Tue, Aug 03, 2021:On Demand
Background/Question/Methods
Widespread expansion of monocultural oil palm plantations have led to dramatic losses of biodiversity and ecosystem functioning in the lowland tropics. Establishing islands of native trees may alleviate negative ecological impacts, but scientific evidence of the potential positive effects and trade-offs of tree diversity enrichment is still lacking. Here, we assess restoration success in a biodiversity enrichment experiment where 52 tree islands of systematically varying sizes and levels of tree diversity were established in an oil palm plantation. We measured biodiversity of 15 taxonomic groups from soil microbes to birds, and 19 ecosystem functions representing a range of services.
Results/Conclusions Compared to conventionally managed controls, the tree islands hosted a higher species diversity of trees, birds and soil fauna, and a lower diversity of pathotrophic fungi and seed rain. Planted tree diversity and island size affected multi-diversity and ecosystem functions directly and indirectly, mediated by changes in vegetation structure. Tree diversity enhanced structural complexity and density, which increased productivity, nutrient cycling, pollination and multi-diversity. Through increased tree dominance, larger tree islands hosted more abundant and species-rich communities of several groups. Trade-offs with oil palm yield existed locally but were minimized at the tree island scale, when considering positive effect on the yield on the surrounding oil palm plantation. We provided the first empirical evidence of ecological restoration in oil palm plantations, and showed that in some configurations biodiversity and ecosystem functioning can be enhanced without losing yield.
Results/Conclusions Compared to conventionally managed controls, the tree islands hosted a higher species diversity of trees, birds and soil fauna, and a lower diversity of pathotrophic fungi and seed rain. Planted tree diversity and island size affected multi-diversity and ecosystem functions directly and indirectly, mediated by changes in vegetation structure. Tree diversity enhanced structural complexity and density, which increased productivity, nutrient cycling, pollination and multi-diversity. Through increased tree dominance, larger tree islands hosted more abundant and species-rich communities of several groups. Trade-offs with oil palm yield existed locally but were minimized at the tree island scale, when considering positive effect on the yield on the surrounding oil palm plantation. We provided the first empirical evidence of ecological restoration in oil palm plantations, and showed that in some configurations biodiversity and ecosystem functioning can be enhanced without losing yield.