甘肃玛曲高寒天然草地优势种群及光合特征研究

为进一步掌握、了解优势种群，更好的治理我国青藏高原草地退化提供理论依据。采用样方调查法，在甘肃省玛曲县研究了高寒天然草地优势种群及其光合特征，并对特征指标与覆盖度进行了灰色关联度分析。结果表明：异针茅、柴胡、瑞玲草、冷地早熟禾和草玉莓是玛曲高寒草地的主要优势种群。种群特征与覆盖度的灰色关联度依次为：地上生物量>高度>密度。种群光合特性指标与覆盖度的灰色关联度依次为：胞间CO2浓度>蒸腾速率>净光合速率>气孔导度。玛曲高寒草地优势种群的形成主要决定于植株个体与外界气体的交换能力。提高玛曲高寒草地的生产能力，应在维护生物多样性的基础上，加强对优势种群的培育。

Study on the Dominant Species and Photosynthetic Characteristics of Natural Alpine Meadow in Maqu County Gansu Province

In order to approach improvement ways of deteriorated grassland on Qinghai-Tibet Plateau, in this paper, the quadrant survey method was used to study the dominant species and photosynthetic characteristics of alpine meadow in Maqu county, Gansu province. The feature index and vegetation cover degree were also analyzed by mean of the grey correlative degree. Results showed that Stipa aliena, Bupleurum chinense, Saussurea nigrescens, Poacrymophila keng and Anemone revelries were main dominant species in this area. The grey correlative degree between the population feature and vegetation cover degree: aboveground biomass>height>density. The grey correlative degree between photosynthetic character index and vegetation cover degree: intercellular CO2 concentration> transpiration rate> net photosynthetic rate> stomatal conductance. The formation of dominant populations depends on the capability to exchange gases between individual plant and outside. To improve the alpine meadow productivity, we should cultivate dominant species basing on the maintenance of biodiversity.