修剪对茶树修剪凋落物水文特性的影响

Effects of pruning on hydrological characteristics of tea tree litter

【目的】分析修剪强度对茶树枝叶凋落物生物量及生态水文特性的影响,为茶园凋落物水文服务功能的定量化研究与评估提供理论依据。【方法】以14年生黄观音茶园为研究对象,采用田间修剪与室内持水模拟试验相结合的方法,测量、计算3种不同修剪强度(0~20、0~15和0~7 cm)凋落物的生物量、持水、失水特性,并将其与时间的相关性进行拟合分析。【结果】3种不同修剪强度下茶树枝叶凋落物的生物量为1.75~2.49 t/ha。修剪凋落物最大持水率排序为中度修剪(121.33%)>重度修剪(113.69%)>轻度修剪(106.16%);重度和中度修剪处理(2.89和2.83 t/ha)的最大持水量显著高于轻度修剪处理(1.86 t/ha)(P<0.05);但重度、中度与轻度修剪最大失水量表现为中度修剪(0.84 t/ha)>重度修剪(0.73 t/ha)>轻度修剪(0.67 t/ha)。修剪凋落物吸水速率在0.5 h内最高,表明其具有短时间内迅速拦截降水,减少地表径流形成的作用;凋落物的持水量、持水率、失水量、失水率与浸水时间(t)的最佳拟合方程为W=a+blnt;吸水速率、失水速率与时间(t)最佳拟合方程为幂函数V=atb。【结论】茶园成龄后,中度和重度修剪下枝叶凋落物的持水量差别不明显,但均高于轻度修剪,表明中度或重度修剪可提高茶园生态水文功能。

【Objective】The effects of pruning intensity on biomass,ecological and hydrological characteristics of litter of tea leaves were studied,and the theoretical basis was provided for the quantitative study and evaluation of litter hydrological service function in tea garden.【Method】Taking the14-year-old Huangguanyin tea garden as research object,combining field pruning and indoor water holding simulation test,litter biomass,water holding and dehydration characteristics of litter under three different pruning intensities(0-20,0-15and0-7cm)were measured.Correlation between biomass,water holding and water loss characteristics with time of litter were analyzed.【Result】The biomass of tea leaf litter was1.75-2.49t/ha under three different pruning intensities.The maximum water holding capacity of litter was moderate pruning(121.33%)>severe pruning(113.69%)>light pruning(106.16%).The maximum water holding capacity of severe(2.89t/ha)and moderate(2.83t/ha)pruning treatments was significantly higher than that of light pruning(1.86t/ha)(P<0.05);but the maximum water loss capacity was moderate pruning(0.84t/ha)>severe pruning(0.73t/ha)>light pruning(0.67t/ha).The water absorption rate of litter in the first0.5h was the maximum,indicating that it could intercept precipitation within a short time quickly,reduced the formation of surface runoff.The best fit equation for litter water holding capacity,water holding rate,water loss capacity,water loss rate and soaking time(t)was W=a+blnt;the best fit equation for water absorption rate,water loss rate and time(t)was power function V=atb(a,b were coefficient).【Conclusion】As tea garden grows,the difference in water holding capacity between moderate and severe pruning is not obvious,but the water holding capacities are larger than that of light pruning.Therefore,moderate and severe pruning can improve ecological hydrological functions in tea garden.