Ecological Indicators (Sep 2021)
Determining the effects of biotic and abiotic factors on the ecosystem multifunctionality in a desert-oasis ecotone
Abstract
Questions: Differences in the vertical structures of communities, nutrient cycling, multiple diversity attributes, and environmental factors are important forces driving ecosystem multifunctionality. However, the mechanisms underlying these processes remain unclear. Location: The study took place at the Ebinur Lake Wetland Nature Reserve of the Xinjiang Uygur Autonomous Region, China. Methods: This study integrated taxonomic diversity, functional diversity, phylogenetic diversity, and environmental factors to evaluate ecosystem multifunctionality and the factors influencing nutrient cycling within 66 dryland communities with different vertical structures. Results: Both unweighted and weighted diversity had significant impacts on ecosystem multifunctionality and the cycling of C, N, and P. However, only weighted diversity had a significant impact on the woody and herb layers. The main factors influencing ecosystem multifunctionality at the community level were soil moisture and functional diversity, whereas those influencing the woody layer were soil moisture and plant functional traits, and those influencing the herb layer were phylogenetic diversity and taxonomic diversity. The multifunctionality of the woody layer and community showed a positive relationship with changes in soil moisture and salinity. Conclusions: The results of the study showed the existence of both mass ratio effects and richness effects of ecosystem multifunctionality at the community level, whereas the woody and herb layers were mainly affected by the complementary effects. Biotic and abiotic factors explained the multifunctionality and nutrient cycling of the ecosystem at the community level to a greater extent than those in the woody and herb layers separately. In addition, biotic and abiotic factors explain ecosystem multifunctionality more than nutrient cycling, and ecosystem multifunctionality was found to explain more than a single nutrient cycle. The multifunctionality of the ecosystem and the ability to restore specific nutrient cycles can be maximized through the hierarchical assessment of community diversity to prevent desertification in drylands.
