SummaryThe potential for widespread sink‐limited plant growth has received increasing attention in the literature in the past few years. Despite recent evidence for sink limitations to plant growth, there are reasons to be cautious about a sink‐limited world view. First, source‐limited vegetation models do a reasonable job at capturing geographic patterns in plant productivity and responses to resource limitations. Second, from an evolutionary perspective, it is nonadaptive for plants to invest in increasing carbon assimilation if growth is primarily sink‐limited. In this review, we synthesize the potential evidence for and underlying physiology of sink limitation across terrestrial ecosystems and contrast mechanisms of sink limitation with those of source‐limited productivity. We highlight evolutionary restrictions on the magnitude of sink limitation at the organismal level. We also detail where mechanisms regulating sink limitation at the organismal and ecosystem scale (e.g. the terrestrial carbon sink) diverge. Although we find that there is currently no direct evidence for widespread organismal sink limitation, we propose a series of follow‐up growth chamber manipulations, systematized measurements, and modeling experiments targeted at diagnosing nonadaptive buildup of excess nonstructural carbohydrates that will help illuminate the prevalence and magnitude of organismal sink limitation.

中文翻译：

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源与汇对树木生长的限制：从生理机制到进化限制和陆地碳循环影响


摘要在过去几年中，广泛的汇限制植物生长的潜力在文献中受到了越来越多的关注。尽管最近有证据表明汇限制了植物生长，但有理由对汇限制的世界观持谨慎态度。首先，源受限植被模型在捕捉植物生产力的地理模式和对资源限制的响应方面做得相当不错。其次，从进化的角度来看，如果生长主要受汇限制，那么植物投资于增加碳同化是不适应性的。在这篇综述中，我们综合了陆地生态系统中汇限制的潜在证据和潜在的生理学，并将汇限制的机制与源限制生产力的机制进行了对比。我们强调了生物体水平上汇限制幅度的进化限制。我们还详细说明了在生物和生态系统尺度（例如陆地碳汇）调节汇限制的机制在哪些方面存在分歧。尽管我们发现目前没有直接证据表明广泛的生物体汇限制，但我们提出了一系列后续生长室操作、系统化测量和建模实验，旨在诊断过量非结构性碳水化合物的非适应性积累，这将有助于阐明有机体汇限制的普遍性和程度。