The effect of buffer strip width and selective logging on streamside plant communities

Abstract Background Riparian forests surrounding streams host high biodiversity values, but are threatened by clear-cut logging. Narrow buffer strips of about 15 m are commonly left between the stream and the clear-cut, but studies suggest that the buffer width should be at least 30 m to protect riparian plant communities. Moreover, selective logging is often allowed on the buffer strips in order to increase economic gain. We used an experiment of 43 riparian sites where buffer strip width and selective logging within the strip were manipulated and supplemented with unlogged control sites. We report the short-term changes in the community composition of vascular plants and mosses near the stream (0–15 m distance). Results 15-meter buffers are not enough to protect the vascular plant communities from changes caused by a clear-cut irrespective of the selective logging on the buffer strip. For moss communities 15-m buffers were not enough if they were selectively logged. Relative to the control sites, we observed no significant changes in community composition of vascular plants or mosses in the sites with 30-m buffer strips, whether selectively logged or not. Conclusions We conclude that buffer strips of 15 m are not sufficient to protect streamside plant communities even in the short term, but that buffers of 30 m should be left on both sides of the stream. Selective logging appears not to have effects on buffers that are at least 30 m wide. Thus, it may be more reasonable to increase buffer width and to allow selective logging on the wider buffer in order to compensate for the economic losses than to leave all trees on a narrow and ecologically insufficient buffer

What are the impacts of manipulating grazing and browsing by ungulates on plants and invertebrates in temperate and boreal forests? : A systematic review protocol

Background: Livestock grazing and 'overabundance' of large wild herbivores in forested areas have long been perceived as conflicting with the aims of both silviculture and forest conservation; however, certain kinds of herbivory can help to maintain habitat values in forest ecosystems. Management of grazing/browsing in protected forests can, therefore, be a critical tool for biodiversity conservation. However, it is not clear what impacts of wild ungulates or livestock are tolerable or desirable in forests set aside for conservation or restoration. The primary aim of the proposed systematic review is to clarify how the diversity of plants and invertebrates is affected by manipulation of the grazing/browsing pressure by livestock or wild ungulates. The ultimate purpose of the review is to investigate whether such manipulation is useful as a means of conserving or restoring biodiversity in forest set-asides. Methods: The review will examine primary field studies of how fencing or other kinds of manipulation of the grazing/browsing pressure by livestock or wild ungulates affects plants or invertebrates. We will consider studies made in boreal or temperate forests anywhere in the world, incorporating investigations made not only in protected areas but also in stands under commercial management. Non-intervention or alternative levels of grazing pressure will be used as comparators. Relevant outcomes include abundance, diversity and composition of plants and invertebrates, tree regeneration, and performance of focal/target species. Relevant studies will mainly be selected from a recent systematic map of the evidence on biodiversity impacts of active management in forest set-asides. A search update will be made with a subset of the search terms used for the systematic map. Searches for additional literature will be made in bibliographies of existing reviews. Relevant studies will be subject to critical appraisal and categorised as having high, medium or low susceptibility to bias. Studies with high susceptibility to bias will be excluded from the review. Useful outcomes and data on interventions and other potential effect modifiers will be extracted from included articles. A narrative synthesis will describe the quality and findings of all studies in the review. Where studies report similar outcomes, meta-analysis will be performed

A synthesis of multi-taxa management experiments to guide forest biodiversity conservation in Europe

Most European forests are used for timber production. Given the limited extent of unmanaged (and especially primary) forests, it is essential to include commercial forests in the conservation of forest biodiversity. In order to develop ecologically sustainable forest management practices, it is important to understand the management impacts on forest-dwelling organisms. Experiments allow testing the effects of alternative management strategies, and monitoring of multiple taxa informs us on the response range across forest-dwelling organisms. To provide a representative picture of the currently available information, metadata on 28 multi-taxa forest management experiments were collected from 14 European countries. We demonstrate the potential of compiling these experiments in a single network to upscale results from the local to continental level and indicate directions for future research. Among the different forest types, temperate deciduous beech and oak-dominated forests are the best represented in the multi-taxa management experiments. Of all the experimental treatments, innovative ways of traditional management techniques (e.g., gap cutting and thinning) and conservation-oriented interventions (e.g., microhabitat enrichment) provide the best opportunity for large-scale analyses. Regarding the organism groups, woody regeneration, herbs, fungi, beetles, bryophytes, birds and lichens offer the largest potential for addressing management–biodiversity relationships at the European level. We identified knowledge gaps regarding boreal, hemiboreal and broadleaved evergreen forests, the treatments of large herbivore exclusion, prescribed burning and forest floor or water manipulations, and the monitoring of soil-dwelling organisms and some vertebrate classes, e.g., amphibians, reptiles and mammals. To improve multi-site comparisons, design of future experiments should be fitted to the set-up of the ongoing projects and standardised biodiversity sampling is suggested. However, the network described here opens the way to learn lessons on the impact on forest biodiversity of different management techniques at the continental level, and thus, supports biodiversity conservation in managed forests