Artigo

Rain forest fragmentation and the dynamics of Amazonian tree communities

Few studies have assessed effects of habitat fragmentation on tropical forest dynamics. We describe results from an 18-yr experimental study of the effects of rain forest fragmentation on tree-community dynamics in central Amazonia. Tree communities were assessed in 39 permanent, 1-ha plots in fores...

ver descrição completa

Autor principal: Laurance, William F.
Outros Autores: Ferreira, Leandro Valle, Rankin-de Mérona, Judy M., Laurance, Susan G.W.
Grau: Artigo
Idioma: English
Publicado em: Ecology 2020
Assuntos:
Community Dynamics
Habitat Fragmentation
Rainforest
Tree
Amazonia
South America
Acesso em linha: https://repositorio.inpa.gov.br/handle/1/19301
id oai:repositorio:1-19301
recordtype dspace
spelling oai:repositorio:1-19301 Rain forest fragmentation and the dynamics of Amazonian tree communities Laurance, William F. Ferreira, Leandro Valle Rankin-de Mérona, Judy M. Laurance, Susan G.W. Community Dynamics Habitat Fragmentation Rainforest Tree Amazonia South America Few studies have assessed effects of habitat fragmentation on tropical forest dynamics. We describe results from an 18-yr experimental study of the effects of rain forest fragmentation on tree-community dynamics in central Amazonia. Tree communities were assessed in 39 permanent, 1-ha plots in forest fragments of 1, 10, or 100 ha in area, and in 27 plots in nearby continuous forest. Repeated censuses of >56 000 marked trees (≤10 cm diameter at breast height) were used to generate annualized estimates of tree mortality, damage, and turnover in fragmented and continuous forest. On average, forest fragments exhibited markedly elevated dynamics, apparently as a result of increased windthrow and microclimatic changes near forest edges. Mean mortality, damage, and turnover rates were much higher within 60 m of edges (4.01, 4.10, and 3.16%, respectively) and moderately higher within 60-100 m of edges (2.40, 1.96, and 2.05%) than in forest interiors (1.27, 1.48, and 1.15%). Less-pronounced changes in mortality and turnover rates were apparently detectable up to ~300 m from forest edges. Edge aspect had no significant effect on forest dynamics. Tree mortality and damage rates did not vary significantly with fragment age, suggesting that increased dynamics are not merely transitory effects that occur immediately after fragmentation, while turnover rates increased with age in most (8/9) fragments. These findings reveal that fragmentation causes important changes in the dynamics of Amazonian forests, especially within ~100 m of habitat edges. A mathematical 'core-area model' incorporating these data predicted that edge effects will increase rapidly in importance once fragments fall below ~100-400 ha in area, depending on fragment shape. Accelerated dynamics in fragments will alter forest structure, floristic composition, biomass, and microclimate and are likely to exacerbate effects of fragmentation on disturbance-sensitive species. 2020-06-15T22:07:10Z 2020-06-15T22:07:10Z 1998 Artigo https://repositorio.inpa.gov.br/handle/1/19301 10.1890/0012-9658(1998)079[2032:RFFATD]2.0.CO;2 en Volume 79, Número 6, Pags. 2032-2040 Restrito Ecology
institution Instituto Nacional de Pesquisas da Amazônia - Repositório Institucional
collection INPA-RI
language English
topic Community Dynamics
Habitat Fragmentation
Rainforest
Tree
Amazonia
South America
spellingShingle Community Dynamics
Habitat Fragmentation
Rainforest
Tree
Amazonia
South America
Laurance, William F.
Rain forest fragmentation and the dynamics of Amazonian tree communities
topic_facet Community Dynamics
Habitat Fragmentation
Rainforest
Tree
Amazonia
South America
description Few studies have assessed effects of habitat fragmentation on tropical forest dynamics. We describe results from an 18-yr experimental study of the effects of rain forest fragmentation on tree-community dynamics in central Amazonia. Tree communities were assessed in 39 permanent, 1-ha plots in forest fragments of 1, 10, or 100 ha in area, and in 27 plots in nearby continuous forest. Repeated censuses of >56 000 marked trees (≤10 cm diameter at breast height) were used to generate annualized estimates of tree mortality, damage, and turnover in fragmented and continuous forest. On average, forest fragments exhibited markedly elevated dynamics, apparently as a result of increased windthrow and microclimatic changes near forest edges. Mean mortality, damage, and turnover rates were much higher within 60 m of edges (4.01, 4.10, and 3.16%, respectively) and moderately higher within 60-100 m of edges (2.40, 1.96, and 2.05%) than in forest interiors (1.27, 1.48, and 1.15%). Less-pronounced changes in mortality and turnover rates were apparently detectable up to ~300 m from forest edges. Edge aspect had no significant effect on forest dynamics. Tree mortality and damage rates did not vary significantly with fragment age, suggesting that increased dynamics are not merely transitory effects that occur immediately after fragmentation, while turnover rates increased with age in most (8/9) fragments. These findings reveal that fragmentation causes important changes in the dynamics of Amazonian forests, especially within ~100 m of habitat edges. A mathematical 'core-area model' incorporating these data predicted that edge effects will increase rapidly in importance once fragments fall below ~100-400 ha in area, depending on fragment shape. Accelerated dynamics in fragments will alter forest structure, floristic composition, biomass, and microclimate and are likely to exacerbate effects of fragmentation on disturbance-sensitive species.
format Artigo
author Laurance, William F.
author2 Ferreira, Leandro Valle
Rankin-de Mérona, Judy M.
Laurance, Susan G.W.
author2Str Ferreira, Leandro Valle
Rankin-de Mérona, Judy M.
Laurance, Susan G.W.
title Rain forest fragmentation and the dynamics of Amazonian tree communities
title_short Rain forest fragmentation and the dynamics of Amazonian tree communities
title_full Rain forest fragmentation and the dynamics of Amazonian tree communities
title_fullStr Rain forest fragmentation and the dynamics of Amazonian tree communities
title_full_unstemmed Rain forest fragmentation and the dynamics of Amazonian tree communities
title_sort rain forest fragmentation and the dynamics of amazonian tree communities
publisher Ecology
publishDate 2020
url https://repositorio.inpa.gov.br/handle/1/19301
_version_ 1787141498247053312
score 11.653393

Registros relacionados