Abstract
This project aims to estimate the effects of habitat loss and fragmentation on biodiversity of macrofauna using mussel beds as a model system. Habitat loss is a main cause for species extinctions and biodiversity declines, while habitat fragmentation (producing higher patchiness) may be positive or negative for biodiversity. The effects of habitat loss and fragmentation have rarely been studied in marine habitats. Theory predicts an extinction threshold, a specific habitat amount in the landscape, above which the survival probability of an organism stays constant and below which this probability drops steeply. This model predicts that reproduction, emigration, survival, and habitat fragmentation affect the threshold, but empirical tests are needed. The specific objectives are to: i) estimate whether there is a critical amount of mussel habitat needed (test threshold theory) to sustain a high species diversity and abundance, ii) experimentally estimate effects of habitat loss and fragmentation of mussel beds on species richness and composition, density, survival, migration, growth and fecundity, iii) model data and results obtained to refine predictions of the critical mussel habitat amount needed to sustain a high diversity and abundance. Thus, this project will be able to predict how much mussel habitat should be conserved for persistence of populations and diversity, and the relative importance of habitat fragmentation and different population processes for this threshold.
Sweden