Does plant ecosystem thermoregulation occur? An extratropical assessment at different spatial and temporal scales
Does plant ecosystem thermoregulation occur? An extratropical assessment at different spatial and temporal scales
复制标题
植物生态系统是否发生温度调节？
DOI：
10.1111/nph.18632
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发表时间：
2022
期刊：
影响因子：
9.4
通讯作者：
Yeung, Henry C. H.
中科院分区：
文献类型：
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作者：
Guo, Zhengfei;Still, Christopher J.;Lee, Calvin K. F.;Ryu, Youngryel;Blonder, Benjamin;Wang, Jing;Bonebrake, Timothy C.;Hughes, Alice;Li, Yan;Yeung, Henry C. H.
植物生态系统对冠层温度 (Tc) 的温度调节程度对于评估生态系统的新陈代谢和气候变化恢复能力至关重要，但仍存在争议，人们的意见从无到中等温度调节能力。利用来自 FLUXNET 和卫星的 Tc、气温 (Ta) 以及其他环境和生物变量的全球数据集，我们测试了“有限恒温”假设（由 Tc&Taregression 斜率 < 1 或 Tc<Taaround 表示）在全球温带地区，包括时间和空间维度。在每日、每周和每月的时间尺度上，超过 80% 的地点/生态系统在中午左右的斜率 ≥1 或 Tc>Ta，否定了上述假设。对于那些不支持该假设的地点，它们的 Tc-Ta 差异 (ΔT) 表现出相当大的季节性，与叶面积指数呈负相关，部分相关，这意味着一定程度的温度调节能力。在空间上，位点平均 ΔT 比斜率指标表现出更大的变化，这表明 ΔT 是检测生物群落之间温度调节差异的更敏感的指标。此外，这种大的空间范围ΔT变化（0-6°C）主要由环境变量（38%）解释，其次由生物因素（15%）解释。这些结果表明，全球温带地区存在不同的温度调节模式，大多数生态系统否定了“有限恒温”假说，但它们的温度调节仍然存在，这意味着斜率< 1或Tc<Ta不是植物温度调节的必要条件。
To what degree plant ecosystems thermoregulate their canopy temperature (Tc) is critical to assess ecosystems' metabolisms and resilience with climate change, but remains controversial, with opinions from no to moderate thermoregulation capability.With global datasets ofTc, air temperature (Ta), and other environmental and biotic variables from FLUXNET and satellites, we tested the ‘limited homeothermy’ hypothesis (indicated byTc&Taregression slope < 1 orTc<Taaround midday) across global extratropics, including temporal and spatial dimensions.Across daily to weekly and monthly timescales, over 80% of sites/ecosystems have slopes ≥1 orTc>Taaround midday, rejecting the above hypothesis. For those sites unsupporting the hypothesis, theirTc–Tadifference (ΔT) exhibits considerable seasonality that shows negative, partial correlations with leaf area index, implying a certain degree of thermoregulation capability. Spatially, site‐mean ΔTexhibits larger variations than the slope indicator, suggesting ΔTis a more sensitive indicator for detecting thermoregulatory differences across biomes. Furthermore, this large spatial‐wide ΔTvariation (0–6°C) is primarily explained by environmental variables (38%) and secondarily by biotic factors (15%).These results demonstrate diverse thermoregulation patterns across global extratropics, with most ecosystems negating the ‘limited homeothermy’ hypothesis, but their thermoregulation still occurs, implying that slope < 1 orTc<Taare not necessary conditions for plant thermoregulation.