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Aridity drives plant biogeographical sub regions in the Caatinga, the largest tropical dry forest and woodland block in South America
- Source :
- PLoS ONE, Vol 13, Iss 4, p e0196130 (2018), PLoS ONE
- Publication Year :
- 2018
- Publisher :
- Public Library of Science (PLoS), 2018.
-
Abstract
- Our aims were to quantify and map the plant sub regions of the the Caatinga, that covers 844,453 km2 and is the largest block of seasonally dry forest in South America. We performed spatial analyses of the largest dataset of woody plant distributions in this region assembled to date (of 2,666 shrub and tree species; 260 localities), compared these distributions with the current phytogeographic regionalizations, and investigated the potential environmental drivers of the floristic patterns in these sub regions. Phytogeographical regions were identified using quantitative analyses of species turnover calculated as Simpson dissimilarity index. We applied an interpolation method to map NMDS axes of compositional variation over the entire extent of the Caatinga, and then classified the compositional dissimilarity according to the number of biogeographical sub regions identified a priori using k-means analysis. We used multinomial logistic regression models to investigate the influence of contemporary climatic productivity, topographic complexity, soil characteristics, climate stability since the last glacial maximum, and the human footprint in explaining the identified sub regions. We identified nine spatially cohesive biogeographical sub regions. Current productivity, as indicated by an aridity index, was the only explanatory variable retained in the best model, explaining nearly half of the floristic variability between sub regions. The highest rates of endemism within the Caatinga were in the Core and Periphery Chapada Diamantina sub regions. Our findings suggest that the topographic complexity, soil variation, and human footprint in the Caatinga act on woody plant distributions at local scales and not as determinants of broad floristic patterns. The lack of effect of climatic stability since the last glacial maximum probably results from the fact that a single measure of climatic stability does not adequately capture the highly dynamic climatic shifts the region suffered during the Pleistocene. There was limited overlap between our results and previous Caatinga classifications.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Atmospheric Science
Topography
lcsh:Medicine
Woodland
Forests
01 natural sciences
Mountains
Aridity index
lcsh:Science
Climatology
Multidisciplinary
Geography
Ecology
Eukaryota
Last Glacial Maximum
Plants
Terrestrial Environments
Droughts
Phylogeography
Biogeography
Research Article
Tropical and subtropical dry broadleaf forests
Ecological Metrics
Forest Ecology
010603 evolutionary biology
Ecosystems
03 medical and health sciences
Paleobotany
Paleoclimatology
Endemism
Spatial Analysis
Tropical Climate
Landforms
Plant Dispersal
Ecology and Environmental Sciences
lcsh:R
Organisms
Biology and Life Sciences
Paleontology
Species diversity
Geomorphology
Species Diversity
South America
Arid
Index of dissimilarity
Logistic Models
030104 developmental biology
Earth Sciences
lcsh:Q
Physical geography
Paleobiology
Subjects
Details
- ISSN :
- 19326203
- Volume :
- 13
- Database :
- OpenAIRE
- Journal :
- PLOS ONE
- Accession number :
- edsair.doi.dedup.....629cbfc58ccd6440d31950b210232c64