title: Tree species richness decreases while species evenness increases with disturbance frequency in a natural boreal forest landscape.
abstract: Understanding species diversity and disturbance relationships is important for biodiversity conservation in disturbance-driven boreal forests. Species richness and evenness may respond differently with stand development following fire. Furthermore, few studies have simultaneously accounted for the influences of climate and local site conditions on species diversity. Using forest inventory data, we examined the relationships between species richness, Shannon's index, evenness, and time since last stand-replacing fire (TSF) in a large landscape of disturbance-driven boreal forest. TSF has negative effect on species richness and Shannon's index, and a positive effect on species evenness. Path analysis revealed that the environmental variables affect richness and Shannon's index only through their effects on TSF while affecting evenness directly as well as through their effects on TSF. Synthesis and applications. Our results demonstrate that species richness and Shannon's index decrease while species evenness increases with TSF in a boreal forest landscape. Furthermore, we show that disturbance frequency, local site conditions, and climate simultaneously influence tree species diversity through complex direct and indirect effects in the studied boreal forest.
authors: Faculty of Natural Resources Management Lakehead University 955 Oliver Road Thunder Bay ON P7B 5E1 Canada.
authors: Daniel
authors: D
authors: Yeboah
authors: Faculty of Natural Resources Management Lakehead University 955 Oliver Road Thunder Bay ON P7B 5E1 Canada.
authors: Han Y H
authors: HY
authors: Chen
authors: Ontario Ministry of Natural Resources 435 James Street South, Suite 221D Thunder Bay ON P7E 6S7 Canada.
authors: Steve
authors: S
authors: Kingston
keywords: Climate; intermediate disturbance hypothesis; soil drainage class; species diversity; structural equation models; time since fire