摘要
[目的]揭示杨树人工林皆伐对滩地蒸发散和产流的影响。[方法]基于涡度相关系统对长江滩地杨树人工林皆伐前后水汽通量连续3年(2010―2012年)的观测数据,通过对比皆伐前、后气候条件相似的2个时段(1整年)的蒸发散,揭示皆伐后研究区蒸发散的变化,并基于水量平衡反推研究区产流的变化。[结果]皆伐后土壤温度和水位上升,土壤表层含水量全年均值减小约0.03;研究区蒸发散皆伐前、后具有相似的日变化规律和季节动态特征,但皆伐后的全年蒸散量仅为皆伐前的66.3%;皆伐后研究区产流率(产流量/降雨量)从皆伐前的0.53上升至0.62;皆伐前、后7、8、12月的干旱指数(潜在蒸发散/降雨量)均大于1,其他时期均小于1。[结论]滩地杨树人工林皆伐后滩地蒸发散减少而产流率增加,加剧夏季干旱的可能性有所降低,但洪水爆发期间削减洪峰的能力也减弱。
[ Objective] To reveal the effects of clearcutting a poplar plantation at the floodplain of Yangtze River on evapotranspiration （ET） and water yield （WY）. [ Method] Based on 3-years＇ consecutive observation data of water vapor flux from a poplar plantation on the floodplain of Yangtze River during the years before and after clearcutting by eddy eovariance system, the variation of ET post-clearcutting was investigated by comparing the ETs in two peri- ods （a whole year before and after clearcutting, respectively） with similar weather conditions. Then the variation of IVY post-clearcutting was calculated by water balance. [ Result ] （ 1 ） After elearcutting, both soil temperature and ground water level increased obviously while the soil water content decreased by about 0.03. （2） The ETs before and post clearcutting had the similar seasonal and diurnal dynamics; Nevertheless, the annual ET post-clearcutting was only 66.3% of that before clearcutting. （3） The WY ratio （V/Y/precipitation） increased from 0.53 to 0.62 af- ter clearcutting. （4） The dryness index （potential ET/precipitation） was larger than 1 in July, August, and De- cember, while less than 1 in other months in both betbre and post cleareutting period. [ Conclusion ] Clearcutting a poplar plantation on the floodplain of Yangtze River leads to a decrease of ET and an increase of WY ratio. As a re- sult, it is less likely to intensify regional drought in summer, but the capacity of the floodplain for flood peak clip- ping during flooding would also decline.
出处
《林业科学研究》
CSCD
北大核心
2017年第3期486-493,共8页
Forest Research
基金
国家科技支撑课题"长江防护林质量调控与高效经营技术研究与示范(2015BAD07B04)"和"生态经济型血防林构建技术研究与示范(2015BAD07B07)"
关键词
杨树人工林
长江滩地
皆伐
蒸发散
涡度相关
产流
poplar plantation
floodplain of Yangtze River
cleareutting
evapotranspiration
eddy covarianee
water yield
