Drought events have been shown to impact species distributions and are predicted to increase in frequency as the climate changes. As this occurs, ecologists predict species distributions will shift dependent upon species ability to track climate. These shifts in species distribution are expected to be particularly acute in arid and...
Tropical island ecosystems have proven to be inordinately vulnerable to invasions by exotic plants and animals. Today these islands only contain small
remnant populations of the original flora and fauna, and these populations are facing increasing pressure from invasive plants. This paper attempts to answer four important questions whose solutions...
Regression equations applicable to biomass components of standsof western hemlock [Tsuga heterophylla (Raf.) Sarg.} were developedby destructive sampling of a thinned and an unthinned stand ofwestern hemlock near Seaside, Oregon. Equations predicted more live-branchbiomass and less dead-branch biomass per tree for the thinnedstand, but equations for biomass of foliage, twigs,...
Climate change and the increase in meteorological drought have generated global concern over the persistence of ecosystems already in decline from decreased moisture. Evidence suggests dryland ecosystems have been more impacted by drought because of their tightly coupled growth-water relationships and high sensitivity to environmental shift. Removal of competing vegetation...
This dissertation investigated potential ecological limitations to seedling regeneration in young, seasonally dry, evergreen forest restoration plantations in northern Thailand. We explored whether recruitment of colonizing tree species in the restoration plantations can be attributed to seed dispersal mode (i.e. abiotic or animal dispersal) and seed size. We did this...
The application of modern land management practices beginning at the turn of the 20th century is widely believed to have dramatically transformed forest landscapes of the inland Pacific Northwest. Restoring historical conditions to make forests resilient to future climate and disturbance regimes is a major goal of federal forest managers....
Changes in climate caused by increased concentrations of carbon dioxide (CO₂) in the Earth’s atmosphere have led land and ocean surface temperatures to increase by 0.85°C and sea level to increase by 19 cm relative to preindustrial times. Global climate change will lead to further alterations in mean temperature and...
Methods for obtaining accurate, spatially explicit estimates of biomass density in tropical forests are required to reduce uncertainties in the global carbon cycle, and to support international climate agreements and emerging carbon markets. Three-dimensional (3-D) remote sensing techniques sensitive to the vertical structure of vegetation provide a unique opportunity for...
Forest management is rapidly undergoing a transformation from a discipline based on efficient commodity production to one for multiple uses, especially on federally managed land in the United States. This new management paradigm has challenged silviculturists to develop and adapt forest management techniques that can deal with increased demands. Using...
Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then...