不同种植密度条件下单混种作物的生长曲线  

The research of growth curve for monoculture and mixture planting crops grown under different density conditions

作　　者：关佳威 姬明飞[1] 王志强[1] 樊哲翾 冉金枝[1] 邓建明[1] 

机构地区：[1]草地农业生态系统国家重点实验室兰州大学生命科学学院,甘肃兰州730000

出　　处：《草业科学》2015年第8期1243-1251,共9页Pratacultural Science

基　　金：国家973计划课题(2014CB954203);国家自然科学基金优青项目(31322010)和面上项目(31270753)

摘　　要：代谢比例理论(Metabolic Scaling Theory)认为,植物小个体或幼苗的生物量和物质能量代谢速率之间的异速生长指数为1,而随着植物个体的逐渐增大,其代谢异速生长指数逐渐趋近于3/4。2012年,Deng等基于代谢比例理论建立了植物小个体的动态生长模型。然而,对于受到种内或种间不同竞争压力的植物个体来说,其生长过程无疑将受到邻体竞争的影响,他们是否仍然遵循上述植物小个体的动态生长模型尚不得而知。本研究针对此科学问题选取了春小麦(Triticum aestivum)、胡麻(Linum usitisimum)、玉米(Zea mays)3种作物分别进行两两组合混合种植以及单独种植,种植密度分别为高、中、低3种不同密度梯度;在作物出苗至成熟期间,分别对株高、基茎、冠幅、生物量、以及不同时期样方植物密度共进行6次跟踪测定。通过对Deng等建立的植物小个体动态生长模型的拟合分析,发现在种植密度梯度下不论单种还是混种,其植物个体的生长曲线均符合植物小个体动态生长模型,且具有相似生态位的物种混种条件下的个体生长状况要好于单种条件下的个体生长状况,而低密度条件下的生长状况亦显著优于中、高密度个体生长状况。总之,不同竞争压力下的植物个体,其生长速率和成熟大小虽有所变化,但其生长曲线均符合上述生长模型的预测。该研究不但对植物小个体生长模型和代谢理论的可靠性进行了进一步的验证,而且还使该理论的应用与发展得到进一步的完善。According to metabolic scaling theory（ MST）,plant metabolic rate is nearly isometric to body size（ biomass） for seedlings and samplings,and the scaling power is convergent to a constant 3 /4 with the increasing plant size. Recently,we developed the dynamic growth model of individual sampling and seedling based on MST. However,plant individual which grown under intra-species or inter-species competition pressure,will be strongly affected by the neighbors competition during development,it＇s unclear whether the growth model is suitable to the plant individuals with different pressure from intra- and inter-speciesneighbor competition. Therefore,three crops including spring wheat,flax,corn were selected and planted by monoculture and pair combination mixture cultivation ways,with three originally sowing densities（ i. e. high,middle and low densities）. We tracked the dynamic growth of individual plants in each plot for six times from germination to mature period including plant height,caudex,canopy and biomass. After fitting the growth curves based on the dynamic growth model proposed by Deng et al.（ 2012）,we found that the growth curvesof plant individuals conform to the modelregardless of density gradient and planting way. However,the plant grows better and has bigger mature size for the species with similar nichesand in mixture cultivation plots than that in monoculture cultivation plots. Furthermore,and the growth rates and mature sizes decrease with the increasing densities or competition intensities for all species and planting ways. In a word,although the growth rate and mature size of plant vary with the competitive pressureof neighbors,growth curves of plant individual is still conformed to our growth model under different intra- and inter-speciescompetitive pressure.In current paper,we not only examined the growth model of small plant and the metabolic scaling theory,but also further pushing the development of metabolic theory.

关 键 词：作物 单混种 密度 生长曲线 

分 类 号：S352.3[农业科学—作物栽培与耕作技术]