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以我国北方大面积发生的入侵植物少花蒺藜草为对象,研究了其对科尔沁沙质草地土壤氮库和地上植物氮库的影响,并在室内条件下,以自然生境中少花蒺藜草伴生牧草披碱草和扁穗冰草为对照,利用~(15)N同位素技术分析了少花蒺藜草的生物固氮能力.结果表明:与对照裸地和本地植物鹅观草样地相比,少花蒺藜草入侵地土壤总氮库分别显著增加47.5%和20.8%,土壤铵态氮库分别显著降低25.6%和25.2%.与鹅观草相比,少花蒺藜草地上部分植物氮库显著降低18.7%.少花蒺藜草的~(15)N原子丰度、~(15)N原子百分超、~(15)N原子加权百分超均显著低于披碱草和扁穗冰草.少花蒺藜草和披碱草的氮肥利用率分别为48.5%和47.0%,差异不显著.与披碱草相比,少花蒺藜草生物固氮率为60.2%Ndfa.少花蒺藜草对氮素高效利用的特征,揭示了其适应沙质草地生态系统并蔓延的一种生态适应机制.
In order to study the effects of the small size of Tribulus terrestris on the large-scale invasion of Horqin sandy grassland in Northern China, the effects of soil nitrogen pool and aboveground plant nitrogen pool on the soil nitrogen pools in Horqin sandy grassland were studied. Under natural conditions, The forage plants of Elymus grassland and Agropyron chinense were used as control, and the biological nitrogen fixation ability of Quercus glauca was analyzed by using ~ (15) N isotope technique.The results showed that compared with the control The total nitrogen pool in the soil infested by S. quinoa increased significantly by 47.5% and 20.8%, while the soil ammonium nitrogen pool significantly decreased by 25.6% and 25.2%, respectively. 18.7% .The abundance of ~ (15) N atom, ~ (15) N atom% and ~ (15) N atom weighted percentage of S. porcupin were significantly lower than those of Elymus spp. Compared with Elymus sibirica, the nitrogen fixation rate of S. trifoliata was 60.2% Ndfa. Compared with Eisenia notoginseng, the nitrogen utilization rate of S. trifoliata was 48.5% and 47.0%, respectively, Efficient use of the characteristics revealed its adaptation to sandy grassland ecosystem and spread of a kind of ecological adaptation mechanism.