摘要
间伐不仅能改变人工林林木生长状况,还会影响整个森林碳储量,研究间伐对人工林碳固存的长期影响,有助于准确评价人工林的碳汇功能,为人工林的科学经营管理提供参考。2016年8月,以黄土高原森林区营造于1962年,间伐于1985年的4种(强度间伐、中度间伐、轻度间伐、对照)油松人工林为对象,保留密度分别为800,1 500,2 200,2 900株/hm^2,研究了间伐对油松人工林不同植被层、叶凋落物、粗木质残体和土壤有机碳库的影响。结果表明:轻度和中度间伐下油松人工林系统碳储量较对照显著提高了28.54%和21.33%,强度间伐碳储量(154.66t/hm^2)与对照(169.26t/hm^2)无显著差异。乔木层是油松人工林的主要碳库,占人工林总碳储量的64.85%~74.62%。不同处理下乔木层树干碳储量所占比例最高(52.05%~56.43%),树根和树枝次之(22.27%~22.60%和17.73%~18.32%),树叶最低(3.56%~7.01%)。中度和强度间伐下在提高林下灌草多样性的同时,总的灌草碳储量分别比对照高24.27%和25.24%。间伐显著降低了叶凋落物碳储量,其中,强度间伐下的叶凋落物只有对照的48.15%。土壤碳库的变化主要是由土壤表层0—20cm有机碳变动所引起,中度和强度间伐土壤表层碳储量较对照分别减少了17.68%和33.76%,而轻度间伐(51.23t/hm^2)与对照(50.96t/hm^2)无显著差异。土壤表层碳储量与植物多样性和基础呼吸呈显著负相关。轻度和中度间伐有助于森林生态系统碳固定,其中轻度间伐不仅有利于地上植被碳固定,而且还有助于土壤碳库的维持。
The growth condition of crop trees as well as the entire forest carbon storage can be affected by thinning.Studying the long-term effects of thinning on the carbon sequestration of plantations contributes to accurately evaluate the carbon sink function and the scientific management of plantations.The Pinus tabulaeformis plantations constructed in 1962 on the Loess Plateau forest area,were thinned to 4 different densities:800(Heavy),1 500(Medium),2 200(Light)and 2 900(Unthinning)stem/hm 2 in 1985.In August 2016,the effects of thinning on different vegetation layers,leaf litter,coarse wood debris and soil organic carbon pools were studied.The results showed that the total carbon storages of the Pinus tabulaeformis plantations under Light and Medium thinning were significantly increased by 28.54%and 21.33%respectively compared with the control,but no significant difference observed between the Heavy(154.66 t/hm 2)and the control(169.26 t/hm 2).The arbor layers were the main carbon pools of plantations,accounting for 64.85%~74.62%of the total carbon storage.Under different treatments,the carbon storage of stems in the arbor layers was the highest(52.05%~56.43%),followed by the roots and branches(22.27%~22.60%and 17.73%~18.32%),and the lowest in leaves(3.56%~7.01%).While Medium and Heavy thinning improved the diversity of shrubs and herbs,the total carbon storages of shrubs and herbs under those were 24.27%and 25.24%respectively higher than that of the control.Thinning significantly reduced leaf litter,which under heavy t hinning declined to 48.15%of the control.The changes of soil carbon pool were mainly caused by the disturbance of topsoil 0-20 cm.The surface carbon storages under Medium and Heavy thinning fell by 17.68%and 33.76%respectively compared with the control,while the difference between Light thinning(51.23 t/hm 2)and the control(50.96 t/hm 2)was not significant.There was a significant negative correlation between soil surface carbon storages and plant diversities and basal respirations.In conclusion,Light and Medium thinning could increase carbon sequestration in forest ecosystems,and Light thinning was not only conducive to carbon sequestration in above-ground vegetation but also contributed to the maintenance of soil carbon pools.
作者
段梦成
王国梁
史君怡
周昊翔
DUAN Mengcheng;WANG Guoliang;SHI Junyi;ZHOU Haoxiang(Institute of Soil and Water Conservation,Northwest A&F University,Yangling, Shaanxi 712100;University of Chinese Academy of Sciences,Beijing 100049)
出处
《水土保持学报》
CSCD
北大核心
2018年第5期190-196,共7页
Journal of Soil and Water Conservation
基金
国家重点研发计划项目(2017YFC0504601)；中国科学院科技服务网络计划项目(KFJ-STS-ZDTP-036)；国家自然科学基金项目(41671513)
关键词
间伐
碳储量
粗木质残体
基础呼吸
thinning
carbon storage
coarse wood debris
basal respiration
