Dai Shiyu, Wei Ting, Tang Juan, Xu Zhixiong, Gong Hede
School of Geography and Ecotourism, Southwest Forestry University, Kunming 650224, China.
Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences, Jingdong, Puer City 676209, China.
Plants (Basel). 2023 Mar 10;12(6):1277. doi: 10.3390/plants12061277.
The study of litter can provide an important reference for understanding patterns of forest nutrient cycling and sustainable management. Here, we measured litterfall (leaves, branches, etc.) from a wet, evergreen, broad-leaved forest in Ailao Mountains of southwestern China on a monthly basis for 11 years (2005-2015). We measured the total biomass of litter fall as well as its components, and estimated the amount of C, N, P, K, S, Ca, and Mg in the amount of litterfall. We found that: The total litter of evergreen, broadleaved forest in Ailao Mountains from 2005 to 2015 was 7.70-9.46 t/ha, and the output of litterfall differed between years. This provides a safeguard for the soil fertility and biodiversity of the area. The total amount of litterfall and its components showed obvious seasonal variation, with most showing a bimodal pattern (peak from March to May and October to November). The majority of litterfall came from leaves, and the total amount as well as its components were correlated with meteorological factors (wind speed, temperate and precipitation) as well as extreme weather events. We found that among years, the nutrient concentration was sorted as C > Ca > N > K > Mg > S > P. The nutrient concentration in the fallen litter and the amount of nutrients returned showed a decreasing trend, but the decreasing rate was slowed through time. Nutrient cycling was influenced by meteorological factors, such as temperature, precipitation, and wind speed, but the nutrient utilization efficiency is high, the circulation capacity is strong, and the turnover time is short. Our results showed that although there was nutrient loss in this evergreen, broad-leaved forest, the presence of forest litterfall can effectively curb potential ecological problems in the area.
凋落物研究可为理解森林养分循环模式和可持续管理提供重要参考。在此，我们对中国西南部哀牢山一片湿润常绿阔叶林的凋落物（树叶、树枝等）进行了为期11年（2005 - 2015年）的月度测量。我们测量了凋落物的总生物量及其组成部分，并估算了凋落物中碳、氮、磷、钾、硫、钙和镁的含量。我们发现：2005年至2015年哀牢山常绿阔叶林的总凋落物量为7.70 - 9.46吨/公顷，且年凋落量有所不同。这为该地区的土壤肥力和生物多样性提供了保障。凋落物总量及其组成部分呈现出明显的季节变化，多数呈双峰模式（3月至5月和10月至11月出现峰值）。大部分凋落物来自树叶，其总量及其组成部分与气象因素（风速、温度和降水量）以及极端天气事件相关。我们发现，年间养分浓度排序为碳>钙>氮>钾>镁>硫>磷。凋落物中的养分浓度和归还的养分数量呈下降趋势，但下降速率随时间减缓。养分循环受温度、降水和风速等气象因素影响，但养分利用效率高、循环能力强且周转时间短。我们的结果表明，尽管这片常绿阔叶林中存在养分流失，但森林凋落物的存在可有效遏制该地区潜在的生态问题。
