伐桩注水对毛竹光合蒸腾特性月变化的影响

Effect of Water Storage in Their Stumps on Annual Variation of Photosynthesis and Transpiration Characteristics of Phyllostachys edulis

为了探求毛竹光合蒸腾特性对注水伐桩的响应机制。在试验毛竹林中选取10 m×20 m样地9块,设置伐桩不灌水(CK)、注水伐桩12个(T1)和注水伐桩18个(T2)的3个灌水梯度处理样地各3块,测定各处理下2 a生毛竹光合蒸腾指标及林内各主要环境因子,研究不同数量注水伐桩下毛竹光合蒸腾特性差异及其与林内主要环境因子间的关系。试验表明:(1)不同处理间毛竹的净光合速率、蒸腾速率全年均表现为T2>T1>CK,T1、T2处理毛竹净光合速率、蒸腾速率与CK处理相比最大增幅均出现在5月;(2)不同处理间毛竹水分利用效率、气孔导度和气孔限制值全年基本表现为T2>T1>CK,T1、T2处理毛竹水分利用效率与CK处理相比最大增幅分别出现在11月和7月,T1、T2处理毛竹气孔导度与CK处理相比最大增幅分别出现在5月和10月,T1、T2处理毛竹气孔限制值与CK处理相比最大增幅均出现在1月和10月。(3)不同处理间毛竹胞间CO2浓度全年基本表现为CK>T1>T2,T1、T2处理毛竹胞间CO2浓度与CK处理相比最大增幅均出现在10月。(4)在毛竹林中增加注水伐桩能够在一定程度上改变毛竹净光合速率和蒸腾速率与林内环境因子之间的相关关系。增加注水伐桩能够显著提高毛竹的光合蒸腾能力,增加毛竹光合产物的积累,同时能够改善毛竹的生长状况,研究为毛竹林节水灌溉措施的制定和培育生产提供了理论参考。

In order to investigate the responses of photosynthesis of Phyllostachys edulis（Moso bamboo）to water storage in their stumps,10 m×20 m plots of 9 blocks were selected in the experiment,and the experiment was carried out with three different irrigation treatments,i.e.K（0 stumps with water storage）,1（12 stumps with water storage） and T2（18 stumps with water storage） and the physiological parameters of photosynthesis and transpiration of 2-year-old Moso bamboo and main environmental factors of stands were measured.To study the differences in photosynthetic and transpiration characters of Moso bamboo with differrent amounts of water storage in stumps.The results showed that：（1） among the different treatments,the photosynthetic rate and transpiration rate of Moso bamboo throughout the year were in the order of T2T1CK,the net photosynthetic rate and transpiration rate of bamboo in T1 and T2 treatments,compared with the CK treatment,the largest increase both appeared in May;（2） among the different treatments of bamboo water,the use efficiency,stomatal conductance and stomatal limitation value of the annual basic were expressed as T2 T1CK,the water use efficiency of Moso bamboo in T1,T2 treatments,compared with CK,the largest increase was observed in November and July,the stomatal conductance of Moso bamboo in T1 and T2 treatments,compared with CK,the largest increase occurred in May and October respectively.The stomatal limitation of Moso bamboo in T1 and T2 treatments,compared with CK,the largest increase occurred respectively in January and October;（3） the intercellular CO_2 concentration in different treatments showed CKT1T2 for the whole year,and the maximum intercellular CO_2 concentration increase in T1 and T2 treatments were in October;（4） the increase of water storage in stumps could change the relationship between the net photosynthetic rate and transpiration rate of Moso bamboo and environmental factors to a certain extent.The increase of storage in stumps could increase the photosynthesis and transpiration capacity of bamboo,increase the accumulation of photosynthetic products,and improve the growth of bamboo.This study provides the theoretical reference for the establishment and cultivation of water-saving irrigation measures for Moso bamboo forest.