A methodology for systematic mapping in environmental sciences

Systematic mapping was developed in social sciences in response to a lack of empirical data when answering questions using systematic review methods, and a need for a method to describe the literature across a broad subject of interest. Systematic mapping does not attempt to answer a specific question as do systematic reviews, but instead collates, describes and catalogues available evidence (e.g. primary, secondary, theoretical, economic) relating to a topic or question of interest. The included studies can be used to identify evidence for policy-relevant questions, knowledge gaps (to help direct future primary research) and knowledge clusters (sub-sets of evidence that may be suitable for secondary research, for example systematic review). Evidence synthesis in environmental sciences faces similar challenges to those found in social sciences. Here we describe the translation of systematic mapping methodology from social sciences for use in environmental sciences. We provide the first process-based methodology for systematic maps, describing the stages involved: establishing the review team and engaging stakeholders; setting the scope and question; setting inclusion criteria for studies; scoping stage; protocol development and publication; searching for evidence; screening evidence; coding; production of a systematic map database; critical appraisal (optional); describing and visualising the findings; report production and supporting information. We discuss the similarities and differences in methodology between systematic review and systematic mapping and provide guidance for those choosing which type of synthesis is most suitable for their requirements. Furthermore, we discuss the merits and uses of systematic mapping and make recommendations for improving this evolving methodology in environmental sciences

Evidence for the effects of neonicotinoids used in arable crop production on non-target organisms and concentrations of residues in relevant matrices: a systematic map protocol

Background Neonicotinoid insecticides (NNIs) have been routinely used in arable crop protection since their development in the early 1990s. These insecticides have been subject to the same registration procedures as other groups of pesticides, thus meet the same environmental hazard standards as all crop protection products. However, during the last 10 years the debate regarding their possible detrimental impact on non-target organisms, particularly pollinators, has become increasingly contentious and widely debated. Against this background, legislators and politicians in some countries, have been faced with a need to make decisions on the future registration of some or all of this class of insecticides, based on published evidence that in some areas is incomplete or limited in extent. This has created much concern in agricultural communities that consider that the withdrawal of these insecticides is likely to have significant negative economic, socio-economic and environmental consequences. Methods The proposed systematic map aims to address the following primary question: What is the available evidence for the effects of neonicotinoids used in arable crop production on non-target organisms and concentrations of residues in relevant matrices? The primary question will be divided into two sub-questions to gather research literature for (1) the effect of NNIs on non-target organisms (2) the occurrence of concentrations of NNIs in matrices of relevance to non-target organisms (i.e. exposure routes). The systematic map will focus on NNIs used in arable crop production: imidacloprid, clothianidin, thiamethoxam, acetamiprid, thiacloprid and dinotefuran. Separate inclusion criteria have been developed for each sub-question. Traditional academic and grey literature will be searched for in English language and a searchable databases containing extracted meta-data from relevant included studies will be developed

Updating and amending systematic reviews and systematic maps in environmental management

Systematic reviews and systematic maps aim to provide an overview of the best available evidence to inform research, policy and practice. However, like any form of review, they will require updating periodically to ensure that the most recent evidence has been incorporated. Here we outline two types of review revisions as recognised in medicine: updates and amendments. Updates involve a search for new studies, expanding the evidence base through time. Any other change (e.g. in screening or synthesis) or correction to the original report is an amendment. Decisions as to whether/when it is appropriate to undertake an update or amendment must be made on a case-by-case basis, considering issues such as the reliability and scope of the existing review or map, likely volume of new evidence, resources available, and the likely value of including new information. Careful, consistent reporting is necessary to ensure transparency and repeatability, particularly where there are deviations from the original methods, and authors should highlight key advances relative to the original report. Updating environmental systematic reviews and maps will be an increasingly important activity as the numbers of both primary studies and synthetic reports in the literature continue to grow

Water chemistry and endangered white-clawed crayfish: A literature review and field study of water chemistry association in Austropotamobius pallipes

Populations of the endangered white-clawed crayfish (Austropotamobius pallipes) have rapidly declined in distribution and density in recent decades as a result of invasive crayfish, disease and habitat degradation. The species is thought to be particularly sensitive to water chemistry, and has been proposed as a bio-indicator of water quality. Here we detail the results of a systematic review of the literature regarding the chemistry of waterbodies inhabited by white-clawed crayfish, along with a wide-scale field study of the chemistry of crayfish-inhabited waterbodies in the UK. We use these data to examine potentially significant variables influencing crayfish distribution. Several variables appear to have thresholds that affect crayfish distribution; crayfish presence was associated with high dissolved oxygen, low conductivity, ammonium, sodium, and phosphate, and to a lesser extent low sulphate, nitrate, and total suspended solids. Some variables (magnesium, potassium, sodium, sulphate, nitrate, and total suspended solids) may be tolerated at moderate to high concentrations in isolation (indicated by the presence of some populations in high levels of these variables), but suites of chemical conditions may act synergistically in situ and must be considered together. Recent efforts to conserve white-clawed crayfish have included relocations to Ark Sites; novel protected habitats with reduced risk of the introduction of disease, invasive crayfish and habitat degradation. We use our findings to propose the first detailed guidelines for common water chemistry variables of potential Ark Sites for the conservation of the species throughout its European range

Updating and amending systematic reviews and systematic maps in environmental management

Systematic reviews and systematic maps aim to provide an overview of the best available evidence to inform research, policy and practice. However, like any form of review, they will require updating periodically to ensure that the most recent evidence has been incorporated. Here we outline two types of review revisions as recognised in medicine: updates and amendments. Updates involve a search for new studies, expanding the evidence base through time. Any other change (e.g. in screening or synthesis) or correction to the original report is an amendment. Decisions as to whether/when it is appropriate to undertake an update or amendment must be made on a case-by-case basis, considering issues such as the reliability and scope of the existing review or map, likely volume of new evidence, resources available, and the likely value of including new information. Careful, consistent reporting is necessary to ensure transparency and repeatability, particularly where there are deviations from the original methods, and authors should highlight key advances relative to the original report. Updating environmental systematic reviews and maps will be an increasingly important activity as the numbers of both primary studies and synthetic reports in the literature continue to grow

Human well-being impacts of terrestrial protected areas

© 2013 Pullin et al.; licensee BioMed Central Ltd. Background: Establishing Protected Areas (PAs) is among the most common conservation interventions. Protecting areas from the threats posed by human activity will by definition inhibit some human actions. However, adverse impacts could be balanced by maintaining ecosystem services or introducing new livelihood options. Consequently there is an ongoing debate on whether the net impact of PAs on human well-being at local or regional scales is positive or negative. We report here on a systematic review of evidence for impacts on human well-being arising from the establishment and maintenance of terrestrial PAs. Methods: Following an a priori protocol, systematic searches were conducted for evidence of impacts of PAs post 1992. After article title screening, the review was divided into two separate processes; a qualitative synthesis of explanations and meaning of impact and a review of quantitative evidence of impact. Abstracts and full texts were assessed using inclusion criteria and conceptual models of potential impacts. Relevant studies were critically appraised and data extracted and sorted according to type of impact reported. No quantitative synthesis was possible with the evidence available. Two narrative syntheses were produced and their outputs compared in a metasynthesis. Results: The qualitative evidence review mapped 306 articles and synthesised 34 that were scored as high quality. The quantitative evidence review critically appraised 79 studies and included 14 of low/medium susceptibility to bias. The meta-synthesis reveals that a range of factors can lead to reports of positive and negative impacts of PA establishment, and therefore might enable hypothesis generation regarding cause and effect relationships, but resulting hypotheses cannot be tested with the current available evidence. Conclusions: The evidence base provides a range of possible pathways of impact, both positive and negative, of PAs on human well-being but provides very little support for decision making on how to maximise positive impacts. The nature of the research reported to date forms a diverse and fragmented body of evidence unsuitable for the purpose of informing policy formation on how to achieve win-win outcomes for biodiversity and human well-being. To better assess the impacts of PAs on human well-being we make recommendations for improving research study design and reporting

What are the impacts of within-field farmland management practices on the flux of greenhouse gases from arable cropland in temperate regions? A systematic map protocol

Background: Reducing greenhouse gas emissions is a vital step in limiting climate change and meeting the goals outlined in the COP 21 Paris Agreement of 2015. Studies have suggested that agriculture accounts for around 11% of total greenhouse gas emissions and the industry has a significant role in meeting international and national climate change reduction objectives. However, there is currently little consensus on the mechanisms that regulate the production and assimilation of greenhouse gases in arable land and the practical factors that affect the process. Practical advice for farmers is often overly general, and models based on the amount of nitrogen fertiliser applied, for example, are used despite a lack of knowledge of how local conditions affect the process, such as the importance of humus content and soil types. Here, we propose a systematic map of the evidence relating to the impact on greenhouse gas flux from the agricultural management of arable land in temperate regions. Methods: Using established methods for systematic mapping in environmental sciences we will search for, collate and catalogue research studies relating to the impacts of farming in temperate systems on greenhouse gas emissions. We will search 6 bibliographic databases using a tested search string, and will hand search a web-based search engine and a list of organisational web sites. Furthermore, evidence will be sought from key stakeholders. Search results will then be screened for relevance at title, abstract and full text levels according to a predefined set of eligibility criteria. Consistency checking will be employed to ensure the criteria are being applied accurately and consistently. Relevant studies will then be subjected to coding and meta-data extraction, which will be used to populate a systematic map database describing each relevant study's settings, methods and measured outcomes. The mapping process will help to identify knowledge gaps (subjects lacking in evidence warranting further primary research) and knowledge clusters (subjects with sufficient studies to allow a useful full systematic review), and will highlight best and suboptimal research methods

Maximizing Legacy and Impact of Primary Research: A Call for Better Reporting of Results

Much of the scientific literature in existence today is based on model systems and case studies, which help to split research into manageable blocks. The impact of this research can be greatly increased in meta-analyses that combine individual studies published over time to identify patterns across studies; patterns that may go undetected by smaller studies and that may not be the main subject of investigation. However, many potentially useful studies fail to provide sufficient data (typically means, true sample sizes, and measures of variability) to permit meta-analysis. Authors of primary research studies should provide these summary statistics as a minimum, and editors should require them to do so. By putting policies in place that require these summary statistics to be included, or even those that require raw data, editors and authors can maximize the legacy and impact of the research they publish beyond that of their initial target audience

Shades of grey: Two forms of grey literature important for reviews in conservation

Methods for reviewing research, such as systematic reviews and syntheses, are becoming increasingly common in conservation. It is widely recognised that grey literature, research not published in traditional academic journals, forms a vital part of the evidence base of these reviews. To date guidance and practice in searching for and including grey literature in conservation reviews has taken a broad approach, involving searching of a wide variety of resources. We argue that there are two distinct forms of grey literature and that each must be considered separately in order to assess potential importance and an appropriate searching strategy for every review undertaken. �File drawer� research is as yet unpublished academic research that is important for countering possible publication bias and can be targeted via specific repositories for preprints, theses and funding registries, for example. �Practitioner-generated research� includes organisational reports, government papers and monitoring and evaluation reports, and is important for ensuring comprehensiveness in conservation reviews. By considering the relative importance and appropriate strategies for inclusion of both types of grey literature, reviewers can optimise resource efficiency and comprehensiveness, and minimise publication bias