Treesearch

Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd-infection dynamics and for formulating conservation strategies.We experimentally investigated intraspeci...

Copper is currently used as the key component in wood preservatives despite the known tolerance of many brown-rot Basidiomycetes. Copper-tolerant fungi, like Fibroporia radiculosa, produce and accumulate high levels of oxalate when exposed to copper. To gain insight into the mechanism of oxalate production, four F. radiculosa isolates decaying untreated and 1.2% ammoniacal copper citrate-treated wood were evaluated for the differential expression of citrate synthase, isocitrate lyase, glyoxylate dehydrogenase, a succinate/fumarate antiporter, and a copper resistance-associated ATPase pump....

Communicating the scientific knowledge generated by the Pacific Northwest Research Station is integral to our mission. The 2014 Science Accomplishments reports highlights the breadth of the station’s research, the relevance of our science findings, and the application of these findings. The photographs throughout the report showcase the region where we work and how science is done.

The scientific and policy literature on climate change increasingly recognizes the vulnerabilities of indigenous communities and their capacities for resilience. The role of gender in defining how indigenous peoples experience climate change in the United States is a research area that deserves more attention. Advancing climate change threatens the continuance of many indigenous cultural systems that are based on reciprocal relationships with local plants, animals, and ecosystems. These reciprocal relationships, and the responsibilities associated with them, are gendered in many indigenous...

Recent patterns of prolonged regional drought in southern boreal forests of the Great Lakes region, USA, suggest that the ecological effects of disturbance by wildfire may become increasingly severe. Losses of forest soil organic matter (SOM) during fire can limit soil nutrient availability and forest regeneration. These processes are also influenced by the composition of postfire SOM. We sampled the forest floor layer (i.e., full organic horizon) and 0-10cm mineral soil fromstands dominated by coniferous (Pinus banksiana Lamb.) or deciduous (Populus tremuloides Michx.) species 1-2months...

Oak decline is a widely distributed disease that results from an interacting set of factors in the Central Hardwood Region. Episodes of decline have been reported since before the turn of the twentieth century and from every state in the region. It is a stress-mediated disease that results from the interactions of physiologically mature trees, abiotic and biotic stressors that alter carbohydrate physiology, and opportunistic fungal pathogens and inner bark-feeding insects. Symptoms include reduced radial growth and slow, progressive crown dieback. Decline occurs over several years or...

There’s a tendency to think of the hardwood forests of the South as pristine, undisturbed, and unchanging places that provide habitat for diverse animal and plant species. Indeed, having large blocks of mature forest is important for many wildlife species. The leafy tree canopy, tall trunks, hard mast, dead trees with holes, cool and shady micro-environment, and thick leaf litter provide places to nest, forage, and hide for birds, salamanders, and other animals.

The first enzyme with dye-decolorizing peroxidase (DyP) activity was described in 1999 from an arthroconidial culture of the fungus Bjerkandera adusta. However, the first DyP sequence had been deposited three years before, as a peroxidase gene from a culture of an unidentified fungus of the family Polyporaceae (probably Irpex lacteus). Since the first description, fewer than ten basidiomycete DyPs have been purified and characterized, but a large number of sequences are available from genomes. DyPs share a general fold and heme location with chlorite dismutases and other DyP-type related...

Land managers need to include climate change in their decisionmaking, but the climate models that project future climates operate at spatial scales that are too coarse to be of direct use. To create a dataset more useful to managers, soil and historical climate were assembled for the United States and Canada at a 5-arcminute grid resolution. Nine CMIP3 future climate projections were downscaled to this grid and the MC1 dynamic global vegetation model was run over the historical and future climates. Climate variables included monthly mean temperature, precipitation, minimum temperature,...

Douglas-fir is an iconic tree in the Pacific Northwest. Although individual trees may appear to be identical, genetic differences within each tree have resulted from adaptation to the local environment. These genetic differences over time have resulted in differences among populations that are important to the species' survival and growth in changing climates. Current climate models project that over the next 50 years, the Pacific Northwest will experience an increase in summer temperatures. Combined with less winter snowpack, warmer summer temperatures will likely lead to more frequent...