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Questions: In production forest landscapes, threatened species are increasingly confined to fragments of natural forest. Protecting such fragments is a priority to halt further biological degradation, but its effectiveness depends on external impacts on the fragments. In this study, we ask: how does woody vegetation in protected old-forest fragments vary depending on management of their adjacent areas, also in combination with natural site conditions? What are the management impacts on habitat quality of the fragments in the long term? Location: Pinus-dominated and Picea mixed-wood forests in Estonia (hemiboreal Europe). Methods: Forest structure and microclimate were measured at the edge and interior of protected old-forest fragments. Woody vegetation layers, shrub species composition, coarse woody debris, and presence of cut stumps were measured in 107 fragments (adjacent to clearcuts, partial cuts, and unthinned production forests) and in 20 control stands embedded within natural forest. Air temperature and humidity were measured at the edges vs the interior of mixed-woods. Edge age effects were explored along 80 years of post-harvest chronosequences. Results: All edge types studied had multiple, partly forest-type-specific, external effects on stand structure. Some clear-cutting effects on woody layers reversed in later decades, but there was also persistent impoverishment of deadwood pools of the fragments probably related to unreported tree removal. There was a likely indirect pathway of edge effects through overstorey loss, and shrub cover was reduced in the long term. Exotic species were rare. Edges at clear-cut stands influenced humidity regimes rather than temperature regimes. Conclusions: The moderate external effects on stand structure were tightly linked to low overstorey mortality and a lack of exotic species across the forest landscapes studied. Changes in these key factors constitute risks for the future. Protecting setasides from occasional tree cutting, and establishing forest buffers around small fragments and as a precautionary strategy are current priorities in these forest landscapes. [ABSTRACT FROM AUTHOR]

Abstract: The expanding practice of live-tree retention on clear-cuts represents a model case for conservation planning, because the high mortality of those trees requires balancing conflicting management goals in unpredictable conditions over long time frames. We explored the habitat provisioning function of dying retention trees for polypore and epixylic lichen assemblages. We sampled fallen trunks and snags created by known retention-tree deaths during the first post-harvest decade on 46 cut areas in Estonia, hemiboreal Europe. Those trees (particularly large fallen aspens) hosted a species-rich polypore assemblage that included several species of conservation concern. Lichen colonization of wood was slower and most species were found on pine snags. At the tree scale, the total species richness was highest on the trees that had died by trunk breakage creating both a snag and a log. To represent all species at the cutover scale, equal retention of different tree species and dead-wood types was sufficient for common species, but selective retention appeared necessary for species of conservation concern. The most frequent polypore species of conservation concern were either characteristic of specific substrates (notably aspen trunks) or early-successional stand conditions. We conclude that (i) dying retention trees are unlikely to provide dead-wood continuity at the stand scale and this function should be assessed at the landscape scale; (ii) effective habitat provisioning should include predicting and affecting the causes of tree death and linked management decisions based on the diversity, size, and longevity of the trees in specific landscape contexts. [Copyright &y& Elsevier]