A 2-PHASE MOSAIC IN A SAVANNA GRASSLAND

被引：20

作者：

CARTER, AJ

OCONNOR, TG

机构：

[1] Resource Ecology Group, Department of Botany, University of the Witwatersrand, Johannesburg, 2050, Private Bag 3, P.O.Wits

来源：

JOURNAL OF VEGETATION SCIENCE | 1991年 / 2卷 / 02期

关键词：

CLONAL GROWTH; SETARIA; SMALL-SCALE PATTERN; THEMEDA; TREE CANOPY;

D O I：

10.2307/3235955

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

A two-phase grassland mosaic was described using species association measures and pattern analysis techniques on local frequency data from six transects of contiguous quadrats. One phase consisted of almost mono-specific patches of Setaria incrassata, which was negatively or not associated with ten common species. The other phase was dominated by Themeda triandra which was positively associated with several species. PQV analyses revealed similar, significant, anisotropic scales of contagion of Setaria and Themeda, with phases alternating over 9 m up-slope and 4 m along the contour. Setaria was associated with a tree canopy and deeper soils of higher organic carbon content than Themeda, which was negatively associated with tree canopies. Excavation of Setaria rhizomes indicated mean densities of 20.5 putative genets/m2 and 3.6 ramets per genet. Dense clonal growth, seedling recruitment and a competitive exclusion mechanism may contribute to patch maintenance.

引用

页码：231 / 236

页数：6

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