Treesearch

Breeding dispersal, the movement from one breeding territory to another, is rare for philopatric species that evolved within relatively stable environments, such as the oldgrowth coniferous forests of the Pacific Northwest. Although dispersal is not inherently maladaptive, the consequences of increased dispersal on population dynamics in populations whose historical dispersal rates are low could be significant, particularly for a declining species. We examined rates and possible causes of breeding dispersal based on a sample of 4,118 northern spotted owls (Strix occidentalis caurina)...

After a century of intensive logging, federal forest management policies were developed in the 1990s to protect remaining large trees and old forests in the western US. Today, due to rapidly changing ecological conditions, new threats and uncertainties, and scientific advancements, some policy provisions are being re-evaluated in interior Oregon and Washington. The case for re-evaluation is clearest where small-to large-sized, immature, fast-growing, fire-intolerant trees have filled in forests after both a long period of fire exclusion and the harvest of large, old trees. This infilling...

Adult salmonid migration to natal habitats and spawning are affected both by physiological factors and environmental conditions. While research has focused on physiological thresholds that influence the initiation of migration, few studies have investigated the relationship between both hydrological and thermal conditions and salmon spawning throughout the course of the reproductive period. We examined whether Oregon coastal coho salmon (Oncorhynchus kisutch) returning to three tributaries of the Smith River watershed (in the central Oregon Coast Range) responded to the stream hydroregime...

Emerging infectious diseases have been especially devastating to amphibians, the most endangered class of vertebrates. For amphibians, the greatest disease threat is chytridiomycosis, caused by one of two chytridiomycete fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Research over the last two decades has shown that susceptibility to this disease varies greatly with respect to a suite of host and pathogen factors such as phylogeny, geography (including abiotic factors), host community composition, and historical exposure to pathogens;...

The objectives of the effectiveness monitoring plan for the marbled murrelet (Brachyramphus marmoratus) include mapping nesting habitat at the start of the Northwest Forest Plan (NWFP) and estimating changes in that habitat every 5 years. Using Maxent species distribution models, we modeled the amount and distribution of probable nesting habitat in the murrelet’s range in the NWFP area in 1993, 1 year prior to the start of the NWFP, and 25 years later (2017). Within the higher probability nesting habitat, we then estimated the amount of contiguous habitat (core) versus the amount of...

Old-growth forests serve as critical habitat for many sensitive species, but management practices have diminished their prevalence, and former regions of old-growth are now dominated by second-growth stands lacking the structural heterogeneity, diversity, and species richness that these older forests possess. In western Washington state in the Pacific Northwest of the United States, the Olympic Habitat Development Study was designed to address this issue and hasten the development of specific old-growth features in second-growth stands using variable-density thinning. One concern with such...

The inclusion of diverse individuals in ecological sciences has shown little progress over the past 2 decades for various reasons, including structural barriers in societies, organizations, and academia. Collaboration networks are important for productivity, promotion, and scientific impact, yet the extent to which the structure of these networks affects the inclusion of minoritized people remains unknown. Here, we evaluated trends in published research between 1965 and 2017 within the U.S. fisheries science academic co-authorship network and evaluated its structural composition, focused...

• The success of invasive plants is influenced by many interacting factors, but evaluating multiple possible mechanisms of invasion success and elucidating the relative importance of abiotic and biotic drivers is challenging, and therefore rarely achieved. • We used live, sterile or inoculated soil from different soil origins (native range and introduced range plantation; and invaded plots spanning three different countries) in a fully factorial design to simultaneously examine the influence of soil origin and soil abiotic and biotic factors on the growth of invasive Pinus contorta. • Our...

Freshwaters are important, interconnected, and imperiled. Aquatic ecosystems, including freshwater fishes, are closely tied to the terrestrial ecosystems they are embedded within, yet available spatially explicit datasets have been underutilized to determine associations between freshwater fishes and forested areas. Here, we determined the spatial co-occurrence between freshwater fish distributions and forests within 2129 watersheds of the conterminous United States. We identified 21% of freshwater fishes as associated with forested areas, and 2% as strictly present only in highly forested...

Airborne volcanic ejecta (tephra) can strongly influence forest ecosystems through initial disturbance processes and subsequent ecological response. Within a tephra-disturbed forest, large trees may promote plant growth and create favorable sites for colonization. Three primary ways trees can influence posteruption vegetation response include: (1) amelioration of volcanic substrates, (2) providing source propagules from the tree or from associated epiphytes, and (3) sheltering understory vegetation, thereby increasing the rate of recovery near tree bases. Here, we evaluate Valdivian...