An ecohydrological perspective of reconstructed vegetation in the semi-arid region in drought seasons
An ecohydrological perspective of reconstructed vegetation in the semi-arid region in drought seasons
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DOI：
10.1016/j.agwat.2020.106488
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发表时间：
2021-01-01
影响因子：
6.7
通讯作者：
Guo, Fuqiang
中科院分区：
文献类型：
--
作者：
Cheng, Yiben;Zhan, Hongbin;Guo, Fuqiang
长期以来，荒漠化严重威胁着中国北方的生态安全，中国为此建立了世界上最大的防护林工程。经过40年的植被重建，中国北方荒漠化趋势得到扭转。然而，中国北方的防护林工程同时也出现了退化的迹象，因此其有效性受到各国科学家的质疑。为了研究半干旱地区植被重建过程对该地区降水水分再分配过程的影响，以及重建后的植被如何在旱季存活。本研究选择了樟子松为研究对象。以毛乌素桑迪蒙古栎林为研究对象，采用新型蒸渗仪、树干流量计、微型气象站等监测手段，对土壤深层水分入渗、树干通量进行了监测。本研究的目的是了解PSM林是如何改变该地区降水再分配过程的，以及PSM林是如何调节自身蓄水量以适应年降水量变化的。在2017年等丰水年，DSR仅为0.4 mm，土壤蓄水量减少16 mm，蒸散量为324.6 mm;在2016年等丰水年，DSR为1.4 mm，土壤蓄水量扩大38.06 mm，结果表明，毛乌素地区PSM的耗水量与降水补给量达到平衡，但阻碍了降水对深层土壤的补给水和地下水。雨养的PSM茎可以作为一个水库单元来补充水分消耗和调节蒸散强度，以适应年降水量的变化。本研究对半干旱地区重建植被利用降水的规模和树干贮水的利用机理有了进一步的认识。
Desertification has long seriously threatened the ecological security of northern China, for which China has established the world's largest shelterbelt project. After 40 years of reconstruction of vegetation, the trend of desertification in northern China has been reversed. The shelterbelt forest project in northern China, however, at the same time, tells signs of degradation, and therefore its effectiveness has been questioned by scientists from various countries. In order to study the impact of the vegetation reconstruction process in the semi-arid area on the precipitation water redistribution process in this area, and how the reconstructed vegetation survives in dry season. This study selected the reconstruction Pinus sylvestris var. Mongolica (PSM) forest on Mu Us sandy land as the research object, and used new lysimeters, stem flow meters, miniature weather stations, etc. to monitor the deep soil water penetration, stem flux. The purpose of this current study is to find out how PSM forest changed the process of precipitation water redistribution in this area, and how PSM adjusts its own water storage capacity to adapt to the annual precipitation changes. In wet years such as 2017, DSR is only 0.4 mm, soil water storage is reduced by 16 mm, and evapotranspiration is 324.6 mm. In a wet year such as 2016, the DSR is 1.4 mm, the soil water storage is enlarged by 38.06 mm, and the evapotranspiration is 466.94 mm. The results showed that the water consumption of PSM in Mu Us area and the precipitation water replenishment in this area reached a balance but blocked precipitation to recharge deep soil water and groundwater. The rain-fed PSM stem can be used as a reservoir unit to supply water consumption and adjusting the evapotranspiration intensity to adapt to changes in annual precipitation. This research has advanced our understanding of the scale of reconstruction vegetation utilization of precipitation and the utilization mechanism of tree stem storage water in semi-arid areas.