Exclusion effects on vegetation characteristics and their correlation to soil factors in the semi-arid rangeland of Mu Us Sandland, China |
| |
Authors: | Yang Xiaohui Zhang Kebin Hou Ruiping and Ci Longjun |
| |
Institution: | (1) Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China;(2) Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Beijing, 100091, China;(3) College of Soil and Water Conservation, Beijing Forestry University, Beijing, 100083, China |
| |
Abstract: | Exclusion has been applied as a main measure for re-vegetation all over the world. This paper, by comparing the results of
year-round exclusion, seasonal exclusion, and non-exclusion, quantified the vegetation variations under three different exclusion
measures and their correlation to soil factors. The analysis results for community species component and plant diversity using
multi-response permutation procedures (MRPPs) showed that exclusion did change the species component and increase plant diversity
remarkably, while the period of exclusion had no significant influence on these two community features. The indicator species
analysis and calculation of similarity indices indicated that community for year-round exclusion were becoming xerophytization
and unpalatability, and showed highly spatial heterogeneity of plant species distribution, whereas community for seasonal
exclusion was under stable non-equilibrium condition. Detrended correspondence analysis (DCA) and detrend canonical correspondence
analysis (DCCA) results of relationship between plant species and soil variables demonstrated that soil moisture was a controlling
factor for plant species component, microbiotic soil crust cover, soil organic matter, and soil bulk density had significant
effects on soil moisture, among which microbiotic soil crust was a leading factor owing to its limitation to rainfall infiltration
on the one hand, and its constraints to entrance of herbaceous seeds into soil or to germination of soil seeds on the other
hand. As a result of long-term removal of animal grazing, crust kept intact in year-round exclusion community, which was a
main reason of community xerophytization. It was also obvious from ordination results that some important environmental factors,
such as tempo-spatial change of rainfall and corresponding tempo-spatial change of soil moisture, were neglected during direct
gradient analysis. In addition, biodiversity was close related to soil nutrients as well as to soil moisture condition (soil
water content and crust cover), and it had positive relation to available N, and negative relation to available P. Higher
soil N had advantage to non-leguminous plants growth on nutrition-poor sand land definitely. The impact of P to community
component was unclear and should be studied from plant physiology. Further researches on non-equilibrium theory in semi-arid
rangeland will provide a scientific and flexible animal development paradigm for being implementing livestock fen-raising
and grazing-forbidden policies in China.
__________
Translated from Acta Ecologica Sinica, 2005, 25(12): 3212–3219 译自: 生态学报] |
| |
Keywords: | exclusion treatments vegetation variation soil factors biodiversity multi-response permutation procedures gradient analysis |
本文献已被 SpringerLink 等数据库收录! |
|