摘要
2019年4月1日—10月31日,利用Granier热扩散探针监测银杏树干液流密度的动态变化,并同步观测环境因子的变化,分析银杏蒸腾耗水规律及其对环境因子的响应。结果表明:(1)银杏树干液流启动于4月10日左右,结束于10月20日左右,前后历时194天左右,树干液流密度表现为晴天>阴天>雨天,晴天条件下树干液流密度日变化呈典型的单宽峰曲线,阴天或雨天条件下,由于太阳辐射的波动,树干液流日内变化波动较大。(2)生长季内单株日蒸腾耗水量均值为(6.16±3.32)kg·d^(–1),4—10月的单株日蒸腾耗水量分别为(2.40±1.50)、(7.64±1.35)、(7.78±2.03)、(8.34±2.35)、(8.38±3.05)、(6.64±2.03)、(2.39±1.89)kg·d^(–1);监测时间内,林分蒸腾耗水总量为244.81 mm,小于降雨总量(534.86 mm),但季节性供水不足问题依然存在,6月最为严重。(3)不同时间尺度条件下,影响树干液流的生态因子发生显著变化,小时尺度上,影响液流速率的关键因子为征能量水平的太阳总辐射(Rs)和综合反映空气温度和空气湿度的饱和水汽压差(VPD),而月尺度上,银杏单株日蒸腾耗水量月变化主要与气孔导度、土壤温度呈现极显著正相关。(4)环境因子与树干液流密度相关程度存在季节性差异,Rs和VPD在生长旺盛期与树干液流密度相关性最高,生长初期相关性最低;土壤湿度在生长季初期对树干液流形成极显著胁迫。
To investigate the characteristics of transpiration water consumption of Ginkgo biloba L.in the North China Plain,the Granier-type thermal dissipation probes were used to measure sap flow density in growing season of 2019(Apr.1-Oct.31),and the environmental factors including solar radiation(Rs),air temperature(T),relative humidity(TH),soil temperature,soil humidity and wind speed were measured synchronically,aimed to study the stem sap flow of Ginkgo biloba L.in response to environmental factors.The results showed that the sap flow of Ginkgo biloba L.lasted about 194 days form April 10 to October 20.Sap flow density displayed an obvious pattern with the biggest in a sunny day,next in a cloudy day and finally in a rainy day.The diurnal changes of the sap flow density presented a typical single-peak curve under a sunny day,while it undulated widely under cloudy or rainy days due to the fluctuation of solar radiation.Transpiration water consumption in the whole growing season for the single plant of Ginkgo biloba L.was 1468.59 kg,and daily average was(6.16±3.32)kg·d–1,daily average water consumption for each month(April to October)was(2.40±1.50),(7.64±1.35),(7.78±2.03),(8.34±2.35),(8.38±3.05),(6.64±2.03)and(2.39±1.89)kg·d^(–1)respectively.Though the stand water consumption of Ginkgo biloba L.in growing season was 244.81mm,lower than the rainfall,seasonal water shortage still existed,especially in June.The partial correlation analysis showed stem sap flow density at the hour level was significantly correlated with VPD and Rs(P<0.01),reflecting air temperature,relative humidity and energy level.While at the month level,monthly changes of daily average transpiration water consumption was significantly affected by stomatal conductance and soil temperature.There were seasonal differences on correlation degree,the highest correlation between environmental factors and sap flow appeared at the vigorous growth stage,while the lowest appeared at the early growth stage,soil humidity excluded,which had a extremely
作者
尤海舟
王超
李冬梅
YOU Haizhou;WANG Chao;LI Dongmei(Hebei Academy of Forestry and Grassland Science,Shijiazhuang Hebei 050061,China;Hebei Technical Innovation Center for Forest Improved Varieties,Shijiazhuang Hebei 050061,China;Luannan State-owend Forest Farm,Luannan Hebei 063500,China)
出处
《生态科学》
CSCD
2023年第3期67-74,共8页
Ecological Science
基金
河北省三三三人才工程资助项目(A201803037)
河北省重点研发项目计划(20326810D)。
关键词
华北平原
银杏
树干液流密度
蒸腾耗水量
环境因子
the North China Plain
Ginkgo biloba L.
stem sap flow density
transpiration water consumption
environmental factors
