文献类型：期刊文献

中文题名：六盘山半干旱区华北落叶松人工林林下日蒸散特征及其影响因子

英文题名：Daily Forest Floor Evapotranspiration of Larix principis-rupprechtii Plantation and Its Influencing Factors in the Semi-Arid Area of Liupan Mountains

作者：韩新生[1,2];王彦辉[1];李振华[1,3];王艳兵[1];于澎涛[1];熊伟[1]

第一作者：韩新生

通讯作者：Wang, Yanhui

机构：[1]中国林业科学研究院森林生态环境与保护研究所国家林业和草原局森林生态环境重点实验室,北京100091;[2]宁夏农林科学院荒漠化治理研究所宁夏防沙治沙与水土保持重点实验室,银川750002;[3]新乡学院生命科学技术学院,新乡453000

第一机构：中国林业科学研究院森林生态环境与保护研究所国家林业和草原局森林生态环境重点实验室,北京100091

年份：2019

卷号：55

期号：9

起止页码：11-21

中文期刊名：林业科学

外文期刊名：Scientia Silvae Sinicae

收录：CSTPCD;;EI(收录号：20194807753616);Scopus(收录号：2-s2.0-85075502376);北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：宁夏回族自治区全产业链创新示范项目(QCYL-2018-12);国家重点研发计划(2017YFC0504600;2016YFC0501702);国家自然科学基金重大项目(41390461)、面上项目(41671025);国家林业和草原局宁夏六盘山森林生态定位站和宁夏回族自治区生态修复与多功能林业综合研究中心资助

语种：中文

中文关键词：华北落叶松人工林;林下蒸散;耦合模型;土壤湿度;潜在蒸散;半干旱区

外文关键词：Larix principis-rupprechtii plantation;forest floor evapotranspiration;coupled model;soil moisture;potential evapotranspiration;semi-arid region

摘要：【目的】在半干旱的六盘山北侧叠叠沟小流域研究华北落叶松人工林的林下日蒸散变化特征,分析其对环境变化的响应规律,以期为准确计算和预测森林蒸散、实现森林精细化管理和缓解林水矛盾提供科学依据。【方法】选择华北落叶松人工林典型样地,在2013年8-10月,监测林内外气象条件,并选取能代表多种气象因子综合作用的潜在蒸散作为影响林下蒸散的气象指标;在样地内代表性地点布设11个微型蒸渗仪,其中5个保持自然状态,6个进行防雨处理,以加大土壤湿度变化范围和利于分析土壤湿度对林下蒸散的影响;逐日监测林下蒸散量和蒸渗仪内土壤湿度;分析林下蒸散对土壤湿度和气象因子的响应规律,在此基础上建立考虑二者综合影响的林下日蒸散模型。【结果】研究期间的林下日蒸散波动幅度较大,但随气温、太阳辐射、降雨量逐渐降低而逐渐减小;林下蒸散明显受到诸多气象因子影响,但主要气象因子存在月份和天气类型差异,从8月份的饱和水汽压差变为9月份的太阳辐射和10月份的日最高气温,多云天为潜在蒸散和太阳辐射,晴天为温度,阴雨天为潜在蒸散;除潜在蒸散这个体现多个气象因子综合影响的气象指标外,土壤湿度也是影响林下蒸散的重要因素,且其影响在防雨和自然处理下表现一致;林下日蒸散随潜在蒸散和土壤湿度增加均呈先快速升高、后缓慢升高、在达某个阈值5 mm·d^-1,土壤体积含水量35%或相对含水量056)后趋于平稳的变化趋势;建立了耦合日潜在蒸散(PET,mm·d-1)和土壤体积含水量(VSM,%)影响的林下日蒸散(ETU,mm·d^-1)模型,并基于实测数据拟合了模045PET2+1392PET)[1-EXP(-1292VSM)],精度较高(R2=080)。【结论】六盘山半干旱区华北落叶松人工林林下日蒸散量随潜在蒸散和土壤湿度增加而升高,后增速渐缓并在超过阈值后趋于平稳,综合考虑这二者影响的林下蒸散模型能准确计算和预测林地蒸散。
【Objective】 The variation of daily forest floor evapotranspiration(DFFET) of a larch(Larix principis-rupprechtii) plantation and its response to environmental factors were studied in the small watershed of Diediegou at the northern part of Liupan Mountains, in the semi-arid northwestern China, for an accurate calculation and prediction of the forest evapotranspiration(ET), and for the fine forest management to solve the forest-water contradiction.【Method】 A representative sample plot of larch plantation was selected, and the meteorological conditions both inside and outside the forest plot were monitored in August-October of 2013. The potential evapotranspiration(PET) was selected as a meteorological factor to reflect the integrated effects on DFFET by the various meteorological parameters. Within the plot, 11 micro-lysimeters were set up at representative sites, of which 6 were rain-proof treated to enlarge the soil moisture variation range for a better analysis of the soil moisture effect, while other 5 ones were treated under natural conditions. The DFFET and daily soil moisture in the lysimeter were monitored. Based on the analysis of the responses of DFFET to soil moisture and meteorological factors, a DFFET model was established to reflect the comprehensive effects of environmental factors.【Result】 During the study period, the DFFET showed a large fluctuation range, and characterized by a gradual decrease with declining air temperature, solar radiation and rainfall. The DFFET was obviously influenced by many meteorological factors, but the main meteorological factors differed among months and weather types, from the saturation vapor pressure deficit in August to the solar radiation in September and the daily maximum temperature in October;and from the PET and solar radiation in cloudy days to the temperature in sunny days and the PET in rainy days. Besides the weather parameter of PET which can reflect the integrated impact of many meteorological factors, soil moisture is also an important factor influencing DFFET under both rain-proof and natural conditions. With rising PET and soil moisture, the DFFET increased rapidly at first and then slowly, but leveled off after a certain threshold(PET of 4.5 mm·d^-1, volumetric soil moisture of 35% or relative soil moisture of 0.56) was reached. The model of DFFET(ETU, mm·d^-1) coupling the effects of PET(mm·d^-1) and volumetric soil moisture(VSM,%) was established and well fitted using field measured data, as: ETU=(-0.045 PET2+1.392 PET)(1-EXP(-1.292 VSM)),(R2=0.80).【Conclusion】 The DFFET of the larch plantation in the semi-arid area of Liupan Mountains increased with rising PET and soil moisture, but with a gradually declining rate and finally stabilized after reaching their thresholds. Using a DFFET model considering the effects of both PET and soil moisture can improve the calculation and prediction accuracy..