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Combined impacts of global changes on biodiversity across the USA.

Bellard C, Leclerc C, Courchamp F - Sci Rep (2015)

Bottom Line: Most studies of the effects of global changes on biodiversity focus on a single threat, but multiple threats lead to species extinction.These high cumulative impact values are due mainly to the presence of invasive species, climate change, cropland and pasture areas; additionally, a significant proportion of endemic species are vulnerable to some of these threats where they occur.This analysis provides a useful means of identifying where conservation measures and monitoring programs that should consider multiple threats should be implemented in the future.

View Article: PubMed Central - PubMed

Affiliation: 1] Genetics, Evolution &Environment, Div Biosciences, Center for Biodiversity, Environment &Research, University College of London [2] Ecologie, Systématique &Evolution, UMR CNRS 8079, Univ. Paris-Sud, F-91405 Orsay Cedex, France.

ABSTRACT
Most studies of the effects of global changes on biodiversity focus on a single threat, but multiple threats lead to species extinction. We lack spatially explicit assessments of the intensity of multiple threats and their impacts on biodiversity. Here, we used a novel metric of cumulative threats and impacts to assess the consequences of multiple threats on 196 endemic species across the USA. We predict that large areas with high cumulative impact scores for amphibians, birds, mammals, and reptiles will be concentrated in the eastern part of the USA by the 2050 s and 2080  . These high cumulative impact values are due mainly to the presence of invasive species, climate change, cropland and pasture areas; additionally, a significant proportion of endemic species are vulnerable to some of these threats where they occur. This analysis provides a useful means of identifying where conservation measures and monitoring programs that should consider multiple threats should be implemented in the future.

No MeSH data available.


Related in: MedlinePlus

Cumulative impact maps for all the different taxa and for amphibians, reptiles, birds, and mammals in the 2080s for the A1B emission scenarios.The arrow represents cumulative impact values that go from low (blue) to high (red) values. Figure created in ArcGIS 10.2.1 software.
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f3: Cumulative impact maps for all the different taxa and for amphibians, reptiles, birds, and mammals in the 2080s for the A1B emission scenarios.The arrow represents cumulative impact values that go from low (blue) to high (red) values. Figure created in ArcGIS 10.2.1 software.

Mentions: In addition to the cumulative threats, our cumulative impact index (that is, threats weighted by species vulnerability, and species distribution per pixel) also highlighted the same longitudinal gradient across the USA (Fig. 3). Large areas of moderate to high cumulative impact scores were also concentrated in the eastern part of the USA, while half of the western areas exhibited relatively low impact values (except for the western coastlines). This pattern was consistent across CO2 emission scenarios (B2A and A1B), time horizons (2050s and 2080s) and diversity metrics (phylogenetic and specific) (Figure S4-S5). We also found that the cumulative threat and cumulative impact value patterns differed at a finer scale. Of the states with the five highest cumulative threats, three were also among the states with the five highest cumulative impact values (i.e., except Illinois and Indiana), revealing the need to consider the spatial distribution of both the threats and the species vulnerable to these threats. The spatial variation of cumulative impact values also varied according to the taxa considered. For example, the cumulative impact values were very high for birds on the eastern coast of the USA while the values were lower for amphibians, mammals, and reptiles. High cumulative impact values were also apparent on the western coast and central areas for mammals: the other taxa were predicted to be less impacted there (Fig. 3). Moreover, while we predicted that cumulative impact values for birds, and mammals would be high in Texas, reptiles and amphibians were not predicted to be affected in this area. In addition, we found areas of high cumulative impact values in the eastern part of the USA for mammals (e.g., Idaho and Utah states).


Combined impacts of global changes on biodiversity across the USA.

Bellard C, Leclerc C, Courchamp F - Sci Rep (2015)

Cumulative impact maps for all the different taxa and for amphibians, reptiles, birds, and mammals in the 2080s for the A1B emission scenarios.The arrow represents cumulative impact values that go from low (blue) to high (red) values. Figure created in ArcGIS 10.2.1 software.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493580&req=5

f3: Cumulative impact maps for all the different taxa and for amphibians, reptiles, birds, and mammals in the 2080s for the A1B emission scenarios.The arrow represents cumulative impact values that go from low (blue) to high (red) values. Figure created in ArcGIS 10.2.1 software.
Mentions: In addition to the cumulative threats, our cumulative impact index (that is, threats weighted by species vulnerability, and species distribution per pixel) also highlighted the same longitudinal gradient across the USA (Fig. 3). Large areas of moderate to high cumulative impact scores were also concentrated in the eastern part of the USA, while half of the western areas exhibited relatively low impact values (except for the western coastlines). This pattern was consistent across CO2 emission scenarios (B2A and A1B), time horizons (2050s and 2080s) and diversity metrics (phylogenetic and specific) (Figure S4-S5). We also found that the cumulative threat and cumulative impact value patterns differed at a finer scale. Of the states with the five highest cumulative threats, three were also among the states with the five highest cumulative impact values (i.e., except Illinois and Indiana), revealing the need to consider the spatial distribution of both the threats and the species vulnerable to these threats. The spatial variation of cumulative impact values also varied according to the taxa considered. For example, the cumulative impact values were very high for birds on the eastern coast of the USA while the values were lower for amphibians, mammals, and reptiles. High cumulative impact values were also apparent on the western coast and central areas for mammals: the other taxa were predicted to be less impacted there (Fig. 3). Moreover, while we predicted that cumulative impact values for birds, and mammals would be high in Texas, reptiles and amphibians were not predicted to be affected in this area. In addition, we found areas of high cumulative impact values in the eastern part of the USA for mammals (e.g., Idaho and Utah states).

Bottom Line: Most studies of the effects of global changes on biodiversity focus on a single threat, but multiple threats lead to species extinction.These high cumulative impact values are due mainly to the presence of invasive species, climate change, cropland and pasture areas; additionally, a significant proportion of endemic species are vulnerable to some of these threats where they occur.This analysis provides a useful means of identifying where conservation measures and monitoring programs that should consider multiple threats should be implemented in the future.

View Article: PubMed Central - PubMed

Affiliation: 1] Genetics, Evolution &Environment, Div Biosciences, Center for Biodiversity, Environment &Research, University College of London [2] Ecologie, Systématique &Evolution, UMR CNRS 8079, Univ. Paris-Sud, F-91405 Orsay Cedex, France.

ABSTRACT
Most studies of the effects of global changes on biodiversity focus on a single threat, but multiple threats lead to species extinction. We lack spatially explicit assessments of the intensity of multiple threats and their impacts on biodiversity. Here, we used a novel metric of cumulative threats and impacts to assess the consequences of multiple threats on 196 endemic species across the USA. We predict that large areas with high cumulative impact scores for amphibians, birds, mammals, and reptiles will be concentrated in the eastern part of the USA by the 2050 s and 2080  . These high cumulative impact values are due mainly to the presence of invasive species, climate change, cropland and pasture areas; additionally, a significant proportion of endemic species are vulnerable to some of these threats where they occur. This analysis provides a useful means of identifying where conservation measures and monitoring programs that should consider multiple threats should be implemented in the future.

No MeSH data available.


Related in: MedlinePlus