Projecting global biodiversity indicators under future development scenarios

Piero Visconti, Michel Bakkenes, Daniele Baisero, Thomas Brooks, Stuart H. M. Butchart, Lucas Joppa, Rob Alkemade, Moreno Di Marco, Luca Santini, Michael Hoffmann, Luigi Maiorano, Robert L. Pressey, Anni Arponen, Luigi Boitani, April E. Reside, Detlef van Vuuren and Carlo Rondinini

Conservation Letters, DOI: 10.1111/conl.12159

Fig1

Projected LPI (A,B,C) and RLI (D,E,F) for terrestrial carnivores and ungulates under 2 global socio-economic scenarios. Business-as-usual in red and Consumption Change in blue. (A,D) Species can adapt to climate change, (B,E), maximum dispersal under land-use and climate change, (C,F) and no dispersal under land-use and climate change.

To address the ongoing global biodiversity crisis, governments have set strategic objectives and have adopted indicators to monitor progress towards their achievement. Projecting the likely impacts on biodiversity of different policy decisions allows decision makers to understand if and how these targets can be met. We projected trends in two widely used indicators of population abundance (the Living Planet Index; LPI) and extinction risk (the Red List Index; RLI) under different climate and land-use change scenarios. Testing these on terrestrial carnivore and ungulate species, we found that both indicators decline steadily, and by 2050, under a business-as-usual scenario, the LPI declines by 18–35% while extinction risk increases for 8–23% of the species, depending on assumptions about species responses to climate change. Business-as-usual will therefore fail CBD target 12 of improving the conservation status of known threatened species. An alternative sustainable development scenario reduces both extinction risk and population losses compared with Business-as-usual and could lead to population increases. Our approach to model species responses to global changes brings the focus of scenarios directly to the species level, thus taking into account an additional dimension of biodiversity and paving the way for including stronger ecological foundations into future biodiversity scenario assessments.

Posted in Lab

Habitat availability for amphibians and extinction threat: a global analysis

Gentile Francesco Ficetola, Carlo Rondinini, Anna Bonardi, Daniele Baisero & Emilio Padoa-Schioppa

Diversity and Distributions, DOI: 10.1111/ddi.12296

Aim

Habitat loss and degradation are the factors threatening the largest number of amphibian species. However, quantitative measures of habitat availability only exist for a small subset of them. We evaluated the relationships between habitat availability, extinction risk and drivers of threat for the world’s amphibians. We developed deductive habitat suitability models to estimate the extent of suitable habitat and the proportion of suitable habitat (PSH) inside the geographic range of each species, covering species and areas for which little or no high-resolution distribution data are available.

Methods

We used information on habitat preferences to develop habitat suitability models at 300-m resolution, by integrating range maps with land cover and elevation. Model performance was assessed by comparing model output with point localities where species were recorded. We then used habitat availability as a surrogate of area of occupancy. Using the IUCN criteria, we identified species having narrow area of occupancy, for which extinction risk is likely underestimated.

Results

We developed models for 5363 amphibians. Validation success of models was high (94%), being better for forest specialists and generalists than for open habitat specialists. Generalists had proportionally more habitat than forest or open habitat specialists. The PSH was lower for species having small geographical ranges, currently listed as threatened, and for which habitat loss is recognized as a threat. Differences in habitat availability among biogeographical realms were strong. We identified 61 forest species for which the extinction risk may be higher that currently assessed in the Red List, due to limited extent of suitable habitat.

Main conclusions

Habitat models can accurately predict amphibian distribution at fine scale and allow describing biogeographical patterns of habitat availability. The strong relationship between amount of suitable habitat and extinction threat may help the conservation assessment in species for which limited information is currently available.

Posted in Lab