Habitat management alternatives for conservation forests in the temperate zone: Review, synthesis, and implications

Temperate forests with high values for biological conservation, including old-growth and mid-aged (>50 years) semi-natural forests, cover large areas. Many of the forests are protected, and the protected area is expected to increase. The protection efforts need to be supported by research about habitat management. I reviewed >2000 studies of such forests, selecting 150 studies dealing with trees, bushes and forest structure. Of these, 59% gave no recommendation for management; the forest was used as ecological baseline. Minimal intervention was recommended in 8% of the studies. In the remaining studies (33%), active management of many types was proposed. Based on the review and the literature, I suggest four habitat management alternatives: (1) Minimal intervention, the most common form of management, usually allows continued succession and disturbances in the forests. They should develop as old-growth and act as ecological baselines. (2) Traditional management, based on historical reference, is used to create other forest structures that favour biodiversity (e.g. red-listed taxa) related to past cultural landscapes. (3) Non-traditional management is an action to produce old-growth characteristics or specific forest composition, or to favour one or a few tree species which may or may not have been abundant in the past. (4) Species management, for threatened, indicator and other species, and rewilding, is based on one or a small set of species that is valuable or can shape the forest (rewilding may be included in alternative 1, but emphasizes large predators). Depending on forest size and objectives, combinations of these management types may be used. If the concept of ecological restoration is used, which assumes one best forest habitat, researchers risk overlooking the importance of evaluating all the alternatives 1-4. There is often not only one correct habitat option for conservation forests. Many more studies of the management alternatives are needed, particularly long-term experiments. In addition, management plans, decisions, and actions in practical management of conservation forests need to be studied, to clarify choices and present conditions. (C) 2013 Elsevier B.V. All rights reserved.