Protocols for the assessment of forest management effects on insect biodiversity

Forest management may influence biodiversity in several ways, both negatively, impoverishing the local communities, and positively, restoring diversified micro-habitats. Within the LIFE project MnFor C.BD. "Managing forests for different purposes: carbon, biodiversity and human well-being", we aim to test different types of forest management options, from traditional practices to more innovative actions. The study will take place in a number of Italian forests, distributed from north to south, characterised by different vegetation types: spruce, beech and oak. The management options will be performed simultaneously to allow direct comparison of their effect on insect diversity. Potential target insect groups (e.g. Coleoptera, Diptera, Hymenoptera) will be selected considering their trophic guild and other life-history traits that may influence their sensitivity to forest management. We will perform a pilot study to select the most suitable target groups and sampling design. Traps to be tested will include Malaise traps, window traps and yellow pan traps. These will be positioned in different numbers and activated for the same time period. The experiment will lead to the identification of the most suitable method on the basis of both saturation rate and representativeness of the site's community. Evaluation of the potential use of morpho-species as a proxy for species diversity will be performed. The results of this first experiment will allow to establish the most suitable groups and traps (type and timing) to be used in the sampling design to be used in the subsequent surveys. The sampling design will be spatially randomized and temporally stratified. Traps will be placed in randomly selected locations within each management option performed at each site. The activation of the traps will be repeated once a month during the period of adult activity of target groups for the amount of time determined during the pilot study.