Consequences of global climate change for geographic distributions of cerrado tree species
TL;DR: In this article, the authors applied techniques from the emerging field of ecological niche modeling to develop a first-pass assessment of likely effects of climate change on tree species' distributions in the Cerrado biome by relating known occurrence points to electronic maps summarizing ecological dimensions.
Abstract: The present study applies a series of new techniques to understand the conservation of Cerrado tree species in the face of climate change. We applied techniques from the emerging field of ecological niche modeling to develop a first-pass assessment of likely effects of climate change on tree species’ distributions in the Cerrado biome by relating known occurrence points to electronic maps summarizing ecological dimensions. Distributional data represent 15,657 records for 162 tree species occurring in Cerrado. By focusing on the trees of one important and highly endemic biome, rather than the biota of a political unit, we were able to focus on developing biome-wide projections. An important limitation of this study is that only those species with more than 30 unique occurrence records were used-hence, the study is limited to those species of relatively broad geographic distribution, and does not take into account those species with narrower geographic distributions. Global climate change scenarios considered were drawn from the general circulation models of HadCM2; we assessed both a conservative and a less conservative scenario of how climates could change over the next 50 year using the (Hadley HHGSDX50 and HHGGAX50 scenarios, respectively): HHGSDX50 assumes 0.5%/yr CO2 increase, whereas HHGGAX50 assumes a 1%/yr CO2 increase. Results of predictions of present and future distributions varied widely among species. Present distributional models predicted areas of 655,211-2,287,482 out of the 2,496,230 km2 core area of Cerrado in Brazil. All models used to represent species’ present geographic ranges were highly statistically significant based on independent test data sets of point localities. Most species were projected to decline seriously in potential distributional area, with both scenarios anticipating losses of >50% of potential distributional area for essentially all species. Indeed, out of 162 species examined, between the two climate change scenarios, 18 (HHGSDX50 scenario) - 56 (HHGGAX50 scenario) were predicted to end up without habitable areas in the Cerrado region, and 91 (HHGSDX50 scenario) - 123 (HHGGAX50 scenario) species were predicted to decline by more than 90% in potential distributional area in the Cerrado region. Bearing in mind the limitations of the method, and considering its explicit assumptions, these results nevertheless should be cause for ample concern regarding Cerrado biodiversity. Since only 2.25% of the Cerrado biome is presently protected, this future scenario presents a pessimistic forecast, which would likely include widespread species loss from the biome, as well as dramatic shifts to the south and east, further complicating conservation planning efforts.
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TL;DR: Estimating a global mean extinction rate was synthesized in order to determine which factors contribute the greatest uncertainty to climate change–induced extinction risks and suggest that extinction risks will accelerate with future global temperatures.
Abstract: Current predictions of extinction risks from climate change vary widely depending on the specific assumptions and geographic and taxonomic focus of each study. I synthesized published studies in order to estimate a global mean extinction rate and determine which factors contribute the greatest uncertainty to climate change–induced extinction risks. Results suggest that extinction risks will accelerate with future global temperatures, threatening up to one in six species under current policies. Extinction risks were highest in South America, Australia, and New Zealand, and risks did not vary by taxonomic group. Realistic assumptions about extinction debt and dispersal capacity substantially increased extinction risks. We urgently need to adopt strategies that limit further climate change if we are to avoid an acceleration of global extinctions.
1,472 citations
Cites background from "Consequences of global climate chan..."
...Siqueira & Peterson (82) 2003 S Am pl Y SDM U 0....
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TL;DR: In the last 35 years, more than 50% of the Cerrado's approximately 2 million km 2 has been transformed into pasture and agricultural lands planted in cash crops as mentioned in this paper.
Abstract: The Cerrado is one of the world's biodiversity hotspots. In the last 35 years, more than 50% of its approximately 2 million km 2 has been transformed into pasture and agricultural lands planted in cash crops. The Cerrado has the richest flora among the world's savannas (>7000 species) and high levels of endemism. Species richness of birds, fishes, reptiles, amphibians, and insects is equally high, whereas mammal diversity is relatively low. Deforestation rates have been higher in the Cerrado than in the Amazon rainforest, and conservation efforts have been modest: only 2.2% of its area is under legal protection. Numerous animal and plant species are threatened with extinction, and an estimated 20% of threatened and endemic species do not occur in protected areas. Soil erosion, the degradation of the diverse Cerrado vegetation formations, and the spread of exotic grasses are widespread and major threats. The use of fire for clearing land and to encourage new growth for pasture has also caused damage, even though the Cerrado is a fire-adapted ecosystem. Ecosystem experiments and modeling show that change in land cover is altering the hydrology and affecting carbon stocks and fluxes. Cerrado agriculture is lucrative, and agricultural expansion is expected to continue, requiring improvements in and extension of the transportation infrastructure, which will affect not only the Cerrado but also the Amazon forest. Large-scale landscape modification and threats to numerous species have led to renewed interest from various sectors in promoting the conservation of the Cerrado, particularly through strengthening and enlarging the system of protected areas and improving farming practices and thus the livelihoods of local communities.
1,297 citations
Book Chapter•
01 Jan 2007716 citations
01 Jan 2005
TL;DR: The Cerrado is one of the world’s biodiversity hotspots as mentioned in this paper and more than 50% of its aproximately 2 million km 2 has been transformed into pasture and agricultural lands planted in cash crops.
Abstract: The Cerrado is one of the world’s biodiversity hotspots. In the last 35 years, more than 50% of its aproximately 2 million km 2 has been transformed into pasture and agricultural lands planted in cash crops. Cerrado has the richest flora among the world’s savannas (>7,000 species) and high levels of endemism. Species richness of birds, fishes, reptiles, amphibians, and insects is equally high, whereas mammal diversity is relatively low. Deforestation rates have been higher in the Cerrado than in the
480 citations
TL;DR: In this article, the authors present longitudinal studies of 23 extant mammal species, modelling ecological niches and predicting geographical distributions reciprocally between the Last Glacial Maximum and present to test this evolutionary conservatism.
Abstract: Aim Theoretical work suggests that species’ ecological niches should remain relatively constant over long-term ecological time periods, but empirical tests are few. We present longitudinal studies of 23 extant mammal species, modelling ecological niches and predicting geographical distributions reciprocally between the Last Glacial Maximum and present to test this evolutionary conservatism. Location This study covered distributional shifts in mammal species across the lower 48 states of the United States.
452 citations
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TL;DR: A ‘silver bullet’ strategy on the part of conservation planners, focusing on ‘biodiversity hotspots’ where exceptional concentrations of endemic species are undergoing exceptional loss of habitat, is proposed.
Abstract: Conservationists are far from able to assist all species under threat, if only for lack of funding. This places a premium on priorities: how can we support the most species at the least cost? One way is to identify 'biodiversity hotspots' where exceptional concentrations of endemic species are undergoing exceptional loss of habitat. As many as 44% of all species of vascular plants and 35% of all species in four vertebrate groups are confined to 25 hotspots comprising only 1.4% of the land surface of the Earth. This opens the way for a 'silver bullet' strategy on the part of conservation planners, focusing on these hotspots in proportion to their share of the world's species at risk.
24,867 citations
"Consequences of global climate chan..." refers background in this paper
...Over the last 30 yr or so, the Cerrado region has been transformed by rapid expansion of intensive agriculture; according to Myers et al. (2000), only 20% of the original area remains the primary vegetation....
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...This situation is of great concern because this biome is rich in endemic species; indeed, for plants, endemism reaches 44% of the total of 10,000 species (Myers et al. 2000)....
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University of Buenos Aires1, University of Alaska Fairbanks2, University of Chile3, University of California, Berkeley4, Environmental Defense Fund5, National Autonomous University of Mexico6, Technische Universität München7, New Mexico State University8, Duke University9, Arizona State University10, University of Notre Dame11, Stanford University12, Colorado State University13, Commonwealth Scientific and Industrial Research Organisation14
TL;DR: This study identified a ranking of the importance of drivers of change, aranking of the biomes with respect to expected changes, and the major sources of uncertainties in projections of future biodiversity change.
Abstract: Scenarios of changes in biodiversity for the year 2100 can now be developed based on scenarios of changes in atmospheric carbon dioxide, climate, vegetation, and land use and the known sensitivity of biodiversity to these changes. This study identified a ranking of the importance of drivers of change, a ranking of the biomes with respect to expected changes, and the major sources of uncertainties. For terrestrial ecosystems, land-use change probably will have the largest effect, followed by climate change, nitrogen deposition, biotic exchange, and elevated carbon dioxide concentration. For freshwater ecosystems, biotic exchange is much more important. Mediterranean climate and grassland ecosystems likely will experience the greatest proportional change in biodiversity because of the substantial influence of all drivers of biodiversity change. Northern temperate ecosystems are estimated to experience the least biodiversity change because major land-use change has already occurred. Plausible changes in biodiversity in other biomes depend on interactions among the causes of biodiversity change. These interactions represent one of the largest uncertainties in projections of future biodiversity change.
8,401 citations
TL;DR: The large ecological and societal consequences of changing biodiversity should be minimized to preserve options for future solutions to global environmental problems.
Abstract: Human alteration of the global environment has triggered the sixth major extinction event in the history of life and caused widespread changes in the global distribution of organisms. These changes in biodiversity alter ecosystem processes and change the resilience of ecosystems to environmental change. This has profound consequences for services that humans derive from ecosystems. The large ecological and societal consequences of changing biodiversity should be minimized to preserve options for future solutions to global environmental problems.
3,977 citations
TL;DR: Reciprocal geographic predictions based on ecological niche models of sister taxon pairs of birds, mammals, and butterflies in southern Mexico indicate niche conservatism over several million years of independent evolution but little conservatism at the level of families.
Abstract: Theory predicts low niche differentiation between species over evolutionary time scales, but little empirical evidence is available. Reciprocal geographic predictions based on ecological niche models of sister taxon pairs of birds, mammals, and butterflies in southern Mexico indicate niche conservatism over several million years of independent evolution (between putative sister taxon pairs) but little conservatism at the level of families. Niche conservatism over such time scales indicates that speciation takes place in geographic, not ecological, dimensions and that ecological differences evolve later.
1,380 citations
"Consequences of global climate chan..." refers background in this paper
...…conditions present across the geographic distribution of the Cerrado, our models appear not to be extrapolating beyond the environmental conditions on which they were fitted; regardless, though, the predictivity of this approach has proven quite high (Peterson et al. 1999, Martínez-Meyer 2002)....
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...Overall, these analyses assume no evolution in niche characteristics (Peterson et al. 1999), and do not take into account interactions among species such as competition, predation, etc....
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...…espécies arbóreas de Cerrado; mudanças climáticas http://www.biotaneotropica.org.br regions have been published elsewhere (Peterson & Cohoon 1999, Peterson et al. 1999, Peterson 2001, Anderson et al. 2002a, b, Feria & Peterson 2002, Peterson et al. 2002a, Peterson et al. 2002c, Peterson et al.…...
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TL;DR: The essence of the GMS is an underlying generic spatial modelling method which filters out potential sources of errors and is generally applicable however, as the statistical problems arising in arbitrary spatial data analysis potentially apply to any domain.
Abstract: This paper is concerned with the problems and solutions to reliable analysis of arbitrary datasets. Our approach is to describe components of a system called the GARP Modelling System (GMS) which we have developed for automating predictive spatial modelling of the distribution of species of plants and animals. The essence of the system is an underlying generic spatial modelling method which filters out potential sources of errors. The approach is generally applicable however, as the statistical problems arising in arbitrary spatial data analysis potentially apply to any domain. For ease of development, GMS is integrated with the facilities of existing database and visualization tools, and Internet browsers. The GMS is an example of a class of application which has been very successful for providing spatial data analysis in a simple to use way via the Internet.
1,341 citations