土壤厚度对麻疯树生殖与生长性状的影响

The Influences of Soil Depth on the Characteristics of Reproduction and Growth of Jatropha curcas

地形因素对景观格局的塑造受到关注,而土壤资源性因素对生活史性状的影响很少受到重视。本文首次研究了干热河谷麻疯树生长与生殖性状对土壤厚度的反应。结果如下:(1)土壤厚度对雌花数量、性比都存在明显影响,土壤厚度较大时,雌性适合度较高;(2)土壤厚度明显影响到营养性构件大小,土壤资源丰富样地营养性构件明显较大,分支能力较强;(3)土壤厚度较大时,果期构件的果实包装良好,生殖频率、果实数量、千粒重都明显大于土壤厚度较薄样地,而结籽率、败育率变化不明显;(4)土壤厚度较大时,个体高度较大,垂直空间资源利用相对充分,而冠幅和地径则容易受到密度效应制约;(5)土壤厚度较大时,果实及其组分性状都较大,种子产量潜力较大。结论表明:土壤环境资源充沛时,麻疯树雌性适合度明显,这种生殖潜力还与营养性构件和个体生长优势(或者构型)紧密相关;土壤环境资源对生殖潜力的调节是通过提高构型参数来实现的。本文对于认识土壤环境资源对基于种群的景观格局异质性和生活史性状型具有重要作用。在栽培和经营中需要重视深植与土壤调控。

Great importance was given to the function of topography factrors on landscape patterns,but the influence of soil resource factors on life history features did not receive an adequate attention.This paper firstly studied the response of the growth and reproduction of Jatropha curcas in the dry-hot valleys to the soil depth.The results showed that：（1） The soil depth obviously affected both the amounts of female flowers and the sex ratio,and when the soil was deeper,the femate fitness was heigher;（2） The soil depth also affected the size of vegetative modules,implying that the abundant soil plot had the bigger size of vegetative modules with a stronger branching capacity;（3） With the deeper soil,the fruit packaged well in the fruit time,and all reproduction frequency,fruit amounts,weight of 1000 seeds were higher than the thinner soil plot,and seed-set ratio and aborted ratio had no significant difference between soil layers;（4） The deeper soil plot had higher individual height with a relatively full utility of the vertical space resource,but tree crown size and base diameter were affected easily by the density effect of forest;（5） There was a higher capacity of seed product with a bigger fruit and components when the plot had a deeper soil layer.It was concluded that the bigger female fitness and seed product capacity responded to more full environment of soil resource,which were also correlated to vegetative modules and individual size,implying that soil resource adjusted the reproductive capacity through promoting the vegetative growth capacity,such as architecture.This paper indicated that the soil depth was important to adjusting the landscape heterogeneity pattern and life history feature types of population,especially to the species that occupied the whole community.And in pratice of siliviculture and management of economical forest,it was necessary to emphasize the significance of deeper cultivation and soil control in the higher and stabler production of Jatropha curcas.