Florística E Estrutura De Florestas Tropicais Sazonalmente Secas

Abstract

FLORÍSTICA E ESTRUTURA DE FLORESTAS TROPICAIS SAZONALMENTE SECASRESUMO: Neste estudo, objetivou-se caracterizar florística e estruturalmente a comunidade arbórea em uma área de encosta, Caatinga arbórea e em área ecotónal com cerrado no Parque Nacional Cavernas do Peruaçu, Norte de Minas Gerais, buscando testar as seguintes hipóteses: 1-Existem diferenciações florísticas entre os ambientes; 2-Todos os ambientes apresentam as mesmas características quanto à estrutura. , e a equabilidade de Pielou foi de 0,80, 0,84 e 0,85. Com relação à distribuição dos indivíduos em classes de diâmetro, a Caatinga arbórea e encosta apresentaram um mesmo padrão, com uma diminuição gradual do número de indivíduos. Já, o ambiente ecotonal apresentou uma distribuição tendendo a normal. FLORISTIC AND STRUCTURE OF SEASONALLY DRY TROPICAL FORESTSABSTRACT: A floristic and structural survey of the tree community in different environments (slope, Arboreal Caatinga and ecotone to savannah) were carried out in Cavernas do Peruaçu National Park, North of Minas Gerais. We aimed to test the following hypotheses: 1 -There is floristic differentiation among the environments; 2 -All environments have the same structural characteristics. Venn Diagrams were used to compare both the shared and unshared species among the environments. Tree distribution by diameter classes for each environment was made by means of frequency histograms. An Indicator Species Analysis and usual phytossociological parameters were used. A total of 305 species were found, distributed in 173 genera and 48 families, of which 166 were found in the slope, 204 in the Arboreal Caatinga and 155 in the ecotone. 54 species were exclusive to the slope, 65 to the Arboreal Caatinga and 35 to the ecotone and only 69 species were common to all three environments. 1391 individuals were sampled, yielding an estimated density of 1340.62, 1765 and 1280 individuals . , respectively for the slope, Arboreal Caatinga and ecotone. The Shannon diversity index and Pielou's evenness were, respectively, 3.49 and 0.80 for the slope, 3.74 and 0.84 for the Arboreal Caatinga and 3.61 and 0.85 for the ecotone. The Arboreal Caatinga and the slope presented a gradual decrease in frequency towards the higher diameter classes whereas the ecotone tended to follow a normal distribution.

Dynamics of dry tropical forest after three decades of vegetation suppression

“…However, it should be emphasized that comparisons should be made with care and caution, since there are methodological differences between the works. For example, inclusion level based on height (Santana & Souto, 2006;Rodal et al, 2008), in circumference at 0.30 m from the soil (Bessa & Medeiros, 2011;Pereira et al, 2012;Calixto & Drumond, 2014) and at 1.3 m from the soil (Ferraz et al, 2013;Ferraz et al, 2014;Brand et al, 2015;Menino et al, 2015;Souza et al, 2015;Pimentel et al, 2016;present work).…”

First record of Oziroë argentinensis (Lillo & Hauman) Speta (Asparagaceae) for Brazil

“…, Menino et al. ). However, floristic knowledge of these karst areas is still incomplete, as reflected by the continuing discovery of new species (e.g.…”

ULTRASOUND AND WATER IMMERSION TO PROMOTING VIGOR IN SEEDS AND SEEDLINGS OF Cnidoscolus quercifolius

“…Caatinga biome is a Brazilian formation forest with xerophytic plants, some different ecoregions (ANTUNES et al, 2014;APGAUA et al, 2014;ANDRADE et al, 2015;MENINO et al, 2015;SILVA et al, 2018), with high evapotranspiration, and concentrated rainfall in a short period.…”

“…In addition, in Caatinga biome area, is common the disordered anthropogenic actions and climate changes, causing processes such as the loss of biodiversity and desertification (ANTUNES et al, 2014;APGAUA et al, 2014;ANDRADE et al, 2015;MENINO et al, 2015;DRUMOND et al, 2016;SILVA et al, 2018). Walter et al (2019) describes that Caatinga biome area it covers about 53.1% of the territory of the Northeast region of the country, which represents about 882,081 km 2 and more than 20 million people living in this vast location (FERREIRA & CUNHA, 2013).…”

“…Currently, there are some efforts to promote a sustainable production of forest essences from Caatinga biome, for example, studies in seedling formation (ANTUNES et al, 2014;ANDRADE et al, 2015;MENINO et al, 2015), bioecology (APGAUA et al, 2014), morphology (LOUREIRO et al, 2013), satellite analyses (SILVA et al, 2018), and thermal image (DIAS JÚNIOR, et al, 2019). However, for some species in Caatinga species have dormancy and this fact can be disturbing the forest production and this fact is poorly studied (Medeiros et al, 2005) or are recommendation the acid treatments to improve the germination to broken the seed resistance in Euphorbiaceae family (LOUREIRO et al, 2013).…”