| 摘要: |
| 【目的】研究森林抚育间伐强度对华山松天然次生林光合特性的影响，为秦岭华山松林经营提供理论依据。【方法】在秦岭南坡旬阳坝林区华山松天然次生林内设置10块20 m×30 m的研究样地，并对其进行间伐强度分别为0%(CK)，5%，10%，15%和20%的作业，测定不同间伐强度样地内环境因子及华山松的光合生理参数的日变化，并采用Duncan’s新复极差法对华山松光合生理参数进行差异性分析，使用相关性分析研究环境因子与华山松光合生理参数的关系。【结果】光照强度（A）、大气温度（T）随间伐强度的增大而升高；相对湿度（RH）随间伐强度的增大而降低；大气水分亏缺（VPD）在不同时间段随间伐强度变化规律不同。净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）和光能利用率（LUE）随间伐强度增大而显著增大（P<0.05）；气孔限制值（Ls）随间伐强度的增大而显著降低（P<0.05）。相关性分析表明，A与Pn呈显著性正相关关系；Pn与VPD呈负相关关系，间伐强度大于10%时二者相关性显著（P<0.05）；T与Pn的关系随间伐强度的增加由显著正相关转变为不显著负相关关系。【结论】间伐强度为20%有利于秦岭林区华山松天然次生林的光合生产。 |
| 关键词: 间伐 华山松天然次生林 环境因子 光合特性 |
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| 基金项目:林业公益性行业专项“秦岭天然次生公益林抚育经营关键技术研究”（201204502） |
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| Effects of thinning on photosynthesis characteristics of Pinus armandii natural secondary forest in Qinling Mountains |
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LI Ming-yu,DANG Kun-liang,MA Jun,et al
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| Abstract: |
| 【Objective】The objective of this study was to understand the effects of thinning intensity on photosynthetic characteristics of Pinus armandii natural secondary forest in Qinling Mountains to improve management of Pinus armandii forests.【Method】Ten experimental plots (20 m×30 m) with different thinning treatments (0%,5%,10%,15%,and 20%) were selected at Xunyangba forest region on south slope of Qinling Mountains.The in-situ daily processes of photosynthetic characteristics and environmental factors were measured in each plot.The variance of photosynthetic characteristics and environmental factors were analyzed by multiple comparisons and correlation analysis.【Result】Contrary to relative humidity (RH),light intensity (A),air temperature (T) increased along with thinning intensity.The atmospheric water vapor pressure deficit (VPD) varied at different times.The net photosynthetic rate (Pn),stomatal conductance (Gs),transpiration rate (Tr) and instantaneous light energy utilization (LUE) significantly increased as the increase of thinning intensity（P<0.05）.The limiting value of stomata (Ls) decreased significantly （P<0.05）.Correlation analysis showed that the light intensity (A) and net photosynthetic rate (Pn) were significantly positive correlated (P<0.05);Pn and VPD had significantly negative correlation (P<0.05);while the relationship between T and Pn changed from significantly positive correlation to insignificantly negative relationship.【Conclusion】The thinning intensity of 20% was advantageous to the growth of P.armandii forest in Qinling Mountains. |
| Key words: thinning Pinus armandii natural secondary forest environment factors photosynthetic characteristics |
