民勤荒漠区主要植物的物候特性与牧草利用

Study on the Phenological Characteristics of the Main Plant Species and the Use of Pastures in the Minqin Desert Areas

通过设置样方、样点和运用物候观测,对退化荒漠植物群落进行轻度放牧利用分析,即运用植被状况与降水量的关系,分析限制植物生长的因素;运用不同稳定性沙丘的植被状况和土壤种子库资料,分析荒漠草地的可利用性和可利用程度;运用物候资料分析民勤荒漠区(灌木和草本植物)牧草利用的主要季节。结果表明:民勤荒漠草地土壤种子库中植物种子丰富,影响当地植物密度和植被盖度的关键因素是降水,可进行轻度放牧。轻度放牧时,要依据牧草展叶盛期的开始序列和果熟期的开始序列选择植物群落,实行小规模、间歇式轮牧。展叶盛期为一年中牧草的第1个利用季节,果熟期为一年中的第2个利用季节。

Research on grazing intensity is a hot field in grassland research in recent years. Is it possible that the moderate grazing results in a degeneration of desert plant communities？ What is the basis for the use of moderate grazing and how can a rational grazing be implemented？ In order to find the solutions of these issues, in this paper the phenological characteristics of the main plant species and the use of pastures in the Minqin desert areas are analyzed. A key factor restricting plant growth is analyzed using the relationship between vegetation status and precipitation. The availability and accessibility of the extent of desert steppes are researched using the data of vegetation and soil seed bank of the sand dunes with different stability levels. The main season of the use of shrubs and herbaceous plants is analyzed using the phenological data in the Minqin desert areas. The results show that plant seeds are rich in soil seed bank in the Minqin desert steppes. Precipitation is the key factor restricting plants density and vegetation coverage. It is possible to graze moderately in the steppes. It is necessary to choice the plant communities according to their leaf shooting stage and fruitmature stage to graze by taking an intermittent rotation way. The first grazing season is from the beginning of leaf shooting stage, and the second one is from the beginning of fruitmature stage.