Rapid Expansion of Melica przewalskyi Causes Soil Moisture Deficit and Vegetation Degradation in Subalpine Meadows |
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| Authors: | Fu‐Yuan Gao Fu‐Xi Shi Hui‐Min Chen Xin‐Hou Zhang Xue‐Yang Yu Qian Cui Cheng‐Zhang Zhao |
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| Affiliation: | 1. Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China;2. Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China;3. University of Chinese Academy of Sciences, Beijing, China;4. Research Center of Wetland Resources Protection and Industrial Development Engineering of Gansu Province, College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China |
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| Abstract: | Invasive noxious plants have important impacts on community dynamics and ecosystem functions in grasslands. Since the 1960s, the noxious plant Melica przewalskyi has spread rapidly and formed different size of patches in subalpine meadows of the Qilian Mountains, Northwest China. In this study, the species richness, vegetation structure, and soil water content are investigated from the patch edge to the center in four sizes of M. przewalskyi patches (i.e., small patch, <100 cm in canopy diameter; middle patch, 100–200 cm; large patch, 200–300 cm; and the largest patch, >300 cm). The results show that while the patches grow continuously, the dominant species changes from Stipa krylovii to M. przewalskyi with an increasing trend in plant productivity and decreasing trend in species richness and soil water content. Plant height, density, coverage, and above‐ground biomass of M. przewalskyi population increases from the patch edge to the center in small, middle, and large patches, whereas it is precisely the opposite in the largest patch. Interestingly, soil water content exhibits a decreasing trend from the patch edge to the center in all patches. The results indicate that the rapid spread of M. przewalskyi may well alter vegetation pattern and cause a severe soil moisture deficit, which would further drive the degradation of ecosystem functioning in subalpine meadows. |
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| Keywords: | invasive noxious plants patch Qilian Mountains soil water content spatial distribution pattern |
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