Dinâmica estrutural da comunidade lenhosa em Floresta Estacional Semidecidual na transição Cerrado-Floresta Amazônica, Mato Grosso, Brasil

Abstract

ABSTRACT(Structural dynamics of the woody community in a semideciduous forest in the Cerrado-Amazon Forest transition of Mato Grosso, Brazil). Understanding ecological processes, especially the structural and floristic changes in natural ecosystems, is essential before conserving and/or restoring these areas. The aim of this study was to assess the changes that occurred in the woody plant community from 2003 to 2008. Sixty permanent plots of 10 x 10 m were established, in which all individuals with diameter at breast height ≥ 5 cm were sampled. A total of 1,140 ind. ha -1 were recorded in 2003 (basal area 24.35 m 2 ha -1 ) and 1,071 ind. ha -1 in 2008 (basal area of 22.04 m 2 ha -1 ). The recruitment (2.76% year -1 ) did not compensate mortality (3.95% year -1 ) and the basal area gain (0.54% year -1 ) did not exceed the loss (3.77% year -1 ). Because of this unbalance, the half-life (17.3 years) was lower than the doubling time (29.9 years), resulting in low stability (12.6 yrs) and replacement (23.6 yrs) in relation to other seasonal forests. The parameters of community and species dynamics suggest that the forest is undergoing changes characterized mainly by the density and biomass reduction of trees, which may be related to an increase in lianas, an early rebuilding phase of the forest silvigenetic cycle or even the severe drought that occurred in the region in 2005.

Tree Diameter Growth Following Silvicultural Treatments in a Semi-Deciduous Secondary Forest in Central Brazil

“…In nine secondary forests in Brazil, the annual change in basal area ranged between 0.53% and 4.1% (MEWS et al, 2011). These indices are lower than found in this forest, with silvicultural treatments, which confirms the effectiveness of this experiment.…”

Disequilibrium and hyperdynamic tree turnover at the forest–cerrado transition zone in southern Amazonia

“…Cerradão has been classified as 'mesophyllous sclerophyllous forest' (Rizzini 1979), a transitional forest, characterised by the presence of species from both savanna and forest. The gallery forests are narrow strips of evergreen or semi-deciduous mesophytic forests that occur along water courses in the Cerrado biome (Ratter et al 1973(Ratter et al , 1997Ribeiro and Walter 2008), and the monodominant and semi-deciduous seasonal forests of this study are typical forests representing the periphery of the Amazon forest (Ratter et al 1973;Pires and Prance 1985;Marimon et al 2001;Marimon 2005;Mews et al 2011b). Trees were identified to species level; a detailed description of the species composition of these plots has been published elsewhere (Marimon et al 2001(Marimon et al , 2002Marimon 2005; (Table 1).…”

“…Seven plots were selected to sample this transition zone, five (one cerrado sensu stricto, one cerradão and three gallery forests) in the Parque Municipal do Bacaba, an ecological reserve (14 • 41' S and 52 • 20' W) and two (one monodominant forest and one semi-deciduous seasonal forest) in the nearby reserve of Fazenda Vera Cruz (14 • 50' 47" S and 52 • 08' 37" W) ( Table 1). The climate of all localities was type Aw, according to Köppen's classification, with a dry season from April to September and a wet season from October to March, and the annual rainfall averaging ca.1400 mm and a mean annual temperature of 25 • C (Marimon et al 2010;Mews et al 2011b). The distance between cerrado sensu stricto, cerradão and gallery forest plots was ca.…”

Tree Component Demography in an Upper Montane Mixed Ombrophilous Forest Under Chronic Anthropogenic Disturbances

“…On the other hand, it is possible to observe a degradation process, synthesized by the reduction of individuals and basal area, in forests subject to intense or chronic disturbances. Some authors have observed these patterns in forest remnants subject to cattle presence and selective logging in Minas Gerais, Brazil (Machado and Oliveira Filho, 2010); in a transition forest between the Brazilian Cerrado and the Amazon, suggesting the influence of a strong drought as a determining factor (Mews et al, 2011); and in alluvial forest remnants subject to anthropic disturbances, after a heavy flood in the south of Minas Gerais, Brazil (Silva et al, 2011). Moreover, studies carried out in transformed landscapes have shown that disturbances caused by selective logging without planning and/or cattle grazing have negatively influenced richness by favoring pioneer species rather than late ones and therefore either slowing the process of succession down or limiting it (Clark and Covey, 2012;Zamorano-Elgueta et al, 2014;Arroyo Rodríguez et al, 2015).…”

“…Hence, approaches of this nature have been carried out in a large number of phytophysiognomies in Brazil (Formento et al, 2004;Oliveira Filho et al, 2007;Schorn and Galvão, 2009;Figueiredo Filho et al, 2010;Mews et al, 2011). These studies have demonstrated different patterns that, in general, reflect the existing history of disturbances.…”