摘要
为研究气候变化背景下降水格局变化对森林生长和碳固持的影响,2012年在我国南亚热带地区选择广泛分布的马尾松(Pinus massoniana)人工林为研究对象,分别设置3块20 m×20 m的模拟降雨减少50%和对照样地,每个样地随机设置5个距地面40 cm的1 m×1 m的凋落物收集框,2016年1—12月每隔1月收集各样地林冠层凋落物,比较研究减水处理对凋落物组分产量和基本化学性质的短期影响。结果表明:马尾松人工林针叶凋落物量及其所占比例显著高于其他凋落物组分(P<0.05),减雨处理对马尾松人工林凋落叶和总量无显著影响(P>0.05)。与对照相比,减雨处理分别增加凋落针叶含碳量和凋落果含氮量27.4 g/kg和5.1 g/kg,以及凋落针叶的木质素含量、阔叶纤维素含量和皮半纤维素含量3.9%、5.2%和4.0%(P<0.05),但显著降低凋落皮碳、纤维素含量和凋落果的碳氮比(P<0.05)。凋落物N、P含量具有协同性,含碳量与木质素含量显著正相关(P<0.05)。模拟降雨减少处理初期并未显著改变南亚热带马尾松人工林总凋落物量,但增加了凋落针叶的木质素含量和含碳量。本研究预示短期穿透雨减少可能降低南亚热带马尾松人工林凋落物的分解能力,由此降低马尾松人工林土壤中凋落物源性碳的输入量。
To explore the impacts of precipitation pattern change on forest growth and carbon sequestration under climate change, a manipulation experiment of throughfall reduction was conducted in a Pinus massoniana plantation in southern subtropical China since 2012, which included three 20 m×20 m plots with a 50% throughfall exclusion and their respective control plots. Litterfall samples were collected from January to December every two months in 2016, from five 1 m×1 m aboveground （40 cm） litterfall traps in each plot, and were separated into different components to measure the mass percentage, biomass, and basic chemical properties. The results showed that litterfall quantity and the proportion of needles were both significantly higher than other litterfall components in the plantation （P 〈 0.05）. The short-term manipulated drought did not significantly affect the needle quantity or total litterfall （P 〉 0.05）. Compared to the control, the throughfall treatment enhanced the C content of needle litterfall and N content of fruit litterfall by 27.4 g/kg and 5.1 g/kg, respectively （P 〈 0.05）. The treatment also increased the lignin content of needle litterfall, cellulose content of broadleaf litterfall, hemicellulose content of skin litterfall by 3.9%, 5.2%, and 4.0%, respectively, while it decreased the C and cellulose content of skin litterfall as well as the C：N ratio of fruit litterfall （P 〈 0.05）. The positive correlations between the N and P content of the litterfall, and between the C and lignin content of the litterfall, were both significant （P 〈 0.05）. These results indicated that the short-term experimental throughfall reduction did not significantly alter total litterfall, while it increased the lignin and C content of needle litterfall, in a southern subtropical P. massoniana plantation. Our study further suggests a possible decrease in the decomposition ability of litterfall, which could reduce the input of litter-derived soil carbon in a southern subtropical P. massonia
作者
杨予静
刘世荣
陈琳
王晖
卢立华
YANG Yujing;LIU Shirong;CHEN Lin;WANG Hui;LU Lihua(Key Laborntory of Forest Ecology and Environment, China＇ s State Forestry Administration, Institute of Forest Ecology, Environment and Protection Chinese Academy of Forestry, Beijing 100091, China;Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Pingxiang 532600, China;Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang 532600, China)
出处
《生态学报》
CAS
CSCD
北大核心
2018年第13期4770-4778,共9页
Acta Ecologica Sinica
基金
国家国际科技合作专项项目(2015DFA31440)
国家林业公益性行业科研专项(201404201)
关键词
模拟降雨减少
人工林
凋落物
马尾松
manipulated precipitation reduction
plantation
litterfall
Pinus massoniana
