Gap disturbance regime and composition in the Atlantic Montane Rain Forest: the influence of topography

Abstract

In the Atlantic Montane Rain Forest of south-eastern Brazil, a field study was carried out to describe the forest disturbance regime, analyse canopy gap composition and evaluate the influence of habitat parameters on gap tree species composition. We characterized canopy gaps considering the group of variables as follows: area, type and number of tree/ branch falls, topographic position, soil coverage and surrounding canopy trees. Gap composition was assessed at species level by measuring all individuals inside gaps higher than one meter. Mean gap area of the 42 canopy gaps analysed was 71.9 ± 9.0 m 2 (mean ± SE). Out of the studied gaps, 35.7% were created by uprooted and by snapped trees, 16.7% by dead-standing trees and 11.9% by the fall of large branches. The disturbance regime was characterized by gap openings predominantly smaller than 150 m 2 and by spatial patterning related to topography. Ridges had smaller gaps and higher proportions of gaps created by branch falls; slopes had bigger gaps generally created by uprooting events. The more abundant and frequent species were shade tolerant and the more species-rich families found inside gaps did not differ from the forest as a whole. Pioneer species were rare and restricted to medium and large size classes. The Indicator Species Analysis and the Canonical Correspondence Analysis indicated gap area, topography and the percentage of soil cover by the genera Calathea and Ctenanthe were the predominant variables correlated with woody species distribution. So, topography emerged as an important issue not only to the gap disturbance regime, but also to gap colonization. In respect to the influence of gap processes on the Atlantic Montane Rain Forest regeneration, our results support the view that canopy gap events may not be working as promoters of community wide floristic shifts.

How Forest Gap and Elevation Shaped Abies faxoniana Rehd. et Wils. Regeneration in a Subalpine Coniferous Forest, Southwestern China

“…As an important factor of gap characteristics that determines species composition, understanding the effect of gap size on natural regeneration has attracted the attention of many researchers [11][12][13]. In general, gap size is considered an important and direct influence on resource sequestration, gap microclimate and vegetation growth in a forest gap [14][15][16][17]. Additionally, as an important geographical factor, elevational gradients have predictable changes in numerous environmental factors (e.g., temperature and solar radiation) altitudinally on a single mountain, but also have remarkable influence on plant regeneration along with these environmental drives [14].…”

“…In general, gap size is considered an important and direct influence on resource sequestration, gap microclimate and vegetation growth in a forest gap [14][15][16][17]. Additionally, as an important geographical factor, elevational gradients have predictable changes in numerous environmental factors (e.g., temperature and solar radiation) altitudinally on a single mountain, but also have remarkable influence on plant regeneration along with these environmental drives [14]. However, despite numerous studies conducted to describe the relationship between gap characteristics and regeneration in various forest ecosystems [18,19], most of the studies on forest gaps have either focused on gaps created at the same altitude or ignored the altitude factor [20].…”

Spatial and temporal distribution of species diversity in semideciduous seasonal forests with occurrence of fire

“…65 (2): 525-534. Epub 2017 June 01.Key words: Atlantic Forest, Brazil, forest fragmentation, anthropogenic disturbance, long-duration study, spatial dependence, geostatistics.example, habitat degradation results in reductions of both forest cover and species diversity (Ribeiro, Martensen, Metzer, Tabarelli, Scarano, & Fortin, 2011) with serious implications for forest ecosystem functioning and organization (Silva-Matos, Fonseca, & Silva-Lima, 2005;Lima & Moura, 2008;Pereira, Filho, Eisenlohr, Miranda, & Filho, 2015). The spatial distribution of forest species is an interactive Forest fragmentation is one of the principal factors promoting forest degradation.…”

A Influência Da Topografia Na Distribuição De Gramíneas Em Um Fragmento De Floresta Atlântica Urbana Montanhosa – Maciço Da Tijuca/Rj

“…Tal heterogeneidade implica particularidades em seu funcionamento, podendo ajudar a determinar a velocidade e a magnitude tanto do efeito de borda quanto da regeneração florestal. Nas últimas duas décadas, diversos estudos vêm buscando relacionar diferenças topográficas (especialmente de orientação e inclinação de encostas) a fatores ecológicos como estrutura da vegetação (Oliveira et al, 1995;Clark e Clark, 2000;Robert e Moravie, 2003;Lima e Moura, 2006), composição florística (Slik e Eicchorn, 2003;Lima e Moura, 2006;Zeleny e Chytry, 2007), 2 Matriz é o termo comumente utilizado para designar o tipo de uso do solo/cobertura vegetal em que se encontra inserido um fragmento florestal. No caso da Floresta da Tijuca, que se constitui como um grande fragmento florestal com diversos tipos de uso à sua volta, o termo "matriz", em seu sentido original, não se adequa perfeitamente, mas o significado funcional permanece útil.…”

“…De forma mais genérica, chamamos aqui de matriz o tipo de uso/cobertura adjacente à floresta. Geomorfologia, v.12, n.2, p.3-14, 2011 parâmetros de solo (Zueng-Sang Chen et al, 1997;Fox, Maselli e Carrega, 2008;Wang et al, 2009), crescimento, mortalidade e recrutamento de plântulas e juvenis (Herwitz e Young, 1994;Bellingham e Tanner, 2000;Comita et al, 2009;Li, Feng-Rui et al, 2009), suscetibilidade à formação de clareiras no dossel (Gale, 2000;Ashton et al 2001;Lima e Moura, 2008), formação de húmus (Descheemaeker et al, 2009), padrões de distúrbio, sucessão e taxas de desenvolvimento local da vegetação (Hadley, 1994), e regeneração florestal (Yamagawa et al, 2006;Marangon et al, 2008). No contexto da dinâmica de bordas, porém, a topografia é ainda escassamente investigada.…”