三江平原湿地小叶章生产力模拟模型

A MODEL TO SIMULATE NET PRIMARY PRODUCTION OF DEYEUXIA ANGUSTIFOLIA IN WETLANDS IN SANJIANG PLAIN,CHINA

利用气象台站的常规观测资料,依据植物生长模拟理论,以d为步长,建立了湿地小叶章(Deyeuxiaangusti-folia)植被生产力动态模拟模型。该模型包括3个子模块1)光合作用与呼吸作用;2)干物质积累;3)同化物分配,主要考虑了温度和积水因子对植物生长的影响。并利用实测资料对该模型进行了检验,结果表明小叶章地上活体、枯落物、茎、叶各器官枯落物的模拟值与实测值之间均呈极显著的线性相关(R2分别为0.98、0.99、0.99和0.92)。在相邻区域的检验结果也表明,季节性积水沼泽化草甸小叶章的地上生物量明显高于常年积水沼泽。两类湿地小叶章地上生物量的模拟值与实测值之间均呈极显著线性相关(R2分别为0.66和0.79)。相近区域长期定位观测点连续2年的模拟结果与实测值之间也具有极显著的线性相关(R2分别为0.97和0.76)。

Background and Aims Carbon sequestration in ecosystems is determined largely by primary production of ecosystems. The application of long-term observation of vegetation biomass limits ecological and global change research. Therefore, it is necessary to apply simulation models to estimate an ecosystem＇ s input of organic carbon and forecast the impact of climate change. Methods Based on the principles of plant physiology, a simulation model was developed to simulate primary production of Deyeuxia angustifolia in wetland ecosystems. It is driven by conventional parameters observed from meteorological stations. This model consists of three main function modules： photosynthesis-respiration, accumulation of assimilated matter and distribution of assimilated matter. The effects of temperature, waterlog- ging and increased concentration of atmosphere CO2 on the growth of D. angustifolia were taken into account in this model. The model was validated by comparing observed and simulated data of aboveground living and litter biomass of D. angustifolia. Key Results The dynamics of aboveground living biomass, total litter, stem litter and leaf litter of D. angustifolia were simulated correctly. The liner correlation between simulated and observed values was highly significant. Conclusions Validation results from an adjacent area and a field experiment station also showed that the simulated values were significantly correlated with observed values in seasonally and permanently waterlogged D. angustifolia ecosystems. Daily changes of primary production, biomass and liter of D. angustifolia in wetland ecosystems could be effectively simulated by this model.