Background: Protected areas (PAs) have become one of the most important instruments to preserve nature and, when effective, can significantly reduce human pressure and derived threats to biodiversity. However, evidence suggests that despite the growing number and coverage of PAs worldwide, biodiversity trends continue to deteriorate, and human pressure increases outside and inside PAs. While many studies have focused on the effectiveness of PAs in maintaining ecological features, less attention has been given to the threat reduction potential of PAs, despite threats being one of the main factors leading to the need to conserve biodiversity. It is therefore essential to understand PAs' role in addressing threats. In this paper, we describe the protocol for conducting a systematic review to explore and review the evidence surrounding the effectiveness of PAs as an intervention to reduce threats to biodiversity. We will examine the role of PAs in addressing several types of threats. Thus, our primary research question is: How effective are protected areas for reducing threats to biodiversity?
Methods: This protocol follows the Collaboration for Environmental Evidence guidelines for evidence synthesis and complies with the ROSES (Reporting Standards for Systematic Evidence Synthesis) reporting framework. We will use a comprehensive search, covering databases such as Web of Science-core collection and Scopus and organizational websites to capture relevant grey literature. Our search terms and strategies aim to find studies assessing change of threats given in PAs at any scale and ecosystem type capturing literature in English. Independent reviewers will screen search results at the title-abstract, and full text levels. In order to evaluate the relevance of the evidence, we will use the Collaboration for Environmental Evidence Critical Appraisal Tool. The results will be presented as a narrative synthesis supported by quantitative data. Additionally, a meta-analysis, if possible, will be performed.
Background: Cultivated peatlands are widespread in temperate and boreal climate zones. For example, in Europe about 15% of the pristine peatland area have been lost through drainage for agricultural use. When drained, these organic soils are a significant source of greenhouse gas (GHG) emissions. To reach climate goals, the agricultural sector must reduce its GHG emissions, and one measure that has been discussed is changing land use from cropland to ley production or perennial green fallow. This management change leads to lower reported emissions, at least when using the IPCC default emission factors (EF) for croplands and grasslands on organic soils (IPCC 2014). However, there was a limited background dataset available for developing the EFs, and other variables than management affect the comparison of the land use options when the data originates from varying sites and years. Thus, the implications for future policies remain uncertain. This protocol describes the methodology to conduct a systematic review to answer the question of whether ley production or perennial green fallow can be suggested as a valid alternative to annual cropping to decrease GHG emissions on organic soils in temperate and boreal climate.
Methods: Publications will be searched in different databases and bibliographies of relevant review articles. The comprehensiveness of the search will be tested through a list of benchmark articles identified by the protocol development team. The screening will be performed at title and abstract level and at full text level, including repeatability tests. Eligible populations are organic agricultural soils in temperate and boreal climate regions. Interventions are grasslands without tillage for at least 3 years, and comparators are annual cropping systems within the same study as the intervention. The outcome must be gas fluxes of either carbon dioxide (CO2), nitrous oxide (N2O), or methane (CH4), or any combination of these gases. Studies will go through critical appraisal, checking for internal and external validity, and finally data extraction. If possible, a meta-analysis about the climate impact of perennial green fallow compared to annual cropping on organic soils will be performed.