Jia Yangyang, Sun Yu, Zhang Tao, Shi Zhaoyong, Maimaitiaili Baidengsha, Tian Changyan, Feng Gu
College of Resources and Environmental Sciences China Agricultural University Beijing China.
Cultivation and Farming Research Institute Heilongjiang Academy of Agriculture Science Harbin China.
Ecol Evol. 2020 Feb 12;10(4):2196-2212. doi: 10.1002/ece3.6057. eCollection 2020 Feb.
Global climate change is one of the most pressing conservation challenges; in particular, changes in precipitation regimes have already substantially influenced terrestrial ecosystems. However, the mechanisms influencing precipitation changes on individual plants and the plant communities in desert grasslands have yet to be fully elucidated. We therefore examine the influence of increased precipitation on plant community compositions in the Gurbantunggut Desert, Xinjiang, northwestern China, from 2005 to 2009. We found that growth of all plant species and the community productivities increased markedly with enhanced water input. Cover of ephemeral synusia also significantly increased due to increased precipitation, implying that the role of the ephemeral community for stabilization of sand dunes was strengthened by increased precipitation. The response of plant community compositions to increased precipitation was primarily reflected as changes in plant density, while increased precipitation did not affect plant species richness and the diversity index. Dominant species drove the response of plant density to increasing precipitation during the five-year study period. However, the relative responses of rare species were stronger than those of the dominant species, thereby potentially driving species turnover with long-term increased precipitation. This finding improved our understanding of how increased precipitation drives the changes in plant community composition in desert grasslands and will help to better predict changes in the community composition of ephemerals under future global climate change scenarios.
全球气候变化是最紧迫的保护挑战之一；特别是，降水格局的变化已经对陆地生态系统产生了重大影响。然而，影响荒漠草原中单个植物和植物群落降水变化的机制尚未完全阐明。因此，我们研究了2005年至2009年期间降水增加对中国西北新疆古尔班通古特沙漠植物群落组成的影响。我们发现，随着水分输入的增加，所有植物物种的生长和群落生产力都显著提高。由于降水增加，一年生短命植物层片的盖度也显著增加，这意味着降水增加增强了一年生短命植物群落在稳定沙丘方面的作用。植物群落组成对降水增加的响应主要表现为植物密度的变化，而降水增加并未影响植物物种丰富度和多样性指数。在为期五年的研究期间，优势物种主导了植物密度对降水增加的响应。然而，稀有物种的相对响应比优势物种更强，因此随着降水长期增加，可能会推动物种更替。这一发现增进了我们对降水增加如何驱动荒漠草原植物群落组成变化的理解，并将有助于更好地预测未来全球气候变化情景下一年生短命植物群落组成的变化。
