Abstract: Wood-fall is an important organic matter and energy source in oligotrophic deep-sea environment, which has important impacts on biodiversity, species evolution and biogeochemical cycle. We reviewed recent research advances of deep sea wood-fall ecosystem from the following aspects: (1) The source, formation and ecological characteristics of deep sea wood-fall ecosystem; (2) The biodiversity, community composition and driving factors of deep sea wood-fall; (3) Ecological functions of deep sea wood-fall. In general, wood-fall ecosystem is a highly fragmented island-like ecosystem, which creates biodiversity hotspots in the oligotrophic seafloor by attracting specific benthic organisms and chemosynthetic microorganisms in deep sea. The unique three-dimensional structure of wood-fall can provide habitat and shelter for deep sea organisms, and promote the evolution of new species. The wood-fall is also a “stepping stone” for the migration and dispersal of species in the chemosynthetic ecosystem. The diversity and community structure of benthic organisms and microorganisms in deep sea wood-fall are influenced by environmental factors and ecosystem carriers. Moreover, chemosynthetic microorganisms in the wood-fall ecosystem can participate in the deep-sea biogeochemical cycling, especially the carbon cycle and sulfur cycle, through diverse pathways. Herein, we suggest to further study the deep-sea wood-fall ecosystem from the following aspects: (1) The community structure and ecological succession of deep sea wood-fall ecosystem; (2) The novel microorganisms and related functional genes related to cellulose degradation in the deep sea wood-fall ecosystem; (3) The driving mechanism of deep sea wood-fall microbiome on biogeochemical cycles.

Key words: deep sea wood-fall, deep sea ecosystem, biodiversity, community structure, ecological function