Ecohydrological Controls on Watershed Response to Land Use Change in the Montane Cloud Forest Zone in Central Veracruz, Mexico

一年中大部分时间被雾或薄雾覆盖的生态系统可能对供水至关重要，因为雾的存在会增加总的水输入。 这可能是因为雾凝结在树叶上并滴到地面，减少了光线和温度，因此蒸发的水分较少，并且可以直接被树叶吸收。 然而，目前关于雾如何影响生态系统水平衡的知识非常贫乏。这项研究量化了墨西哥韦拉克鲁斯云雾森林区的雾对水运动的影响。 本项目的目标是确定云雾林转换为牧场，松树重新造林和年轻的再生林如何影响径流。 这将通过将水文、生态生理、大气和土壤过程的实地测量与流域建模相结合来实现。 云雾森林，加上其他雾/云淹没的生态系统，在地球上占据了7000多万公顷的土地，但其中许多已经被砍伐或受到转换和气候变化的威胁。 当高大的森林被较矮的植被取代时，雾-植被相互作用的丧失可能对水文平衡产生不可逆转的后果，从而影响低洼地区主要人口中心的供水。 这项研究填补了目前对云雾森林的理解的一个重要空白。土地利用的变化？影响水资源。 通过查明造成水流量和时间变化的机制，将有可能提出具体的管理和政策建议，以保护供水和扭转退化进程。 水文计划（GEO），国际科学工程办公室，新兴前沿（BIO/OAD）和环境生物学部门正在为这项研究提供额外的支持。

Ecosystems that are covered in fog or mist for much of the year may be critical for water supply because the presence of fog can increase total water inputs. This can occur because fog condenses on tree leaves and drips to the ground, reduces light and temperature so less water evaporates, and can be directly absorbed by leaves. However, current knowledge about how fog influences ecosystem water balance is extremely poor. This research quantifies the effect of fog on water movement through individual plants to entire watersheds in a cloud forest zone in Veracruz, Mexico. The goal of this project is to determine how conversion of cloud forest to pasture, pine reforestation, and young regenerating forest affects streamflow. This will be accomplished by combining field measurements of hydrological, ecophysiological, atmospheric and soil processes with watershed modeling. Cloud forests, combined with other fog/cloud inundated ecosystems, occupy over 70 million hectares on earth, yet many have already been deforested or are threatened by conversion and climate change. Loss of fog-vegetation interactions when tall forests are replaced by shorter vegetation may have irreversible consequences for the hydrological balance, thereby affecting water supply to major population centers in lower-lying regions. This research fills an important gap in current understanding of how cloud forests?and their alteration by land use?affect water resources. By identifying the mechanisms that cause changes in water flow amounts and timing, it will be possible to make specific management and policy recommendations for protecting water supply and reversing processes of degradation. Additional support for this research is being provided by the Hydrology Program (GEO), the Office of International Science & Engineering, Emerging Frontiers (BIO/OAD), and the Division of Environmental Biology.