补播对天祝高寒退化草地植被和土壤理化性质的影响

为了探究补播对高寒退化草地植被组成以及土壤理化性质的影响,于2007―2009年在甘肃省天祝县开展了退化草地补播垂穗披碱草(Elymus nutans)+无芒雀麦(Bromus inermis)+中华羊茅(Festuca sinensis)改良治理退化草地的研究。结果表明,补播有效增加了禾草类和莎草类植被,提高了退化草地地上和地下生物量。补播后第3年,土壤表层物理性状、养分以及微生物生物量与不补播相比,具有明显优势。土壤表层0-40cm,土壤容重降低、孔隙度变大、含水量提高,土壤养分和微生物生物量C、N含量升高,退化草地得到了有效治理。

Effects of over-seeding on plant community and soil physical and chemical properties of degraded grassland in Tianzhu County

In order to understand the effects of over-seeding on vegetation composition,soil physical and chemi-cal properties,a field experiment was conducted to determine the effect of over-seeding Elymusnutans,Bro-musinermis,Festuca sinensis seeds on degraded grassland during the period of 2007 to 2009 in Tianzhu county. The results of this study showed that over-seeding increased the aboveground and belowground biomass and in-creased the percentage of sedge and gramineain plant community composition.After three years of over-see-ding,the soil physical,chemical properties and microbial biomass contenthadbeen obviously improved when compared to control,indicating that soil bulk density at 0 ― 20 cm became low,and that porosity,moisture content,nutrient content and microbial biomass content C &N became higher.These implied that the degraded grassland had been improved by over-seeding.