文献类型：期刊文献

中文题名：冠层高度对毛竹叶片光合生理特性的影响

英文题名：Effects of Canopy Height on Photosynthetic Physiology Characteristics of Phyllostachys pubescens Leaves

作者：曹永慧[1] 周本智[1] 王小明[1] 顾连宏[2]

第一作者：曹永慧

机构：[1]中国林业科学研究院亚热带林业研究所,国家林业局钱江源森林生态系统定位观测研究站,浙江富阳311400;[2]美国橡树岭国家实验室环境科学部,田纳西州橡树岭37831

年份：2016

卷号：36

期号：11

起止页码：2256-2266

中文期刊名：西北植物学报

外文期刊名：Acta Botanica Boreali-Occidentalia Sinica

收录：CSTPCD;;北大核心:【北大核心2014】；CSCD:【CSCD2015_2016】；

基金：浙江省自然科学基金项目(LY13C160002);国家自然科学基金(31600503);国家林业局948项目(2014-4-57);中央级公益性科研院所基本科研业务费专项(RISF2013002);中国林业科学研究院基本科研业务费专项资金项目--海内外杰出学者讲习计划(CAFYBB2011007)

语种：中文

中文关键词：毛竹;光合作用;蒸腾作用;水分利用效率;冠层高度;季节差异;日变化

外文关键词：Phyllostachys pubescens ; photosynthesis; transpiration; water use efficiency; canopy height seasonal variation; diurnal variation.

分类号：Q945.78

摘要：借助LI-6400便携式光合作用系统,研究了冠层高度对不同林龄毛竹(Phyllostachys pubescens)叶片光合生理特性和水分利用效率(WUE)的季节性影响,为促进毛竹林碳汇能力和生产力提升的林分结构调整等可持续栽培技术提供理论依据。结果表明:(1)出笋期,不同竹龄毛竹叶片净光合速率(Pn)和蒸腾速率(Tr)的日均值呈现出冠层上部小于冠层下部的梯度变化趋势,且2a生毛竹不同冠层Pn日均值大于3a生毛竹;孕笋行鞭期,不同林龄毛竹各时间点Pn值和日均值、以及2年生毛竹各时间点的Tr值均为冠层上部大于冠层下部。各生长季节,不同林龄毛竹个体叶片的气孔导度(Gs)均与Tr的变化趋势一致。(2)2年生毛竹各季节仅冠层上部叶片会出现"光合午休",而3年生毛竹仅于出笋期时各冠层叶片出现"光合午休"现象。(3)出笋期毛竹叶片WUE日均值随着冠层高度增加而增加,这种变化趋势不受竹龄影响;而孕笋行鞭期,仅2年生毛竹叶片WUE日均值随着冠层高度增加而下降。不同冠层高度的孕笋行鞭期毛竹叶片WUE日均值都显著高于出笋期;冠层高度对毛竹叶片气体交换特性和WUE的影响受生长发育关键期的季节因素影响,且毛竹叶片WUE与Gs之间存在负相关关系,其不受毛竹个体年龄和叶片冠层高度影响。(4)不同生长季节各冠层叶绿素a/b值均随着冠层高度下降而降低,不同林龄毛竹叶片叶绿素含量基本随着冠层自上而下呈逐渐增加的趋势。各生长季节,不同林龄个体叶片氮素含量、比叶重随冠层高度垂直变化趋势与叶片Pn日均值的垂直变化趋势一致。研究认为,毛竹不同冠层部位叶片通过改变形态、氮素含量来适应不同生长季节生长环境的变化,以便充分利用光能提高光合能力。
The carbon sequestration ability, water use efficiency （WUE） and other photosynthetic physiology characteristics for different aged of Phyllostachys pubescens individuals were analyzed at two canopy layers with a LI 6400 portable photosynthesis system. The results showed that： （1） the daily average net photosynthetic rate （Pn） and the transpiration rate （Tr） of P.pubescens were lower for upper canopy leaves than those of lower canopy leaves regardless of bamboo age during the culm elongation period. During the shoot development period, the upper canopy leaves had a higher Pn value at each time point and a higher daily average Pn than that of the lower canopy leaves regardless of bamboo age. Meanwhile, the Tr value for upper canopy leaves of 2 year old bamboo was higher at each time point than that for lower canopy leaves. The vertical change of stomatal conductance （Gs） for different age groups was consistent with that of Tr, regardless of the growing season. （2） A reduction of photosynthesis at noon was observed at different canopy layers of 3 year old bamboo and the upper canopy of 2 year old bamboo during the culm elongation period, while it only occurred in the upper canopy of 2 year old bamboo during the shoot development period. （3） The daily average of WUE in the culm elongation period increased along with canopy height regardless of age. While, the daily average of WUE decreased with increasing canopy height during the shoot development period for 2 year old individuals. So, the canopy height had obvious effects on bamboo leaf photosynthesis and WUE, which also impacted by growing seasons. There was negative relationship between Gs and WUE for bamboo with all ages and canopy layers. We wanted to explore the variable stomata behavior of moso bamboo at different ages during its important growing seasons and in order to improving WUE and lay the foundation for further mechanistic research on water use strategy for bamboo. （4） The chlorophyll a/b values decreased with the decrease of canopy height in different growing seasons. While the chlorophyll content of all ages of bamboo was increased with the decrease of canopy height. The vertical variation of leaf nitrogen content and leaf mass per area within canopy was consistent with that of leaf net photosynthetic rate regardless of the growing seasons. The results indicated that the leaf morphology and nitrogen content in the different canopies could change with the growth environment in different growing seasons, and make full use of light energy to improve the photosynthetic capacity. Our data could provide a scientific basis for developing sustainable cultivation technologies and enhancing moso bamboo timber production and carbon sequestration.