Estimations of evapotranspiration in an age sequence of Eucalyptus plantations in subtropical China

Eucalyptus species are widely planted for reforestation in subtropical China. However, the effects of Eucalyptus plantations on the regional water use remain poorly understood. In an age sequence of 2-, 4- and 6-year-old Eucalyptus plantations, the tree water use and soil evaporation were examined by linking model estimations and field observations. Results showed that annual evapotranspiration of each age sequence Eucalyptus plantations was 876.7, 944.1 and 1000.7 mm, respectively, accounting for 49.81%, 53.64% and 56.86% of the annual rainfall. In addition, annual soil evaporations of 2-, 4- and 6-year-old were 318.6, 336.1, and 248.7 mm of the respective Eucalyptus plantations. Our results demonstrated that Eucalyptus plantations would potentially reduce water availability due to high evapotranspiration in subtropical regions. Sustainable management strategies should be implemented to reduce water consumption in Eucalyptus plantations in the context of future climate change scenarios...

桉树属（Eucalyptus）植物在中国亚热带地区被广泛用于造林恢复工程。然而，桉树人工林对区域水资源利用的影响仍未得到充分认知。本研究选取林龄分别为2年、4年及6年的桉树人工林，通过耦合模型估算与野外实地观测的手段，对林木耗水与土壤蒸发过程进行了系统探究。结果显示，各林龄梯度的桉树人工林年蒸散量依次为876.7、944.1与1000.7毫米，分别占当年降水量的49.81%、53.64%及56.86%。此外，2年生、4年生与6年生桉树人工林的年土壤蒸发量分别为318.6、336.1与248.7毫米。本研究结果表明，亚热带地区的桉树人工林因较高的蒸散水平，可能会降低区域水资源可利用性。在未来气候变化情景下，应制定可持续经营策略以降低桉树人工林的水资源消耗……