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数据源、时间范围、空间尺度等的差异导致许多物候变化对陆地生态系统碳收支影响的研究缺少可比性。该文基于4级碳通量填充数据,采用相对阈值方法提取了两个北美典型温带阔叶林站Harvard Forest(HF)和University of Michigan Biological Station(UMBS)共20年的物候参数(返青期、枯黄期和生长季长度),并研究了物候变化对生态系统生产力的影响。结果表明:1)生长季长度的延长对年累积总初级生产力(GPP)有显著贡献,但由于呼吸作用(RE)的干扰,生长季长度变化对年净生态系统生产力(NEP)的影响并不显著;2)返青期的提前对上半年生态系统总初级生产力的贡献最为显著,二者的相关系数分别为0.76(HF)和0.93(UMBS);3)枯黄期的延迟对生产力的影响并不显著;4)随着春季返青期的提前或秋季枯黄期的延迟,上、下半年GPP和RE的累积量虽均有增加趋势,但由于各自增加的幅度不确定,导致年NEP与二者的响应关系复杂。
Differences in data sources, time frames, spatial scales, etc. have led to a lack of comparability of the studies on the impact of many phenological variations on the carbon budget of terrestrial ecosystems. Based on the four-level Flux Fill Data, the relative threshold method was used to extract the phenological parameters of two North American typical temperate broad-leaved forest stands, Harvard Forest (HF) and University of Michigan Biological Station (UMBS) Yellowing and growing season length), and studied the impact of phenological changes on ecosystem productivity. The results showed that: 1) The prolongation of the growing season contributed significantly to the annual total primary productivity (GPP). However, the effect of the growth season on the annual net ecosystem productivity (NEP) was not affected by the respiration (RE) Significant; 2) The early retreat phase contributed most significantly to the total primary productivity of the ecosystem in the first half of the year, with a correlation coefficient of 0.76 (HF) and 0.93 (UMBS), respectively; and 3) Significant; 4) With the advance of spring rejuvenation period or the delay of autumn yellowing period, although the accumulative amounts of GPP and RE in the second and second half both increased, the annual increase of both NPP and RE The response is complex.