Florística, fitogeografia e conservação na Mata Atlântica: uma experiência nas cabrucas do Assentamento Pau-Brasil, Extremo Sul da Bahia

Abstract

The Ombrophilous Forest strip belonging to the south of Bahia and the north of Espírito Santo is one of the main centers of endemism in the Atlantic Forest and has a vast richness of species. The cabruca system ensured a large part of the conservation of the region's biodiversity and wealth. The Pau-Brasil Settlement, Itamaraju-BA, has an area of 325 ha with cocoa cultivated in the cabruca system, implemented about 90 years ago. The research aimed to carry out the floristic characterization of the cabruca areas, compare the alpha diversity with that of other cabrucas, conduct a phytogeographic analysis, by comparing the location with the floristic characteristics of other places in the Atlantic Forest, and draw up a list of marketable native species, as an alternative to generate income for residents. The floristic survey was carried out from January 2019 to January 2020, through 32 collection expeditions. For identification, specialized literature, herbarium collection and expert consultation were used. The vegetation and phytophysiognomies classifications followed the Brazilian Vegetation Technical Manual and the flora analysis. The comparison of diversities between cabrucas was carried out using the t Test and Pearson correlation methods, and the similarity between Atlantic Forest remnants with Jaccard index and UPGMA for clustering, conducted in PAST 3.09. For the list of marketable native species, a literature search was carried out based on the potential use of the species. Documents present on the Google Scholar platform were collected. Then, a ranking of species was generated, using the Ordering Index (Ranking) to classify those with the highest number of uses. The best ranked species (R = 1°–6°) were analyzed in articles published on the Web of Science, Portal Periódicos CAPES, Scopus and SciELO platforms in the period 2010-2020 and the Value in Use (VU) was calculated. 1,800 samples belonging to 96 families, 253 genera and 366 species were collected, recorded in four phytophysiognomies within the cabruca sites: 1) cabrucas in forests; 2) cabrucas in riparian forests; 3) rock outcrop vegetation; and 4) cabrucas in disturbed areas. Four new species were found belonging to the families Araceae (2 spp.), Connaraceae (1 sp.) and Salicaceae (1 sp.), 67 spp. endemic species of the Atlantic Forest biome and 15 spp. endangered. The vegetation is characterized as Submontane Dense Ombrophilous Forest and the flora of the Settlement was grouped with that of a protected area of Sustainable Use: RPPN Serra do Teimoso Natural Reserve; the floristic analysis showed low similarity between the fragments, confirming the heterogeneity of the biome. The diversity of the place was greater than that of all the other cabrucas inventoried. The search on Google Scholar gathered 4,476 materials and 4,106 on the other platforms, with information on 159 (69%) of the 231 native species analyzed. It was possible to define 13 categories of uses and select 29 species with the highest Ordering Indices (OI = 0.0013 to 0.0024). Among the species with the greatest multiplicity of uses are Eugenia uniflora (pitanga), Bixa orellana (annatto) and Eschweilera ovata (biriba) (VU = 0.0003-0.0017). The studied cabrucas have a high floristic diversity and mostly a native flora, resembling flora in medium stage of regeneration. The number of new species and endemisms make the place a hot-point within the formation of the Coastal Forest of Bahia. In order for conservation to be combined with the economy of cabrucas, the community can choose to use all species with raised potential, as well as the development of the generated proposals