Partial migration is a common migratory behavior where some individuals in a population migrate and others do not. Patterns of partial migration can vary dramatically, especially for species that inhabit a wide range of environments. I described and predicted spatial variation in marine migration (anadromy) of female Oncorhynchus mykiss (steelhead...
Apex predators have experienced catastrophic declines throughout the world as a result of human persecution and habitat loss. These collapses in
top predator populations are commonly associated with dramatic increases in the abundance of smaller predators. Known as “mesopredator release,”
this trophic interaction has been recorded across a range of...
We described and predicted spatial variation in marine migration (anadromy) of female Oncorhynchus mykiss in the John Day River watershed, Oregon. We collected 149 juvenile O. mykiss across 72 sites and identified locations used by anadromous females by assigning maternal origin (anadromous versus non-anadromous) to each juvenile. These assignments used...
Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content...
Gonadal infections by a novel microsporidium were discovered in 34% (13/38) of arrow gobies, Clevelandia ios, sampled over a 3-yr period from Morro Bay Marina in Morro Bay, California. Gonadal tumors had been reported in arrow gobies from this geographic area. The infected gonads, found primarily in females, typically appeared...
The ascomycete fungus Tolypocladium inflatum, a pathogen of beetle larvae, is best known as the producer of the immunosuppressant drug cyclosporin. The draft genome of T. inflatum strain NRRL 8044 (ATCC 34921), the isolate from which cyclosporin was first isolated, is presented along with comparative analyses of the biosynthesis of...
Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by...
High nitrogen (N) accumulation in terrestrial ecosystems can shift patterns of nutrient limitation and deficiency beyond N toward other nutrients, most notably phosphorus (P) and base cations (calcium [Ca], magnesium [Mg], and potassium [K]). We examined how naturally high N accumulation from a legacy of symbiotic N fixation shaped P...
This study investigated how lidar-derived vegetation indices, disturbance history from Landsat time series (LTS)
imagery, plot location accuracy, and plot size influenced accuracy of statistical spatial models (nearest-neighbor
imputation maps) of forest vegetation composition and structure. Nearest-neighbor (NN) imputation maps were
developed for 539,000 ha in the central Oregon Cascades,...
Human alterations to nutrient cycles[superscript 1,2] and herbivore communities³⁻⁷
are affecting global biodiversity dramatically². Ecological theory predicts
these changes should be strongly counteractive: nutrient addition
drives plant species loss through intensified competition for
light, whereas herbivores prevent competitive exclusion by increasing
ground-level light, particularly in productive systems[superscript 8,9]. Here we...