Effects of forestry practices on the conservation of soil and forest ecosystem health and functioning: an umbrella review protocol

Background: Forests host a majority of the world’s terrestrial biodiversity and provide habitats and numerous resources, making them a vitally important ecosystem for plants, animals and humans alike. However, forest ecosystems are continuously lost under pressures such as land use change and fragmentation, logging activities and climate change. Timber and other forest resources are in high demand, so different economic and environmental interests lead to conflicts between resource extraction and biodiversity conservation. Nonetheless, forest management practices differ in their intensity and conclusively in their impacts on forest ecosystem health. Although various evidence syntheses have been conducted for specific forestry practices or geographic regions, a global overview of these impacts is still lacking. We use an umbrella review of existing evidence syntheses to fill this knowledge gap and to provide a basis for designing better informed forest management strategies and policies. We address the research questions: 1. How do different forestry practices affect the conservation of soil and forest ecosystem health and functioning? 2. Which evidence synthesis gaps exist with regards to the effects of forestry practices on forest and soil health? and 3. What is the quality and reliability of evidence from existing meta-analyses and syntheses on impacts of forestry practices on forest and soil health?Methods: The review will be conducted using a standardised methodology for systematic reviews. We use relevant keywords on forest management and forest health to construct search strings for multiple published and grey literature databases. Inclusion criteria require that studies are meta-analyses reporting a quantitative effect size, focus on forest ecosystems, assess the effect of pre-defined forest management practices on pre-defined forest health indicators at different levels of intensity, and that the full manuscript is written in English. Relevant evidence syntheses are identified, collected and their quality critically appraised. A pre-defined list of data is extracted from the manuscripts into a global dataset, with a particular focus on the effect size and measures of heterogeneity. Finally, data synthesis will focus on narrative, tabular, and graphic summaries of the dataset to answer the research questions, highlight evidence gaps and make recommendations for future reviews, policies and decision-making.