It’s Day 7 of 12 Days Of Conifers and we’re headed to the eastern slope of the Sierra Nevada and into the sagebrush country at the edge of the Great Basin.
12 Days of Conifers: Pinyon, Juniper, and the Greater Sage-Grouse
Today’s conifers are pinyon pine and juniper (primarily Pinus monophylla, Juniperus osteosperma, and Juniperus occidentalis).,
Pinyon pine and juniper are characteristic of the dry eastern slopes of the Sierra Nevada, extending into the Great Basin. Both types of trees have seeds that are commonly eaten by people—pine nuts are harvested from pinyon pines, and juniper berries (which are actually modified cones) are used to flavor gin, among other culinary uses.
Hundreds of years ago, pinyon and juniper were a native part of Great Basin sagebrush ecosystems, but they were not common. As the name would imply, sagebrush country is dominated by, well, sagebrush (Artemisia sp.). But since the 1800s, parts of the sagebrush steppe are looking more and more like conifer country, as pinyon and juniper species encroach into the sagebrush. Changing land use practices, especially livestock grazing, climate, and changes in fire frequency have been identified as causes.
USGS ecologist Pete Coates has spent many years studying the sagebrush ecosystem, with a particular focus on its most famous bird, the greater sage-grouse (Centrocercus urophasianus). The greater sage-grouse depends on sagebrush, which provides the bird with food and cover from predators. In contrast, greater sage-grouse do not care for conifers. Coates’s research has found that greater sage-grouse avoid habitats dominated by pinyon and juniper.
Managing ecosystem boundaries like the edge of the Great Basin can be a real challenge. As climate and land use changes shift the species composition of Western ecosystems, land managers have to make difficult choices about what the land should look like going forward. USGS ecosystems research gives managers a clearer picture of how plants, animals, and people interact.