Outcome-based Evaluation of Conifer Removal in Lakeview, Oregon
The overall objective of a study conducted by Oregon State University and partners has been to expand the existing database and provide a longer-term assessment of the effects of juniper removal on sage grouse habitat use and demography. The specific objectives that have reached conclusion are:
1) modeling of sage grouse habitat selection during nesting and brood-rearing before and after juniper treatments;
2) modeling the demographic and population response of sage grouse to juniper management; and,
3) modeling landscape resistance to sage grouse movements in relation to juniper.
The project objectives for 2018-2020 shifted to:
1) establish a baseline characterization of thermal environments for sage grouse broods,
2) establish temporal variation in space of broods and how it relates to conifer, and
3) examine the effects of conifer avoidance of chick survival.
The study area is located in the Warner Mountains in Lake County, Oregon. In 2018, the study area was expanded to include areas in Washoe County, Nevada and Modoc County, California. Please access additional information on this research via the links below:
2020 Warner Sage Grouse Research Field Season Report (available here)
2019 Warner Sage Grouse Research Field Season Report (available here)
Andrew Olsen dissertation: Greater Sage Grouse Demography, Habitat Selection, and Habitat Connectivity in Relation to Western Juniper and its Management
Sage Grouse Initiative Science Communication, Sage Grouse Populations Grow When Conifers are Removed, 2019.
The Wildlife Society 2019 Symposium: Cut a Tree, Grow a Grouse: Implications of Juniper Removal for Sage Grouse Population Growth
“One key aspect of this research is the scale of the treatments - they encompass the entire watershed,” said Christian Hagen, a professor and researcher at Oregon State University who is part of this ongoing study. “This is what likely leads to the effects we observed. Small isolated treatments may not deliver the same conservation outcome.”
These photos show what a portion of Olsen’s study site looked like before and after conifer removal. Photo: Todd Forbes.
NEW RESEARCH SHOWS SAGE GROUSE POPULATIONS GROW 12% WHEN CONIFERS ARE REMOVED
In the last two centuries, woody plants have been expanding into the world’s vast grasslands and shrub-steppe rangelands. In the U.S., the expansion of conifers into the Great Plains and sagebrush-steppe has created a cascade of effects that include altered water regimes, habitat loss, increased fire severity, and more. In the last two decades, land managers, both public and private, have begun to understand the scope of this problem, pinpoint effective management solutions, and implement those solutions. These efforts have given scientists the chance to study how wildlife like sage grouse respond to conifer reduction efforts.
Andrew Olsen is one of these scientists; he has spent the last several years studying how sage grouse populations responded to sustained conifer removal efforts near the Warner Mountains in south central Oregon. Olsen’s research offers fresh insights into the outcomes produced by conifer removal.
“I think there are two key takeaways from my research: 1) conifer removal is an effective tool for increasing sage grouse populations, and 2) sage grouse populations may take several years to respond to management actions because they are long lived and have lower reproductive output compared to other game birds.” - Andrew Olsen, Oregon State University
