摘要
本文根据对松嫩平原碱化草甸天然虎尾草种群的调查和分析,选用相关性最好的函数关系作为虎尾草种群的种内竞争和密度制约特征。结果表明:平均株丛重与株丛密度之间表现为幂函数y=ax^(-b)关系;平均植株重与密度之间在拔节孕穗期为幂函数y=ax^(-b)关系,在籽实成熟期为指数函数y=ae^(-bx)关系;分蘖率与密度之间呈线性y=a-bx关系;抽穗率、单位面积穗重、平均穗重、平均穗状花序数、平均小穗数和地上生物量诸数量性状的密度制约特征均表现为指数函数y=a^(-bx)关系。根据拔节孕穗期和籽实成熟期诸相应性状参数的比较,反映了随着虎尾草的生长发育,因种内竞争,各数量性状的密度制约作用增大。
Chloris virgata is an annual tuft grass which is more alkali tolerance. According to the investigation and the analysis of natural Ch. virgata population of alkalization meadow in the Songnen plain of China, the best correlations among simulated functions were selected to be the specifiitics of intraspecific competition and density dependence of the population in this paper. The results showed that there were the power function y = ax-b between mean tuft weight and the tuft density;the power function y = ax-b in joint-booting stage, and the exponential funfiaon y = ae-bx in ripening stage, between mean plantweight and the density; the linear function y = a-bx between tillering rate and the density; the exponential functiony = ae-bx between earing rate, ear weight per unit area, mean weight per ear, mean number of spike per ear, mean numler of spikelet per ear, or above-ground biomass, and the density of the population. Through comparisons of the parameters to corresponding specificities in both growth periods of joint-booting stage and ripening stage, the results showed that due to intraspecific competition, all the quantitative specificities of the population had their effects of density dependence increased along with growth and development of Ch.virgata.
出处
《生态学报》
CAS
CSCD
北大核心
1992年第3期266-272,共7页
Acta Ecologica Sinica
基金
国家自然科学基金
关键词
碱化草甸
虎尾草
种群密度
intraspecific competition, density dependence, alkalization meadow, population of Chloris virgata.
