摘要
林冠光能截取(LI)与叶片光合生理特性的关联性反映了植物功能性状对光环境变化的响应及适应,是冠层结构和环境条件综合作用的结果。在张掖市黑河干流边缘的洪泛平原湿地随机选择10个样地,按等分原则将样地内的旱柳(Salix matsudana)冠层分为上、中、下3个层次,研究了旱柳冠层各层次LI与叶片蒸腾速率(T_r)、净光合速率(P_n)的相互关系。结果表明:随着旱柳冠层下降,叶面积指数(LAI)、平均叶倾角(MLA)、叶厚度、光合有效辐射(PAR)、LI、T_r和P_n均呈逐渐减小趋势,叶面积呈逐渐增加趋势,叶片含水量呈先增大后减小的趋势,叶片聚集类型由聚集为主转向分散为主;在树冠上层和下层,LI与T_r、P_n均呈显著正相关(P<0.05),中层呈极显著正相关(P<0.01)。在旱柳冠层内部,上层倾向于减小LI、T_r与P_n的保守性生存模式,中层和下层选择增大LI、T_r与P_n的开拓性模式,反映了湿地植物在异质性生境中根据其功能需求在自身性状之间进行的资源优化配置。
The correlation between canopy light interception（ LI） and leaf photosynthetic physiological characteristics reflects the response and adaptation of plant functional traits to the changes of light conditions,which is the result of integrative effects of canopy structure and environmental conditions. A total of 10 plots were randomly selected from the floodplain wetlands on the edge of the Heihe River in Zhangye City,Gansu Province,China. According to the principle of equal division,the canopy of Salix matsudana in those plots was divided into the upper,middle,and lower levels. The relationship between LI,transpiration rate（ Tr）,and net photosynthetic rate（ Pn） of each canopy level was examined. The results showed that,with the decreases of canopy level of S. matsudana,leaf area index（ LAI）,mean leaf angle（ MLA）,leaf thickness,photosynthetically active radiation（ PAR）,LI,Tr,and Pn showed a decreasing trend,while leaf area was gradually increasing. Leaf moisture content first increased and then decreased. The type of leaf aggregation changed from aggregation to dispersion. In the upper and lower canopy,the relationships between LI and Tr and Pn showed significant positive correlations（ P〈0. 05）. In the middle layer,they showed significant positive correlations（ P〈0. 01）. Inside the canopy,the upper leaves used conservative survival strategy that reduced LI,Tr and Pn,while the middle and lower leaves showed the exploitative strategy that increased LI,Tr and Pn,reflecting the optimal allocation of resources between wetland plant＇s traits according to functional requirements in heterogeneous habitats.
作者
姚文秀
赵成章
陈静
王建良
李群
张伟涛
YAO Wen-xiu,ZHAO Cheng-zhang,CHEN Jing,WANG Jian-liang,LI Qun,ZHANG Wei-tao(College of Geography and Environmental Science, Northwest Normal University, Research Center of Wetland Resources Protection and Industrial Development Engineering of Gansu Province, Lanzhou 730070, China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2018年第5期1334-1340,共7页
Chinese Journal of Ecology
基金
国家自然科学基金项目(41461013
91125014)
甘肃省生态学重点学科基金项目资助
关键词
冠层结构
蒸腾速率
净光合速率
旱柳
张掖湿地
canopy structure
transpiration rate
net photosynthetic rate
Salix matsudana
Zhangye wetland.
