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Providing evidence to improve practice

Individual study: Preliminary effects of fire and mechanical fuel treatments on the abundance of small mammals in the mixed-conifer forest of the Sierra Nevada

Published source details

Amacher A.J., Barrett R.H., Moghaddas J.J. & Stephens S.L. (2008) Preliminary effects of fire and mechanical fuel treatments on the abundance of small mammals in the mixed-conifer forest of the Sierra Nevada. Forest Ecology and Management, 255, 3193-3202


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Remove understorey vegetation in forest Terrestrial Mammal Conservation

A replicated, randomized, controlled, before-and-after study in 2001–2003 of a forest in California, USA (Amacher et al. 2008) found that mechanically removing understorey vegetation in forest, to reduce fuel load and associated wildfire risk, did not increase abundances of California ground squirrels Spermophilus beecheyi, long-eared chipmunks Tamias quadrimaculatus, brush mice Peromyscus boylii or deer mice Peromyscus maniculatus, compared to using prescribed burning. Changes in capture rates between before and after treatments did not differ significantly between understorey removal plots and fire plots for California ground squirrel (understorey removal: 2.6 to 11.0; fire: 4.2 to 7.6/100 trap nights), long-eared chipmunk (understorey removal: 0.7 to 2.4; fire: 0.7 to 1.7/100 trap nights) or brush mouse (understorey removal: 0.6 to 1.4; fire: 0.1 to 1.4/100 trap nights). Deer mouse abundance declined with understorey removal (from 2.0 to 1.2/100 trap nights) compared to an increase with fire (from 0.5 to 2.0/100 trap nights). Forests stands were 14–29 ha each. In four stands, 90% of understorey trees were removed in 2001–2002. Four different stands were burned in October–November 2002. Small mammals were live-trapped over nine consecutive days and nights in July–August of 2001 (pre-treatment) and 2003 (post-treatment).

(Summarised by Nick Littlewood)

Use prescribed burning Terrestrial Mammal Conservation

A replicated, randomized, controlled, before-and-after study in 2001–2003 of a forest in California, USA (Amacher et al. 2008) found that prescribed burning increased abundance of deer mouse Peromyscus maniculatus, but not California ground squirrels Spermophilus beecheyi, long-eared chipmunks Tamias quadrimaculatus or brush mice Peromyscus boylii. Deer mouse abundance increased with fire (after: 2.0; before: 0.5/100 trap nights) and declined at the same time in unburned plots (after: 1.3; before: 1.9/100 trap nights). Changes in capture rates from before to after treatments did not differ between burned and unburned plots for California ground squirrel, long-eared chipmunk or brush mouse (see paper for data). Forests stands were 14–29 ha each. Four stands were burned in October–November 2002 and four stands were not burned. Small mammals were live-trapped over nine consecutive days and nights in July–August 2001 (pre-burn) and 2003 (post-burn).

(Summarised by Nick Littlewood)