Management diversity begets biodiversity in production forest landscapes

How to manage forest for biodiversity conservation is an ongoing debate. We argue that maximizing biodiversity in managed forest landscapes requires a diversity of forest management regimes in space and time. This will generate high levels of habitat heterogeneity at a landscape scale, which in turn will support various groups of forest species. Based on concepts from landscape ecology, we formulate five hypotheses on how management diversity, i.e. combining various management approaches can benefit overall biodiversity across a production forest landscape. First, management diversity will increase habitat diversity and, therefore, beta diversity (the habitat diversity hypothesis). Second, asynchrony in management timing will enhance long-term availability of different habitat types (the spatio-temporal heterogeneity hypothesis). Third, management to create spatial adjacency or proximity of stands with different management or successional stages will increase biodiversity by providing simultaneous access to multiple resources (the interspersion hypothesis). Fourth, heterogeneous unmanaged set-aside forests, interspersed with managed forests, are needed for complete biodiversity conservation (the natural forest hypothesis). Fifth, management diversity will create functional landscape connectivity between protected forests for multiple species through time (the temporary corridor hypothesis). Although strongly grounded in landscape and forest ecology, these five hypotheses remain largely under-investigated, and we suggest methods for how they can be tested. In the meantime, we suggest that increasing forest management diversity represents a risk-spreading approach for adaptation to global change, and therefore is likely a reasonable objective for sustainable forestry moving forward.