Warm springs alter timing but not total growth of temperate deciduous trees
Warm springs alter timing but not total growth of temperate deciduous trees
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DOI：
10.1038/s41586-022-05092-3
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发表时间：
2022-08-10
期刊：
影响因子：
64.8
通讯作者：
Anderson-Teixeira, Kristina J.
中科院分区：
文献类型：
--
作者：
Dow, Cameron;Kim, Albert Y.;Anderson-Teixeira, Kristina J.
随着气候变化，春季气温升高导致温带落叶林提前落叶（1-3）和开始吸收CO2（1，3），导致生长季节长度（3）和年CO2吸收量（1，3 -7）增加的趋势。然而，人们对春季温度如何影响树干生长知之甚少（8，9），这会将碳封存在生态系统中停留时间较长的木材中（10，11）。在这里，我们表明，温暖的春季温度转移落叶树木的茎直径生长早，但没有一致的影响生长高峰期的长度，最大增长率，或年增长率，使用测树仪带测量440棵树在两个森林。后一项发现在百年尺度上得到了来自北美东部108个森林的207个树木年轮年表的证实，其中年轮宽度对生长高峰期的温度比春季更敏感。这些发现意味着，任何额外的CO2吸收年与温暖的春季温度（4，5）并没有显着增加封存在长寿的木质茎生物量。相反，与全球碳循环模型（1，12）的预测相矛盾，我们的实证结果表明，春季气温变暖不太可能增加木本生产力，足以加强温带落叶林的长期CO2汇。
As the climate changes, warmer spring temperatures are causing earlier leaf-out(1-3) and commencement of CO2 uptake(1,3) in temperate deciduous forests, resulting in a tendency towards increased growing season length(3) and annual CO2 uptake(1,3-7). However, less is known about how spring temperatures affect tree stem growth(8,9), which sequesters carbon in wood that has a long residence time in the ecosystem(10,11). Here we show that warmer spring temperatures shifted stem diameter growth of deciduous trees earlier but had no consistent effect on peak growing season length, maximum growth rates, or annual growth, using dendrometer band measurements from 440 trees across two forests. The latter finding was confirmed on the centennial scale by 207 tree-ring chronologies from 108 forests across eastern North America, where annual ring width was far more sensitive to temperatures during the peak growing season than in the spring. These findings imply that any extra CO2 uptake in years with warmer spring temperatures(4,5) does not significantly contribute to increased sequestration in long-lived woody stem biomass. Rather, contradicting projections from global carbon cycle models(1,12), our empirical results imply that warming spring temperatures are unlikely to increase woody productivity enough to strengthen the long-term CO2 sink of temperate deciduous forests.