青海共和盆地草地生产力模拟及其影响因素分析  

Modeling Grassland Productivity Based on DEM in Gonghe Basin of Qinghai Province

作　　者：孙建光[1] 李保国[1] 卢琦[2] 

机构地区：[1]中国农业大学资源与环境学院,北京100094 [2]中国林业科学研究院,北京100091

出　　处：《资源科学》2005年第4期44-49,共6页Resources Science

基　　金：国家"十五"科技攻关重大项目(编号:2002BA517A09-01)。

摘　　要：基于DEM构建了青海共和盆地草地生产力的模型,并且进一步构建了基于作物水分耗散和放牧因子校正的青海共和盆地草地生产力模型,研究结果表明:①共和盆地草地的光温生产潜力15·3t/hm2,光温生产潜力约为光合生产潜力的53%,而且在山区约为44%,滩地约为54%,河谷约为58%,所以在共和盆地温度应当是限制牧草生产能力的一个非常重要的因子,并且在山区温度对牧草的生产能力的影响较大;②共和盆地牧草的气候生产潜力约6·6t/hm2,气候生产潜力是光温生产潜力的43%,是光合生产潜力的23%;而且河谷、滩地牧草的气候生产潜力分别约为光温生产潜力的34%和41%,山地约为69%,水分对牧草的气候生产潜力影响在河谷和滩地要大于山地,尤其是草原化荒漠和荒漠化草原气候生产力相对较低;共和盆地的实际草地生产力是气候生产力的1/5~1/12;经过作物水分需求和放牧的校正,草地生产力平均2·2t/hm2,与实际生产力很接近。所以牧草水分需求和放牧强度对草地生产力影响很大,尤其反映出草地放牧已成为草地生产力降低,草地退化的重要原因之一。Based on DEM, a model of climatically potential productivity in grassland has been built in Gonghe basin in Qinghai province. Furthermore, a modified model of grassland productivity on the basis of consideration into crop water consumption and grazing intensity has also been made in combination with the observation of grassland biomass in Gonghe basin. The results indicate that 1) Photosynthetic-temperature potential productivity in Grassland ranges from 4.0 to 23.8t/hm^2 with an average of 15.3 t/hm^2, which accounts for 53% of photosynthetic potential productivity, 58% in valley, 54% in lowland, and 44% in highland. Therefore, temperature has more influences on grass productivity in highland than that in valley and lowland; 2) climate potential productivity in grassland ranges from 3.45t/hm^2 to 8.98 t/hm^2,with a mean value of 6.6 t/hm^2, accounting for 43% of photosynthetic-temperature potential productivity, 23% of photosynthetic potential productivity, 34% of photosynthetic-temperature potential productivity in valley, 41% in lowland, and 69% in highland. Water has more influence on grass productivity in valley and lowland than that in highland and especially in the grass-desert area and desertification-grassland areas; 3) Grassland actual productivity in Gonghe basin is estimated to 1/5～1/12 of grassland climate potential productivity, according to the data from field survey. Taking the factors of plant water consumption and grazing intensity into consideration, the estimated productivity of grassland is 0.95t/hm^2～3.9t/hm^2, 2.2 t/hm^2 on average, accounting for 33.3% of climatic potential productivity, and very close to actual grassland productivity. Obviously, grassland water consumption and grazing intensity has a great influence on actual grassland productivity, implying that over grazing is one of main causes of grassland degeneration in Gonghe basin in Oinghai Province.

关 键 词：青海共和盆地 草地生产力 影响因素分析 光温生产潜力 气候生产潜力 光合生产潜力 气候生产力 模拟 作物水分 生产能力 生产力模型 荒漠化草原 实际生产力 研究结果 放牧强度 草地退化 牧草 DEM 滩地 河谷 构建 校正 因子 

分 类 号：S812[农业科学—草业科学]