Although the environmental change by canopy gap formation in a forest improves the light availability for the saplings on the forest floor, it may result in stresses on the saplings due to high radiation and drought. In large-scale gaps, the photosynthesis of shade-tolerant species may be inhibited by high radiation and drought stress if they lack effective tolerance or avoidance mechanisms for...

In this paper we reexamine how heterogeneous environments can enable protected polymorphisms. Building on the classical models by Levene and Dempster of dispersal and selection in two habitats, we systematically investigate how the maintenance of polymorphisms is affected by (i) local versus global density regulation and (ii) constant versus variable output from habitats to the next generation....

Instream flow needs (IFN) assessment studies are performed to provide guidelines for stream water management and to assess the impacts of different water projects such as weirs, dams and stream diversions on the available fish habitat. The physical habitat simulation is one of the IFN assessment methods and also a powerful tool in management of river ecosystem that has not become a common metho...

The focus of this paper is the relationship between the dispersal rate and the conditions for invasion of a rare allele that improves performance in a marginal sink habitat at the expense of reducing fitness in the main source habitat. Classic multiple-niche population-genetic models predict that the conditions for the invasion of such an allele always become more favourable as the dispersal ra...

objective: ageing of the stored seed is a natural phenomenon and the seeds tend to lose viability even under ideal storage conditions. accelerated ageing has been recognized as a good predictor of the storability of seed lots. aged seeds show decreased vigor and produce weak seedlings that are unable to survive once reintroduced into a habitat. the characteristics of the chemical composition of...

Habitat loss can alter animal movements and disrupt animal seed dispersal mutualisms; however, its effects on spatial patterns of seed dispersal are not well understood. To explore the effects of habitat loss on seed dispersal distances and seed dispersion (aggregation), we created a spatially explicit, individual-based model of an animal dispersing seeds (SEADS-Spatially Explicit Animal Disper...