Community dynamics in a species-rich patch of old-growth forest in a global changing scenario

Abstract

Ecological theory predicts that, in mature ecosystems, species richness, the number of individuals and the biomass of individuals will remain in a relatively stable state of equilibrium. The aim of this study was to test that theory. In 2001 and 2010, we conducted censuses of all trees with a circumference at breast height ≥ 10 cm in a one-hectare plot in a seasonal semideciduous old-growth forest in southeastern Brazil. We compared the two censuses in terms of species richness and diversity, computing growth, recruitment and mortality rates, as well as gains and losses of basal area. . Overall turnover (the mean difference between mortality and recruitment) was lower than would be expected for a seasonal semideciduous forest, indicating stability and slight successional advance. This interpretation is supported by the observation that pioneer species and canopy species both showed higher mortality than recruitment. However, uncommon species (< 10 individuals in the 2001 census) showed higher mortality than recruitment and became rarer, whereas most species that were abundant in 2001 became more abundant by 2010. These observations, as well as the decline in species richness, although statistically not significant, match the predictions of ecological theory for scenarios in which formerly contiguous ecosystems become fragmented and the remnants become isolated within the landscape. Nevertheless, further censuses are needed in order to test the idea that the observed patterns are not explained by natural oscillations but are consequences of environmental changes related to human activity.

Tree Diversity and Dynamics of the Forest of Seu Nico, Viçosa, Minas Gerais, Brazil

“…The FSN has never been logged ( Campos et al 2006 ); despite selective wood and non-timber extraction, the fragment maintained primary forests characteristics such as high percentage of non-pioneer, animal-dispersed, understory and endemic species as well as high species richness and diversity ( Gastauer 2012 , Gastauer and Meira Neto 2013a , Gastauer and Meira Neto 2013b ).…”

“…Global changes such as habitat destruction, fragmentation and climate change threaten species richness and diversity of tropical forests ( Wright 2010 , Gastauer and Meira Neto 2013b , Magnago et al 2014 ). To outline and understand their influences on tropical forest communities, long term monitoring studies, so-called community dynamics, are necessary ( Losos and Leigh 2004 , Wright 2005 , Ernest et al 2009 , Laurance et al 2014 ).…”

“…Once covering up to 1,500,000 km 2 ( Câmara 2005 ), only about 11 % of the original Brazilian Atlantic Forest remains, most of it as small secondary forest patches ( Ribeiro et al 2009 ). Species rich old-growth forests such as the Forest of Seu Nico (FSN) in the Viçosa municipality, Minas Gerais, Brazil are extremely rare and poorly studied ( Campos et al 2006 , Gastauer and Meira Neto 2013a , Gastauer and Meira Neto 2013b ). The aim of this data paper is to distribute dynamics data from the FSN Dynamics Plot in order to increase knowledge about community composition and maintenance in the Brazilian Atlantic Forest.…”

Colonization-related functional traits of plants in a 50-hectare plot of secondary tropical forest

“…The Brazilian Atlantic Forest is not only one of the most diverse tropical forests worldwide, but also one of the most threatened, mainly because of intense disturbance leading to habitat loss and fragmentation (Ribeiro et al 2009;Magnago et al 2015). Nonetheless, there still remains high plant diversity, even on the most fragmented Atlantic Forest landscapes, although taxonomic, functional, and phylogenetic diversities are vanishing (Gastauer & Meira-Neto 2013;Matos et al 2017). The future of the Brazilian Atlantic Forest is uncertain and its fragments essentially composed of secondary forests, forecast homogenized landscapes with much lower diversity (Ribeiro et al 2009;Solar et al 2015).…”

Drivers of the growth–survival trade‐off in a tropical forest

“…The growth–survival trade‐off mediates plant growth between the conflicting strategies of acquisitive species that grow quicker and accumulate biomass without adaptations/structures to resist/tolerate stressful conditions, and conservative species that grow slower and accumulate biomass with defenses/structures to tolerate stressful conditions (Muller‐Landau, ; Muller‐Landau et al., ; Wright, Muller‐Landau, Condit, & Hubbell, ). Understanding which, and how, cross‐species functional traits contribute to the growth–survival trade‐off is key to improving our knowledge of the functioning of tropical forests, from local to global scales, since plant growth is a key factor for crucial ecosystem functions and processes such as carbon sequestration, energy flow and species coexistence (Chazdon et al., ; Gastauer & Meira Neto, ; Wright, ).…”