不同生境狗牙根种群克隆构型和生物量的特征研究

Clone Architecture and Biomass Characteristics of Cynodon dactylon Population in Different Habitats

为研究不同生境狗牙根(Cynodon dactylon)种群克隆构型和生物量的特征,以河南省南阳市唐河县3种不同生境的狗牙根种群为研究对象,对其直立茎密度、直立茎高度、匍匐茎长度、间隔子长度、分枝强度、分枝角度、直立茎生物量、匍匐茎生物量、地下根系生物量、地上生物量、总生物量以及根冠比等指标进行了测定和分析。结果表明:从克隆构件生态可塑性看,在光照充足的生境中,狗牙根的直立茎密度较高、直立茎高度较低、匍匐茎长度较长、间隔子长度较短、分枝强度较大以及分枝角度较小;而在光照不足的生境中,狗牙根上述构件特征呈现出相反的趋势。样地A和样地C的狗牙根种群克隆构型趋向于“密集型”类型,样地B克隆构型趋向于“游击型”类型。从生物量生态可塑性看,在践踏和光照不足的生境中,狗牙根的直立茎生物量、匍匐茎生物量、地下根系生物量、地上生物量、总生物量以及根冠比都居于较低的水平;而在生长条件较好的生境中,其上述各项指标都居于较高的水平。不同生境狗牙根种群的克隆构型和生物量呈现较强的生态可塑性。

The characteristics of the clonal architecture and biomass of Cynodon dactylon population in different habitats were studied based on the erect stem density, erect stem height, stolon length, spacer length, branching intensity, branching angle, erect stem biomass, stolon biomass, underground root biomass, aboveground biomass, total biomass and root-shoot ratio of C. dactylon population among three different habitats in Tanghe Country, Henan. Higher erect stem density, lower erect stem height, longer stolon length, shorter spacer length, bigger branching intensity and smaller branching angle were observed in the habitat of sufficient light, while the characteristics of the above mentioned showed an opposite trend in the habitat of insufficient light. The clonal architecture of C. dactylon population tended to be “phalanx” in sample plot A and C, but “gurilla” in sample plot B. The erect stem biomass, stolon biomass, underground root biomass, aboveground biomass, total biomass and root-shoot ratio of C. dactylon were all at low level with habitats of insufficient light or trampled. The above indicators were relatively high in the habitats of better growing conditions. There was significant ecological plasticity in the clonal architecture and biomass of C. dactylon population in different habitations.