青海高寒区域金露梅灌丛草甸灌木和草本植物固碳量的比较

以青海海北高寒区域金露梅（PotentillafruticosaLinn.）灌丛草甸为研究对象,分析了6月至9月金露梅灌丛草甸灌木和草本植物不同部位的生物碳量,并据此对灌木及草本植物的年净初级生产碳量进行了比较。结果显示：金露梅灌丛草甸灌木植物地上部和地下部不同层次的生物量和碳含量均有明显差异,根据生物量所占比例确定其地上部和地下部的平均碳含量分别为0.50和0.48。依据不同月份灌丛冠面最大长度、最小宽度和最大高度,采用方程“Wij=e〔aln（A·B·H）＋b〕”计算灌木地上当年新生生物碳量、地上多年累积生物碳量和地下多年累积生物碳量,相关性均极显著（P〈0.01）,表明利用该方程评估金露梅灌丛草甸灌木不同部位的生物碳量是可行的。不同月份金露梅灌丛草甸灌木地上当年新生生物碳量、地上多年累积生物碳量和地下多年累积生物碳量分别为9.36-21.15、78.07-90.12和74.37-101.22g·m-2,差异不明显；其地上部和地下部净初级生产碳量分别为33.20和26.85g·m-2,总计为60.05g·m-2。金露梅灌丛草甸草本植物地上部和地下部净初级生产碳量分别为111.41和445.41g·m-2,总计为556.82g·m-2。如果根据草本和灌木占地面积78%和22%进行加权计算,则金露梅灌丛草甸当年的总净初级生产碳量为447.53g·m-2,其中灌木的净初级生产碳量仅占2.95%,且金露梅灌丛草甸地下部与地上部净初级生产碳量的比值为3.75。研究结果显示：青海高寒区域金露梅灌丛草甸以草本固碳为主,且地下部净初级生产碳量明显高于其地上部。

Comparison on fixed carbon amount of shrub and herb of Potentilla fruticosa shrub meadow in alpine region of Qinghai Province

Taking Potentilla fruticosa Linn. shrub meadow in alpine region of Qinghai Province as the research object, the biomass carbon content of different parts of shrub and herb in P. fruticosa shrub meadow from June to September was analyzed, and on this basis, the annual net primary carbon production （ NPCP） of shrub and herb was also compared. The results show that there are obvious differences in biomass and carbon content of different layers in above- and under-ground parts of shrub inP. fruticosa shrub meadow, and according to the proportion of biomass, average carbon content of above-and under-ground parts is determined as 0. 50 and 0. 48, respectively. Based on the maximum length, minimum width and maximum height of canopy surface of shrub in different months, the newly biomass carbon content at current year in above-ground part, the perennial accumulation biomass carbon contents in above- and under-ground parts of shrub were calculated by the equation “Wij = e〔aln（A·B·H）＋b〕 ”, with the extremely significant correlation （P〈0. 01）, it means that it is feasible to evaluate biomass carbon content in different parts of shrub in P. fruticosa shrub meadow by this equation. The newly biomass carbon content at current year in above-ground part, the perennial accumulation biomass carbon contents in above- and under-ground parts of shrub in P . fruticosa shrub meadow among different months is 9. 36-21. 15, 78. 07-90. 12 and 74. 37-101. 22 g·m-2 , respectively, with no obvious difference. And NPCP in above- and under-ground parts of shrub is 33. 20 and 26. 85 g·m-2 , respectively, and total is 60. 05 g·m-2 . NPCP in above- and under-ground parts of herb in P. fruticosa shrub meadow is 111. 41 and 445. 41 g·m-2 , respectively, and total is 556. 82 g·m-2 . If weighted calculation is carried out according to occupied area of herb and shrub of 78% and 22% , respectively, total NPCP of P. fruticosa shrub meadow in current year is 447. 53 g·m-2 , in which, NPCP of shrub accounts for only 2. 95% ,