围栏封育对新疆蒿类荒漠草地植被及土壤养分的影响

以新疆封育3年的蒿类荒漠草地为对象,研究干旱区封育对草地植被及土壤养分的影响.结果表明:封育后荒漠草地群落的盖度、产量明显增加(P<0.05),分别比对照提高了11.0%,51.6 g/m~2,且盖度、产量的增加主要是由藜科草类引起;荒漠草地80%以上的地下生物量集中在0～40 cm土层中,且封育促进了0～10 cm土层内生物量的增加(P<0.05);与放牧地相比,封育后土壤有机质、全氮、全磷、全钾及速效氮、磷、钾含量均有所提高,且在0～10 cm的土层中差异显著(P<0.01),而pH值略有上升.

Effect of Enclosure on Vegetation and Soil Nutrient of Sagebrush Desert Grassland in Xinjiang

The serious degeneration of spring and autumn sagebrush desert steppes has become as a bottleneck of restricting the development of seasonal animal husbandry in north Xinjiang.In order to regenerate the sagebrush desert steppes,enclosure is widely applied.In this study,the effects of enclosure on vegetation and soil nutrient of a sagebrush desert grassland after fenced for 3 years in Xinjiang are investigated.The study area(43°53′N,87°46′E,840 m a.s.l.),a typical spring and autumn sagebrush desert steppe in Lucaogou Township of Midong District,Urumqi City,is located in the northern slope of the Bogda Mountain,where the annual precipitation is 236 mm,the vegetation is dominated by sagebrush subshrubs,and the dominant species is Seriphidium transiliense commonly accompanied by Kochia prostrate,Ceratocarpus arenarius,Petrosimonia sibiriea,Piptatherum kokanicum,etc.In the study,the vegetation coverage,density and yield in the plots of 1 m×1 m and soil nutrient in sample plots of 20 cm×30 cm are measured and analyzed.The results show that,compared with the grazing zones,the vegetation coverage and the productivity of the fenced desert grassland are obviously increased(P<0.05),with a increase rate of 11.0%and 51.6 g/m~2 respectively,due especially to the increase of the yield and coverage of chenopodiaceae plant.More than 80% of underground biomass of the fenced desert grassland is distributed in soil layer of 0～40 cm in depth,and the biomass in soil layer of 0～10 cm in depth is obviously increased after fenced(P<0.05).Compared with the grazing zones,the eontents of soil organic matter,total nitrogen,total phosphorus,total potassium,available soil nitrogen,phosphorus and potassium are obviously increased,and their differences in soil layer of 0～10 cm in depth are significant(P<0.01).The pH value is slightly increased.