Carbon fixation by biological soil crusts following revegetation of sand dunes in arid desert regions of China: A four-year field study
Carbon fixation by biological soil crusts following revegetation of sand dunes in arid desert regions of China: A four-year field study
复制标题
DOI：
10.1016/j.catena.2012.05.009
复制
发表时间：
2012-10-01
期刊：
影响因子：
6.2
通讯作者：
Jia, R. L.
中科院分区：
文献类型：
--
作者：
Li, X. R.;Zhang, P.;Jia, R. L.
生物土壤结皮是干旱、半干旱地区生态系统碳输入的重要来源，而干旱、半干旱地区维管植物的生长受到环境和土壤水分的限制。植被固定沙丘可以促进生物多样性干细胞在桑迪土壤表面的定殖和发育，使生物多样性干细胞由早期的蓝藻和藻类为主的演替阶段向后期的地衣和苔藓为主的演替阶段转化。本研究估计的两个演替阶段的生物质干细胞的固碳四年的实地观察的基础上。通过对10个样地每个结皮阶段的净光合速率的测定，结合计算结皮隐花植物叶状体的湿润日数，对两种BSC的固碳作用进行了比较。然而，昼夜固碳的两个BSC在很大程度上是由地壳含水量，而不是光合作用的光子通量和温度。早期BSC的最佳重量含水量范围为1- 3.5%，晚期BSC的最佳重量含水量范围为1-5%。蓝藻-藻类占优势的结皮的年固碳量为11.36 g Cm（-2）yr（-1），地衣-苔藓占优势的结皮的年固碳量为26.75 g Cm（-2）yr（-1）。后者具有较高的碳输入，由于较高的持水能力，延长潮湿的白天和较高的叶绿素含量，以及较高的光捕获。这些发现表明生物活性干细胞的恢复有望显著增加进入桑迪荒漠生态系统的碳输入。(c)2012爱思唯尔有限公司版权所有。
Biological soil crusts (BSCs) are important sources of carbon input to ecosystems in arid and semiarid regions, where vascular plants are restricted by the rigorous environment and limited soil water. Sand dune stabilization by revegetation can enhance colonization and development of BSCs on sandy soil surfaces, and convert BSCs from the early successional stage dominated by cyanobacteria and algae to the later stage dominated by lichens and mosses. This study estimated the carbon fixation by two successional stages of BSCs based on four years of field observations. Carbon fixation by two BSCs has been compared via estimating daily carbon fixation using measuring net photosynthesis with ten sampling plots per crust stage in situ, combining with calculating the wet daytime of crustal cryptogam thallus. However, diurnal carbon fixation of both BSCs was largely determined by crustal water content rather than photosynthesis photon flux and temperature. The range of optimal gravimetric water content for early BSCs was 1-3.5%, and 1-5% for the later BSCs. The annual carbon fixation was 11.36 g C m(-2) yr(-1) for cyanobacteria-algae dominated crusts and 26.75 g C m(-2) yr(-1) for lichen-moss dominated crusts. The latter had a higher carbon input due to a higher water-holding capacity, prolonging wet daytime and higher chlorophyll content, as well as higher light capture. These findings indicate the recovery of BSCs is expected to significantly increase carbon input into sandy desert ecosystems. (c) 2012 Elsevier B.V. All rights reserved.