Fitossociologia Do Componente Arborescente-Arbóreo De Uma Floresta Estacional No Vale Do Rio Uruguai, Brasil

Abstract

RESUMOO status de degradação das florestas no oeste catarinense repercute em um número pequeno de áreas conservadas que possibilitem estudos sobre diversidade e estrutura de comunidades florestais, a fim de criar aporte teórico para estratégias de preservação, manejo e restauração ecossistêmica. O objetivo do presente estudo foi descrever a diversidade e a estrutura de um remanescente de Floresta Estacional Decidual Submontana localizado no município de São João do Oeste -SC. Para o inventário, foram demarcadas 102 unidades amostrais de 10 × 10 m, dispostas em uma grade contínua de 6 × 17 parcelas, nas quais foram amostradas todas as plantas da sinúsia arborescente-arbórea com PAP ≥ 15 cm. Ocorreram 1441,18 árvores vivas e 93,14 plantas mortas em pé/ha. As 79 espécies encontradas pertencem a 61 gêneros e 33 famílias. O índice de diversidade de Shannon (H') foi de 3,21 e o índice de equabilidade de Pielou (J')foi de 0,735. A estrutura vertical da vegetação amostrada foi dividida em arvoretas (2-11 m), dossel (12-17 m) e emergentes (18-25 m). O remanescente florestal estudado constitui um importante ecossistema de referência para a implementação de estratégias de preservação, manejo e restauração de florestas estacionais. Palavras-chave: componente lenhoso; estrutura florestal; subformação submontana; Floresta Estacional Decidual. ABSTRACTThe degradation status of the forests in western Santa Catarina state reflects in a reduced number of conserved areas that enable studies on forest communities diversity and structure in order to create strategies for ecosystems preservation, management and restoration. The objective of this study was to describe the diversity and structure of a forest remnant of Seasonal Submontane Deciduous Forest located in the municipality of São João do Oeste, Santa Catarina state. For the inventory, we demarcated 102 sampling units of 10 × 10 m, continuously arranged in a grid of 6 × 17 plots, in which all plants of the arborescent-arboreal sinusiae with perimeter at breast height (PBH) ≥ 15 cm were sampled. We surveyed 1441.18 living trees and 93.14 standing dead plants per ha. The 79 species found belong to 61 genera and 33 families. Sorocea bonplandii, Nectandra megapotamica, Inga marginata, Ocotea diospyrifolia and Trichilia claussenii presented the highest importance value indexes. The Shannon diversity index (H') was 3.21 and the Pielou equability (J') was 0.735. The vertical structure of the vegetation sampled was divided into treelets (2-11 m), canopy (12-17 m) and emerging trees (18-25 m). The studied forest fragment is an important reference ecosystem for the implementation of strategies for preservation, management and restoration of seasonal forests.

Patterns of Plant Diversity and Composition in Wetlands Across a Subtropical Landscape: Comparisons Among Ponds, Streambanks and Riverbanks

“…Finally, it is noteworthy that each studied ecosystem makes essential or disproportionately greater contributions to the conservation of some plant species at the landscape scale. This is especially true for ponds, as riparian areas, in general, tend to have a floristic composition more similar to that of uplands (see Table S2; Ruschel et al 2005;Giehl and Jarenkow 2008;Inácio and Jarenkow 2008;Grasel et al 2017Grasel et al , 2020. Some examples of species that in the study region are unique to, or much more abundant in, particular ecosystems studied, at least in terms of wetlands, include: Eleocharis contracta, Hibiscus striatus, Hydrolea spinosa, Hygrophila costata, Lemna valdiviana, Ludwigia peruviana, Luziola peruviana and Osmunda spectabilis (and many others) in ponds; Asplenium claussenii, Dennstaedtia dissecta, Dennstaedtia globulifera, Didymochlaena truncatula and Parapolystichum effusum in streambanks; and Carex sellowiana, Exostigma rivulare, Galianthe brasiliensis, Goniopteris riograndensis, Selaginella muscosa, Selaginella sulcata and Stenandrium mandioccanum in riverbanks (see Table S2).…”