Diversidade arbórea das florestas alto montanas no Sul da Chapada Diamantina, Bahia, Brasil

Abstract

RESUMO -(Diversidade arbórea das fl orestas alto-montanas no Sul da Chapada Diamantina, Bahia, Brasil). A região do extremo Sul da Chapada Diamantina abriga as maiores altitudes do Nordeste brasileiro. Situam-se nessas serras as maiores elevações da região Nordeste, entre elas, o Pico do Barbado (2.033 m.s.n.m.). Dois dos rios mais importantes da Bahia nascem nestas serras: o Rio de Contas e o Rio Paramirim. A região é bem conhecida botanicamente, porém, este foi o primeiro inventário quantitativo realizado enfocando as formações fl orestais. Comparou-se a composição fl orística de 12 fragmentos de fl oresta montana, entre 1.350 e 1.750 m.s.n.m., tendo sido amostrados os indivíduos com PAP≥ 8 cm. Registrou-se a presença de 116 espécies em 84 gêneros de 48 famílias. As famílias com maior número de espécies foram Myrtaceae (N=20) e Lauraceae (N=10). Os gêneros com maior número de espécies foram Ocotea (N=7), Myrcia (N=5), Eugenia (N=4) e Miconia (N=4). A maioria das espécies apresentou padrão de distribuição amplo, mas foram encontradas espécies comuns a formações fl orestais de altitude do Sudeste e Sul do Brasil, como Drimys brasiliensis Miers (Winteraceae) e Weinmannia paulliniifolia Pohl (Cunnoniacae). A fl ora dos fragmentos estudados compartilha baixo número de espécies com as formações estacionais deciduais do entorno da Chapada Diamantina, indicando que estas fl orestas são únicas e merecem atenção especial, para sua conservação. Palavras-chave: Diversidade arbórea, fl oresta alto-montana, Chapada Diamantina, fi togeografi a ABSTRACT -(Tree diversity of high montane forests in southern Chapada Diamantina, Bahia, Brazil). The southernmost region of Chapada Diamantina, nearest to Rio de Contas harbours the highest peaks of the Brazilian northeastern region, including Pico do Barbado (2,033 m.a.s.l.) and the source of the two important rivers in Bahia state (Rio de Contas and Rio Paramirim). The region is well known botanically. This was the fi rst quantitative study to survey the fl oristic composition of 12 fragments of montane forests (1,350 m.a.s.l. to 1750 m.a.s.l.) including trees ≥ 8 cbh. A total of 117 species, 84 genera and 48 families were found. The richest families were Myrtaceae (N=20) and Lauraceae (N=10). The richest genera were Ocotea (N=7), Myrcia (N=5), Eugenia (N=4) and Miconia (N=4). Most species had wide geographic distributions, but some are found only in montane forests of southeastern and southern Brazil such as Drimys brasiliensis Miers (Winteraceae) and Weinmannia paulliniifolia Pohl (Cunnoniacae). The fragments studied have low similarity with seasonally dry tropical forests that surround Chapada Diamantina, emphasizing the uniqueness of these forests and the need for protection.

Species richness and distribution of bryophytes within different phytophysiognomies in the Chapada Diamantina region of Brazil

“…Many of the taxa classified as having a restricted or moderate distribution had previously been recorded only for the southeastern region of Brazil, particularly in mountainous areas, where environmental conditions, such as the mild temperatures and cloud cover associated with the upper elevations, enable the survival of species less tolerant to heat and desiccation. This corroborates the findings of Nascimento et al (2010) regarding the floristic and biogeographical relationships between the arboreal flora of the upper montane forests in the south of the Chapada Diamantina ecoregion and those of the seasonal forest and rain forest formations in the Atlantic Forest of southeastern and southern Brazil, those authors having identified great floristic affinity between the two regions. In that same study, the authors point out a floristic continuation between the Serra do Espinhaço, to the south, and the central-south portion of the Chapada Diamantina ecoregion, as well as the occurrence of an extensive biogeographical province that connects the Chapada Diamantina ecoregion with the Serra da Mantiqueira, forming a corridor composed of campos rupestres and shrub-tree vegetation.…”

Diversity and distribution of the bryophyte flora in montane forests in the Chapada Diamantina region of Brazil

“…In two different studies, each employing a different approach to evaluating tree flora, Funch et al (2008) and Nascimento (2010) investigated floristic relationships between forest areas within the Chapada Diamantina region (lower and upper montane forests) and other types of forests, including the coastal Atlantic Forest. Those authors obtained similar results, in terms to the groups found, the lower and upper montane forests from Chapada Diamantina having been shown to form distinct groups, despite the fact that there is greater floristic affinity among those groups than between the Chapada Diamantina region and the coastal Atlantic Forest areas.…”

Soil-vegetation relationships and community structure in a "terra-firme"-white-sand vegetation gradient in Viruá National Park, northern Amazon, Brazil

“…This species is also endemic in Brazil and widely distributed in all states (Sobral et al 2010); it has been reported for Campinaranas of the Serra do Cachimbo (PA) and Parintins (AM) , in the savannas of Roraima (Miranda and Absy 2000), in the transition Cerrado-flooded forest in São Paulo, in the Cerrado in Maranhão (Conceição and Aragão 2010), in rainforests in all states of the northeastern region (Nascimento et al 2010), and in montane shrub grassland in the Serra dos Carajás (Nunes et al 2015). However, E. puniciflora was not sampled in Campinaranas of Cruzeiro do Sul (AC) and Vigia do Nazaré (PA) (Ferreira 2009).…”