强遮荫巨桉林下鸭茅的光合特性、生物量及经济效益评价  

A Study on the Photosynthetic Characteristics and Biomass of Dactylis glomerata under Eucalyptus grandis Forests with High Shading Rates

作　　者：沈迪玉[1] 白燕[1] 陈小红[1] 万雪琴[1] 尹丽[1] 弓平[1] 陈飞[1] 

机构地区：[1]四川农业大学生态林业工程四川省重点实验室

出　　处：《四川林业科技》2010年第4期53-58,共6页Journal of Sichuan Forestry Science and Technology

基　　金：国家科技部“十一五”科技支撑计划(2006BAC01A11,2008BADC2B01)资助

摘　　要：试验研究了＂巨桉＋鸭茅＂林草复合种植模式中不同林冠遮荫水平（71.5%、81.5%、88.0%、90.7%、92.8%）对4龄、2龄鸭茅的光合特性、生长指标及生物量的影响。结果表明：各遮荫水平下,不同年龄鸭茅光合日变化差异均不显著;随着遮荫水平和年龄的增加,鸭茅的生长指标逐渐变小,长势变差,生物量积累减少。试验中的遮荫水平均已超过适宜的遮荫水平,对鸭茅的生长已经产生抑制作用,结合经济效益的分析可知,2 a生鸭茅在遮荫90.7%时,4 a生85.0%时,其经济产出等于投入,不能获取经济效益,当低于此遮荫水平,种植鸭茅将收益大于投入。Studies were made of the effect of different shading rates（71.5%,81.5%,88.0%,90.7% and 92.8%） on the photosynthetic characteristics,growth index and biomass of different age＇s Dactylis glomerata which was planted in Eucalyptus grandis forest.The results showed that the diurnal variation of photosynthesis exhibited a single peak curve and had no obvious difference between Dactylis glomerata of different ages under different shading rates.With the increment of shading rates and the ages of Dactylis glomerata,its growth index was gradually decreasing,its growth became poor,and its biomass accumulation reduced.The results revealed that the shading rates in the study were higher than the most adaptive level for Dactylis glomerata,and showed inhibition on its growth.Combined with the analysis on the economic benefit,it was shown that when the two years old Dactylis glomerata was planted under shading rates of 90.7%,or the four years old was planted under shading rates of 85.0%,the output of planted Dactylis glomerata was equal to the production input and the economic benefit couldn＇t be obtained.If the shading rate was less than this level,the output would be more than the production input.

关 键 词：巨桉 遮荫水平 鸭茅 光合特性 生物量 

分 类 号：S792.39[农业科学—林木遗传育种]