Response of the cover of berry-producing species to ecological factors on the Kenai Peninsula, Alaska, USA

Abstract

Land managers on the Kenai Peninsula have responded to recent extensive infestations of forests by spruce beetles ( Dendroctonus rufipennis (Kirby)) and associated increased fire risk with a variety of management approaches. To provide additional ecological information upon which to base these management prescriptions, we evaluated the response of the cover of berry species to variations in landscape factors and environmental conditions, including crown closure. Data were sufficient to describe the response of cover of bunchberry dogwood ( Cornus canadensis ), black crowberry ( Empetrum nigrum ), false toadflax ( Geocaulon lividum ), strawberryleaf raspberry ( Rubus pedatus ), lingonberry ( Vaccinium vitis-idaea ), and a combination of 24 other species through multinomial logistic regression. Crown closure and forest overstory type significantly influenced the cover of all berry species. Increasing crown closure had a negative effect on all berry species except strawberryleaf raspberry. Level of infestation by spruce beetles was significantly related to the cover of all species except lingonberry. Our findings indicate that spruce forests may be managed to enhance berry cover and that choice of management technique (e.g., timber harvest, prescribed fire) will likely result in different outcomes.