Humberto Suzán-Azpiri

Autonomous University of Queretaro · Facultad de Ciencias Naturales

Small-scale agroecological practices in the urban areas of Querétaro, México, as in other mid-sized cities, could maintain agrobiodiversity pools and sufficient productivity for a food sovereignty baseline. The application of agroecological principles fosters agrobiodiversity and socio-ecological resilience in urban food production. Emerging urban...

Currently, Salmonella spp. is the bacterium causing that causes the highest number of food-borne diseases (FADs) in the world. It is primarily mainly associated with contaminated water used to that irrigates crops from intensive livestock farming. However, literature emphasizes that the reservoirs for Salmonella spp. remain in wildlife and there ar...

Arid and semiarid ecosystems contain relatively high species diversity and are subject to intense use, in particular extensive cattle grazing, which has favored the expansion and encroachment of perennial thorny shrubs into the grasslands, thus decreasing the value of the rangeland. However, these environments have been shown to positively impact g...

La modelación de la biomasa en plantaciones forestales es una alternativa para cuantificar el carbono almacenado en la vegetación. Las predicciones son importantes para las decisiones productivas o para los esfuerzos de mitigación de cambio climático. Un aspecto importante es la relación de la humedad de suelo (q) con la biomasa. Se usó el modelo 3...

Abstract. Vegetation fixes C in its biomass through photosynthesis or might release it into the atmosphere through respiration. Measurements of these fluxes would help us understand ecosystem functioning. The eddy covariance technique (EC) is widely used to measure the net ecosystem exchange of C (NEE) which is the balance between gross primary pro...

Mistletoes nutrient and water uptake can alter the gas exchange activity of their host plants, leading them to a diminished photosynthetic capacity and poor water use efficiency. This is particularly important in semi-arid areas, where water availability is a limiting factor. The aim of this study was to evaluate gas exchange (photosynthetic net ra...

Having an aesthetic form is one of the desirable aspects of trees used to create or reforest urban green areas, which is often achieved by procedures that require a great effort. The understanding of factors affecting the architecture of plants in natural conditions may be useful to promote a desirable shape during the growth process. Under the hyp...

Background: Fungi have multiple uses in temperate areas of México, but an important decrease in the traditional knowledge of uses and customs of mushrooms becomes a fundamental issue for fungi conservation. However, only few studies quantify the traditional ethnomycological knowledge in México, and this study is the first quantitative report for Q...

In Central Mexico, a traditional alcoholic beverage (pulque) is obtained from wild and cultivated species of the genus Agave. We evaluated the spatial distribution of Agave plants under distinct management scenarios in Queretaro, Mexico. Six sites were selected: two in crop fields, three in natural managed areas, and one in a non-disturbed natural...

p> Background : Environmental conditions in edges of vegetation fragments affect life cycle characteristics of the native biota (edge effect). We evaluated the edge effect on two Bursera species, which are representative of the mature community of the tropical deciduous forest (TDF) in Mexico. Hypothesis . We expected a population structure reflec...

El metano (CH4) contribuye al cambio climático y su fuente antropogénica más importante es la fermentación entérica del ganado. A nivel continental el Panel Intergubernamental de Cambio Climático establece factores de emisión entérica de CH4 por defecto (Tier I); pero las decisiones y evaluación de la mitigación necesitan estimaciones más exactas....

Methane (CH4) contributes to climatic change and livestock enteric fermentation is the most important anthropogenic source. The Intergovernmental Panel on Climate Change establishes continental default emission factors for enteric methane (Tier I); but decisions and evaluation of mitigation needs more precise estimates. Therefore, the objective was...

Psittacanthus calyculatus (Loranthaceae) is a neotropical hemiparasitic mistletoe and one of the most abundant and widely distributed species of the genus. Like most mistletoes, the interaction with its hosts and dispersers are directly related with its distribution and community dynamics. For the last decade, the infested areas in central México h...

The niche breadth of a species reflects its ability to inhabit different conditions, and to use different resources, hence, species with wider niche are expected to be more resilient to anthropogenic derived climate change. We estimated the niche breadth of all species of the genus Astrophytum from macro-environmental variables and measures of loca...

Alteration of climatic conditions and the urban heat island effect (UHI) are consequences of increased human population and activities in urban zones. Determining the magnitude of the UHI is important to improve urban planning in medium-size cities like Queretaro. Increase and conservation of vegetated areas is a mitigation option for UHI. Here we...

Alteration of climatic conditions and the urban heat island effect (UHI) are consequences of increased human population and activities in urban zones. Determining the magnitude of the UHI is important to improve urban planning in medium-size cities like Querétaro. Increase and conservation of vegetated areas is a mitigation option for UHI. Here we...

Prairie dogs (Cynomys spp.) have been eliminated from over 95% of their historic range in large part from direct eradication campaigns to reduce their purported competition with cattle for forage. Despite the longstanding importance of this issue to grassland management and conservation, the ecological interactions between cattle and prairie dogs h...

A partir de un análisis de componentes principales (ACP), se plantea la interpretación y clasificación de tres ambientes de competencia sobre el desarrollo de individuos de P. pseudostrobus integrando resultados previamente publicados dentro del mismo ensayo; las variables evaluadas fueron: el crecimiento (altura y diámetro a la base del tallo), pr...

We evaluated seed germination and further seedling growth from Ferocactus histrix seeds treated with mechanical scarification and gibberellin immersions (5% and 10%). Scarified seeds presented higher germination rates (90%), whereas 10% gibberellin produced 62% germination. There were also statistical differences in time for 50% germination (P < 0....

From a principal component analysis (PCA), is is proposed the interpretation and classification of three main environments competition on the development of individuals of P. pseudostrobus integrating previous results within the same trial. The variables were: growth (height and base diameter), chlorophyll production (chlorophyll pigments total, a,...

Competition intensity at which individual plants grow is an important factor in their survival, biomass production and architecture; characteristics that interact with their genotype. In this study, we evaluated the effect of different levels of competition in 13 juvenile families of Pinus pseudostrobus Lindl. half-siblings in terms of plant surviv...

Resumen Las presiones antropogénicas y naturales, como el cambio de uso de suelo y el cambio climático, modifican la capacidad de germinación y latencia en semillas. El presente trabajo analizó la respuesta germinativa relacionada con el tamaño de semilla en 8 procedencias de Yuca filifera, colectadas dentro del periodo 1998-2012. Las variables de...

Competition intensity at which individual plants grow is an important factor in their survival, biomass production and architecture; characteristics that interact with their genotype. In this study, we evaluated the effect of differentlevels of competition in 13 juvenile families of Pinus pseudostrobus Lindl. half-siblings in terms of plant surviva...

Grass pasture is important for the short term sustainability of agroforestry systems. Growth rate (GR) and pasture dry matter accumulation (DMA) were studied in order to understand competition relationships, by establishing: 1) the decrease as a result of the effect of shade, and 2) the relation with environmental variables, in a eucalypt (Eucalypt...

Grass pasture is important for the short term sustainability of agroforestry systems. Growth rate (GR) and pasture dry matter accumulation (DMA) were studied in order to understand competition relationships, by establishing: 1) the decrease as a result of the effect of shade, and 2) the relation with environmental variables, in a eucalypt (Eucalypt...

Recognition of the accurate spatial distribution of species in the habitat is fundamental to analyze species interactions (positives as nurse plant interactions and negatives such as competition) and also to create viable conservation and management plans. We present here three study cases to illustrate the power of spatial analysis by distance ind...

Taxodium mucronatum is a riparian species subjected to anthropocentric pressures. In 8 sites under contrasting disturbance conditions we compared the population structure and individual growth for 2 years, implementing two 500 m2 quadrats in each population where we measured for each individual >5cm the diameter at 1.5m, height, basal area, canopy...

Taxodium mucronatum is a riparian species subjected to anthropocentric pressures. In 8 sites under contrasting disturbance conditions we compared the population structure and individual growth for 2 years, implementing two 500 m2 quadrats in each population where we measured for each individual >5cm the diameter at 1.5m, height, basal area, canopy...

Interception losses are a major influence in the water yield of vegetated areas. For most storms, rain interception results in less water reaching the ground. However, fog interception can increase the overall water storage capacity of the vegetation and once the storage is exceeded, fog drip is a common hydrological input. Fog interception is disr...

Olneya tesota (ironwood) is a keystone tree species that modifies the structure and function of Sonoran desert ecosystems. Presently, extraction of trees and branches in the region constitutes a severe risk for ironwood populations. We analyzed the size structure, two damage indicators (damaged basal area or “DBA” and percents of damaged individual...

Background/Question/Methods Ariocarpus kotschoubeyanus is a Mexican endemic species, officially classified as endangered since it is threatened by illegal extraction. We analyzed the nurse plant interactions to understand the recruitment, distribution and survival patterns of the populations. We used the SADIE system (Spatial analysis by Distance I...

Located on the Central Highlands of México, El Bajío is an important agricultural region that faces water shortage, and therefore, it is necessary to increase aquifer recharge and decrease irrigated area. Reforestation and agricultural reconversion based on tropical deciduous forest shrub species can help to achieve these goals. Probability maps of...

Located on the Central Highlands of México, El Bajío is an important agricultural region that faces water shortage, and therefore, it is necessary to increase aquifer recharge and decrease irrigated area. Reforestation and agricultural reconversion based on tropical deciduous forest shrub species can help to achieve these goals. Probability maps of...

The Ahuehuete or Mexican baldcypress (Taxodium mucronatum Ten.) is an important tree species of the riparian gallery forests of México and Guatemala. This study is the first demographic survey of T. mucronatum in the Central State of Querétaro, México. Populations with more than 200 individuals having a diameter at breast height > 10 cm, were surve...

Habitat fragmentation commonly influences distribution of zoonotic disease reservoirs. In Panama, populations of rodent hosts of hantaviruses are favored by small habitat fragments isolated by agricultural lands. We expected a similar relationship between landscape characteristics and host distribution at fine geographical scales in southern Panama...

Recruitment and survival of cacti in North American deserts are facilitated under the canopy of nurse plants. In the Sonoran desert, the giant cardon cactus (Pachycereus pringlei) is associated with ironwood (Olneya tesota) and mesquite (Prosopis glandulosa) trees. We hypothesized that P. pringlei seedlings would perform better under ironwood than...

One of the two species from the genus Lophophora is the false peyote Lophophora diffusa, an endemic cactus species of the xerophytic shrubland at Querétaro, México, considered threatened from illegal extraction due to its hallucinogenic and medicinal properties. We analyzed the spatial distribution of L. diffusa and its association with the locally...

Maize is the main staple food in the Mexican diet and is also the most important irrigated crop. However, water shortage is very serious in México, and food security cannot be maintained without irrigation. To address this problem, the effect of maize density sowing was evaluated using a subsurface drip irrigation system. There were no differences...

Maize is the main staple food in the Mexican diet and is also the most important irrigated crop. However, water shortage is very serious in México, and food security cannot be maintained without irrigation. To address this problem, the effect of maize density sowing was evaluated using a subsurface drip irrigation system. There were no differences...

The proportion of viable seeds and loss of viability due to age, as well as the conditions which promote germination in Taxodium mucronatum from two different cohorts (2000 and 2002), were determined in the State of Querétaro, México. Seeds from the 2002 cohort had a viability of over 50%, whereas those of 2000 presented a viability of 30% or less....

The proportion of viable seeds and loss of viability due to age, as well as the conditions which promote germination in Taxodium mucronatum from two different cohorts (2000 and 2002), were determined in the State of Querétaro, México. Seeds from the 2002 cohort had a viability of over 50%, whereas those of 2000 presented a viability of 30% or less....

Pinus nelsoni Shaw and Pinus cembroides Zucc. are the most important pinyon pine species in the northern region of the Sierra Madre Oriental in Mexico. A demographic study of these two species was conducted between 1996 and 1998. The two species differed in their size structure: P. cembroides had a higher proportion of large individuals and seedlin...

Legume trees have been harvested in the Sonoyta Valley since 1975. We estimated the effects of this woodcutting along the border between Organ Pipe Cactus National Monument (U.S.A.) and Sonora, Mexico. We placed 10 × 100 m transects in ephemeral watercourses and uplands on both sides of the international boundary at different distances from the bor...

The geographic distribution of the genus Ariocarpus in the State of Tamaulipas, Mexico was determined based on literature, herbarium vouchers, botanical gardens and several field trips in 1991 and 1992. Three species and two subspecies were detected: Ariocarpus agavoides, A. kotschoubeyanus, A. retusus subsp. retusus and A retusus subsp. trigonus....

Rare and endangered plants possessing crassulacean acid metabolism (CAM), such as cacti, usually present limited reproductive capacities and very slow growth rates. The use of in vitro culture can overcome these difficulties. The massive in vitro production of new propagules which result in totally regenerated plants is described for two endangered...

Wild congeners of domesticated crops increasingly serve as sources of genes for improving crop cultivars. Although wild congeners have been included in seed collections for ex situ storage, there has been little work to protect populations of these wild species in their natural habitats for in situ conservation. We assessed the distribution of chil...

An increasing trend in desert ironwood(Olneya tesota)exploitation has affected the population structure, growth and recruitment of this species near the Gulf of California in the Sonoran Desert. In a survey of protected and unprotected sites in Mexico and United States, we determined that the damage has resulted in a significant reduction in the am...

An increasing trend in desert ironwood (Olneya tesota) exploitation in Sonora has affected the population structure, growth, and recruitment of this species near the Gulf of California in the Sonoran desert. In a survey of protected and unprotected sites in Mexico and the United States, we determined that the damage has resulted in a significant re...

The function of Olneya tesota (ironwood) as a nurse plant and habitat modifier species in the Sonoran Desert was evaluated at five study sites (using 75 250-m2 sample plots) from Bahia Kino, Sonora to Organ Pipe Cactus National Monument, Arizona. Beneath the canopy of O. tesota trees 75 perennial plant species were found. A principal component ordi...

The Sonoran night-blooming cereus (Peniocereus striatus) is a rare cactus found in the Sonoran Desert. Its survival is dependent on maintenance of its habitat and its ability to recruit. This study evaluates the role of nurse plants in P. striatus survival and the floral and pollination ecology controlling recruitment. A strong association was dete...

Forest mensuration, distribution, seed germination, floristic composition and ethnobotanic studies and site classification were developed in natural Pinus nelsonii populations. -from English summary

El maíz es el principal grano en la dieta mexicana y también es el cultivo irrigado más importante. Sin embargo, la escasez de agua es grave en México y la seguridad alimentaria no puede mantenerse sin irrigación. Para ayudar a resolver este problema, se examinó el efecto de la densidad de siembra de maíz en un sistema de riego subsuperficial. Se d...