摘要
基于定位观测,研究了三峡水库消落带不同海拔区段狗牙根的种群密度、形态性状和生物量及其分配.结果表明:在3个海拔区段,狗牙根种群密度的大小为浅水位区段(海拔165～170m)>未经水淹区段(海拔>172m)>深水位区段(海拔145～150m);根径和根系长度的大小为深水位区段>浅水位区段>未经水淹区段;种群总生物量和根、茎、叶生物量及茎生物量分配比率为浅水位区段>未经水淹区段和深水位区段,根、叶生物量分配比率和地下/地上生物量的变化为深水位区段>浅水位区段和未经水淹区段.浅水位区段的狗牙根种群应对水陆生境变化特有的适应策略是加速伸长生长,增加茎生物量分配;深水位区段的策略是增加分枝节间数量、分枝数量和叶生物量分配;二者共有的适应策略是加速根系生长、增加分蘖数量和地下生物量分配,为在陆地环境中的快速生长提供营养和能量储备.
This paper studied the population density,morphological characteristics,and biomass and its allocation of Cynodon dactylon at different altitudinal sections of the hydro-fluctuation belt in Three Gorges Reservoir area,based on located observations.At the three altitudinal sections,the population density of C.dactylon was in the order of shallow water section（165-170 m elevation） non-flooded section（above 172 m elevation） deep water section（145-150 m elevation）,the root diameter and root length were in the order of deep water section shallow water section non-flooded section,the total biomass,root biomass,stem biomass,leaf biomass,and stem biomass allocation ratio were in the order of the shallow water section non-flooded section deep water section,and the root biomass allocation ratio,leaf biomass allocation ratio,and underground biomass/aboveground biomass were in the order of deep water section shallow water section non-flooded section.The unique adaption strategies of C.dactylon to the flooding-drying habitat change in the shallow water section were the accelerated elongation growth and the increased stem biomass allocation,those in the deep water section were the increased node number of primary and secondary branches,increased number of the branches,and increased leaf biomass allocation,whereas the common strategies in the shallow and deep water sections were the accelerated root growth and the increased tillering and underground biomass allocation for preparing nutrition and energy for the rapid growth in terrestrial environment.
出处
《应用生态学报》
CAS
CSCD
北大核心
2011年第11期2829-2835,共7页
Chinese Journal of Applied Ecology
基金
国家“十二五”林业科技支撑计划项目(2011BAD38BO4)
国家“十一五”林业科技支撑计划项目(2006BAD03A313)资助
关键词
三峡库区
消落带
狗牙根
种群密度
生物量
Three Gorges Reservoir area
hydro-fluctuation belt
Cynodon dactylon
population density
biomass.
