Effects of non-rainfall water inputs on ecosystem functions

Non-rainfall water inputs (NRWIs) are the least studied hydrological components in most ecosystems. These NRWI components potentially play an important role in ecosystem dynamics and are particularly important for water-limited systems. In this review, we summarized recent advances investigating the effects of NRWIs on various ecosystem functions, including vegetation-water relations, biogeochemical cycling, groundwater recharge, as well as reptile and invertebrate adaptations. We also identified key knowledge gaps such as the mechanisms of NRWIs alleviating vegetation water stress, sources of the NRWI components and their quantitative contributions to ecosystem functions. To better predict the ecosystem responses to climate change especially in drylands, a better understanding and quantification of NRWI contributions is essential. (C) 2016 Wiley Periodicals, Inc.