Books by Nicolas Urbina-Cardona
Perspectives in Ecology and Conservation , Nov 25, 2019
Climate and land-use change, raise significant threats to biodiversity, affecting species ranges ... more Climate and land-use change, raise significant threats to biodiversity, affecting species ranges worldwide. Both factors operate on different scales, so including spatial traits that allow them to be appropriately evaluated is relevant to the early identification of extinction risks. We aimed to evaluate the potential effects of climate and land-use change on the extent of suitable habitat of a set of species of Andean anurans; to assess the loss of the area of occupancy (AOO); and to estimate the risk of extinction according to the percentages of loss of the extent of suitable habitat and AOO. We modeled the current and future potential distributions of 30 endemic anurans from the Colombian Andes. We calculated the change in current potential distributional ranges and in the extent of suitable habitat under two climatic regimes and land-use scenarios. We quantified the AOO using the 2 × 2 km grid method and assessed its loss based on habitat availability in the combined scenarios. We used the percentage losses of the extent of suitable habitat and AOO to estimate and compare the extinction risks according to IUCN criteria. We found that climate and land-use change will cause a relative loss of 63.4 % to 79.4 % of the current extent of suitable habitat and 49.6 % to 72.6 % of AOO of the Andean anurans by the year 2050. The loss of AOO made it possible to detect twice as many species at high risk of extinction than the loss of the extent of suitable habitat. The effects of climate change and habitat loss could lead to potential extinction events in Andean frogs. Extent of suitable habitat, and especially the area of occupancy are appropriate spatial traits that could be used to assess extinction risks in species sensitive to local habitat modification by climate change and land-use change.
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Papers by Nicolas Urbina-Cardona
CALDASIA, 2021
El presente estudio buscó determinar el efecto de la heterogeneidad espacial, producto de los mos... more El presente estudio buscó determinar el efecto de la heterogeneidad espacial, producto de los mosaicos
vegetales y gradientes ambientales y estructurales del páramo, sobre la estructura del ensamblaje de anuros
en un sector del Parque Nacional Chingaza. Se registraron variables ambientales y estructurales en seis
mosaicos de vegetación y se calcularon métricas de paisaje en áreas de influencia de 50 y 100 m, a partir de
fotografías aéreas tomadas con dron. Al concluir 162 horas/persona de muestreo, se encontraron 45 individuos
pertenecientes a cuatro especies. Las variables mayormente relacionadas con la estructura de los ensamblajes
de anuros, variaron con el área de influencia, así: (a) a nivel del gradiente ambiental-estructural
en los mosaicos de vegetación (escala de microhábitat), el porcentaje de frailejones, número de troncos de
frailejones caídos, temperatura del aire y velocidad del viento fueron las más determinantes; (b) a nivel
de la unidad de paisaje, el área de influencia de 50 m, se evidenció el efecto del número de clases y en particular
la extensión de las clases de turbera y vegetación de turbera. Finalmente, (c) al área de influencia de
100 m, la configuración de las unidades de paisaje fue más importante, principalmente la extensión de las
clases de turbera y matorrales bajos entremezclados con pajonales y frailejonales. Los resultados sugieren
que los anuros presentan una respuesta dependiente de la escala ante la heterogeneidad espacial, aspecto
que se debe considerar en los planes de manejo del área protegida al momento de estructurar esquemas de
monitoreo poblacional.
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Amphibian communities in two contrasting ecosystems: functional diversity and environmental filters, 2020
Functional diversity is a tool for understanding biological communities and the influence of envi... more Functional diversity is a tool for understanding biological communities and the influence of environmental filters on assembly rules. However, few studies explore the relationships of diversity metrics across contrasting ecosystems. We evaluated the effect of ecosystems (tropical dry forest and pine-oak forest) and seasons (wet and dry) on the functional diversity and community composition of amphibians in western Mexico. Our study showed that associations among metrics of diversity were not constant across contrasting ecosystems. The amphibian communities were related to changes in the environmental variables of elevation, temperature and relative humidity. We analyzed the functional diversity of the amphibian community based on 11 traits related to reproduction, trophic flow and habitat use. Seven functional groups with distinct ecological characteristics were detected, of which, four presented functional redundancy and two were represented by a single species. While the tropical dry forest during the wet season showed the highest species richness, the richness and diversity of functional groups were significantly lower than in the pine-oak forest in both seasons. These results suggest that the seasonal drought in the tropical dry forest could act as an environmental filter, promoting dominance of similar functional traits among species, while limiting similarity could be acting in the pine-oak forest, in the face of relatively stable hydric conditions, allowing a greater functional diversity. Analysis of the relationship between biological communities and ecosystem functioning is necessary to undertake conservation strategies.
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Global Ecology and Conservation, 2020
Over 70% of land in the tropics is in some form of agricultural matrix which poses a threat to bi... more Over 70% of land in the tropics is in some form of agricultural matrix which poses a threat to biodiversity. In Colombia, montane regions are dominated by varying intensities of agriculture and high levels of biodiversity and endemism. Globally, Colombia has the second largest number of amphibian species and is also the third largest coffee producer. Our study region, the Sierra Nevada de Santa Marta (SNSM), has high levels of amphibian endemism (38% and 10 threatened endemics) and is the fourth largest coffee growing region in Colombia. The SNSM rises from the sea to 5,775 m in just 42 km, with a direct overlap between coffee and amphibian habitat occurring across 600e1,800 m. We examined how land cover and elevation (from 800 to 3,700 m asl) influenced amphibian community structure, species richness, and abundance. We conducted surveys from September 2017 to July 2018 at 35 transects across five major land cover types: forest, ecotone, p aramo, pasture, and shade coffee. In total, we recorded 19 species (366 individuals ; 16 endemic species). Land cover was the main determinant of amphibian community structure, while the interaction between elevation and land cover was the main determinant of species richness and abundance. Forest and ecotone contained 73% of overall richness (14 species) with one species found exclusively in ecotone and three exclusively in forest. Pasture and coffee supported 42% (8 species) of species with only two species found exclusively at these land cover types. Shade coffee had low species richness and abundance and we detected just one endemic species in this land cover. The preservation of ecotone, transitional degraded habitat that occurs between two or more types of contiguous land cover types, represents an opportunity to safeguard microhabitats and microclimates. Conservation in the region should be collaborative and include private landowners, NGO's, government agencies, and academics. Conservation actions should prioritize protecting extant natural habitat, restoring degraded habitats, increasing the heterogeneity of production systems, and improving landscape connectivity and watershed health. To achieve those actions, local communities will require economic incentives to maintain forest cover and reduce the contamination of streams through agricultural runoff.
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Biodiversity and Conservation, 2020
Functional diversity is a tool for understanding biological communities and the influence of envi... more Functional diversity is a tool for understanding biological communities and the influence of environmental filters on assembly rules. However, few studies explore the relationships of diversity metrics across contrasting ecosystems. We evaluated the effect of ecosystems (tropical dry forest and pine-oak forest) and seasons (wet and dry) on the functional diversity and community composition of amphibians in western Mexico. Our study showed that associations among metrics of diversity were not constant across contrasting ecosystems. The amphibian communities were related to changes in the environmental variables of elevation, temperature and relative humidity. We analyzed the functional diversity of the amphibian community based on 11 traits related to reproduction, trophic flow and habitat use. Seven functional groups with distinct ecological characteristics were detected, of which, four presented functional redundancy and two were represented by a single species. While the tropical dry forest during the wet season showed the highest species richness, the richness and diversity of functional groups were significantly lower than in the pine-oak forest in both seasons. These results suggest that the seasonal drought in the tropical dry forest could act as an environmental filter, promoting dominance of similar functional traits among species, while limiting similarity could be acting in the pine-oak forest, in the face of relatively stable hydric conditions, allowing a greater functional diversity. Analysis of the relationship between biological communities and ecosystem functioning is necessary to undertake conservation strategies.
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Ecology, 2019
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Global Ecology and Conservation, 2019
Tree density affects species diversity in forest plantations. Understory species diversity, tree ... more Tree density affects species diversity in forest plantations. Understory species diversity, tree regeneration, and soil physicochemical characteristics were assessed under three planting densities of Pinus massoniana in Taizishan Mountains, Hubei, China. There was a higher degree of shrub and herb species diversity in lower density stands. Total species richness was higher for herbs (n ¼ 42) than for shrubs (n ¼ 30) but the two groups exhibited a similar pattern with greater species richness at lower stand density. Changes in community structure and composition were more frequent in high density stands. Community structure in low and medium density stands was more similar to one another than to high stand densities for both herbs and shrubs. The regeneration status of tree species was more abundant in low and medium density stands. Low and medium density stands had significantly more favorable chemical properties such as soil organic matter, total phosphorus, available phosphorus, and nitrogen, as well as on physical soil properties such as non-capillary pores and minimum water holding capacity. Lower planting density was beneficial with regard to natural regeneration, plant species diversity, and soil quality. Reducing tree density of existing high-density P. massoniana plantations can promote both understory plant species diversity and tree regeneration to sustain forest ecosystem services.
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Perspectives in Ecology and Conservation, 2019
Climate and land-use change, raise significant threats to biodiversity, affecting species ranges ... more Climate and land-use change, raise significant threats to biodiversity, affecting species ranges worldwide.
Both factors operate on different scales, so including spatial traits that allow them to be appropriately
evaluated is relevant to the early identification of extinction risks. We aimed to evaluate the potential
effects of climate and land-use change on the extent of suitable habitat of a set of species of Andean
anurans; to assess the loss of the area of occupancy (AOO); and to estimate the risk of extinction according
to the percentages of loss of the extent of suitable habitat and AOO. We modeled the current and future
potential distributions of 30 endemic anurans from the Colombian Andes. We calculated the change in
current potential distributional ranges and in the extent of suitable habitat under two climatic regimes
and land-use scenarios. We quantified the AOO using the 2 × 2 km grid method and assessed its loss
based on habitat availability in the combined scenarios. We used the percentage losses of the extent of
suitable habitat and AOO to estimate and compare the extinction risks according to IUCN criteria. We
found that climate and land-use change will cause a relative loss of 63.4 % to 79.4 % of the current extent
of suitable habitat and 49.6 % to 72.6 % of AOO of the Andean anurans by the year 2050. The loss of AOO
made it possible to detect twice as many species at high risk of extinction than the loss of the extent of
suitable habitat. The effects of climate change and habitat loss could lead to potential extinction events
in Andean frogs. Extent of suitable habitat, and especially the area of occupancy are appropriate spatial
traits that could be used to assess extinction risks in species sensitive to local habitat modification by
climate change and land-use change.
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Science , 2019
Habitat loss is the primary driver of biodiversity decline worldwide, but the effects of fragment... more Habitat loss is the primary driver of biodiversity decline worldwide, but the effects of fragmentation (the spatial arrangement of remaining habitat) are debated. We tested the hypothesis that forest fragmentation sensitivity-affected by avoidance of habitat edges-should be driven by historical exposure to, and therefore species' evolutionary responses to disturbance. Using a database containing 73 datasets collected worldwide (encompassing 4489 animal species), we found that the proportion of fragmentation-sensitive species was nearly three times as high in regions with low rates of historical disturbance compared with regions with high rates of disturbance (i.e., fires, glaciation, hurricanes, and deforestation). These disturbances coincide with a latitudinal gradient in which sensitivity increases sixfold at low versus high latitudes. We conclude that conservation efforts to limit edges created by fragmentation will be most important in the world'stropicalforests.
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Ecology and Evolution , 2019
Species recovery after forest disturbance is a highly studied topic in the tropics, but considera... more Species recovery after forest disturbance is a highly studied topic in the tropics, but considerable debate remains on the role of secondary forests as biodiversity repositories, especially regarding the functional and phylogenetic dimensions of biodiversity. Also, studies generally overlook how alpha and beta diversities interact to produce gamma diversity along successional gradients. We used a metacommunity approach to assess how species sorting (i.e., environmental filtering) and mass effect (i.e., source-sink dynamics) affect 14 complementary metrics of amphibian taxonomic, functional, and phylogenetic diversity along a successional gradient in southern Mexico. As amphibians have narrow environmental tolerances and low dispersal capabilities, we expected that species sorting may be relatively more important than mass effect in structuring amphibian communities. Between 2010 and 2012, we sampled frogs, salamanders, and caecilians in 23 communities distributed in four successional stages: young (2-5 years old) and intermediate (13-28 years old) secondary forests, old-growth forest fragments, and old-growth continuous forest. We assessed 15 ecologically relevant functional traits per species and used a time-calibrated molecular phylogeny. We recorded 1,672 individuals belonging to 30 species and 11 families. Supporting our expectations from the species sorting perspective, from the poorest (younger forests) to the best quality (continuous forest) scenarios, we observed (a) an increase in alpha diversity regardless of species abundances; (b) a clear taxonomic segregation across successional stages; (c) an increase in functional richness and dispersion; (d) an increase in mean phylogenetic distance and nearest taxon index; and (e) a reduction in mean nearest taxon distance. However, 10 species occurred in all successional stages, resulting in relatively low beta diversity.
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Ecology Letters , 2020
Decades of research suggest that species richness depends on spatial characteristics of habitat p... more Decades of research suggest that species richness depends on spatial characteristics of habitat patches, especially their size and isolation. In contrast, the habitat amount hypothesis predicts that (1) species richness in plots of fixed size (species density) is more strongly and positively related to the amount of habitat around the plot than to patch size or isolation; (2) habitat amount better predicts species density than patch size and isolation combined, (3) there is no effect of habitat fragmentation per se on species density and (4) patch size and isolation effects do not become stronger with declining habitat amount. Data on eight taxonomic groups from 35 studies around the world support these predictions. Conserving species density requires minimising habitat loss, irrespective of the configuration of the patches in which that habitat is contained.
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Ecosystem Services , 2017
We analyze scientific literature that report tools to spatially model ecosystem services (ES). In... more We analyze scientific literature that report tools to spatially model ecosystem services (ES). In the 65 articles reviewed, the most used model starting in 2001 was SWAT and starting in 2009 the most commonly used was InVEST. Eighty percent of the scientific articles have been published from 2010 to 2015 suggesting that spatial modeling of ES is an emergent research field. Only 4 of the 9 tools encountered in our review are backed by papers, the others only offer grey literature. The spatial modeling of ES is mainly done in the U.S.A. and China, and the most frequently evaluated ES are related to hydrological services (water provision and quality treatment), climate regulation and soil formation. Most of the studies are done along hydrological basins, at different spatial scales and based upon different map resolution ranging from 20 to 900 m. With concern, we observe the lack of validation of the spatial models and the tools' lack of integrated validation modules. As long as the tools used to spatially model ecosystem services continue to be used as black boxes, the models they generate will suffer from a high degree of uncertainty and will not be reliable for decision making purposes.
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Nature , 2017
Forest edges influence more than half of the world’s forests and contribute to worldwide declines... more Forest edges influence more than half of the world’s forests and contribute to worldwide declines in biodiversity and
ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here
we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying
edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species.
We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that
live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for
Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200–400 m from sharp high-contrast
forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger
reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to
restructure ecological communities on a global scale.
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BIOTROPICA , 2018
Land-use change is the main cause of deforestation and degradation of tropical forest in Mexico. ... more Land-use change is the main cause of deforestation and degradation of tropical forest in Mexico. Frequently, these lands are abandoned leading to a mosaic of natural vegetation in secondary succession. Further degradation of the natural vegetation in these lands could be exacerbated by stochastic catastrophic events such as hurricanes. Information on the impact of human disturbance parallel to natural disturbance has not yet been evaluated for faunal assemblages in tropical dry forests. To evaluate the response of herpetofaunal assemblages to the interaction of human and natural disturbances, we used information of pre-and post-hurricane herpetofaunal assemblages inhabiting different successional stages (pasture, early forest, young forest, intermediate forest, and old growth forest) of dry forest. Her-petofaunal assemblages were surveyed in all successional stages two years before and two years after the hurricane Jova that hit the Pacific Coast of Mexico on October 2011. We registered 4093 individuals of 61 species. Overall, there were only slight effects of successional stage, hurricane Jova or the interaction between them on abundance, observed species richness and diversity of the herpeto-fauna. However, we found marked changes in estimated richness and composition of frogs, lizards, and snakes among successional stages in response to hurricane Jova. Modifications in vegetation structure as result of hurricane pass promoted particular changes in each successional stage and taxonomic group (anurans, lizards, and snakes). Secondary forests at different stages of succession may attenuate the negative effects of an intense, short-duration, and low-frequency natural disturbance such as hurricane Jova on successional herpetofaunal trajectories and species turnover.
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Ecography, 2018
Habitat fragmentation accompanies habitat loss, and drives additional biodiversity change; but fe... more Habitat fragmentation accompanies habitat loss, and drives additional biodiversity change; but few global biodiversity models explicitly analyse the effects of both fragmentation and loss. Here we propose and test the hypothesis that, as fragment area increases, species density (the number of species in a standardised plot) will scale with an exponent given by the difference between the exponents of the species-area relationships for islands (z ~ 0.25) and in contiguous habitat (z ~ 0.15), and test whether scaling varies between land uses. We also investigate the scaling of overall abundance and rarefaction-based richness, as some mechanisms make different predictions about how fragment area should affect them. The relevant data from the taxonomically and geographically broad PREDICTS database were used to model the three diversity measures, testing their scaling with fragment area and whether the scaling exponent varied among land uses (primary forest, secondary forest, plantation forest, cropland and pasture). In addition, the consistency of the response of species density to fragment area was tested across three well represented taxa (Magnoliopsida, Hymenoptera and 'herptiles'). Species density and total abundance showed area-scaling exponents of 0.07 and 0.16, respectively, and these exponents did not vary significantly among land uses; rarefaction-based richness by contrast did not increase consistently with area. These results suggest that the area-scaling of species density is driven by the area-scaling of total abundance, with additive edge effects (species moving into the small fragments from the surroundings) opposing-but not fully overcoming-the effect of fragment area on overall density of individuals. The interaction between fragment area and higher taxon (plants, vertebrates and invertebrates), which remained in the rarefied richness model, indicates that mechanisms may vary among groups.
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Ecology and Evolution , 2019
1. Species recovery after forest disturbance is a highly studied topic in the tropics, but consid... more 1. Species recovery after forest disturbance is a highly studied topic in the tropics, but considerable debate remains on the role of secondary forests as biodiversity repositories, especially regarding the functional and phylogenetic dimensions of biodiversity. Also, studies generally overlook how alpha and beta diversities interact to produce gamma diversity along successional gradients. 2. We used a metacommunity approach to assess how species sorting (i.e., environmental filtering) and mass effect (i.e., source-sink dynamics) affect 14 complementary metrics of amphibian taxonomic, functional, and phylogenetic diversity along a successional gradient in southern Mexico. As amphibians have narrow environmental tolerances and low dispersal capabilities, we expected that species sorting may be relatively more important than mass effect in structuring amphibian communities. 3. Between 2010 and 2012, we sampled frogs, salamanders, and caecilians in 23 communities distributed in four successional stages: young (2-5 years old) and intermediate (13-28 years old) secondary forests, old-growth forest fragments, and old-growth continuous forest. We assessed 15 ecologically relevant functional traits per species and used a time-calibrated molecular phylogeny. 4. We recorded 1,672 individuals belonging to 30 species and 11 families. Supporting our expectations from the species sorting perspective, from the poorest (younger forests) to the best quality (continuous forest) scenarios, we observed (a) an increase in alpha diversity regardless of species abundances; (b) a clear taxonomic segregation across successional stages; (c) an increase in functional richness and dispersion; (d) an increase in mean phylogenetic distance and nearest taxon index; and (e) a reduction in mean nearest taxon distance. However, 10 species occurred in all successional stages, resulting in relatively low beta diversity. This supports a
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Tropical Conservation Science , 2019
We sampled the snake fauna in 13 landscapes along 80 km of highway and in the adjacent vegetation... more We sampled the snake fauna in 13 landscapes along 80 km of highway and in the adjacent vegetation cover in the Colombian Llanos. We registered 119 snakes belonging to 33 species. Traffic levels significantly influenced rates of snake road kill, while adjacent vegetation cover, rainfall seasonality, and landscape structure and composition did not. We classified the species into seven ecological groups based upon foraging strategy, body length, and habitat preferences. Although most of the road-killed species had an active foraging strategy, all of the ecological groups contained some species that were killed on the highway, as well as some species that inhabited adjacent vegetation cover but that were not detected on the highway. The different ecological groups were not associated with different landscape characteristics. Six of the 13 landscapes that presented the lowest species richness of road-killed species had a different ecological group represented by each of the species documented as road kills. Thus, considering the ecological group that a species belongs to provides a complementary analytical approach that permits a fuller understanding of the ecological effects of roads on the functional role of the species in the ecosystem. We recommend focusing mitigation measures on highway sectors with the greater vehicular flow, employing both preventive measures such as posting driver advisories and installing speed radars and conducting environmental education programs to raise awareness of local drivers.
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Books by Nicolas Urbina-Cardona
Papers by Nicolas Urbina-Cardona
vegetales y gradientes ambientales y estructurales del páramo, sobre la estructura del ensamblaje de anuros
en un sector del Parque Nacional Chingaza. Se registraron variables ambientales y estructurales en seis
mosaicos de vegetación y se calcularon métricas de paisaje en áreas de influencia de 50 y 100 m, a partir de
fotografías aéreas tomadas con dron. Al concluir 162 horas/persona de muestreo, se encontraron 45 individuos
pertenecientes a cuatro especies. Las variables mayormente relacionadas con la estructura de los ensamblajes
de anuros, variaron con el área de influencia, así: (a) a nivel del gradiente ambiental-estructural
en los mosaicos de vegetación (escala de microhábitat), el porcentaje de frailejones, número de troncos de
frailejones caídos, temperatura del aire y velocidad del viento fueron las más determinantes; (b) a nivel
de la unidad de paisaje, el área de influencia de 50 m, se evidenció el efecto del número de clases y en particular
la extensión de las clases de turbera y vegetación de turbera. Finalmente, (c) al área de influencia de
100 m, la configuración de las unidades de paisaje fue más importante, principalmente la extensión de las
clases de turbera y matorrales bajos entremezclados con pajonales y frailejonales. Los resultados sugieren
que los anuros presentan una respuesta dependiente de la escala ante la heterogeneidad espacial, aspecto
que se debe considerar en los planes de manejo del área protegida al momento de estructurar esquemas de
monitoreo poblacional.
Both factors operate on different scales, so including spatial traits that allow them to be appropriately
evaluated is relevant to the early identification of extinction risks. We aimed to evaluate the potential
effects of climate and land-use change on the extent of suitable habitat of a set of species of Andean
anurans; to assess the loss of the area of occupancy (AOO); and to estimate the risk of extinction according
to the percentages of loss of the extent of suitable habitat and AOO. We modeled the current and future
potential distributions of 30 endemic anurans from the Colombian Andes. We calculated the change in
current potential distributional ranges and in the extent of suitable habitat under two climatic regimes
and land-use scenarios. We quantified the AOO using the 2 × 2 km grid method and assessed its loss
based on habitat availability in the combined scenarios. We used the percentage losses of the extent of
suitable habitat and AOO to estimate and compare the extinction risks according to IUCN criteria. We
found that climate and land-use change will cause a relative loss of 63.4 % to 79.4 % of the current extent
of suitable habitat and 49.6 % to 72.6 % of AOO of the Andean anurans by the year 2050. The loss of AOO
made it possible to detect twice as many species at high risk of extinction than the loss of the extent of
suitable habitat. The effects of climate change and habitat loss could lead to potential extinction events
in Andean frogs. Extent of suitable habitat, and especially the area of occupancy are appropriate spatial
traits that could be used to assess extinction risks in species sensitive to local habitat modification by
climate change and land-use change.
ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here
we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying
edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species.
We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that
live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for
Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200–400 m from sharp high-contrast
forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger
reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to
restructure ecological communities on a global scale.
vegetales y gradientes ambientales y estructurales del páramo, sobre la estructura del ensamblaje de anuros
en un sector del Parque Nacional Chingaza. Se registraron variables ambientales y estructurales en seis
mosaicos de vegetación y se calcularon métricas de paisaje en áreas de influencia de 50 y 100 m, a partir de
fotografías aéreas tomadas con dron. Al concluir 162 horas/persona de muestreo, se encontraron 45 individuos
pertenecientes a cuatro especies. Las variables mayormente relacionadas con la estructura de los ensamblajes
de anuros, variaron con el área de influencia, así: (a) a nivel del gradiente ambiental-estructural
en los mosaicos de vegetación (escala de microhábitat), el porcentaje de frailejones, número de troncos de
frailejones caídos, temperatura del aire y velocidad del viento fueron las más determinantes; (b) a nivel
de la unidad de paisaje, el área de influencia de 50 m, se evidenció el efecto del número de clases y en particular
la extensión de las clases de turbera y vegetación de turbera. Finalmente, (c) al área de influencia de
100 m, la configuración de las unidades de paisaje fue más importante, principalmente la extensión de las
clases de turbera y matorrales bajos entremezclados con pajonales y frailejonales. Los resultados sugieren
que los anuros presentan una respuesta dependiente de la escala ante la heterogeneidad espacial, aspecto
que se debe considerar en los planes de manejo del área protegida al momento de estructurar esquemas de
monitoreo poblacional.
Both factors operate on different scales, so including spatial traits that allow them to be appropriately
evaluated is relevant to the early identification of extinction risks. We aimed to evaluate the potential
effects of climate and land-use change on the extent of suitable habitat of a set of species of Andean
anurans; to assess the loss of the area of occupancy (AOO); and to estimate the risk of extinction according
to the percentages of loss of the extent of suitable habitat and AOO. We modeled the current and future
potential distributions of 30 endemic anurans from the Colombian Andes. We calculated the change in
current potential distributional ranges and in the extent of suitable habitat under two climatic regimes
and land-use scenarios. We quantified the AOO using the 2 × 2 km grid method and assessed its loss
based on habitat availability in the combined scenarios. We used the percentage losses of the extent of
suitable habitat and AOO to estimate and compare the extinction risks according to IUCN criteria. We
found that climate and land-use change will cause a relative loss of 63.4 % to 79.4 % of the current extent
of suitable habitat and 49.6 % to 72.6 % of AOO of the Andean anurans by the year 2050. The loss of AOO
made it possible to detect twice as many species at high risk of extinction than the loss of the extent of
suitable habitat. The effects of climate change and habitat loss could lead to potential extinction events
in Andean frogs. Extent of suitable habitat, and especially the area of occupancy are appropriate spatial
traits that could be used to assess extinction risks in species sensitive to local habitat modification by
climate change and land-use change.
ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here
we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying
edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species.
We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that
live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for
Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200–400 m from sharp high-contrast
forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger
reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to
restructure ecological communities on a global scale.