title: Litter quality mediated nitrogen effect on plant litter decomposition regardless of soil fauna presence.
abstract: Nitrogen addition has been shown to affect plant litter decomposition in terrestrial ecosystems. The way that nitrogen deposition impacts the relationship between plant litter decomposition and altered soil nitrogen availability is unclear, however. This study examined 18 co-occurring litter types in a subtropical forest in China in terms of their decomposition (1 yr of exposure in the field) with nitrogen addition treatment (0, 0.4, 1.6, and 4.0 mol·N·m-2·yr-1) and soil fauna exclusion (litter bags with 0.1 and 2 cm mesh size). Results showed that the plant litter decomposition rate is significantly reduced because of nitrogen addition; the strength of the nitrogen addition effect is closely related to the nitrogen addition levels. Plant litters with diverse quality responded to nitrogen addition differently. When soil fauna was present, the nitrogen addition effect on medium-quality or high-quality plant litter decomposition rate was -26% ± 5% and -29% ± 4%, respectively; these values are significantly higher than that of low-quality plant litter decomposition. The pattern is similar when soil fauna is absent. In general, the plant litter decomposition rate is decreased by soil fauna exclusion; an average inhibition of -17% ± 1.5% was exhibited across nitrogen addition treatment and litter quality groups. However, this effect is weakly related to nitrogen addition treatment and plant litter quality. We conclude that the variations in plant litter quality, nitrogen deposition, and soil fauna are important factors of decomposition and nutrient cycling in a subtropical forest ecosystem.
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Key Laboratory of Forest Ecology and Management, Shenyang, 110164, China.|Huitong Experimental Station of Forest Ecology, Chinese Academy of Sciences, Huitong, 418307, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Key Laboratory of Forest Ecology and Management, Shenyang, 110164, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chao
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Key Laboratory of Forest Ecology and Management, Shenyang, 110164, China.|Huitong Experimental Station of Forest Ecology, Chinese Academy of Sciences, Huitong, 418307, China.
authors.forename: Qingpeng
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Key Laboratory of Forest Ecology and Management, Shenyang, 110164, China.|Huitong Experimental Station of Forest Ecology, Chinese Academy of Sciences, Huitong, 418307, China.
authors.forename: Qingkui
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Key Laboratory of Forest Ecology and Management, Shenyang, 110164, China.
authors.forename: Yunting
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Key Laboratory of Forest Ecology and Management, Shenyang, 110164, China.|Huitong Experimental Station of Forest Ecology, Chinese Academy of Sciences, Huitong, 418307, China.
authors.forename: Silong
authors.initials: S
authors.lastname: Wang
mesh_terms: D002681:China; D017753:Ecosystem; D009584:Nitrogen; D018515:Plant Leaves; D012987:Soil
chemical_list: D012987:Soil; D009584:Nitrogen
keywords: nitrogen addition; plant litter decomposition; plant litter quality; soil fauna; subtropical forest