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多年冻土区冻土生态系统对气候变化极其敏感,利用在长江黄河源区实测的高寒草甸和高寒草原植被生物量数据以及青藏高原降水、气温以及地温等的空间分布规律,建立了长江黄河源区高寒草甸与高寒草原等主要高寒生态系统地上与地下现存生物量对气候要素变化的多元回归模型.预测分析表明:如果未来10 a气温增加0.44℃.(10a)-1,在降水量不变的情况下,高寒草甸和高寒草原地上生物量分别递减2.7%和2.4%,如果同时降水量小幅度增加8 mm.(10a)-1,则地上生物量可基本保持现状水平略有减少;在气温增加2.2℃.(10a)-1,在降水量不变的情况下,高寒草甸和高寒草原地上生物量年分别平均减少达6.8%和4.6%,如果同期降水量增加12 mm.(10a)-1,高寒草甸地上生物量可基本维持现状水平略有增加,而高寒草原地上生物量则递增5.2%.高寒草原植被地上生物量对气候增暖的响应幅度显著小于高寒草甸,而对降水增加的响应程度大于高寒草甸.明确高寒草地植被生物量随气候变化的演变趋势,对于青藏高原生态环境保护和研究气候变化对青藏高原生态系统碳循环和河源区水循环的影响具有重要意义.
Permafrost ecosystems in permafrost regions are extremely sensitive to climate change. Based on the measured biomass of alpine meadow and alpine steppe in the source regions of Yellow River and the spatial distribution of precipitation, air temperature and ground temperature in the Qinghai-Tibet Plateau, the Yellow River The multivariate regression model of the variations of above-ground biomass and aboveground biomass to the climate factors in the source alpine meadow and alpine steppe, etc. The prediction analysis shows that if the temperature increases 0.44 ℃ (10a) -1 in the next 10 years, Under the same conditions, the aboveground biomass of alpine meadow and alpine steppe decreased by 2.7% and 2.4%, respectively. Above-ground biomass could be basically maintained at the same level if the amount of simultaneous precipitation increased slightly by 8 mm. (10a) -1 (10a) -1. On the condition of constant precipitation, the aboveground biomass of alpine meadow and alpine steppe decreased by an average of 6.8% and 4.6% respectively. If the precipitation increased by 12 mm (10a) -1, the aboveground biomass of alpine meadow could be slightly increased while the aboveground biomass of alpine steppe increased by 5.2%. Aboveground biomass of alpine steppe vegetation had a significantly smaller response to climate warming Alpine meadow and alpine meadows, and the response to the increase of precipitation is more than that of the alpine meadow.It is clear that the biomass of alpine grassland changes with the trend of climate change, and the impacts of climate change on the carbon cycle of the ecosystem and the water cycle of Heyuan The impact is of great significance.