Agriculture, habitat loss and spatial patterns of human occupation in a biodiversity hotspot

Diniz‐Filho, José Alexandre Felizola; Oliveira, Guilherme de; Lobo, Fábio Carneiro; Ferreira, Laerte Guimarães; Bini, Luis Maurício; Rangel, Thiago Fernando L.V.B.

doi:10.1590/s0103-90162009000600007

Cited by 28 publications

(13 citation statements)

References 33 publications

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“…Although Least Concern seems to be the most adequate category for this species given its current distribution, further studies are needed to assess population trends of O. cleberi. Additionally, it should be noted that this species is apparently endemic to the Cerrado biodiversity hotspot (Myers et al, 2000;Silva and Bates, 2002), a region under intensive land-use, high rates of deforestation and habitat loss (Diniz-Filho et al, 2009), and modest conservation efforts (Klink and Machado, 2005). These results highlight the major threat to the conservation of small mammals in Brazil: the scarcity of basic knowledge, mostly about taxonomy, systematics, distribution and natural history of species occurring in habitats, which are being cleared at a fast pace (Costa et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

Taxonomic and conservation status of the elusive Oecomys cleberi (Rodentia, Sigmodontinae) from central Brazil

Rocha¹,

Fonseca²,

Zhen³

et al. 2012

Mammalian Biology

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a b s t r a c tThe arboreal mouse Oecomys cleberi was described in 1981 based on just one specimen from Distrito Federal in central Brazil, and it has not been recorded ever since. Its taxonomic status as a valid species has been questioned and it is currently listed as Data Deficient in terms of conservation status. Here we used ancient DNA methods to obtain a partial mitochondrial cytochrome b gene sequence from the holotype of Oecomys cleberi. Very low levels of genetic divergence (0.6% on average) allowed us to associate sequences from specimens previously identified as O. bicolor to O. cleberi. Comparative analyses of morphological and molecular data confirmed the taxonomic status of O. cleberi as a valid species, and increased our knowledge on its geographic distribution to at least three additional localities in the Cerrado of central Brazil. Cytochrome b sequences of O. cleberi formed a well-supported monophyletic group and diverged 6.8% on average from those of O. bicolor, its sister species from the Amazon. We refined and improved the morphological description of O. cleberi based on the examination of 15 museum specimens, including the holotype, and suggest that other field and museum records of this species may have also been misidentified as O. bicolor. Considering that O. cleberi may be more common and widespread than previously suspected, we suggest the conservation status of Least Concern for this species. However, further studies are needed to understand population trends of O. cleberi, given that it is apparently endemic to the Cerrado biodiversity hotspot.

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Section: Discussionmentioning

confidence: 99%

Taxonomic and conservation status of the elusive Oecomys cleberi (Rodentia, Sigmodontinae) from central Brazil

Rocha¹,

Fonseca²,

Zhen³

et al. 2012

Mammalian Biology

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“…In the Cerrado, the main agricultural frontier of the country, the prevalence of fires over remnant vegetation is associated with the still very active and significant clearings [61][62][63][64], although the intensity and spreading of fires, over both natural and converted areas, are also dependent on the severity of the climatic events, as previously discussed. In fact, the occurrence of fires in the Cerrado is highly seasonal.…”

Section: Burned Areas and Land Cover Classesmentioning

confidence: 99%

Distribution Patterns of Burned Areas in the Brazilian Biomes: An Analysis Based on Satellite Data for the 2002–2010 Period

2012

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Fires modify the structure of vegetation communities, the carbon and water cycles, the soil's chemistry, and affect the climate system. Within this context, this work aimed to understand the distribution patterns of burned areas in Brazil, during the period of 2002 to 2010, taking into consideration each one of the six Brazilian biomes (Amazon, Caatinga, Cerrado, Atlantic Forest, Pampa and Pantanal) and the respective major land cover classes. Data from the MODIS MCD45A1 product (burned area), as well as thermal anomalies (MOD14 and MYD14) and precipitation (TRMM), were analyzed according to the 2002 Brazilian official land cover and land use map (PROBIO). The Brazilian savanna biome, known as Cerrado, presented the largest concentration of burned areas detected by MODIS (73%), followed by the Amazon (14%), Pantanal (6%), Atlantic Forest (4%), Caatinga (3%), and Pampa (0,06%) biomes. Indeed, in the years of 2007 and 2010, 90% and 92% of Brazil's burned areas were concentrated in the Cerrado and Amazon biomes, respectively. TRMM data indicated that during these two years there was a significant influence of La Niña, causing low rainfall in the Amazon, Cerrado, Caatinga, and Atlantic Forest biomes. Regarding the land cover classes, approximately 81% of the burned areas occurred over remnant vegetation areas. Although no unequivocal correlation can be established between burned areas and new land conversions, the conspicuous concentration of fire scars, particularly in Amazon-Cerrado transition (i.e., the Arc of Deforestation) is certainly not a simple coincidence. Such patterns and trends corroborate the need of improved territorial governance, in addition to the implementation of systematic fire warning and preventive systems.

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“…This implies that mechanisms previously described for individual hypotheses potentially interact to shape fish richness pattern in reservoirs. Substantial redundancy among groups of variables is commonly reported in studies of species richness gradients conducted over large spatial scales for which most variation cannot be entirely partitioned among the components, and the unique effect of each set of predictors is generally low (Diniz‐Filho et al ., ). Regarding the exclusive effect of components, local factors were relevant to explain the richness pattern in reservoirs, especially for data set I, indicating that singly the described mechanisms for S‐AH and THAH are the most effective to structure the species richness in reservoirs.…”

Section: Discussionmentioning

confidence: 97%

Diversity gradients of Neotropical freshwater fish: evidence of multiple underlying factors in human‐modified systems

Bailly

Cassemiro

Winemiller

et al. 2016

Journal of Biogeography

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Aim Contemporary patterns of species diversity are the result of a hierarchy of natural processes and modern anthropogenic influences. However, studies of these patterns in human-modified systems from a macroecological perspective are lacking. Considering that fish assemblages in reservoirs reflect both longterm evolutionary responses of species and shorter term responses to anthropogenic stressors, we employed a multi-hypothesis approach using different magnitudes of predictors to analyse the processes that drive fish diversity in reservoirs at a broad spatial scale.Location Brazil.Methods We derived species richness from an extensive database of fish inhabiting Neotropical reservoirs, and using multiple regression analysis, we tested seven hypotheses that link species richness to continuous variables associated with regional, local and population components. We analysed the spatial structure using Moran's I autocorrelation coefficients and used spatial eigenvector mapping to explicitly account for the spatial component when testing the hypotheses by multiple regressions. Partial regressions were performed to map the relative contributions of the different components in explaining species richness.Results Predictors related to six hypotheses were retained in the best-fit models, and our data supported the species-energy, metabolic, species-area, species-distance from the source and time of habitat alteration hypotheses. However, the predictions of the population abundance hypothesis (PAH) were not supported by the data. The shared effects of the different components explained the greatest proportion of the variation in species richness, indicating that distinct mechanisms related to these alternative hypotheses interact or are not spatially independent.Main conclusions Our findings indicate that the latitudinal diversity gradient typically displayed by freshwater fish is maintained in human-modified habitats, such as reservoirs, and that multiple mechanisms drive fish diversity in reservoirs over large spatial scales. The lack of support for the PAH implies that mechanisms structuring diversity patterns can be influenced by anthropogenic stressors.

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Agriculture, habitat loss and spatial patterns of human occupation in a biodiversity hotspot

Cited by 28 publications

References 33 publications

Taxonomic and conservation status of the elusive Oecomys cleberi (Rodentia, Sigmodontinae) from central Brazil

Taxonomic and conservation status of the elusive Oecomys cleberi (Rodentia, Sigmodontinae) from central Brazil

Distribution Patterns of Burned Areas in the Brazilian Biomes: An Analysis Based on Satellite Data for the 2002–2010 Period

Diversity gradients of Neotropical freshwater fish: evidence of multiple underlying factors in human‐modified systems

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