The Ecosystem Pressure-Volume Curve
The Ecosystem Pressure-Volume Curve
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DOI：
10.1101/2022.09.12.507627
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发表时间：
2022-09
期刊：
影响因子：
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通讯作者：
O. Binks;P. Meir;Maurizio Mencuccini
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文献类型：
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作者：
O. Binks;P. Meir;Maurizio Mencuccini
生态系统压力-体积曲线（EPV）是植被含水量与地面-面积基础上的水势代表值之间的关系。EPV试图将我们对小尺度可测量过程的详细和物理上严格的理解与适用于生态系统和气候科学的空间尺度相协调。成功地弥合这一规模上的差距可能使我们能够使用实地测量来解释遥感数据，然后利用遥感数据来了解植被-气候相互作用。在这里，我们清楚地定义的EPV的想法，评估的限制，应用价值的水含量和水潜力的生态系统在地面面积的基础上，并讨论实际的方法来构建EPV与现有的数据。我们还提出了第一个EPVs的基础上，从九个不同的地块，包括热带雨林，稀树草原，温带森林，并在亚马逊雨林（Caxiuanã，帕拉州，巴西）的长期干旱实验的数据。初步调查结果表明，各地点之间的一致性很高。特别是，整个生态系统的水与生物量之比似乎被限制在1：3左右。九个地点中有七个的“相对最大储水量”（在生态系统遭受生理损害之前，总储水量比可能损失的比例）接近9.1% +/-1.8标准差。相对生态系统容量可能会随着站点生物量的增加而增加（P = 0.091），但在站点之间变化不大，平均值为0.068 MPa−1 +/-0.029标准差。这些初步估计表明，EPV的想法可能会揭示有用的趋势，整个生态系统，潜在的铺平道路，增加遥感数据的生态生理意义，并使一种替代方法，模拟长期的生态系统，气候反馈的基础上平衡热力学。
The ecosystem pressure-volume curve (EPV) is the relationship between vegetation water content and a representative value of water potential applied on a ground-area basis. The EPV attempts to reconcile our detailed and physically rigorous understanding of small-scale field-measureable processes to the spatial scale applicable to ecosystem and climate science. Successfully bridging that gap in scale potentially allows us to use field measurements to interpret remote sensing data, and then remote sensing data to inform our understanding of vegetation-climate interactions. Here we clearly define the idea of the EPV, evaluate the limitations of applying values of water content and water potential to ecosystems on a ground area basis, and discuss practical ways to construct the EPV with existing data. We also present the first EPVs based on data from nine different plots, including tropical rainforest, savanna, temperate forest, and a long-term drought experiment in Amazonian rainforest (Caxiuanã, State of Pará, Brazil). The initial findings suggest high levels of consistency among sites. In particular, the ratio of water to biomass across ecosystems appears to be constrained to around 1:3. Seven of nine sites had closely converging ‘relative maximum water storage’ (the proportion of total stored water than can be lost before an ecosystem succumbs to physiological damage) at 9.1% +/-1.8 standard deviation. Relative ecosystem capacitance may increase with site biomass (P = 0.091), but varied little across sites with a mean of 0.068 MPa−1 +/-0.029 standard deviation. These first estimates suggest that the EPV idea may reveal useful trends across ecosystems, potentially paving the way to increasing the ecophysiological significance of remote sensing data, and enabling an alternative method for modelling long-term ecosystem-climate feedbacks based on equilibrium thermodynamics.