The multifunctional roles of vegetated strips around and within agricultural fields

Background Agriculture can have substantial negative impacts on the environment. The establishment and management of vegetated strips adjacent to farmed fields (including various field margins, buffer strips and hedgerows) are commonly advocated mitigation measures for these negative environmental impacts. However, it may be difficult to obtain reliable evidence on the effects of implementation and management of vegetated strips, even though a substantial body of evidence exists. We describe a systematic map of research relating to vegetated strips in boreo-temperate farming systems to answer the question: What evidence exists regarding the effects of field margins on nutrients, pollutants, socioeconomics, biodiversity, and soil retention in boreo-temperate systems? Methods We searched 13 bibliographic databases, 1 search engine and 37 websites of stakeholder organisations using a predefined and tested search string focusing on a comprehensive list of English language vegetated strip synonyms. Searches in Danish, Finnish, Spanish, and Swedish were also conducted using web searches. We screened search results at title, abstract and full text levels, recording the number of studies deemed non-relevant (with reasons at full text). A systematic map database of meta-data (i.e. descriptive summary information about the settings and methods) for relevant studies was produced following full text assessment. The systematic map database is provided as an evidence atlas: interactive, web-based geographical information system. Results Over 31,000 search results were identified, resulting in a total of 1072 relevant primary research studies and 130 evidence reviews. Articles used a variety of terminology to describe vegetated strips, with 'field margin', 'hedgerow', 'shelterbelt' and 'riparian buffer' most common. The volume of primary research is increasing linearly year-by-year, whilst the increase in reviews has tailed off in the last 10 years. The USA and UK were most frequently studied and reviewed. Arable systems were investigated in c. 70% of primary research but 50% of reviews. Some 50% of primary research vegetated strips were field edge and 25% riparian, whilst riparian and field edge strips were roughly equally the focus of around a half of all described strips in reviews. Terrestrial biodiversity, nutrients (nitrogen and phosphorus) and soil/water loss or retention were the most commonly measured outcomes in primary studies and reviews, although some other