Long-term Research Station of Alpine Forest Ecosystem, Provincial Key Laboratory of Ecological Forestry Engineering, Institute of Ecology and Forestry, Sichuan Agriculture University, Chengdu 611130, China; Institute of Environment Sciences, University of Quebec at Montreal, Montreal, QC H3C 3P8, Canada.
Long-term Research Station of Alpine Forest Ecosystem, Provincial Key Laboratory of Ecological Forestry Engineering, Institute of Ecology and Forestry, Sichuan Agriculture University, Chengdu 611130, China; Collaborative Innovation Center of Ecological Security in the Upper Reaches of the Yangtze River, Chengdu 611130, China.
Sci Total Environ. 2016 Oct 1;566-567:279-287. doi: 10.1016/j.scitotenv.2016.05.081. Epub 2016 May 22.
Litter decomposition is a biological process fundamental to element cycling and a main nutrient source within forest meta-ecosystems, but few studies have looked into this process simultaneously in individual ecosystems, where environmental factors can vary substantially. A two-year field study conducted in an alpine forest meta-ecosystem with four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana) that varied widely in chemical traits showed that both litter species and ecosystem type (i.e., forest floor, stream and riparian zone) are important factors affecting litter decomposition, and their effects can be moderated by local-scale environmental factors such as temperature and nutrient availability. Litter decomposed fastest in the streams followed by the riparian zone and forest floor regardless of species. For a given litter species, both the k value and limit value varied significantly among ecosystems, indicating that the litter decomposition rate and extent (i.e., reaching a limit value) can be substantially affected by ecosystem type and the local-scale environmental factors. Apart from litter initial acid unhydrolyzable residue (AUR) concentration and its ratio to nitrogen concentration (i.e., AUR/N ratio), the initial nutrient concentrations of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also important litter traits that affected decomposition depending on the ecosystem type.
凋落物分解是元素循环的基础生物学过程，也是森林元生态系统的主要养分来源，但很少有研究同时在单个生态系统中研究这个过程，因为环境因素可能会有很大的差异。一项为期两年的野外研究在一个具有四种凋落物物种（即柳属植物：川滇柳、杜鹃属植物：拉普杜鹃、桧属植物：沙地柏和松属植物：日本落叶松）的高山森林元生态系统中进行，这些物种在化学特性上差异很大，结果表明，凋落物物种和生态系统类型（即林地表层、溪流和河岸带）都是影响凋落物分解的重要因素，其影响可以通过温度和养分供应等局部尺度环境因素来调节。无论物种如何，凋落物在溪流中的分解速度最快，其次是河岸带和林地表层。对于给定的凋落物物种，k 值和极限值在生态系统之间差异显著，这表明凋落物分解速率和范围（即达到极限值）可能会受到生态系统类型和局部尺度环境因素的显著影响。除了凋落物初始不可水解酸残渣（AUR）浓度及其与氮浓度的比值（即 AUR/N 比值）外，磷（P）、钾（K）、钙（Ca）和镁（Mg）的初始养分浓度也是影响分解的重要凋落物特性，具体取决于生态系统类型。
