TY - JOUR
T1 - Plant β-diversity in fragmented rain forests
T2 - Testing floristic homogenization and differentiation hypotheses
AU - Arroyo-Rodríguez, Víctor
AU - Rös, Matthias
AU - Escobar, Federico
AU - Melo, Felipe P.L.
AU - Santos, Bráulio A.
AU - Tabarelli, Marcelo
AU - Chazdon, Robin
PY - 2013/11
Y1 - 2013/11
N2 - Land-use change is the main driver of global biodiversity loss, but its relative impact on species turnover (β-diversity) across multiple spatial scales remains unclear. Plant communities in fragmented rain forests can undergo declines (floristic homogenization) or increases (floristic differentiation) in β-diversity. We tested these alternative hypotheses analysing a large vegetation data base from a hierarchically nested sampling design (450 plots in 45 forest patches in 3 landscapes with different deforestation levels) at Los Tuxtlas rain forest, Mexico. Differences in β-diversity across spatial scales (i.e. among plots, among patches, and among landscapes) were analysed using multiplicative diversity decompositions of Hill numbers. Plant β-diversity among plots within forest patches decreased in landscapes with higher deforestation levels, leading to floristic homogenization within patches. This homogenization process can be explained by the loss of rare and shade-tolerant plant species, and the recruitment and dominance of disturbance-adapted species, and can limit the accumulation of species (γ-diversity) in landscapes with higher deforestation. Nevertheless, the landscape with the highest deforestation level showed the highest floristic differentiation among patches. This landscape showed the greatest isolation distances between patches; a landscape spatial pattern that can limit the interchange of seeds (and species) between patches. Because the study patches are undergoing secondary succession following disturbances (e.g. logging, edge effects), different disturbance regimes and increased distance among patches could lead to higher β-diversity. Synthesis. These findings indicate that patterns of floristic homogenization and differentiation depend on the landscape configuration and on the spatial scale of analysis. At the landscape scale, our results suggest that, in accordance with non-equilibrium dynamics and the landscape-divergence hypothesis, patches located in landscapes with different forest cover and different connectivity can experience contrasting successional pathways due to increasing levels of compositional differentiation between patches. These novel findings add further uncertainties to the maintenance of biodiversity in severely deforested tropical landscapes and have key ecological implications for biodiversity conservation planning.
AB - Land-use change is the main driver of global biodiversity loss, but its relative impact on species turnover (β-diversity) across multiple spatial scales remains unclear. Plant communities in fragmented rain forests can undergo declines (floristic homogenization) or increases (floristic differentiation) in β-diversity. We tested these alternative hypotheses analysing a large vegetation data base from a hierarchically nested sampling design (450 plots in 45 forest patches in 3 landscapes with different deforestation levels) at Los Tuxtlas rain forest, Mexico. Differences in β-diversity across spatial scales (i.e. among plots, among patches, and among landscapes) were analysed using multiplicative diversity decompositions of Hill numbers. Plant β-diversity among plots within forest patches decreased in landscapes with higher deforestation levels, leading to floristic homogenization within patches. This homogenization process can be explained by the loss of rare and shade-tolerant plant species, and the recruitment and dominance of disturbance-adapted species, and can limit the accumulation of species (γ-diversity) in landscapes with higher deforestation. Nevertheless, the landscape with the highest deforestation level showed the highest floristic differentiation among patches. This landscape showed the greatest isolation distances between patches; a landscape spatial pattern that can limit the interchange of seeds (and species) between patches. Because the study patches are undergoing secondary succession following disturbances (e.g. logging, edge effects), different disturbance regimes and increased distance among patches could lead to higher β-diversity. Synthesis. These findings indicate that patterns of floristic homogenization and differentiation depend on the landscape configuration and on the spatial scale of analysis. At the landscape scale, our results suggest that, in accordance with non-equilibrium dynamics and the landscape-divergence hypothesis, patches located in landscapes with different forest cover and different connectivity can experience contrasting successional pathways due to increasing levels of compositional differentiation between patches. These novel findings add further uncertainties to the maintenance of biodiversity in severely deforested tropical landscapes and have key ecological implications for biodiversity conservation planning.
KW - Community assembly
KW - Compositional dissimilarity
KW - Diversity partitioning
KW - Environmental filtering
KW - Habitat fragmentation
KW - Multiscale analysis
KW - Secondary succession
KW - Wet forest
UR - http://www.scopus.com/inward/record.url?scp=84885864436&partnerID=8YFLogxK
U2 - 10.1111/1365-2745.12153
DO - 10.1111/1365-2745.12153
M3 - Artículo
SN - 0022-0477
VL - 101
SP - 1449
EP - 1458
JO - Journal of Ecology
JF - Journal of Ecology
IS - 6
ER -