Habitat destruction and land use change are making the world in which natural populations live increasingly fragmented, often leading to local extinctions. Although local populations might undergo extinction, a metapopulation may still be viable as long as patches of suitable habitat are connected by dispersal, so that empty patches can be recolonized. Thus far, metapopulations models have eith...

Here we present a method for determining whether habitat patches are truly functioning as habitat islands. We do so by assessing if the species distribution pattern across the islands, when compared to a mainland pattern, conforms to the predictions of the theory of island biogeography. The putative islands in our study are a series of hummocks in a swamp in the ES George Reserve, Pinckney, MI....

North America's coastal mountains are particularly vulnerable to climate change, yet harbour a number of endemic species. With little room "at the top" to track shifting climate envelopes, alpine species may be especially negatively affected by climate-induced habitat fragmentation. We ask how climate change will affect the total amount, mean patch size, and number of patches of suitable habita...

The Levins metapopulation model describes the dynamics of several populations in patches of suitable habitat. These populations may go extinct, leaving empty patches of suitable habitat, but these empty patches may be recolonized by other populations via dispersal. The metapopulation can therefore persist if recolonizations balance local extinctions. This simple model has been criticized for it...

Metapopulations are models of ecological systems, describing the interactions and the behavior of populations that live in fragmented habitats. In this paper, we present a model of metapopulations based on the multivolume simulation algorithm tau-DPP, a stochastic class of membrane systems, that we utilize to investigate the influence that different habitat topologies can have on the local and ...

Metapopulation models have been used to better understand the conditions necessary for the persistence of the metapopulation. In this paper, we study a stochastic patch occupancy model that incorporates variation in quality and connectivity of the habitat patches. Two important assumptions are imposed in our analysis. Firstly, the distance between patches has a special form. This amounts to ass...

JOHNSON, BRENDA LYNN. The Effects of Habitat Fragmentation and Connectivity on Plant Disease. (Under the direction of Nick M. Haddad.) Within a large-scale habitat corridor experiment, I performed both experimental and observational studies to determine the effects of habitat fragmentation, habitat edge, and patch connectivity on the movement and incidence of fungal plant diseases. Increased sp...

Many services generated by forest ecosystems provide essential support for human well-being. However, the vulnerability of these services to environmental change such as forest fragmentation are still poorly understood. We present spatial modeling of the generation of ecosystem services in a human-dominated landscape where forest habitat patches, protected by local taboos, are located in a matr...

The effect of forest fragmentation on cove-forest herbs was studied in the Southern Blue Ridge Provjnce. Patches of mesic forests were sampled with 4 ha study plots. The coverage and density of herb species were greater in large patches (>200 ha) than in small patches (cl0 ha). Several ant-dispersed species, such as Disporum mud&urn and Uvularia gmndijlorw, were more likely to be absent from sm...