灌木层的叉叶苏铁种内和种间竞争.

Abstract; Based on the field investigation data of 48 Cycas micholitzii target trees and 757 eompetitive trees in Guangxi, this paper analyzed the intraspeeific and interspecific competition intensity of Cycas micholitzii. The Hegyi individual competitive indices (/c) model was used to explore the effects of species competition on the natural regeneration of Cycas micholitzii. ITie results showed that the intraspeeific and interspecific competition intensity of Cycas micholitzii accounted for 3.79% and 96.21% of the total competition intensity, respectively, indicating a remarkable effect on the interspecific competition. The value of the main competition intensity was laid out in numerical order, i. e., Lysidice rhodostegia> Litsea glutinosa>Ficus erecta var. beecheyana>Oimocarpus longan> Cipadessa cinerascens>Alchornea trewioides > Cycas micholitzii. Notably, the competition intensity of Cycas micholitzii decreased between the height of objective trees and the competition intensity and between competitive and objective trees in the whole forest and the Cycas micholitzii population nearly conformed to a power function, while that between other competitive trees and objective Cycas micholitzii trees conformed to an S curve equation. In conclusion, this model could effectively predict the intraspecific and interspecific competition of Cycas micholitzii. Individuals of Cycas micholitzii<().6 m in height should be protected. Artificial tending measures can be taken to reduce the pressure of interspecific competition in order to increase the natural regeneration success rate of Cycas micholitzii. [ABSTRACT FROM AUTHOR]