Premium
Species diversity and vegetation distribution in nebkhas of Nitraria tangutorum in the Desert Steppes of China
Author(s) -
Zhou Hai,
Zhao WenZhi,
Luo WeiCheng,
Liu Bing
Publication year - 2015
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1007/s11284-015-1277-z
Subject(s) - species richness , vegetation (pathology) , species diversity , shrub , canonical correspondence analysis , ecology , botany , biology , medicine , pathology
Nebkhas (phytogenic miniature dunes) are mounds composed of wind‐borne sediment within or around shrub canopies and often develop under plants, creating microenvironments that affect the distribution of vegetation. In our study we investigated the vegetation of 397 nebkhas populated with the shrub Nitraria tangutorum in Yanchi County, in the northwest of China. We measured nebkha size (height, width and length) and soil moisture (from 0 to 100 cm). Distinct microsites of each nebkha (crest, mid‐slope, bottom, edge and internebkha space) were identified and plant species diversity was also measured. Four vegetation groups ( N. tangutorum – Chloris virgata + Eragrostis pilosa , N. tangutorum – Artemisia scoparia , N. tangutorum – Salsola collina + Bassia dasyphylla , N. tangutorum – Agriophyllum squarrosum ) were described by two way indicator species analysis (TWINSPAN) on the basis of classification and, concomitantly, the relationships between species composition and environmental gradients were explained by canonical correspondence analysis (CCA). Regression analysis indicated that as height and area of the nebkhas increased, species richness increased linearly, while the other species diversity indices (Simpson index, Pielou index and Shannon–Wiener evenness index) increased logarithmically. The response of species richness to heterogeneity of the microenvironment resulted from the four aspects (east, south, north and west) of the nebkhas, and varied among the different microsites of the nebkhas. Species composition was correlated with spatial variability in soil moisture along the gradient from the nebkha crest to the internebkha space. It appeared that the microheterogeneity of the nebkhas promoted the abundance of plant species.