作物生态位构建的模型及其进化惯量与动量的试验研究

物种生态位构建与其进化关系的研究属于生态位理论的新进展。以半干旱区作物为对象,系统地分析了生态位内涵的发展及生态位构建机理,研究了作物种与环境变化间协同进化的特殊规律,提出用作物生态位的适合程度测定其进化惯量,用现实生态位对其中心点的偏离程度测定进化动量,并建立了相应的数学模型,进行实例的计算分析,主要结果有：①作物种的生态位构建机制,从进化尺度上具体描述了作物通过其新陈代谢、活动与选择来确定自身的生态位（包括部分的产生、毁灭）。基于Hutchinson的生态位理论,建立了 n维超体积生态位的构建模式。②根据进化惯量与进化动量对生态位构建的作用,所进行的实例计算与分析的结果显示：自然选择与人工选择的压力具有异向性,生态位构建导致了进化惯量和进化动量不同的变化规律;作物的传统品种与新品种相比,具有较强的进化惯量与较弱的进化动量;在自然选择与人工选择双重作用下,作物生态位的构建机制有其特殊性。③在作物种进化与可变环境资源的耦合关系分析中,随着土壤养分的增加,作物进化惯量递增而进化动量递减,这从进化角度上揭示了土壤养分变化对作物生态位构建的影响。以上结果可为作物品种选育与农田人工调控提供理论依据。

The Niche Construction Model of Crop and its Research on Evolutionary Inertia and Evolutionary Momentum

The research of the relation between niche construction of crop and its evolution belongs to the new field in the niche theory. Taken the crop in semi arid region as the object,the paper systematically analyzes the development of the niche connotation and the mechanism of the niche construction,researches the special law of the cooperated evolution between the crop species and the change of their environments,proposes the evolutionary inertia measured by the fitness of the crop niche and the evolutionary momentum measured by the deviation between the real niche and the center point,and constructs the corresponding mathematical model and analyzes the real experiment data.The main results are: (1) Niche construction describes the crop species with evolution scale,materially.Crops determine its niche through metabolism,action and selection,including some creation and destruction of its niche.Based on the Hutchinson's niche theory ,the paper build up the pattern of n dimensional hypervolume niche construction. (2) On the change of evolutionary inertia and momentum with the effect of niche construction,the calculation and analysis show that the pressures of the natural selection and the artificial selection have different directions,and the niche construction can lead to different law of evolutionary inertia and weaker evolutionary mementum.Due to the double effects of natural and artificial selection,the rule of crop is special compared with the natural one in the natural one in the niche construction. (3) On the relation between the crop evolution and the changeable resources in its enviroments,the evolutionary inertia increases and the evolutionary momentum decrease with the increasing of the soil nutrients.It is the evolutionary effect on niche construction by soil nutrients.The above results can be the theoretical supports to the breed and selection of the crop species and the artificial regulation of the crop fields.