摘要
群落优势种重要值的变化可以表征植被的演替状况。研究了鄂尔多斯高原飞播后不同演替阶段的沙地植被 ,以及两种优势克隆植物羊柴 (H edysarum laeve)和油蒿 (Artemisia ordosica)种群的空间格局。结果表明 :在调查的尺度内 ,群落水平上 ,演替前期和演替中期的植被盖度空间自相关发生的尺度远小于演替后期。随着植被的演替和发育 ,小于抽样尺度 (<1m)的随机变异逐渐增加。暗示着植被盖度空间格局的变化与羊柴种群和油蒿种群在群落中的地位的变化有关。种群水平上 ,小尺度的空间自相关控制着羊柴种群在 3个演替阶段的空间格局 ;处于前 2个演替阶段的油蒿种群 ,空间格局受更大尺度的过程控制 ,并在自身为建群种的群落随机分布。对于 3个演替阶段的油蒿种群而言 ,发生在小于抽样尺度 (<1m)的随机变异都高于相应的羊柴种群。这两种克隆半灌木的种群空间格局的差异可能与二者克隆构型和克隆性的不同有关。
The sandy vegetation in the Ordos Plateau is highly heterogeneous in space. The changes of important values of dominant plant species are indicative of succession of the plant communities. In the Ordos Plateau, along with the sandy vegetation succession, the important values of the native plant species Artemisia ordosica decreased while the non-native plant species Hedysarum laeve increased. H. laeve with guerrilla-type clonal architecture mainly produces offspring through clonal growth while A.ordosica having phalanx-type clonal architecture mainly through sexual reproduction. In order to investigate the spatial patterns of sandy vegetation and the two plants populations during the vegetation succession process in the Ordos Plateau, we set up one 2m×100m transect along the dune slope where vegetation were at different successional stage. In each 1m×1m quadrate, we measured vegetation coverage, coverage and height of every plant individuals. Using geostatistics software GS^+ (Version 5.3.1, Professional Edition, Gamma Design software), we analyzed the spatial patterns of sandy vegetation coverage and the important values of the two dominant plants H. laeve and A. ordosica. The spatial autocorrelation scales of the vegetation coverage of communities dominated by H. laeve and by H. laeve and A. ordosica were much less than those by A. ordosica within the scales under investigation (50m). With vegetation succession and development, stochastic variation on small scale (<1m) was increasing gradually. This implies that the spatial pattern of the vegetation coverage was related to the two plant populations. Auto-correlation on small scale controlled the spatial patterns of H. leave populations at the three successional stages. The auto-correlation scale was consistent with length to which its rhizomes horizontally spread. The spatial pattern of A. ordosica populations at two successional stages was controlled with some ecological processes working on larger scales. A. ordosica population randomly distributed in the communities dominated by itself. Perhaps it was because A. ordosica population maintains and recruits mainly through seeds. At each of the stages, small-scale (<1m) stochastic variation was larger in A. ordosica population than in H. laeve population. It is likely that spatial patterns of the two clonal plant populations were closely related to their clonalities and clonal architectures. During the sandy vegetation succession in the Ordos Plateau, H. laeve and A. ordosica played different roles.
出处
《生态学报》
CAS
CSCD
北大核心
2004年第11期2374-2381,共8页
Acta Ecologica Sinica
基金
国家重点基础发展规划资助项目 ( 2 0 0 0 01860 7)
国家杰出青年科学基金资助项目 ( 3 982 5 10 6)~~
关键词
油蒿
克隆植物
鄂尔多斯高原
羊柴
空间格局
演替
Artemisia ordosica
clonal plants
Hedysarum laeve
the Ordos Plateau
spatial pattern
succession
