Dynamics of the above-ground standing biomass assets of typical grassland

LI Shi-mei1,2,XIE Gao-di1,ZHANG Cai-xia1,2(1.Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China;2.Graduate University of Chinese Academy of Sciences,Beijing 100049,China)

above-ground standing biomass;standing energy;standing biomass assets;Leymus chinensis;Stipa grandis;Kobresia humilis meadow

Biomass is not only a carrier of material,but also a carrier of energy and value.It is an important index for evaluation of ecosystem structure and function.Based on existing observations at the Inner Mongolia Grassland Ecosystem Research Station and Haibei Alpine Meadow Ecosystem Research Station,the dynamics of the above-ground biomass assets of a Leymus chinensis+Stipa grandis community and a Kobresia humilis meadow were studied.The dynamic curves of above-ground biomass of these two communities were the single peak type,and the maximum above-ground standing biomass of the former was 197.21 g/m2,while that of the latter was 307.75 g/m2.The dynamic curves of above-ground standing energy of these two communities appeared the same shape as the above-ground biomass dynamic curves,whose peak value was 3 637.8 and 5 964.20 kJ/m2,respectively.The accumulative rate of above-ground standing energy was positively correlated to accumulative rate of above-ground biomass.The biomass value curves of the L.chinensis+S.grandis community and K.humilis meadow were quite different from above-ground biomass curve and above-ground standing energy curves,and the peak values of above-ground biomass value of L.chinensis,S.grandis and K.humilis meadow were 584.95,300.93 and 2 066.84 yuan/hm2,respectively.During the process of biomass accumulation,grassland also produces a gas regulation value.The peak value for O2 emission by the L.chinensis+S.grandis community and K.humilis meadow was 742.40 and 1 158.52 yuan/hm2,respectively,while that of CO2 fixation was 1 484.89 and 2 317.20 yuan/hm2.