季节性冻融期长白山森林溪流中凋落叶N、P的释放动态  

Release Dynamics of Nitrogen and Phosphorus of Leaf Litter in A Forest Stream of the Changbai Mountains during Seasonal Freezing-thawing Period

作　　者：陈鸽 王璐[1] 宫雨薇 谭颖 张振兴[1] 杨海军 CHEN Ge;WANG Lu;GONG Yuwei;TAN Ying;ZHANG Zhenxing;YANG Haijun(Ministry of Education Key Laboratory of Vegetation Ecology/Institute of Grassland Science,Northeast Normal University,Changchun 130024,China;Institute of Plateau Lake Ecology and Pollution Management,Yunnan University,Kunming 650000,China)

机构地区：[1]东北师范大学草地科学研究所/植被生态科学教育部重点实验室,吉林长春130024 [2]云南大学高原湖泊生态与治理研究院,云南昆明650000

出　　处：《生态环境学报》2019年第12期2341-2348,共8页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31770508);国家水体污染控制与治理科技重大专项(2017ZX07101003);中央高校基本科研业务费专项资金资助(2412018JC002)

摘　　要：冬季河床凋落叶作为寒冷区森林溪流的主要能量来源,其元素释放动态是土壤-水体营养元素流动的关键纽带,并可能受到凋落叶质量、底栖动物与季节性冻融过程的影响。为了解凋落叶在季节性冻融过程中的分解过程、元素动态及底栖动物在该过程中的作用,以长白山森林源头溪流河岸带代表性植物色木槭(Acer mono)和蒙古栎(Quecus mongolica)为研究对象,采用凋落叶分解袋的方法,分别研究了有无底栖动物定殖的(5 mm和0.3 mm孔径)凋落叶袋中凋落叶的分解动态及N、P元素的动态特征。结果表明:(1)低温条件下,色木槭仍维持较快的分解速率(0.0152±0.0030)d−1,蒙古栎维持中速分解速率(0.0064±0.0017)d−1;(2)底栖动物显著促进了凋落叶的质量损失(P<0.05),其对色木槭凋落叶分解的贡献高于蒙古栎,表明底栖动物对凋落叶的摄食分解具有一定的选择性,其更倾向于选择分解快的高质量凋落叶;(3)冻融期分解过程中蒙古栎凋落叶N元素表现为富集-释放-释放,而色木槭凋落叶N元素在各个时期均表现为释放现象,2种凋落叶P释放动态一致;(4)底栖动物显著促进了凋落叶越冬分解过程中N、P元素的释放(P<0.05);(5)从不同时期的失质量速率及元素释放率可见,底栖动物对凋落叶分解及元素释放动态的主要作用出现在冻结期。Leaf litter from riverbed is the main energy source of forest streams in cold regions in wintertime. Its nutrient release dynamics are the key link of nutrient cycling between soil and water and can be affected by the quality of leaf litter, macroinvertebrates and seasonal freezing-thawing process. This study made a comprehensive investigating of the leaf litter processing, nutrient dynamics and the role of macroinvertebrates during seasonal freezing-thawing process, where two dominant riparian plants, Acer mono and Quecus mongolica were selected in headwater stream forest of the Changbai Mountains. Litterbag method (5 mm and 0.3 mm mesh size) was employed to understand the decomposition dynamics of leaf litter with and without colonized macroinvertebrates, and the dynamics of nitrogen and phosphorus. The results showed that: (1) Acer mono appeared relatively fast decomposition rates (0.015 2±0.003 0) d 1 even in low temperature, while Quecus mongolica showed medium decomposition rates (0.006 4±0.001 7) d 1. (2) Macroinvertebrates promoted the mass loss of leaf litter significantly (P<0.05), and this effect was greater on Acer mono than that on Quecus mongolica. It indicated that macroinvertebrates were selective for feeding and decomposition of leaf litter, and preferred to select high-quality leaf litter with higher decomposition rates. (3) The nitrogen release dynamics of Quecus mongolica leaf litter processing showed enrich-release-release patterns, Acer mono showed obvious release patterns of nitrogen throughout the freezing- thawing process. The release dynamics of phosphorus were observed to be consistent for leaf litter of both plants. (4) Macroinvertebrates significantly promoted the release of nitrogen and phosphorus during the overwintering decomposition of leaf litter (P<0.05). And (5) from the mass loss rates and the element release rates in different periods, it can be seen that the main effect of macroinvertebrates leaf litter processing and the element release dynamics occurred in freezing perio

关 键 词：凋落叶 森林溪流 底栖动物 元素释放动态 

分 类 号：S718.5[农业科学—林学] X171.1[环境科学与工程—环境科学]