The abundance and spatial heterogeneity of coarse woody debris (CWD) on the forest floor is a prominent feature of Pacific Northwest (PNW) forest ecosystems. The effect of CWD on soil solution chemistry, nutrient cycling and availability, soil physical structure and formation of soil organic matter, however, remains unknown. Therefore, studies...
Riparian forests in the Idaho Panhandle, north of Whitebird, were surveyed for rare riparian lichen species. The region was stratified into nine geographic units and by stream size. Eighty-one plots were surveyed for lichen community, stand and river characteristics. Variables important to lichen community composition included regional differences, elevation, climatic...
The unifying purpose of this dissertation was to describe, model, and map
relationships between epiphvtic macrolichen communities and air quality in Ibrests of
northern and central California. First, multivariate analyses were used to subdivide the
large study area into three model areas with similar climate, topography, and lichen
communities: the...
Before the arrival of Euro-Americans, the inland Pacific Northwest was settled by native
people whose frequent intentional burning of the landscape promoted open stands
dominated by large fire-resistant ponderosa pine. Fire suppression for nearly a century,
livestock grazing, and logging of the largest trees has resulted in forests characterized by...
Soil organic matter (SOM) is the terrestrial biosphere's largest pool of organic carbon (C) and is an integral part of C cycling globally. Soil organic matter composition typically can be traced directly back to the type of detrital inputs; however, the stabilization of SOM results as a combination of chemical...
The goal of this dissertation was to improve our understanding of the physiology and life-history of invasive plants and of the mechanisms underlying life-history trade-offs. I compared invasive and noninvasive species of Rubus (blackberry) that grow together in the Pacific Northwest. Three hypotheses were investigated: (1) Invasive Rubus have higher...
An alternative to traditional roofing, extensive green roofs are contained ecosystems consisting of a drainage layer, a thin media profile which is planted with hardy plant species. Extensive green roof plants must maintain multiple functions while growing in a highly aggregate media at a depth of equal to or less...
Arthropods are important food resources for birds. Forest management activities can influence shrub-dwelling arthropods by affecting the structure and composition of understory shrub communities. Changes in abundance and species composition of arthropod communities in turn may influence the distribution and abundance of insectivorous birds. I examined relationships among bird abundance,...