Pine needle scale, Chionaspis pinifoliae (Fitch), is a pest of many species of conifers in urban habitats and Christmas tree farms. We found that the scale was abundant in impoverished habitats, such as ornamental landscapes, and scarce in more natural, park-like habitats. Rates of parasitism were highest in impoverished habitats, suggesting that parasitoids were not effective in suppressing sc...

Title of Document: CRITICAL PATCH SIZES AND THE SPATIAL STRUCTURE OF SALT MARSH COMMUNITIES. Holly Marie Martinson, Ph.D., 2009 Directed By: Professor William F. Fagan, Department of Biology The size, connectivity, and quality of habitat patches can have multifaceted impacts on species and communities. In this dissertation, I combined a multi-year field survey, manipulative field experiments, a...

In the montane forest-grassland mosaics of Western Ghats, land cover conversion to silviculture and agriculture over last five decades has resulted in both loss natural habitats widespread invasion remnant habitat patches. While grassland mosaic been relatively well studied, there have few attempts understand extent which forest (locally known as sholas ) affected by spread exotic species. Here...

—Most scrub–shrub bird species are declining in the northeastern United States, and these declines are largely attributed to regional declines in habitat availability. American Beaver (Castor canadensis; hereafter “beaver”) populations have been increasing in the Northeast in recent decades, and beavers create scrub–shrub habitat through their dam-building and foraging activities. Few systemati...

This study partitions selection in a natural metapopulation of a riparian plant species, Silene tatarica, into individual- and patch-level components by using contextual analysis, in which a patch refers to a spatially distinct stand of individual plants. We estimated selection gradients for two morphological characters (plant height and number of stems), their respective patch means, and plant...

The I-patch is a multi-sided surface representation, defined as combination of implicit ribbon and bounding surfaces, whose pairwise intersections determine the natural boundaries patch. Our goal to show how collection smoothly connected I-patches can be used approximate triangular meshes. We start from coarse, user-defined vertex graph which specifies an initial subdivision surface. Based on t...