Local and non-local controls on seasonal variations in water availability and use by riparian trees along a hydroclimatic gradient
Local and non-local controls on seasonal variations in water availability and use by riparian trees along a hydroclimatic gradient
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地方和非地方对水资源供应的季节性变化以及沿水文气候梯度的河岸树木的利用进行控制
DOI：
10.1088/1748-9326/ac1294
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发表时间：
2021
影响因子：
6.7
通讯作者：
Singer, Michael Bliss
中科院分区：
文献类型：
--
作者：
Sargeant, Christopher I;Singer, Michael Bliss
随着全球气候变化继续影响区域水循环，我们可以预期森林的可用水量将进一步变化，这将给某些物种和生物群落带来挑战。低地落叶河岸林尤其脆弱，因为树种不能迁移出河流走廊，而且它们依赖于根区水分供应，而根区水分供应受当地气候条件（如降水、蒸发和入渗）和非当地水文气候强迫（如水流、融雪、补给）的变化控制。为了确定河岸树木的季节性水源利用如何受到当地与非当地水文气候变化的控制，我们重建了两种具有不同根深的河岸树木使用的季节氧同位素（δ 18o）特征，包括在次年分辨率（每年6个样本）下，沿着Rhône流域内的强水文气候梯度，从12个树级年代际时间序列中获得的~ 800个δ 18o树轮纤维测量值。SE法国。这些结果与来自潜在端元水源和独立水文气候指标的δ 18o测量结果一起进行了评估。因此，我们描述了不同根系深度的潜在水分有效性和树木水源利用的季节演变，并研究了近十年来河岸树木对局地和非局地水文气候强迫季节变化的一般响应。我们发现：(a)基于不同的地下水获取途径，不同物种之间的季节性用水存在差异；(b)根据不断变化的水供应情况，这两个物种的水源大量转换；(c)河岸树木更依赖于当地控制的土壤湿度和下游距离，增加了对当地气温上升的脆弱性。我们还发现，由于高度依赖山区供水，低地河岸洪泛平原上的深根树木可能容易受到气候变化的影响。这种影响在下游更为明显，季节性地下水位下降可能导致深根树木所需的水分流失。
As global climate change continues to impact regional water cycles, we may expect further shifts in water availability to forests that create challenges for certain species and biomes. Lowland deciduous riparian forests are particularly vulnerable because tree species cannot migrate out of the stream corridor, and they rely on root zone water availability that is controlled by variations in both local climate conditions (eg precipitation, evaporation, and infiltration) and non-local hydroclimatic forcing (eg streamflow, snowmelt, recharge). To determine how the seasonal water source usage of riparian trees is controlled by local versus non-local variability in hydroclimatic regime, we reconstructed the seasonal oxygen isotope (δ 18 O) signature of water used by two riparian tree species with contrasting rooting depths, comprising∼ 800 δ 18 O tree-ring cellulose measurements from 12 tree-level decadal time-series at sub-annual resolution (six samples per year), along a strong hydroclimatic gradient within the Rhône River basin, SE France. These results were evaluated alongside δ 18 O measurements made from potential endmember water sources and independent hydroclimatic metrics. Thus we characterize the seasonal evolution of both potential water availability at distinct rooting depths and tree water source use and investigate the generalized riparian tree response to seasonal variations in local versus non-local hydroclimatic forcing over a decade. We show:(a) distinct seasonal water use between species, based on differential access to groundwater;(b) substantial source switching in both species based on evolving water availability; and (c) that riparian trees are more dependent on locally controlled soil moisture with distance downstream, creating increased vulnerability to locally increasing temperatures. We also find that deeply rooted trees in lowland riparian floodplains are potentially vulnerable to climate change because of their high dependence on water supply from mountains. This effect is more pronounced downstream, where seasonal water table decline may lead to loss of water required for deeply rooted trees.
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影响因子：
3.2
作者：
Mayes, Marc;Caylor, Kelly K.;Nagler, Pamela
通讯作者：
Nagler, Pamela
DOI：
10.1073/pnas.1712381114
发表时间：
2017-10-03
影响因子：
11.1
作者：
Fan, Ying;Miguez-Macho, Gonzalo;Otero-Casal, Carlos
通讯作者：
Otero-Casal, Carlos
影响因子：
5.4
作者：
C. Sargeant;M. Singer;C. Vallet-Coulomb
通讯作者：
C. Sargeant;M. Singer;C. Vallet-Coulomb
通过对流降雨的随机模拟解读科罗拉多河流域下游气候变化的表达
DOI：
--
发表时间：
2017
期刊：
影响因子：
--
作者：
M. Singer;K. Michaelides
通讯作者：
K. Michaelides
影响因子：
2.6
作者：
C. Sargeant;M. Singer
通讯作者：
C. Sargeant;M. Singer