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Abstract：
Nonperennial streams dominate global river networks and are increasing in occurrence across space and time. When surface flow ceases or the surface water dries, flow or moisture can be retained in the subsurface sediments of the hyporheic zone, supporting aquatic communities and ecosystem processes. However, hydrological and ecological definitions of the hyporheic zone have been developed in perennial rivers and emphasize the mixing of water and organisms, respectively, from both the surface stream and groundwater. The adaptation of such definitions to include both humid and dry unsaturated conditions could promote characterization of how hydrological and biogeochemical variability shape ecological communities within nonperennial hyporheic zones, advancing our understanding of both ecosystem structure and function in these habitats. To conceptualize hyporheic zones for nonperennial streams, we review how water sources and surface and subsurface structure influence hydrological and physicochemical conditions. We consider the extent of this zone and how biogeochemistry and ecology might vary with surface states. We then link these components to the composition of nonperennial stream communities. Next, we examine literature to identify priorities for hydrological and ecological research exploring nonperennial hyporheic zones. Lastly, by integrating hydrology, biogeochemistry, and ecology, we recommend a multidisciplinary conceptualization of the nonperennial hyporheic zone as the porous subsurface streambed sediments that shift between lotic, lentic, humid, and dry conditions in space and time to support aquatic-terrestrial biodiversity. As river drying increases in extent because of global change, we call for holistic, interdisciplinary research across the terrestrial and aquatic sciences to apply this conceptualization to characterize hyporheic zone structure and function across the full spectrum of hydrological states.
摘要：
非常年河流在全球河流网络中占主导地位，并且在空间和时间上的发生率都在增加。当地表流动停止或地表水变干时，流量或水分可以保留在高压带的地下沉积物中，支持水生群落和生态系统过程。然而,在多年生河流中已经开发了水河带的水文和生态定义，并强调水和生物的混合，分别,来自地表水和地下水。调整此类定义以包括潮湿和干燥的不饱和条件，可以促进表征水文和生物地球化学变异性如何塑造非多年生高压带内的生态群落。提高我们对这些栖息地的生态系统结构和功能的理解。为了概念化非多年生河流的低流区，我们回顾了水源和地表和地下结构如何影响水文和物理化学条件。我们考虑该区域的范围以及生物地球化学和生态学如何随表面状态而变化。然后，我们将这些组成部分与非多年生河流群落的组成联系起来。接下来,我们研究文献，以确定探索非多年生高压带的水文和生态研究的优先事项。最后,通过整合水文学，生物地球化学,和生态，我们建议对非多年生高压带进行多学科的概念化，因为多孔的地下河床沉积物在黄土之间转移，Literic,潮湿,以及空间和时间上的干燥条件，以支持水生陆地生物多样性。随着全球变化，河流干燥程度的增加，我们呼吁整体，跨陆地和水生科学的跨学科研究，以应用这种概念化来表征整个水文状态的低流区结构和功能。
