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| Author(s): |
Pablo Hendrigo Alves de Melo
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Rio Claro. 2022-08-30. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro |
| Defense date: | 2020-01-13 |
| Advisor: | Julio Antonio Lombardi |
| Abstract | |
Carbonatic rocks support important aquifers on which about 20-25% of the world's population depends. In Brazil, these rocks correspond to about 2.8% of the continental area and occur in all Brazilian phytogeographic domains. Commonly associated with limestone outcrops, there is a discussion of the biogeographic history of Seasonally Dry Tropical, guided by the theories of the Pleistocene Arch and Pleistocene Residual Seasonally Dry Forest. Generally, these theories propose that these forests formerly constituted extensive and continuous formation during the last glacial maximum between 18 and 12,000 years before the present. However, the relationship of floristic similarity between limestone outcrops in different phytogeographic domains is not known, nor is the floristic similarity relationship between limestone outcrops in the surrounding matrix. To clarify these issues, a floristic survey of vascular plants was performed in 11 limestone outcrops in Caatinga, Cerrado and the Atlantic Forest. The floristic similarity was calculated between the studied limestone outcrops and between this one and the surrounding matrix. Finally, with the aid of predictive models of species distribution, we evaluated the temporal congruence between events of expansion and/or retraction of interspecific potential distribution area and between species, with the period of relative stability of distribution to dry forests among species between 18 and 12,000 years before the present. The results suggest that floristic composition recorded in limestone outcrops in the Atlantic Forest was very different from those recorded in limestone outcrops in Caatinga and Cerrado. With the exception of ecotonal areas, limestone outcrops in Caatinga and Cerrado showed a poor floristic relationship. Floristic similarity between outcrops within the Cerrado decreases significantly with increasing geographical distance, and in general outcrops present high average floristic dissimilarity with the surrounding matrix. For the models, the results suggest that individual species biogeographic dynamics was not synchronized with the general stability processes proposed for dry forests in the 18 and 12,000 years before the present, since three quarters of the species showed a tendency of regression or expansion of potential distribution area during this period. Thus, the results corroborate the hypothesis that different species did not respond similarly to changes in climate and allowed us to conclude that there was no temporal congruence between expansion and/or species events in the evaluated period. (AU) | |
| FAPESP's process: | 15/13112-7 - Biogeography of seasonal dry forests on limestone outcrops in three Brazilian biomes |
| Grantee: | Pablo Hendrigo Alves de Melo |
| Support Opportunities: | Scholarships in Brazil - Doctorate |