Ecosystem multifunctionality is highly related to the shelterbelt structure and plant species diversity in mixed shelterbelts of eastern China

Global change induced biodiversity loss has greatly affected ecosystem functioning, and thus the multiple services delivered by the ecosystem. Considerable recent works have focused on evaluating how species diversity changes impacts multiple ecosystem functions and services simultaneously (called ecosystem multifunctionality, EMF), but none of these evaluations were conducted in mixed shelterbelt ecosystems, which are valuable in providing multiple ecological benefits for coastal human settlements. Here, we measured the shelterbelt structure, plant species diversity, major individual ecosystem services and the EMFs of four single-species dominated mixed shelterbelts and a non-forested land along the coastal area of Eastern China and quantified how shelterbelt structure and plant species diversity affected EMF in a natural coastal scenario. Among the four mixed shelterbelts, the Populus nigra (PN) dominated mixture had significantly higher shelterbelt porosity and height, while Ligustrum compactum (LC) and Koelreuteria bipinnata (KB) dominated mixtures both had higher species richness. Concerning individual ecosystem services, the PN dominated mixture is statistically better at windbreak, C fixation and O2 releasing, plant diversity maintenance, nutrient transformation and cycling services, while the Taxodium distichum (TD) dominated mixture does better in soil and water conservation, therefore we observed the highest EMF in the PN dominated mixture. Also, we found that both shelterbelt porosity and height had significant positive effects on EMF, while no relationship was detected between shelterbelt permeability and EMF. Plant species richness and Shannon-Wiener index had significantly positive effects on EMF, but Pielow index had no significant effect on EMF. This indicated that the vertical structure of shelterbelts played a more important role than horizontal structure concerning ecosystem functioning, and EMF was not only positively affected by species richness but also species heterogenicity. These results will be informative in the policy-making and functional management of the shelterbelts and deepen the understanding of the biodiversity-ecosystem functioning relationship under alternative environmental scenarios.