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

摘要: Many western conifer forests were historically affected by frequent, low- to mixed-severity fires. A legacy of fire suppression, logging, grazing and other factors has created current forest habitats that do not reflect historical conditions. The increasing size, severity, costs catastrophic wildfires are now focusing wildland management research towards proactive fuel treatments designed reduce hazards across landscapes. As part the National Fire Surrogate (FFS) study, we researched effects three on small mammal populations within Sierra Nevada mixed-conifer forests. Twelve stands selected randomly from a set available stands. Each stand was assigned one four treatment groups: controls, prescribed only, mechanical plus combined. Abundance California ground squirrels (Spermophilus beecheyi), long-eared chipmunks (Tamias quadrimaculatus), brush mice (Peromyscus boylii), deer maniculatus) monitored both pre- post-treatment. Only mouse had significant effect. Deer abundance significantly increased post-treatment only treatments, declined treatments. All species effect year, with higher overall in period. In addition experimental analysis, models containing stand-level covariates vegetation characteristics examined compared using model selection procedures. improved upon analysis for mouse. Brush found have positive association canopy cover. Our results suggest burning negative For species, dominant year suggests other, more regional may abundance. Possible explanations included an increase precipitation post-treatment, major cone crop 2002, decline gray fox (Urocyon cinereoargenteus) occurrence. mouse, evaluation trap locations indicates this associated dense clumps tan oak (Lithocarpus densiflorus) or riparian areas. Leaving areas low cover benefit where reduction implemented. study documented immediate impacts is needed determine if our will persist through time.