Many studies suggest that weedy plant species are most successful when
soil nitrogen in abundant. Consequently, I used soil nitrogen manipulations to
determine if altering nitrogen would affect the establishment of both weedy and
native plant species in a western Oregon wetland prairie. In two studies, we
added carbon amendments...
Forest harvest can have significant impacts on forest ecosystems that may influence the capacity of soils to sequester carbon (C). The microbial community controls decomposition, which is a critical process in partitioning litter- and root-C between CO₂ and storage in semi-permanent soil-C pools. The objectives of this study were to...
Most carbon (C) transformations in soil are carried out by a diverse and complex soil microbial community. The size and composition of the soil microbial community is determined by poorly understood interactions between the quantity and chemical composition of plant inputs, as well as climate. Given the metabolic diversity of...
Successful conservation management requires an understanding of how species respond to intervention. Native and exotic species may respond differently to management interventions due to differences arising directly from their native or exotic origin (i.e., provenance) or from differences in life-history or phylogenetic lineage that are associated with provenance. Thus, selection...
Seasonal and annual patterns of N fluxes and concentrations in streamwater in six conifer-dominated watersheds at the H.J. Andrews Experimental Forest, OR, were studied to gain insight into the factors that influence N retention in this ecosystem. Processes affecting N flux in streamwater differed between organic (DON) and inorganic (DIN;...
By emulating natural disturbances such as wildfire, managers hope to maintain biodiversity in managed forests. Leaving residual (live) trees in harvested areas is key to this strategy. However, the effectiveness of this approach is unknown. I surveyed songbirds in 176 stands in the Rocky Mountains of southeastern British Columbia, Canada,...
This thesis is comprised of two manuscripts that relate to forest-based management strategies in the context of market-based climate change mitigation policies. The work questions the appropriateness of a singular focus on carbon sequestration given the albedo effect and its possible countervailing climatic impacts. Through a review of salient literature...
This study explored scientists' epistemological views of science and compared
views based upon scientists' discipline area and primary investigative approach.
Participants were 24 scientists, averaging 25 years research experience, representing four discipline areas: life science (10), Earth and space science (5), physics (5), chemistry (5); and four investigative approaches: experimental...
Streamside buffer strips provide numerous benefits to stream ecosystems. The buffer strips create shade, provide shelter for wildlife, act as barriers to logging debris during and after timber harvest, and serve as a continued source of large woody debris. Quantifying woody inputs resulting from windthrow provides managers with estimates for...
The study examines the effect of forest clearance on fire occurrences in major islands of Indonesia, namely: Borneo, Sumatra, Sulawesi and Irian Jaya. The working hypothesis of the study is that forest clearing is a necessary predecessor for extensive fires to occur. The study is designed to test the idea...