Senescence in temperate broadleaf trees exhibits species-specific dependence on photoperiod versus thermal forcing
Senescence in temperate broadleaf trees exhibits species-specific dependence on photoperiod versus thermal forcing
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温带阔叶树的衰老表现出对光周期与热强迫的物种特异性依赖性
DOI：
10.1016/j.agrformet.2022.109026
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发表时间：
2022
影响因子：
6.2
通讯作者：
Friedl, Mark A.
中科院分区：
文献类型：
--
作者：
Moon, Minkyu;Richardson, Andrew D.;O'Keefe, John;Friedl, Mark A.
对控制衰老的过程的不完全理解限制了我们预测未来几十年叶片衰老的时间将如何变化的能力。在这项研究中，我们使用分层贝叶斯模型(HBM)，结合在马萨诸塞州中部哈佛森林收集的12种温带落叶树种的27年多的野外观测记录，来研究生物气候控制的可变性如何影响叶片衰老的时间。为了测试我们的结果在更广泛的生物地理范围内的普适性和可扩展性，我们使用了来自遥感的多年陆地表面物候记录，涵盖了新英格兰的所有林地。HBM结果表明，虽然气温是影响叶片衰老时间的一个重要因素，但光周期对所有12种植物的控制作用都是最强的。对光周期依赖性最强的树种，特别是针叶树种，年际变化较小，叶片衰老的时间没有长期趋势。相比之下，对气温依赖程度更高的物种，特别是栎类物种，在对长期变暖的反应中，表现出统计上显著的延迟衰老日期的趋势。使用遥感数据在整个新英格兰地区进行的区域范围内的分析结果证实了在哈佛森林获得的结果。具体地说，相对于以栎属植物为主的生态区，以栎属植物为主的生态区叶片衰老时间的年际变异性较小，与衰老前期平均气温的年际变化相关性较低。这些结果表明，预测未来温带森林中叶片衰老的时间将如何变化，需要特定物种的理解，即生物气候强迫如何控制叶片衰老的时间。
Incomplete understanding of the processes controlling senescence limits our ability to forecast how the timing of leaf senescence will change in coming decades. In this study, we use a hierarchical Bayesian model (HBM) in association with a 27+ year record of field observations for 12 temperate deciduous tree species collected at Harvard Forest in central Massachusetts to examine how variability in bioclimatic controls affects the timing of leaf senescence. To test how general and extensible our results are over a broader biogeographic range, we used a multi-year record of land surface phenology derived from remote sensing encompassing all forested lands in New England. Results from the HBM showed that while air temperature is an important factor that influences the timing of leaf senescence, photoperiod uniformly exerts the strongest control across all 12 species. Species exhibiting the strongest dependence on photoperiod, particularlyAcerspecies, showed low inter-annual variation and no long-term trends in the timing of leaf senescence. In contrast, species with greater dependence on air temperature, particularlyQuercusspecies, showed statistically significant trends toward later senescence dates in response to long-term warming. Results from analyses conducted at regional scale across all of New England using data derived from remote sensing corroborated results obtained at Harvard Forest. Specifically, relative to ecoregions dominated byQuercusspecies,the timing of leaf senescence in ecoregions dominated byAcerspecies exhibited lower interannual variability and lower correlation with year-to-year variation in pre-senescence period mean air temperatures. These results suggest that forecasting how the timing of leaf senescence in temperate forests will change in the future requires species-specific understanding of how bioclimatic forcing controls the timing of leaf senescence.