麻疯树2年生人工林构筑型对修枝与土壤肥沃性的响应

本文首次采用固定枝级划分方法,试验研究了麻疯树构筑型对土壤肥沃性的响应,并探究了构型调控效果的资源反应。结果表明:1)土壤肥沃时麻疯树分枝率高、分枝角度小、枝长较长,构型为密集型;土壤瘠薄时麻疯树分枝率低、分枝角度大、枝长较短,构型为游击型;2)人为修枝也没有明显影响构型对土壤肥沃性的响应策略,但却显著增加了肥沃生境下构型的密集性(30→22°);3)人为修枝改变了贫瘠生境下一级枝长度、一级枝枝径与二级枝长度,具有壮枝作用,而对肥沃生境树体枝条大小影响不明显(二级枝枝径例外);4)据分析,同龄顶芽间距离为间隔子,分枝间夹角为分枝角度,分枝率是分枝强度,类似于克隆植物构型;5)构型枝级划分采用了固定枝序法确定,主干分枝为一级枝,一级枝分支为二级枝,增加了枝级的稳定性,与传统枝级划分方法相反;6)分析还发现,麻疯树构型对资源异质性的响应根源在于一级枝分枝角度,该参数塑造了游击性与密集性的构型特性。

Responses of Architecture of a 2-year-old Plantation of Jatropha curcas to Pruning and Soil Fertilization

In this paper, the method of stable branching order is firstly adopted to study experimentally the response of Jatropha curcas architecture to fertilized soil and the resource reflection of structure control. Results indicated that： 1 ） when soil was fertilized, there were a higher bifurcation ratio, a smaller angle of bifurcation and a longer branch of J. curcas with a Phalanx architecture, but in poor soil there were a low- er bifurcation ratio, a bigger angle of bifurcation and a shorter branch with a Guerrilla; 2） the artficial pruning had no obvious effect on the response of architecture to fertilized soil, however significantly added the Phalanx（ angle from 30° to 22°） 3 ） The artificial pruning changed the length and diameter of the first-class branch and the second-class diameter and had an obvious effect on branch improvement in poor habitat, but had less obvious effect on branch size except the second-class diameter in fertilized habitat; 4） Compared to the typical clone plant, the distance between apical buds of the same age was a spacer length, bifurcation ratio was branching density, and the intersection angle between branches was a bifurcation angle ; 5） Contrary to the traditional classification branchclass, the method of stable branch order was adopted to classify the branch class in this paper, and the bifurcation of trunk was set as the first-class branch and the bifurcation of first-class branch was set as the second-class, thus adding the stability of the branchclass classification; 6） The response of J. curcas architecture to resource heterogeinity contributed to the bifurcation angle of the first-class, which also relatively built the architecture characteristics of Guerrilla and Phalanx.