Abstract

Entering the UN Decade on Ecosystem Restoration, large knowledge gaps persist on how to increase biodiversity and ecosystem functioning in cash crop dominated tropical landscapes. Here, we present findings from a large-scale, five-year ecosystem restoration experiment in an oil palm landscape enriched with 52 tree islands, encompassing assessments of ten indicators of biodiversity and 19 indicators of ecosystem functioning. Tree enrichment enhanced multidiversity by 250% and ecosystem multifunctionality by 75% compared to conventional monocultures. Therein, larger tree islands led to higher multidiversity and multifunctionality gains via changes in vegetation structure. Tree enrichment did not significantly decrease landscape-scale oil palm yield. Our results demonstrate that enriching oil palm dominated landscapes with tree islands is a promising ecological restoration strategy.