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Vegetation of Alejandro Selkirk Island (Isla Masafuera), Juan Fernández Archipelago, Chile 1
Abstract and Figures
We analyzed the vegetation of Alejandro Selkirk Island using the Zürich-Montpellier approach for taking relevés and subsequent classification by a multivariate approach and manual refinement. The resulting vegetation table demonstrates patterns of dominance and variation and the resulting vegetation units that were mapped onto aerial photographs to produce a vegetation map. Additional observations of several inaccessible sectors were gained from photos taken during a boat trip around the island. These results are combined in a colored map that shows the following vegetation units: (1) Dicksonia externa Tree Fern Community (upper montane forest); (2) Lophosoria quadripinnata Fern Community; (3) Fern-Grassland Mosaic; (4) Myrceugenia schulzei Forest (lower montane forest); (5) Anthoxanthum-Nassella Grassland; (6) Coastal Grassland with Juncus procerus; (7) Open Grassland (including Coastal Herb Communities); (8) Rocks, Erosional Zones; and (9) Cultivated and Escaped Plants Near the Settlement. In some cases these units consist of several communities together, often forming mosaic patterns where detailed resolution is not practicable. Unit 7, Open Grassland, has been applied to all areas with a plant cover below 40%, and unit 8, Rocks, Erosional Zones, indicates no or scarce vegetation (cover notably below 10%). Some plant assemblages cannot be shown on the map: (a) the small clusters of Drimys confertifolia; (b) the mostly linearly or patchily arranged Gunnera masafuerae community; (c) several plant assemblages found in the canyons; and (d) the Histiopteris incisa clusters between the tree ferns and tall ferns. We discuss composition of the observed plant communities, especially regarding alien impact, and compare our findings with those on Robinson Crusoe, the largest island of the archipelago.
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... New vegetation maps for all three islands of the Juan Fernández Archipelago have been published recently by Josef Greimler and colleagues ( [32,33] Figures 2 and 3). These maps were based on available topographic maps for the islands, aerial photographs taken The purposes of this paper are to (1) review the present state of vegetation of the islands of the Juan Fernández Archipelago; (2) summarize the historical record of human contacts with the islands and their impacts on the vegetation; (3) demonstrate patterns of genetic variation among populations of endemic species that have resulted from combined natural and human disturbances; and (4) offer recommendations for further conservation of the flora and vegetation. ...
... New vegetation maps for all three islands of the Juan Fernández Archipelago have been published recently by Josef Greimler and colleagues ( [32,33] Figures 2 and 3). These maps were based on available topographic maps for the islands, aerial photographs taken by the Chilean Airforce in 1980 for Robinson Crusoe Island, Bing images taken in 2001 and 2004 provided by ESRI-basemaps for Alejandro Selkirk Island, and ground observations and accompanying photographs from expeditions in 1999, 2000, and 2011. ...
... Vegetation map of Alejandro Selkirk Island[33]. ...
The human footprint on marine and terrestrial ecosystems of the planet has been substantial, largely due to the increase in the human population with associated activities and resource utilization. Oceanic islands have been particularly susceptible to such pressures, resulting in high levels of loss of biodiversity and reductions in the numbers and sizes of wild populations. One archipelago that has suffered from human impact has been the Juan Fernández (Robinson Crusoe) Archipelago, a Chilean national park located 667 km west of Valparaíso at 33° S. latitude. The park consists of three principal islands: Robinson Crusoe Island (48 km2); Santa Clara Island (2.2 km2); and Alejandro Selkirk Island (50 km2). The latter island lies 181 kms further west into the Pacific Ocean. No indigenous peoples ever visited or lived on any of these islands; they were first discovered by the Spanish navigator, Juan Fernández, in 1574. From that point onward, a series of European visitors arrived, especially to Robinson Crusoe Island. They began to cut the forests, and such activity increased with the establishment of a permanent colony in 1750 that has persisted to the present day. Pressures on the native and endemic flora increased due to the introduction of animals, such as goats, rats, dogs, cats, pigs, and rabbits. Numerous invasive plants also arrived, some deliberately introduced and others arriving inadvertently. At present, more than three-quarters of the endemic and native vascular species of the flora are either threatened or endangered. The loss of vegetation has also resulted in a loss of genetic variability in some species as populations are reduced in size or go extinct. It is critical that the remaining genetic diversity be conserved, and genomic markers would provide guidelines for the conservation of the diversity of the endemic flora. To preserve the unique flora of these islands, further conservation measures are needed, especially in education and phytosanitary monitoring.
... The distribution and ecology of the species of Dendroseris on the younger Alejandro Selkirk Island provide some clues as to what might have been the pattern on the older island millions of years ago. The vegetation on the younger island is organized into well-defined zones (Greimler et al., 2013;Fig. 5). ...
... The map of vegetation on Alejandro Selkirk Island, Juan Fernández Archipelago. FromGreimler et al. (2013). ...
Oceanic islands and archipelagos are natural laboratories for investigating patterns and processes of evolution. Islands change through time, resulting in a dynamic ontogeny over millions of years. The combined forces of tectonic plate subsidence and erosion from waves, wind, and rainwater, bring about substantial geomorphological change over millions of years, until islands eventually disappear under the sea. Added to these longer‐term natural changes to the environment of the islands are those in recent centuries from human activities. After humans reach a previously unpopulated island, they utilize the natural resources for their own survival, cutting forests for making houses, boats, and firewood. The size of the human population and the length of time on the island determine the degree of environmental impact. Evolutionary processes in plants of oceanic islands take place during ontogeny of the islands, resulting in population divergence, speciation, and hybridization. Because of the dramatic alterations that many islands suffer over millions of years, the present patterns of distribution and ecology of species within endemic groups may have little to do with those patterns when the species originated. Understanding these environmental changes is fundamental for inferring a founder effect, reasons for levels of genetic variation within and among populations, and modes of speciation. Special caution must be exercised when making comparisons between groups located on islands of different geological ages and that have endured differing environmental modifications from humans. Examples are provided from the Juan Fernández Archipelago and Lord Howe Island.
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... Recomendamos esta categoría de acuerdo con el criterio B2ab(iii) debido a que presenta un AOO de 4 km 2 (< 10 km 2 ) y se reconoce una sola localidad para esta especie. Además, pese a encontrarse dentro de un área protegida (Parque Nacional Archipiélago Juan Fernández), se espera una disminución del área, extensión y/o calidad de su hábitat por la presencia de cabras (Skotts berg, 1953a;Stuessy et al., 1998;Cuevas & van Leersum, 2001;Greimler et al., 2013). Además, debe considerarse en esta categoría de acuerdo con el criterio D, porque la última vez que se observó la única población conocida tenía solo dos individuos vivos (es decir, < 50 individuos; Ricci, 1992Ricci, , 2006. ...
Eryngium L. comprises ca. 250 species and is distributed in every continent, except Antarctica. The species of the genus that inhabit Chile are mostly endemic to that country and are phylogenetically closely related to species from the west coast of the United States of America and Australia. Taxonomic studies of the North American and Australian lineages of Eryngium are in press or in preparation. However, the Eryngium species from Chile have not been revised taxonomically for more than a century. Moreover, many of the species of the genus endemic to Chile show restricted distributions and, therefore, deserve particular attention to evaluate if they are in any category of threat in order to develop conservation policies. The objective of this study is to perform a taxonomic revision of the species of Eryngium from Chile, including an analysis of their conservation status. For this purpose, the vegetative and reproductive morphology and the geographic distribution and habitat of ca. 750 herbarium specimens were analyzed. In addition, the conservation status of the species was evaluated following the Red List categories and criteria of the International Union for Conservation of Nature. In total, 17 species of Eryngium were recognized in Chile, of which 15 are endemic to that country and two also grow in Argentina. A key for the recognition of species is provided. For each species, a list of accepted synonyms, a morphological description, illustration, distribution map, habitats, phenology, and vernacular names are presented. Six new synonyms are proposed (Eryngium polyrhizum Clos and all varieties of E. depressum Hook. & Arn. are synonymized with E. depressum, E. amethystinodes Kuntze is synonymized with E. rostratum Cav., and E. delarocheanum H. Wolff is synonymized with E. paniculatum Cav. & Dombey ex F. Delaroche), and nomenclature problems were analyzed and resolved, including the typification of 23 names. The distribution ranges of six species (Eryngium anomalum Hook. & Arn., E. coquimbanum Phil. ex Urb., E. depressum, E. humifusum Clos, E. pulchellum Phil., and E. rostratum) are rectified. Aproximately 60% of the Eryngium species from Chile belong to a category of threat, and most of them are critically endangered, so they should be special targets for conservation.
... Mature cypselae 1-1.3 cm long x 0.5 cm wide, brown mottled with black; pappus short, deciduous. Distribution and Ecology: Part of "El Tongo" ravine vegetation (Fig. 4) is associated with the Myrceugenia schulzei Johow forest matrix (Greimler et al. 2013). Centaurodendron schilleri is found growing mainly associated with Libertia chilensis Notes: This new species has a partially monocarpic habit, similar to other neoendemic species of Compositae in the Archipelago, i.e., Dendroseris pruinata (Johow) Skottsb. ...
A new endemic species, Centaurodendron schilleri, is described from the Juan Fernández Archipelago, Chile. This is the third species of the endemic genus, Centaurodendron, which is closely related to Plectocephalus of the Chilean mainland. The new species is confined to Alejandro Selkirk Island, whereas the previously known species, C. dracaenoides and C. palmiforme, are confined to Robinson Crusoe Island. In morphological aspects, the new species is more distinct from the other two species than they are from each other. Molecular phylogenetic and biogeographic studies for island and continental species of these genera are in progress. RESUMEN Se describe una nueva especie endémica, del archipiélago Juan Fernández, Centaurodendron schilleri. Esta es la tercera especie del género endémico Centaurodendron, el que se relaciona con Plectocephalus de Chile continental. La especie nueva crece en la isla de Alejandro Selkirk, mientras que C. dracaenoides y C. palmiforme lo hacen exclusivamente en la isla de Robinson Crusoe. En cuanto a la morfología, las dos especies conocidas se parecen más entre sí que cada una con la nueva. Estudios filogenéticos moleculares y biogeográficos sobre el complejo del grupo Plectocephalus s.l. de las islas y del continente están ahora en proceso. Palabras clave: Centaureinae, Centaurodendron, Isla Alejandro Selkirk. A new species of the endemic genus Centaurodendron Johow (Asteraceae, Centaureinae) from Alejandro Selkirk Island, Juan Fernández Archipelago, Chile Una nueva especie del género endémico Centaurodendron Johow (Asteraceae, Centaureinae) de la isla
... The Juan Fernández Islands are the smallest archipelago but the flora has been intensively investigated floristically (Greimler et al., 2013) and evolutionarily (Takayama et al., 2018), including a number of karyological studies but so far no measurements of genome sizes ( Table 1). The closest continental source is South America, which seems to be the ancestral area for several Juan Fernández genera and species (Stuessy et al., 2017). ...
Whole genome duplication or polyploidy is widespread among floras globally, but traditionally has been thought to have played a minor role in the evolution of island biodiversity, based on the low proportion of polyploid taxa present. We investigate five island systems (Juan Fernández, Galápagos, Canary Islands, Hawaiian Islands, and New Zealand) to test whether polyploidy (i) enhances or hinders diversification on islands and (ii) is an intrinsic feature of a lineage or an attribute that emerges in island environments. These island systems are diverse in their origins, geographic and latitudinal distributions, levels of plant species endemism (37% in the Galapagos to 88% in the Hawaiian Islands), and ploidy levels, and taken together are representative of islands more generally. We compiled data for vascular plants and summarized information for each genus on each island system, including the total number of species (native and endemic), generic endemicity, chromosome numbers, genome size, and ploidy levels. Dated phylogenies were used to infer lineage age, number of colonization events, and change in ploidy level relative to the non-island sister lineage. Using phylogenetic path analysis, we then tested how the diversification of endemic lineages varied with the direct and indirect effects of polyploidy (presence of polyploidy, time on island, polyploidization near colonization, colonizer pool size) and other lineage traits not associated with polyploidy (time on island, colonizer pool size, repeat colonization). Diploid and tetraploid were the most common ploidy levels across all islands, with the highest ploidy levels (>8x) recorded for the Canary Islands (12x) and New Zealand (20x). Overall, we found that endemic diversification of our focal island floras was shaped by polyploidy in many cases and certainly others still to be detected considering the lack of data in many lineages. Polyploid speciation on the islands was enhanced by a larger source of potential congeneric colonists and a change in ploidy level compared to overseas sister taxa.
Se describe la morfología de los granos de polen de especies de las Islas de Juan Fernández con el fin de contribuir en el conocimiento de especies con problemas graves de conservación. Se hace la descripción morfológica y mediciones de los granos de polen en base a observaciones en el microscopio óptico y detalles de superficies de los mismos y fotografías en el microscopio electrónico de barrido (SEM). Se describen los granos de pólenes de 33 especies amenazadas, de las cuales 32 son endémicas y una es nativa.
Colonization, levels of speciation and vegetational metamorphosis during ontogeny of oceanic islands over geological time are central evolutionary and biogeographic concerns. A suitable archipelago in which to examine such events is the Juan Fernández (Robinson Crusoe) Archipelago, located at 33° S latitude off the coast of continental Chile and consisting of three major islands: Robinson Crusoe Island, 667 km west of the coastline; Santa Clara Island, 1.6 km off the south-western end of the former island and Alejandro Selkirk Island, 181 km directly further west into the Pacific Ocean. The two largest islands are c. 50 km2, with Santa Clara Island being only 2.1 km2. Radiometric dating for the three islands reveals the ages of Robinson Crusoe Island and Santa Clara Island to be c. 4 My, whereas that of Alejandro Selkirk Island is c. 1 My. Molecular clock estimates of crown-group divergences of endemic taxa fall mostly in these geological ages. Recent investigations have brought together a detailed inventory of the vascular flora of the archipelago with biological, evolutionary and biogeographic information that now supports examining metamorphosis of the vegetation and flora during the 4 My of island ontogeny. Geological dating and geomorphological models are used to infer changes in the landscape on both major islands. It is suggested that the original Robinson Crusoe Island may have been substantially larger and higher than at present (3000 vs. 915 m). Subsidence and erosion of the island led to loss of vegetation zones, especially impacting plants between 1000 and 3000 m. Some species may have adapted to this restructuring, but many would have gone extinct. Alejandro Selkirk Island, now 1 My, is only slightly smaller and lower than the original island (1319 vs. 2000 m), but it has probably lost some higher elevation habitats. The present vegetation of the two islands correlates with these suggestions, with Alejandro Selkirk Island retaining broad zones, but Robinson Crusoe Island having a flora that has been compacted and substantially intermixed with invasive species in recent centuries. Floristic inventory reveals 11 endemic genera, but most of these occur only on Robinson Crusoe Island, which has been the centre of cladogenesis in contrast to greater levels of anagenesis on Alejandro Selkirk Island. The ferns, due to their high dispersability, show almost no cladogenesis. Total endemic species diversity is higher on Robinson Crusoe Island (87) than on Alejandro Selkirk Island (62), and this difference is probably due to the greater age of the island and initial environmental heterogeneity. It is also probable that during this ontogeny, numbers of endemic species on Robinson Crusoe Island have been lost through island subsidence and erosion, loss of habitat and human impact.
Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes – the world’s “hottest” biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e. páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus Gunnera , a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments . Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby Gunnera tracks damp and boggy soils in cool habitats. Colonisation of the northern Andes is related to Quaternary climate change, with subsequent rapid diversification appearing to be driven by their ability to take advantage of environmental opportunities. This study demonstrates the composite origin of a mega-diverse biota.
Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes – the world’s “hottest” biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e. páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus Gunnera , a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments . Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby Gunnera tracks damp and boggy soils in cool habitats. Colonisation of the northern Andes is related to Quaternary climate change, with subsequent rapid diversification appearing to be driven by their ability to take advantage of environmental opportunities. This study demonstrates the composite origin of a mega-diverse biota.
Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes-the world's richest and most diverse biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e., páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus Gunnera, a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments. Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, and whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby Gunnera tracks damp and boggy soils in cool habitats. Colonisation of the northern Andes is related to Quaternary climate change, with subsequent rapid diversification appearing to be driven by their ability to take advantage of environmental opportunities. This study demonstrates the composite origin of a mega-diverse biota.
This work analyses the relationship between human beings and their environment taking into consideration the adjustment and eventual invasión of rabbits in Chile. It argües that in the long run, human actions have unsuspected effects upon the environment. In fact rabbits were seen initially as an opportunity for economic development because of the exploitation of their meat and skin. Later, rabbits became a plague in different áreas of Central Chile, Tierra del Fuego and Juan Fernández islands, which was difficult to control. Over the years rabbits became unwelcome guests in Chile. © 2009 Instituto de Historia. Pontificia Universidad Católica de Chile.
The archipelago of Juan Fernández (Robinson Crusoe) is located to 670 km. west of Valparaiso, in the Pacific Ocean. It is formed by 3 islands, all of volcanic origin: Masatierra (Robinson Crusoe), Masafuera (Alexander Selkirk) and Santa Clara. Johow and Skottsberg have made the most complete inventories of the flora of this archipelago. The most recent study is the one of Danton & Perrier. The documented flora include 423 species of vascular plants, 55 Pteridophyta, 289 Dicotyledoneae and 79 Monocotyledoneae. Of the total number of species, 31.2% are endemic, 18.7% native and 50.1% introduced. The Poaceae family represents 11% of the total flora of the islands and displays 53 species included in 32 genera, of which 9,4% are endemic, 9,4% native and 81,2% alien. In this work a key for the genera and a description of the species are given. Information in relationship to the iconography, distribution, ecology, conservation and examined material is presented. These results are compared and discussed with the ones of Danton & Perrier (2006).
After a short general overview of the Juan Fernandez archipelago (Chile) we present: an alphabetic and anotated list of the native and endemic plants; an alphabetic and anotated list of the introduced plants; an up to date (2006) systematic catalogue of the vascular plants [Pteridophytae and Spermatophytae (Gymnospermae and Angiospermae)], present in these islands. An evaluation of the threatened level (UICN categories), restricted to the geographic area of the archipelago, is designed for each native and endemic plant, to help in the elaboration of the conservation priorities. For each introduced plant, its degree of naturalization and the year of its first signting are specified, as well as an evaluation of its dangerousness to help the preservation of the ecosystems and species. For each taxa present on the archipelago, the distribution island by island is indicated. For the first time the Morros Juanango and Verdugo (big rocks with plants, isolated in the sea) are considered as biogeographic entities. Statistical analyses of all these data are given in tabular and graph form. (bilingual paper french-spanish, Chile).
Island biogeography is the study of the distribution and dynamics of species in island environments. Due to their isolation from more widespread continental species, islands are ideal places for unique species to evolve, but they are also places of concentrated extinction. Not surprisingly, they are widely studied by ecologists, conservationists and evolutionary biologists alike. There is no other recent textbook devoted solely to island biogeography, and a synthesis of the many recent advances is now overdue. This second edition builds on the success and reputation of the first, documenting the recent advances in this exciting field and explaining how islands have been used as natural laboratories in developing and testing ecological and evolutionary theories. In addition, the book describes the main processes of island formation, development and eventual demise, and explains the relevance of island environmental history to island biogeography. The authors demonstrate the huge significance of islands as hotspots of biodiversity, and as places from which disproportionate numbers of species have been extinguished by human action in historical time. Many island species are today threatened with extinction, and this work examines both the chief threats to their persistence and some of the mitigation measures that can be put in play with conservation strategies tailored to islands.
After a short presentation (geography, history, climate, biology) of the Juan Fernández Archipelago (Chile) and its three islands (Robinson Crusoe, Santa Clara and Alexander Selkirk islands), the Fernandezian forest is described with proposal of a new word to name it: myrtisylva -ae (myrtisylva), through the two variants found in the archipelago (low altitud myrtisylva, high altitude myrtisylva), and for each one of the concerned islands. Trees and herbaceous plants checklists, forming the flora of these myrtisylvas, are given. At last, a short analysis of the great threats menacing the future of these original forests is added.
