Agroforestry delivers more ecosystem services than conventional land uses
Agroforestry — managing trees alongside crop or animal-production systems — has been proposed as a means of protecting biodiversity and enhancing ecosystem service supply. A study bringing together evidence has confirmed that agroforestry does have an overall positive effect over conventional (separate) agriculture and forestry. Its environmental benefits, which should be considered in rural planning policy, include reduced nutrient run-off and soil erosion, and biodiversity protection.
This study assessed the evidence that agroforestry systems enhance ecosystem services and biodiversity, compared with conventional systems, taken from over 20 years of research in Europe. The EU-funded2 researchers assessed all scientific publications that compared agroforestry with an alternative land-use system in Europe, and which included quantitative data and indicators that assess biodiversity and ecosystem services. In total, 53 publications were assessed, which included 365 comparisons across 10 European countries.
The effects of agroforestry were measured in two ways: 1.) response ratios, which are a measure widely used for ecology meta-analysis, based on the difference between the value of an indicator (e.g. soil erosion) in an agroforestry system compared to the same indicator in a conventional system; and 2.) Hedges’ g, used on a subset of studies to analyse the effect on biodiversity, based on the differences in biodiversity between plots in agroforestry systems and other land uses. All studies in the biodiversity subgroup were included in the rest of the meta-analysis to assess the overall effect of agroforestry.