Abstract

Clearcutting can have important effects on wildlife. However, the mechanisms by which different species are affected by clearcutting are poorly understood. Here, we performed two experiments to test whether movement behavior influences how a species responds to clearcutting at both individual (survival) and population levels (demographic change). We studied the impact of clearcutting on two rodent species in Pinus radiata plantations in south-central Chile. The study involved a very mobile (Oligorozomys longicaudatus) and a more sedentary (Abrothrix longipilis) species. To study the individual-level response to clearcutting, we radio-tracked 92 (67 A. longipilis and 25 O. longicaudatus) adult male mice from before to after clearcutting and recorded individual survival and movement. To evaluate the population-level response, we recorded the abundance for each species before (winter) and after clearcutting (spring, summer and fall). We also included abundance data in uncut mature stands (controls) to detect seasonal changes in abundance not caused by clearcutting. At the individual level, we found that after clearcutting >80% of O. longicaudatus remained alive, while only 48% of A. longipilis survived. All A. longipilis that survived clearcutting stayed in the stand ("refuge response"), whereas 77% of O. longicaudatus evacuated the stand and relocated to undisturbed sites ("evacuate response") allowing them to survive in neighboring areas. At the population-level, the abundance of A. longipilis showed a significant decline after clearcutting that continued towards spring and summer, but in fall we found no differences between clearcut and uncut mature stands. O. longicaudatus tended to decrease toward spring and summer in both harvested and uncut mature stands, but this trend was not significant. The abundance increased significantly in fall, where the increase in abundance in harvested stands was significantly higher than in uncut mature stands. Our results demonstrate that the short-term effects of clearcutting on abundant small mammal species are species-specific and strongly dependent on the species' movement behavior. Additionally, they showed a rapid population recovery (around 1 year) after high mortality by clearcutting over the less mobile species.