Effects of biotic and abiotic factors on ecosystem multifunctionality of plantations

Mixed forests are better than monoculture forests in biodiversity, stand structure and productivity stability. However, a more comprehensive assessment of the ecosystem functions of monoculture and mixed plantations is lacking. We compared the single functions and ecosystem multifunctionality (EMF) in Fraxinus mandshurica and Larix olgensis mixed plantations with monoculture plantations in Northeast China and discussed the influences of biodiversity and environmental factors on EMF.

The mixed plantations had higher biodiversity and ecological functions. Biodiversity was significantly higher in mixed plantations (such as CWM_MH, Shrub.Shannon, Shrub.Richness, Herb.Shannon, Herb.Richness), but environmental factors differed less among the three forest types, and belowground diversity differed significantly only in the Bacterial.Shannon and Fungal.Shannon. Mixed plantations showed significant differences in single ecological functions relative to monoculture plantations, with more pronounced differences between mixed plantations and Larix olgensis monoculture plantations. Weighted ecosystem multifunctionality was significantly higher in mixed plantations than in monoculture plantations. EMF was mainly driven by tree diversity, environmental factors, shrub and herb species diversity, and soil microbial alpha diversity, which explained 25.35%, 8.94%, 8.83%, and 7.65% of the variation, respectively.

The establishment of mixed plantations can increase the biodiversity of forest stands and improve the ecosystem functions. These results highlight the advantages of multi-species plantations and the necessity of planting them. They are important for the conservation of biodiversity and the sustainable management of plantations.