive patterns are found among the species. Most frugivores are seasonally polyestrous whereas some insectivores are monestrous and at least one is polyestrous. It is postulated that in both insectivores and frugivores birth peaks coincide with maximum food levels. Recapture patterns of several species suggest that home range size may be positively correlated with body size; omnivorous species may have larger home ranges than similarly size species with more restricted diets.
A detailed study of montane and lowland forest areas at 1710 and 380 m respectively is presented; supporting data from three other lowland forests are also given. 1. The soils under the forests are compared. The montane is appreciably more acid in the A1 horizon, has a lower calcium-status, contains more organic matter, has a coarser texture and has freer drainage. 2. The forests are shown to be very similar in structure. The montane forest is somewhat less dense (Table 2), and the trees are of slightly lesser mean height and diameter (Table 3), but there is not much difference in the extent of the canopy holes. Concerning undergrowth plants (Table 4), the montane plot bore fewer saplings and poles (woody plants 3-9 ft, 9-20 ft) but far more cyclanths and palms. The data from the extra lowland plots indicate that the plot studied in detail was essentially typical of forest over a wide area in eastern Ecuador. 3. The stratification of forests is analysed more closely than by other workers and various types are distinguished. It is concluded that stratification of species has not been shown for any species-rich primary tropical lowland rain forest. Stratification of the heights of individuals and of canopy volume or mass is related to species-paucity and to the regeneration pattern. Other forms of stratification are briefly discussed. The montane forest shows no stratification of individuals or, over the whole plot, of canopy volume. No regular strata of individuals have been located in the four lowland forests (cf. Fig. 4). 4. Various evidence is used to show that all the forests investigated are either primary or very old secondary. 5. The leaf size spectra of the montane and lowland forests are similar but the montane has less macrophylls and more notophylls and microphylls. The montane forest has shorter buttresses, more leaning and distorted boles, and less monopodial crowns. 6. Both forests have strong floristic affinities (at the family level) with the Amazonian hylaea; the montane forest also contains a distinctly Andean element. 7. A revised system of synusiae of epiphytes and climbers is presented, together with a detailed analysis of the numbers of species and individuals in different taxonomic groups and arbitrary height classes in the two forest types. The montane forest has a greater abundance of skiophytic bryophytes, pteridophytes, bromeliads, and orchids and of photophytic bryophytes and macrolichens. The lowland forest has more photophytic dicotyledonous climbers and more climbing and epiphytic Araceae. 8. The classification of tropical rain forests is discussed and the three formation-types recognized by Richards (1952) are renamed Lowland Rain forest, Lower Montane Rain forest and Upper Montane Rain forest. The montane forest studied is assigned to the Lower Montane Rain forest formation-type and the lowland forests to the Lowland Rain forest formation-type. The limitations of a single system of formation-types for the whole of the tropics are emphasized.
Regression analyses were computed for the prediction of island species numbers in the British Isles, using as independent variables island area, island elevation, the number of soil types, ⚬ N latitude, the distance from mainland Britain, the Distance from the nearest other island, the number of vegetation types, and latitudinal range. In simple regressions, the number of island soil types was the best single predictor of island species number. In multiple regressions, area, ⚬ N latitude, and distance from Britain also made significant contributions to the prediction of island species numbers. These analyses are discussed in terms of the theory of island biogeography in general and the description of the British Isles in particular. The slope of the log species, log area curve reveals that the plant species distribution pattern on the British Isles is more like that of continents than of islands.
Temperature and moisture stress of conifer saplings and needle nitrogen content of conifer saplings were measured at reference stands representing 16 forest communities in the central portion of the western Cascades province of Oregon. Most species occur over a wide range of temperature and moisture stress; many occupy a wider range of environments in the western Cascades than they do in the eastern Siskiyou Mountains of southwest Oregon. Differences between vegetation zones are reflected in a temperature index; within zones, communities are distinguished by moisture stress and, to a lesser extent, by temperature. In two cases vegetation differences appear to be related to low needle nitrogen contents. Use of complex gradients for vegetation ordination suggests certain environmental differences between communities which are contrary to the differences measured; therefore, we prefer the measured gradients over the complex gradients defined. Species diversity (the total number of vascular species) increases and dominance (Simpson's index) decreases away from moderate environmental conditions to warmer-drier and colder communities. Diversities of different strata are unrelated. Dominance is concentrated in fewer strata of the vegetation on the colder sites. However, discontinuities in the pattern of diversity with environment occur which are not related to major differences in our measured environmental indexes. Evergreenness of shrubs is highest in stands with the lowest foliar nitrogen levels.
During 1969-70, 185 tree species at a Wet forest site and 113 species at a Dry forest site in Costa Rica were systematically observed for changes in leafing, flowering and fruiting. (1) At the Wet forest site, the greatest amount of leaf fall in the overstorey and understorey trees occurred primarily during the first (more severe) dry season. At that time, 17% of the tree species from both storeys lost leaves. (2) At the Dry forest site, the period of greatest leaf fall coincided with the long dry period; at that time 75% of the species lost leaves. (3) Most Wet forest species flushed large quantities of new leaves during the first dry season. This was in contrast to the Dry forest site where most species flushed leaves at the onset of the first rainy season. (4) Two apparent flowering peaks in the overstorey tree species and three apparent flowering peaks in the understorey tree species were recorded during the year at the Wet forest site. These major flowering periods in both layers occurred during wet as well as dry seasons, and two of the peak periods of the overstorey appeared to be out of phase with two of the understorey. The species at the Wet forest site were well represented by both `seasonal' and `extended' flowering species. (5) At the Dry forest site, two peak periods of flowering activity were recognized. One extensive period occurred during the long dry season and a second peak period was recorded at the onset of the rainy season. Most species were of a `seasonal' rather than `extended' flowering nature. (6) With regard to Wet forest fruiting, substantial numbers of species (at least 37) from both storeys were in mature fruit during each month, but a peak in fruiting occurred in both layers during the second dry season (August-October); the fruiting peaks of the two storeys were separated by one month. The disseminules of most Wet forest species were not adapted for wind dispersal. (7) A peak period in the production of mature fruit occurred during the latter part of the long dry season at the Dry forest site. A significant proportion (31%) of the Dry forest species had disseminules adapted for wind dispersal. (8) When phenological patterns of vicarious species of the two forests were compared, only flowering patterns showed similarity (11/27 species). Leafing and fruiting patterns of vicarious species tended to follow the general trends of the respective forest ecosystems. (9) Periodicity patterns of most species in common between the two forest sites were similar. (10) The phenological patterns recorded are discussed in relation to climatic `triggers' (proximate factors) and plant-animal interactions (ultimate factors).
This study describes the distributional patterns of Costa Rican and Panamanian species of Bignoniaceae. These species tend to be wide-ranging but restricted to certain climatic zones. Abundance and ecological importance of Bignoniaceae are greatest in dry areas, but species diversity is generally constant in lowland dry, moist and wet forest habitats. About 20 of the 80 Costa Rican/Panamanian species occur at any suitable site. A comparison of pollination strategies with species distributions suggests unique pollination niches for the strictly sympatric species. In any given area only one (uncommonly two) species with a given pollination strategy is in flower at any one time.