What specific plant traits support ecosystem services such as pollination, bio-control and water quality protection in temperate climates? A systematic map

BACKGROUND: Agricultural intensification has contributed to increased diffuse source pollution within water catchments, reduced heterogeneity within the landscape and caused major declines in farmland wildlife. This decrease in biodiversity has been shown to decrease vital ecosystem services such as pollination, biological pest control (bio-control) and water quality protection. The morphological traits of plant species, such as floral display size and leaf area, provide support to these services and vegetative strips can be established with plants that have these desirable traits to try and restore ecosystem service support to farmland. Vegetative strips are widely used across the world, especially in Europe, however, there is a need to increase their functionality due to issues of land availability and food security. To do this, combinations of plant species that will support specific ecosystem services, have been developed. However, to enable a fully-informed development process, evidence must be collated on which specific plant traits provide the support to the target ecosystem services. The primary objective of this study was to systematically map all evidence for specific plant traits that may provide support for pollinators, bio-control and water quality protection in temperate climates. METHODS: Both published and grey literature were obtained through databases and NGO websites using key search terms. An initial 34,077 articles were identified with a total of 11,705 individual articles, after duplicates were removed. These were screened for inclusion based on criteria such as subject, climate and language. Each article was coded into a Microsoft Access database using generic (e.g. author, publication date, study length) and topic specific (e.g. target system, organism and ecosystem service) keywords. RESULTS: After screening 56 articles were coded into the systematic map. A total of 40 articles identified 37 plant traits for pollinator support, seven identified eight traits for bio-control and nine identified 26 for water quality protection. All articles were published between 1983 and 2017 and they included studies that were undertaken in 22 different countries. DISCUSSION: This systematic mapping process produced a searchable database of literature available on plant traits and the target ecosystem services. It has highlighted that more research has been conducted on plant traits for pollinator support than for bio-control and water quality protection, identifying potential research gaps in these areas. Evidence presented in this map could inform decisions related to the suitability of plant species for inclusion within multifunctional vegetative strips, providing targeted ecosystem services. This information could be used by policy makers to develop an option that could benefit landowners and farmland wildlife concurrently.