• Energy Research

Liana constitutes an important structural and functional component in many forest ecosystems and has profound impacts on forest carbon (C) cycling. However, whether and how liana regulates spatial distributions of litterfall and soil organic C are still poorly understood. To address this critical knowledge gap, we investigated litterfall composition and soil physicochemical characteristics in stands with different densities of liana (Trachelospermum jasminoides (Lindl.) Lem.). Both fresh and decomposed leaf litters were greater in the stands with high density of the liana species T. jasminoides. More liana covered stands also had higher soil respiration rate, soil organic C, and total nitrogen than those with less liana. The findings demonstrate that understory liana can regulate litterfall distribution and thus soil organic C, suggesting that the influences of understory liana on belowground ecological processes should be considered while assessing the role of liana in forest ecosystems.

Multiple facets of global change affect the earth system interactively, with complex consequences for ecosystem functioning and stability. Simultaneous climate and biodiversity change are of particular concern, because biodiversity may contribute to ecosystem resistance and resilience and may mitigate climate change impacts. Yet, the extent and generality of how climate and biodiversity change interact remain insufficiently understood, especially for the decomposition of organic matter, a major determinant of the biosphere–atmosphere carbon feedbacks. With an inter-biome field experiment using large rainfall exclusion facilities, we tested how drought, a common prediction of climate change models for many parts of the world, and biodiversity in the decomposer system drive decomposition in forest ecosystems interactively. Decomposing leaf litter lost less carbon (C) and especially nitrogen (N) in five different forest biomes following partial rainfall exclusion compared to conditions without rainfall exclusion. An increasing complexity of the decomposer community alleviated drought effects, with full compensation when large-bodied invertebrates were present. Leaf litter mixing increased diversity effects, with increasing litter species richness, which contributed to counteracting drought effects on C and N loss, although to a much smaller degree than decomposer community complexity. Our results show at a relevant spatial scale covering distinct climate zones that both, the diversity of decomposer communities and plant litter in forest floors have a strong potential to mitigate drought effects on C and N dynamics during decomposition. Preserving biodiversity at multiple trophic levels contributes to ecosystem resistance and appears critical to maintain ecosystem processes under ongoing climate change.