The influence of small-scale litter structure invertebrate diversity on mixedwood forests

Invertebrates are a key component of forest biodiversity fulfilling functional roles in food webs as herbivores, predators, as a food source for mammals and birds, but also as decomposers and pollinators. Maintaining biodiversity is a primary goal of forest policy, however forest management plans are typically applied at stand or landscape levels whereas invertebrates are also influenced by factors acting at much smaller scales. We aim to examine the relationship between habitat parameters, particularly small-scale structural components of the litter, and invertebrate diversity, and ultimately link these patterns to processes acting at larger scales, which are more applicable to current sustainable forest management policy. Invertebrates from a range of functional groups (spiders, Carabid and Staphylinids beetles, Collembola (springtails), mites) were collected using pitfall traps and Berelese funnel extraction from litter samples in the boreal forest of Northern Alberta, Canada. Eighteen stands were examined from three forest types: deciduous dominated, conifer dominated and a mix of these. Invertebrate diversity was related to litter depth and type as well as factors at the stand scale such as forest structure. Forest management should aim to promote a range of canopy conditions to support a diverse litter structure. This will support a range of functional groups which are key to ecosystem function.