All streams in Oregon that are inhabited by salmon and trout have a statemandated
water temperature standard. However, temperatures of many streams,
especially during summer months, exceed the seven-day average maximum
temperature parameter (200 C for redband trout inhabited streams) accepted by the
Oregon Department of Environmental Quality. To date,...
Within the sagebrush steppe ecosystem, invasive annual grasses are of growing management concern as they outcompete native vegetation, change the fundamental nutrient cycling processes, decrease biodiversity, and increase frequency of wildfires. The most widely used and effective management tool to decrease invasive annual grass abundance, is the use of pre-emergent...
Livestock grazing has been indirectly related to sage-grouse (centrocercus
urophasianus) declines in the western United States and southern Canada; however,
there is a lack of scientific research that directly relates the two. Our objective was
to investigate the influence of livestock herbivory on sage-grouse nesting habitat by
determining the spatial...
The influence of streambank location and timing of herbivory on success of
planted Booth's willow (Salix boothii Dorn) cuttings along a Rosgen C5-type stream
in an eastern Oregon meadow was determined. Willow cuttings were planted on two
morphological locations (i.e. point bar and floodplain) in May of 2002 and 2003....
I developed a priori hypotheses and used logistic regression to model Greater Sandhill
Crane (Grus canadensis tabida) nest success in relation to weather, habitat and management variables for cranes breeding at Malheur National Wildlife Refuge (MNWR) in southeast Oregon. My primary interest was to investigate the effects of habitat conditions...
Experiments focusing on plant growth regulators’ concentrations and combination, mineral salt formulations and TDZ pretreatment formations were conducted to optimize in vitro shoot regeneration from leaf and petiole explants of 'Marion' blackberry. Optimum shoot formation was obtained when stock plants were incubated in TDZ pretreatment medium for three weeks before...
Agricultural production in the Sahelian region of Africa is
among the lowest in the world. Cyclical infestations of locusts and
grasshoppers have contributed to this low productivity. The infestations
appear to be triggered by heavy rainfall at the beginning of a crop season
after extended drought. Because locusts and grasshoppers...
Monotypic stands of crested wheatgrass (Agropyron cristatum [L] Gaertm. and Agropyron desertorum [Fisch.] Schult.), an
introduced grass, occupy vast expanses of the sagebrush steppe. Efforts to improve habitat for sagebrush-associated wildlife by
establishing a diverse community of native vegetation in crested wheatgrass stands have largely failed. Instead of concentrating
on...
Fire has largely been excluded from many mountain big sagebrush communities. Managers are reluctant to
reintroduce fire, especially in communities without significant conifer encroachment, because of the decline in sagebrush-associated
wildlife. Given this management direction, a better understanding of fire exclusion and burning effects is
needed. We compared burned to...
Western rangelands are currently under severe threat from exotic annual grasses. To successfully manage rangelands that are either infested with or susceptible to exotic annual grasses, we must focus on increasing resilience to disturbance and resistance to exotic annual grass invasion. Here, we present a fuel-based model and research framework...