包容生态因子的广义Logistic模型

AN AUGMENTED LOGISTIC MODEL TAKING ACCOUNT OF ECOLOGICAL FACTORS

以Ｌｏｇｉｓｔｉｃ模型为代表的种群（ｘ）生长模型，仅依赖于时间（ｔ），Ｘ＝ｆ（ｔ），它是表达某一环境下生物过程的数学模型，其增长率参数（μ）为常数。本文发展了一种包含生态因子的广义Ｌｏｇｉｓｔｉｃ模型，Ｘ＝ｆ（Ｐ，ｔ），ｐ表示生态因子，认为增长率是与生态因子有关的参数：μ＝μ０ｆ（ｐ），该模型可以概括在不同环境下种群增长的重复试验，使用作物分期播种资料，建立了水稻干物质积累过程与生育阶段（时间）、播种期、太阳辐射、温度之间的关系，结果表明：该模型可以解释干物重变异的９６．９％。

in the growth models,Logistic model is the mathematic model expressing bio-process in certain environment with a constant intrinsic growth rate(μ).The popularity(X) is afunction of time(t) only,i.e.X=f(t).In this paper,an augmented Logistic model taking account of ecological factors was developed,i.e.X=f(p,t),in which p reprents ecological factors.It is considered that the growth rate is the parameter related to ecological factors.So the augmented model may generalize experiments carried out on crops grown under different environments.The relations between the process of dry matter accumulative of rice and development stage(time),sowing date,solar radiation and temperature were built using data from experimental with varying sowing data. The results show that the augmented model may account for 96.6% of deviation of dry matter data..