Dataset Information

Changes in the distribution of mechanically dependent plants along a gradient of past hurricane impact.

ABSTRACT: The severity of the effects that large disturbance events such as hurricanes can have on the forest canopy and the associated mechanically dependent plant community (epiphytes, climbers, etc.) is dependent on the frequency and intensity of the disturbance events. Here we investigate the effects of different structural and environmental properties of the host trees and previously modelled past hurricanes on dependent plants in Cusuco National Park, Honduras. Tree-climbing methods were employed to sample different dependent life-forms in ten 150 × 150 m plots. We identified 7094 individuals of dependent plants from 214 different species. For holo- and hemi-epiphytes, we found that diversity was significantly negatively related to past hurricane impact. The abundance of dependent plants was greatly influenced by their position in tree canopy and hurricane disturbance regimes. The relationship between abundance and mean branch height shifts across a gradient of hurricane impact (from negative to positive), which might result from a combination of changes in abundance of individual species and composition of the dependent flora across sites. Mechanically dependent plants also responded to different structural and environmental conditions along individual branches. The variables that explained much of the community differences of life-forms and families among branches were branch surface area and bryophyte cover. The factors that explained most variation at a plot level were mean vapour pressure deficit and elevation. At the level of the individual tree, the most important factors were canopy openness and past hurricane impact. We believe that more emphasis needs to be placed on the effects that past disturbance events have on mechanically dependent plant communities, particularly in areas that are prone to catastrophic perturbations.

SUBMITTER: Batke SP

PROVIDER: S-EPMC4584959 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Spatial population models predict strong density-dependence and relatively stable population dynamics near the core of a species' distribution with increasing variance and importance of density-independent processes operating towards the population periphery. Using a 10-year data set and an information-theoretic approach, we tested a series of candidate models considering density-dependent and density-independent controls on brook trout population dynamics across a core-periphery distribution gradient within a central Appalachian watershed. We sampled seven sub-populations with study sites ranging in drainage area from 1.3-60 km(2) and long-term average densities ranging from 0.335-0.006 trout/m. Modeled response variables included per capita population growth rate of young-of-the-year, adult, and total brook trout. We also quantified a stock-recruitment relationship for the headwater population and coefficients of variability in mean trout density for all sub-populations over time. Density-dependent regulation was prevalent throughout the study area regardless of stream size. However, density-independent temperature models carried substantial weight and likely reflect the effect of year-to-year variability in water temperature on trout dispersal between cold tributaries and warm main stems. Estimated adult carrying capacities decreased exponentially with increasing stream size from 0.24 trout/m in headwaters to 0.005 trout/m in the main stem. Finally, temporal variance in brook trout population size was lowest in the high-density headwater population, tended to peak in mid-sized streams and declined slightly in the largest streams with the lowest densities. Our results provide support for the hypothesis that local density-dependent processes have a strong control on brook trout dynamics across the entire distribution gradient. However, the mechanisms of regulation likely shift from competition for limited food and space in headwater streams to competition for thermal refugia in larger main stems. It also is likely that source-sink dynamics and dispersal from small headwater habitats may partially influence brook trout population dynamics in the main stem.

Dataset Information

Changes in the distribution of mechanically dependent plants along a gradient of past hurricane impact.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets