Densities of breeding birds and changes in vegetation in an Alaskan boreal forest following a massive disturbance by spruce beetles
Matsuoka SM, Handel CM, Ruthrauff DR. 2001. Densities of breeding birds and changes in vegetation in an Alaskan boreal forest following a massive disturbance by spruce beetles. Canadian Journal of Zoology. 79(9):1678-1690
We examined bird and plant communities among forest stands with different levels of spruce mortality following a large outbreak of spruce beetles (Dendroctonus rufipennis (Kirby)) in the Copper River Basin, Alaska. Spruce beetles avoided stands with black spruce (Picea mariana) and selectively killed larger diameter white spruce (Picea glauca), thereby altering forest structure and increasing the dominance of black spruce in the region. Alders (Alnus sp.) and crowberry (Empetrum nigrum) were more abundant in areas with heavy spruce mortality, possibly a response to the death of overstory spruce. Grasses and herbaceous plants did not proliferate as has been recorded following outbreaks in more coastal Alaskan forests. Two species closely tied to coniferous habitats, the tree-nesting Ruby-crowned Kinglet (Regulus calendula) and the red squirrel (Tamiasciurus hudsonicus), a major nest predator, were less abundant in forest stands with high spruce mortality than in low-mortality stands. Understory-nesting birds as a group were more abundant in forest stands with high levels of spruce mortality, although the response of individual bird species to tree mortality was variable. Birds breeding in stands with high spruce mortality likely benefited reproductively from lower squirrel densities and a greater abundance of shrubs to conceal nests from predators.
- Type
- Journal Article
- Authors
- Matsuoka, Steven; Handel, Colleen; Ruthrauff, Daniel
- Units
- CAKN , WRST
- Keywords
- Birds, Boreal, Communities, FIRE, Forest, Kenai Peninsula, Lutz spruce, Nest Predation, relative importance, spruce bark beetle, stands, sub-alpine forests, Subarctic, throated blue warblers, Vegetation, White Spruce
- Subjects
- Ecological Framework: Biological Integrity | Infestations and Disease | Insect Pests , Ecological Framework: Biological Integrity | Focal Species or Communities | Forest/Woodland Communities , Ecological Framework: Biological Integrity | Focal Species or Communities | Birds