三江源自然保护区高寒草地草情诊断研究

三江源生态保护和建设工程的实施对生态环境产生了积极的影响,草地是该地区最主要的生态系统类型,准确的草情诊断对该地区的生态稳定和畜牧业发展具重要意义,可更好的指导三江源区生态环境的保护和发展.基于长时间序列的遥感观测资料和野外采样数据,通过构建草情诊断基准值,结合草地覆盖度和产草量的变化率,根据加权求和计算出草情指数,诊...

The study of diagnosis of alpine grassland condition in the Sanjiangyuan Nature Reserve

The implementation of ecological protection and construction project has a positive impact on the ecological environment.Alpine grasslands are the main ecosystem type in the Three-River Headwaters Region,China.Accurately monitoring of the condition of grassland is important in guiding the ecological engineering construction and maintaining the balance of grassland ecosystem.Therefore,it is necessary to scientific evaluate the grassland condition.Based on the remote sensing and field sampling data,this paper firstly calculated the average grassland coverage and yield of 5 years before the implementation of the Eco-Project as the reference value of grassland condition,and then based on the weighted sum of grassland coverage and yield changes, the grassland condition index (GCI) was calculated to diagnose the growth status of grassland vegetation after the implementation of the Eco-Project. The results showed that the annual average GCI was 3.47 in the Three-River Headwater Region since the implementation of the Eco-Project. It had a good grassland condition, showing a pattern of getting better from southwest to northeast. The proportion of area with excellent, better and medium grass conditions was significantly higher than that with worse grass condition (P<0.05). The fluctuation of the GCI during 2005-2016 was relatively small, with a variation coefficient of 12.47%. 80.32% of the grassland showed no significant change (P>0.05), 14.61% showed a significant decline trend, and 5.07% showed a significant increase trend (P<0.05). The grassland in the Sanjiangyuan National Park was in good condition. The annual average GCI from high to low was the Yellow River Source Park (3.78), Yangtze River Source Park (3.61), and Lancang River Source Park (3.15). There was no significant change in the GCI of the grasslands above 2/3 in the three parks. The area with significant change in the GCI of the Yellow River Source Park had the highest proportion (17.74%), and the Lancang River Source Park had the lowest (13.49%). The highest percentage of GCI significantly improved area was the Yangtze River Source Park (6.46%), and the lowest was the Lancang River Source Park (3.46%). Since the implementation of the Eco-Protection, grassland has shown good conditions, but some areas have shown a downward trend. We should continue to strengthen the long-term monitoring of grassland condition in Sanjiangyuan Nature Reserve, conduct reasonable grassland condition diagnosis, and increase the ecological protection of areas with poor grass conditions.