Drought Effects in Climate Change Manipulation Experiments: Quantifying the Influence of Ambient Weather Conditions and Rain-out Shelter Artifacts
Drought Effects in Climate Change Manipulation Experiments: Quantifying the Influence of Ambient Weather Conditions and Rain-out Shelter Artifacts
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DOI：
10.1007/s10021-016-0025-8
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发表时间：
2017-03-01
期刊：
影响因子：
3.7
通讯作者：
Jentsch, Anke
中科院分区：
文献类型：
--
作者：
Kreyling, Juergen;Khan, Mohammed A. S. Arfin;Jentsch, Anke
极端干旱事件挑战生态系统的功能。在世界范围内，越来越多的田间试验通过避雨设施研究对干旱的生态反应。然而，很少有荟萃分析在研究的可比性方面面临严峻挑战。这在一定程度上是因为避雨场所干旱压力的积累受到周围天气条件的影响。避雨棚会进一步造成混乱的影响(辐射、温度)，这可能会影响植物的反应。然而，缺乏对在相反的环境天气条件下避雨场所内的生态生理影响和小气候人工制品的量化。在这里，我们研究了植物温度计-标准化的盆栽车前草个体-在与外部小气候条件相反的情况下，在雨棚、雨棚人工制品控制和环境控制下。此外，我们在长期的半自然草地试验中测试了避雨棚对植物反应的伪影。遮阳棚下的气孔导度、最大量子效率和叶水势在高蒸发量的温暖环境条件下表现出低于低蒸发量的寒冷条件下的气孔导度、最大量子效率和叶水势。植物表现与环境温度和蒸汽压差(VPD)高度相关。雨棚伪影对植物反应的影响不显著。避难所仍然是研究生态系统对干旱反应的一个可行工具。然而，利用避雨场所操纵干旱会受到周围天气条件的强烈影响。因此，要将避雨所研究的结果归因于干旱影响以及研究和研究年份之间的可比性，需要量化已实现的干旱压力，例如，将生态系统的反应与所测量的小气候参数，如气温和VPD联系起来。
Extreme drought events challenge ecosystem functioning. Ecological response to drought is studied worldwide in a growing number of field experiments by rain-out shelters. Yet, few meta-analyses face severe challenges in the comparability of studies. This is partly because build-up of drought stress in rain-out shelters is modified by ambient weather conditions. Rain-out shelters can further create confounding effects (radiation, temperature), which may influence plant responses. Yet, a quantification of ecophysiological effects within rain-out shelters under opposing ambient weather conditions and of microclimatological artifacts is missing. Here, we examined phytometers-standardized potted individuals of Plantago lanceolata-under rain-out shelter, rain-out shelter artifact control, and ambient control during opposing outside microclimatological conditions. Furthermore, we tested for artifacts of rain-out shelters on plant responses in a long-term semi-natural grassland experiment. Phytometer plants below the rain-out shelters showed lower stomatal conductance, maximum quantum efficiency, and leaf water potential during warm ambient conditions with high evaporative demand than during cold conditions with low evaporative demand. Plant performance was highly correlated with ambient temperature and vapor pressure deficit (VPD). Rain-out shelter artifacts on plant responses were nonsignificant. Rain-out shelters remain a viable tool for studying ecosystem responses to drought. However, drought manipulations using rain-out shelters are strongly modified by ambient weather conditions. Attributing the results from rain-out shelter studies to drought effects and comparability among studies and study years therefore requires the quantification of the realized drought stress, for example, by relating ecosystem responses to measured microclimatological parameters such as air temperature and VPD.