【摘要】 以2年生马尾松(Pinus massoniana)幼苗为试验对象,采用原位试验,研究了模拟酸雨和接种外生菌根真菌对土壤有机碳含量、土壤团聚体组成及土壤养分(N、P、K)含量的影响。设置3种强度(p H5.6(CK),4.5,3.5)的模拟酸雨条件,每个强度酸雨下分别设置接种外生菌根真菌和不接种外生菌根真菌,共计6个处理。结果表明:p H3.5酸雨处理显著降低了土壤中速效磷、总磷、速效钾、铵态氮、硝态氮及总氮含量,而外接外生菌根真菌则有效缓解了这一情况;与对照比,酸雨处理提高了微团聚体(<0.053 mm,0.053～0.25 mm)含量,降低了大团聚体(0.25～2 mm)含量; pH3.5处理显著降低各粒级尤其是0.25～2 mm粒级团聚体有机碳含量,而接种外生菌根真菌显著增加了有机碳含量;未接种外生菌根真菌土壤中,酸雨处理显著降低了土壤轻组、重组有机碳含量,而接种外生菌根真菌显著提高了土壤轻组、重组有机碳含量;接种外生菌根真菌在一定程度上可以缓解酸雨胁迫对土壤质量的不利影响。更多还原

【Abstract】 Two-year-old seedlings of Pinus massoniana were planted in acidified soils to explore the effects of acid rain and ectomycorrhizal fungi(EMF) on soil organic carbon content,soil aggregate composition and soil nutrient(N,P,K) contents.We set up three levels of simulated acid rain [pH 5.6(CK),pH 4.5,and pH 3.5] and applied two ectomycorrhizal treatments(inoculated,non-inoculated) in each level of acid rain.The pH 3.5 treatment significantly reduced the contents of available P,total P,available K,ammonium N,nitrate N and total N in soil,while inoculation with EMF effectively alleviated such negative effects of pH 3.5 treatment.Acidification treatment increased the content of microaggregates(<0.053 mm,0.053-0.25 mm)and reduced the content of macroaggregate(0.25-2 mm).Compared with control(pH 5.6),the pH 3.5 treatment significantly deceased the contents of organic carbon fractions,especially those with 0.25-2 mm size aggregate.Inoculation with EMF significantly increased the content of organic carbon.Acidification treatment significantly decreased the contents of soil light-fraction organic carbon(LFOC) and heavy-fraction organic carbon(HFOC),whereas inoculation with EMF significantly increased the contents of LFOC and HFOC.Our results indicated that inoculation with EMF could alleviate the negative effects of acid rain stress on soil quality.更多还原