Influence of spring and autumn phenological transitions on forest ecosystem productivity
Influence of spring and autumn phenological transitions on forest ecosystem productivity
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DOI：
10.1098/rstb.2010.0102
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发表时间：
2010-10-12
影响因子：
6.3
通讯作者：
Varlagin, Andrej
中科院分区：
文献类型：
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作者：
Richardson, Andrew D.;Black, T. Andy;Varlagin, Andrej
我们使用涡度协方差测量的净生态系统生产力（NEP）从21个FLUXNET网站（153网站年的数据），调查物候和生产力（在两个NEP和总生态系统光合作用，GEP）在温带和北方森林之间的关系。结果被用来评估四个不同的概念模型的可扩展性。物候指标来自涡度协方差时间序列，从遥感和模型。我们研究了空间模式（跨站点）和时间模式（跨年份）;一个重要的结论是，这两种模式都不能准确地代表生产力如何应对持续气候变化导致的未来物候变化。在春季和秋季，增加GEP导致的“额外”的一天往往被抵消的并发，但较小，增加生态系统呼吸，因此对NEP的影响仍然是积极的。春季生产力异常似乎有结转效应，转化为生产力异常，在接下来的秋天，但目前尚不清楚，这些直接从物候异常的结果。最后，万年青针叶林的生产力是不太敏感的物候比落叶阔叶林的生产力。这对气候变化如何推动混合物种林分内竞争的转变具有影响。
We use eddy covariance measurements of net ecosystem productivity (NEP) from 21 FLUXNET sites (153 site-years of data) to investigate relationships between phenology and productivity (in terms of both NEP and gross ecosystem photosynthesis, GEP) in temperate and boreal forests. Results are used to evaluate the plausibility of four different conceptual models. Phenological indicators were derived from the eddy covariance time series, and from remote sensing and models. We examine spatial patterns (across sites) and temporal patterns (across years); an important conclusion is that it is likely that neither of these accurately represents how productivity will respond to future phenological shifts resulting from ongoing climate change. In spring and autumn, increased GEP resulting from an 'extra' day tends to be offset by concurrent, but smaller, increases in ecosystem respiration, and thus the effect on NEP is still positive. Spring productivity anomalies appear to have carry-over effects that translate to productivity anomalies in the following autumn, but it is not clear that these result directly from phenological anomalies. Finally, the productivity of evergreen needleleaf forests is less sensitive to phenology than is productivity of deciduous broadleaf forests. This has implications for how climate change may drive shifts in competition within mixed-species stands.