Post-cultivation Secondary Succession in a Venezuelan Lower Montane Rain Forest

Abstract

Since tropical rain forests are widely threatened by conversion to agriculture, even within protected areas, an understanding of recovery processes is important for restoration of forest ecosystems and thus conservation of their biodiversity. Secondary succession following land clearance and crop cultivation was studied in a lower montane rain forest in a protected area of the Venezuelan Cordillera de la Costa Central. Forest recovery was studied using a chronosequence of eight 20 · 20 m plots which represented four forest types ca.10 year-old Secondary Forest, ca. 20 year-old Secondary Forest, ca. 35 year-old (uncultivated) secondary forest and mature forest. Species richness and structural complexity increased during succession, with the oldest secondary forest having a physiognomy comparable to the mature forest. Species diversity was lower in the secondary forests than the mature forest, and their floristic composition was distinct. Four phases are hypothesized to occur in the succession process, each with a distinctive species assemblage: initial colonisation by non-woody vegetation; establishment and canopy closure by short-lived small-seeded woody pioneer species; replacement by longer-lived secondary species; and gradual replacement by mature forest large-seeded climax species. Full recovery of the forests in the protected area is likely to take many years, although it may be assisted through conservation management measures.Resumen. Dado que los bosques pluviales tropicales son amenazados significativamente por su conversio´n al uso agrı´cola, au´n en las a´reas protegidas, un entendimiento de los procesos de recuperacio´n es importante para el restablecimiento de estos ecosistemas de bosques y por eso la conservacio´n de su biodiversidad. Con este objetivo se realizo´un estudio de la sucesio´n secundaria en un bosque montano hu´medo bajo, situado en un a´rea protegida de la Cordillera de la Costa Central de Venezuela. La recuperacio´n del bosque despue´s de la deforestacio´n y uso agrı´cola se estudio´mediante el me´todo de la cronosecuencia, que consiste en analizar ocho parcelas de 20 por 20 metros, las cuales representan cuatro tipos de bosques: un bosque secundario de aproximadamente 10 an˜os; un bosque secundario de aproximadamente 20 an˜os; un bosque secundario (no cultivado) de aproximadamente 35 an˜os; y un bosque maduro. Se encontro´que tanto la riqueza de especies como la complejidad estructural se incrementaron con el tiempo a trave´s de un proceso de sucesio´n. La fisonomı´a del bosque secundario de mayor edad fue parecida a la del bosque maduro. Sin embargo, la diversidad de especies fue mas baja en los bosques secundarios que en el bosque maduro, y su composicio´n florı´stica diferente. Se hipotetiza la ocurrencia de cuatro fases diferenciadas en el proceso de sucesio´n en estos bosques, cada una con su propia comunidad bota´nica: colonizacio´n inicial por especies no len˜osas; establecimiento y cierre del dosel arbo´reo superior por especies len˜osas pioneras de vida corta con semillas pe...

Successional patterns of plant species and community diversity in a semi‐deciduous tropical forest under shifting cultivation

“…Both structural attributes of plant diversity and species composition are approaching those of the old-growth forest but still significantly differ, indicating that the length of our chronosequence is too short to see the full recovery of the semi-deciduous forest. Consistent with Howorth & Pendry (2006), large seeded, shade tolerant, small leaved, taller climax species begin to accumulate at this stage. Proportions of epiphytes, deciduous tree species and species with entire, glabreous leaves are also increasing.…”

“…The overall intensity of the disturbance regime is thus lower than in many other studies (e.g. one to several decades of cultivation in Marcano-Vega et al 2002 andHoworth &Pendry 2006, sometimes followed by temporary conversion into pastures before abandonment: Kammesheidt 1998;Marcano-Vega et al 2002;Marin-Spiotta et al 2007). This may overcome deleterious effects of prolonged cultivation, e.g.…”

Atlantic rain forest recovery: successional drivers of floristic and structural patterns of secondary forest in Southern Brazil

“…) Brazilian Atlantic rain forest, as well as in many other Neotropical forests (Guariguata & Ostertag ; Ruiz et al. ; Howorth & Pendry ; Chazdon et al. ).…”

“…Rapid recovery of forest structure is generally described for tropical rain forests (Guariguata & Ostertag ; Kennard ; Chazdon ; Howorth & Pendry ; Chazdon et al. ; Marín‐Spiotta et al.…”

Habitat Quality of the Woolly Spider Monkey (Brachyteles hypoxanthus)

“…As a general trend, the trees of a community become increasingly larger in more advanced secondary forest sites even when growth rates are constrained by phylogeny and edaphic conditions [Sheil, 2001;Howorth and Pendry, 2006]. For foliar chemical attributes, the relative amounts of nitrogen and fibre seem to be inversely related, with earlier successional stages characterised by higher levels of foliar nitrogen and fewer structural tissues [Woodwell et al, 1975;Coley, 1983;Bigelow, 1993].…”