高寒山区凝结水研究进展

Advances in the Study on NRWIs in Alpine Mountains

通过总结高寒山区凝结水的研究现状、梳理近年来的研究进展、归纳凝结水的观测方法,本文阐述了高寒山区凝结水的生态效应及其与冰冻圈水文过程的关系,探讨了未来高寒山区凝结水研究的发展趋势和方向。综述表明:凝结水对高寒山区生态系统有着十分重要的影响,对于维系高寒山区脆弱生态系统有重要意义,在高寒山区生态形成过程中扮演着重要的角色。凝结水是冰冻圈生态水文过程的缓释剂,高寒山区凝结水主要缓解低温造成植被周期性的生理缺水(低温导致土壤水分无法利用),而非干旱胁迫(没有水分);凝结水通过其周期性的水分添加来影响土壤水分有效性,进而影响温度敏感性,从而对土壤呼吸产生周期性影响。凝结水的富集和消散过程,抵消部分蒸发潜热,降低实际蒸散发,对减少蒸发“赤字”有积极作用,间接补给河川径流。在高寒山区,凝结水对海拔的依赖性表明凝结水在高山区可能进一步富集频发,是高寒山区隐形水源的一个潜在探索点,对寒区水汽内循环过程具有显著作用。在我国西北地区暖干向暖湿气候转型中,随着高寒山区水汽含量的增加,造成凝结水量可能呈现增加趋势。

Through a comprehensive review of the No Rainfall Water Inputs(NRWIs)in alpine mountains in recent years and a summarization of technologies in monitoring NRWIs,this paper presents the ecological effect of NRWIs in alpine mountains and its potential correlation with the hydrological process of the cryosphere.In addition,the potential research trench is explored.The results show that NRWIs play a key role in the alpine mountain ecosystem,is significant to the sustainability of the ecosystem and also important to the ecological formation of the alpine mountain region.The NRWIs provides a buffering zone for the cryosphere eco-hydrological process,which can reasonably relieve the periodic physiological water shortage of vegetation resulting from low temperature(below freezing point),rather than drought stress(no water).The NRWIs affects the amount of available water in the soil through a periodical increase of moisture content,which in turn changes temperature sensitivity and further influence soil respiration.The enrichment and dissipation processes of NRWIs water offset part of the latent heat of evaporation,reduce the actual evapotranspiration,have a positive effect on lowering the evaporation deficit,and indirectly recharye the river runoff.In alpine mountains,the dependence of NRWIs on altitude indicates that it may be further enriched and frequently occurred.Thus,is is a potential exploration part for invisible water resources and has a significant effect on the local moisture recycling in the alpine mountains.In the transition process of the climate from warm-dry to warm-wet in Northwest China,the amount of NRWIs may rise with the increase of water vapor content in alpine mountains.