A note on the ecology and management of old-growth forests in the Montane Cordillera

Abstract

The Montane Cordillera ecozone that spans British Columbia's central and southern interior and a portion of southwestern Alberta contains the greatest variety of old-growth coniferous forest types in Canada. The diverse climates of this region, which include some of the driest, warmest, wettest, and coldest found in southern continental Canada, have directly contributed to the richness of old forest types. Associated with this range in climatic conditions are radically different natural disturbance regimes that have profoundly influenced the distribution, abundance, and structural characteristics of old-growth forests. Old forests tend to be more abundant and to contain more old-growth-dependent organisms in wetter climates. The high number of old-growth-dependent epiphytic lichens in old inland rainforests is a clear expression of this phenomenon. Conversely, old forests are much less abundant in dry landscapes. These forests, often dominated by Ponderosa pine (Pinus ponderosa P. Laws. ex C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), have been subject to more frequent natural disturbances, and have been more profoundly influenced by human activities. Although fewer species appear to be dependent on old growth in dry forests, a number of them require certain old-growth structural attributes for their survival. A better understanding of the ecological characteristics of the old-growth forests of Canada's Montane Cordillera will assist in developing informed land-use decisions. Key words: old-growth forest, Montane Cordillera, natural disturbance, landscape ecology and management