黄土高原西部3个降水量梯度近成熟油松人工林碳库特征  

Carbon storage features of Pinus tabulaeformis plantations that are approaching maturity at three sites across a precipitation gradient in western Loess Plateau

作　　者：孙美美[1] 关晋宏[1,2] 吴春荣[3] 岳军伟[2] 李国庆[1,2] 杜盛[1,2] 

机构地区：[1]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100 [2]中国科学院水利部水土保持研究所,杨凌712100 [3]甘肃省治沙研究所,兰州730070

出　　处：《生态学报》2017年第8期2665-2672,共8页Acta Ecologica Sinica

基　　金：中国科学院战略性先导科技专项资助项目(XDA05050202)

摘　　要：森林在陆地生态系统吸收碳素方面起着主要作用,了解其固碳特征对研究地区之间的碳循环至关重要。油松人工林是黄土高原地区一种典型的退耕还林树种,研究其固碳特征有利于综合分析评价油松人工林的生态效益。为了研究黄土高原西部地区油松人工林碳储量及碳密度空间分布特征因降水量不同引起的差异,以黄土高原西部地区3个典型栽培区域的近成熟油松人工林为对象,研究了群落内各组成部分的生物量和碳库特征。乔木层生物量的估算采用以胸径和树高为基础变量的生物量方程,灌木、草本、凋落物采用样方收获法,土壤碳库依据土壤剖面(1 m)和土钻取样相结合的方法测算。结果表明:在兰州官蘑滩地区(372 mm)、太子山(519 mm)和小陇山(632 mm)3个不同降水量区域,油松人工林生物量碳密度分别为(49.08±2.86)t/hm^2、(73.90±9.36)t/hm^2和(82.55±7.36)t/hm^2。小陇山地区的生态系统总碳密度和生物量碳密度与兰州地区存在显著性差异。在3个不同降水量区域,土壤有机碳密度仅在表层土壤(0—10 cm)差异达到显著水平(P<0.05),而土壤总碳密度间差异未达到显著水平(P>0.05)。黄土高原半干旱区近成熟油松人工林的生物量碳密度与年均降水量间呈现出显著正相关关系。在半干旱地区,降水量可能成为影响油松人工林生产力和碳固存的关键因素。Forest is an important vegetation type of terrestrial ecosystems that maintains the dynamic balance of the biosphere and geosphere, and it plays a key role in terrestrial ecosystem carbon sequestration. With the implementation of Grain for Green Project, the Three-North Shelterbelt Project, and other major ecological projects, the total area of plantations has dramatically increased ; thus, the role of plantations in absorbing and fixing CO2 has attracted more attention. Investigating carbon storage of major forest types is important for understanding regional carbon cycles. Pinus. tabulaeformis is a common plantation species in sub-humid and semi-arid regions for the restoration of forest ecosystems. In western Loess Plateau, artificial forests of P. tabulaeformis provide a substantial proportion of the terrestrial ecosystem carbon sink. Tounderstand the carbon storage features of these plantations in response to the precipitation gradient, three typical distribution regions on western Loess Plateau were selected for plot surveys. Tree biomass was estimated separately for stems, branches, leaves, and roots, using previously constructed allometric biomass equations based on the diameter at breast height （DBH） and tree height. Carbon contents in the different parts and layers of the tree were each measured by collecting corresponding samples. Carbon density was calculated by multiplying the biomass of each plant part （from a specific forest area） and the corresponding carbon content. The results showed that in the three sites （Lanzhou, Taizishan, Xiaolongshan ） with precipitation of 372 mm, 519 mm and 632 mm, respectively, biomass carbon densities of P. tabulaeformis plantations were （49.08±2.86） t/hm2, （73.90±9.36） t/hm2, and （82.55±7.36） t/hmz, respectively. Both the ecosystem and biomass carbon density were significantly different （P〈0.05） between Xiaolongshan carbon density of the and Lanzhou. Because the shrubs were sparse, the contribution of trees was greatest, reaching 95.2

关 键 词：油松人工林 生物量碳密度 降水量 黄土高原西部 

分 类 号：S718.5[农业科学—林学]