What Happens to Small Mammals with More Trees?

This article was originally published in The Midden – Great Basin National Park: Vol. 19, No. 1, Summer 2019.

By Bryan Hamilton, Acting Chief of Natural Resource Management

Meg Horner (NPS Biologist) and I recently published a peer-reviewed paper in Rangeland Ecology and Management

The highlights are:
• Conifer encroachment into sagebrush habitat has dramatically reduced small mammal abundance (-270%) and biomass (-230%).
• Sagebrush restoration increased native shrub cover (13%) and invasive, non-native cheatgrass density (380%) but did not increase native herbaceous plant densities.
• Sagebrush restoration reduced the density of the woodland specialist piñon mouse (-80%).
• Overall sagebrush restoration treatmentshad few effects on small mammal diversity.
• Sagebrush restoration maintained small mammal densities in the face of conifer encroachment.

In addition to the effects of restoration and encroachment on small mammals, the paper does a good job of describing the issue of conifer encroachment and the scale of sagebrush restoration. The data is all from Lehman Flat along the Wheeler Peak Scenic Drive.