Hedgerows are linear landscape features of woody vegetation usually located around
agricultural fields. An increasing number of studies have addressed the effects of
hedgerows on biodiversity and ecosystem services. This study is aimed to synthesize
these effects and compare the levels of biodiversity and ecosystem services in farmland
with hedgerows and (1) farmland without hedgerows and (2) nearby natural habitat at
the global scale. We hypothesized that farmland with hedgerows (1) enhances biodiversity
and ecosystem services as compared to farmland without hedgerows but (2) supports
lower levels of biodiversity and ecosystem services than natural habitat. Our systematic
literature review retained 835 observations from 170 primary studies, which were analyzed
following the standard methodology in meta-analyses. Our results partially support
both hypotheses. Farmland with hedgerows exhibited higher levels of biodiversity and
provisioning services than farmland without hedgerows (H1). Farmland with hedgerows
provided similar levels of biodiversity (edge effects) but lower levels of ecosystem
services than natural habitat (H2). The effects of hedgerows on biodiversity and ecosystem
services depended on control ecosystem type (grassland/meadow or forest/woodland)
but were largely independent of climate type (temperate or tropical) and the focus
of spatial scale (field or landscape). In conclusion, conservation and restoration
of hedgerows contribute to people in several ways by enhancing biodiversity and multifunctionality
in agricultural landscapes.
