Impacts of litter addition and root presence on soil nematode community structure in a young Eucalyptus plantation in southern China

Eucalyptus plantations are widely established in degraded ecosystem as a fast-growing species for restoration. However, the impact of Eucalyptus aboveground litter and living root on soil nematode community structure is poorly understood. We conducted a field manipulative experiment to investigate the impact of litter addition and root presence on soil nematode community composition in a young Eucalyptus plantation in southern China. Our results showed that both litter addition and root presence significantly increased soil nematode abundance. Litter addition altered nematode community composition by decreasing relative fungivore abundance, and increasing relative omnivore-predator abundance and the nematode channel ratio. However, no obvious effect of root presence on nematode community was detected. There were interactions between litter addition and root presence on nematode ecological indices. Litter addition increased maturity index and structure index, and reduced enrichment index in the absence of root, but did not change these indices under root presence. Our findings highlight the critical role of aboveground litter resources in shaping nematode community structure and function. Meanwhile, the influence of litter resources on soil nematode community structure and function are regulated by root input. The study provides theoretical support for plantation management in southern China.