Multiple factors influence plant richness and diversity in the cold and dry boreal forest of southwest Yukon, Canada

Abstract

The intermediate disturbance hypothesis (IDH) is regarded as an appropriate model for understanding plant diversity–disturbance relationships in the boreal region. However, concern has been raised over its applicability across such a broad region, in particular, in low productive areas of the region such as the cold, dry region of the southwest Yukon. We examined plant richness and diversity in relation to the IDH in the context of both disturbance and productivity gradients. We then tested whether environmental variation and resource quantity interacted with development stage to shape richness patterns in the region. We found that richness and diversity did not conform to the IDH but that environmental variation and resource quantity influenced richness and diversity patterns. Overall richness and diversity patterns were not influenced by development stage though plant functional group patterns were. Richness patterns varied between plant functional groups suggesting that divergent processes shape inter functional group richness within the same stands. Our findings highlight the influence of multiple factors governing patterns of plant richness and diversity in the cold dry boreal forests of the southwest Yukon.