现有模型：Extant models predict that this growth stimulation will continue to cause a net carbon uptake this century.

提出问题：However, there are indications that increased growth rates may shorten trees′ lifespanand thus recent increases in forest carbon stocks may be transient due to lagged increases in mortality.

主要发现：Here we show that growth-lifespan trade-offs are indeed near universal, occurring across almost all species and climates.

结果：This trade-off is directly linked to faster growth reducing tree lifespan, and not due to covariance with climate or environment. Thus, current tree growth stimulation will, inevitably, result in a lagged increase in canopy tree mortality, as is indeed widely observed, and eventually neutralise carbon gains due to growth stimulation. Results from a strongly data-based forest simulator confirm these expectations.

结论：Extant Earth system model projections of global forest carbon sink persistence are likely too optimistic, increasing the need to curb greenhouse gas emissions.

可能是由于树木生长的刺激，当前陆地植被正在吸收大量的空气二氧化碳。现有模型预测，这种生长刺激将在本世纪继续导致净碳吸收。然而，有证据表明生长速率的加快会减少树木的寿命，因此该影响所带来的滞后死亡会导致现有的森林碳存储增加不能长久。本文中，作者发现生长与寿命之前的平衡确实是比较普遍的，在几乎所有物种和环境气候下均会发生。快速生长会导致树木寿命减少，并且不受气候或环境的影响。因此，因此，当前的树木生长刺激不可避免地会导致冠层树木滞后的死亡率增加，正如我们现在所广泛观察到的那样，并且最终抵消由于前期生长刺激而导致的碳存储增加。基于大数据的森林模拟也证实了该结果的可靠性。现有用于预测全球森林碳汇持久性的地球系统模型项目可能都过于乐观了，因此有必要在现阶段增强温室气体排放的限制。