| 英文摘要: | Front. Ecol. Evol. http://doi.org/zfj (2015)
Efforts to increase the resilience of dry forests to wildfire tend to involve removal of most small trees. However, these small specimens often survive other disturbances such as insect outbreaks and drought, and might therefore provide broader forest resilience. Palaeoecological evidence shows that dry forests of the western US have persisted for thousands of years in the face of multiple disturbances. However, because small trees are thought to have been historically rare, their role in forest resilience remains uncertain.
To investigate whether the removal of small trees might compromise broader forest resilience (that is, to more hazards than just fire), William Baker and Mark Williams from the University of Wyoming, USA, study the historical significance of smaller trees in dry forests in the western USA. Their systematic surveys reveal that small trees dominated (52–92% of total trees) and that the forests contained diverse tree sizes and species (in the late 1800s).
Removal of most of the small trees to reduce wildfire risk may therefore compromise the resilience provided by small trees and diverse tree sizes and species against unpredictable future disturbances. |