【摘要】 丛枝菌根真菌是一种通过土壤侵染植物根系,与寄主植物互利共生的重要有益真菌。探究不同林龄杉木林中菌根侵染状况与土壤养分的变化规律,有利于深入认识丛枝菌根真菌—杉木相互作用的养分调控因素,从而为改善杉木人工林土壤肥力、促进杉木林可持续经营提供依据。分别选取10a、25a、45a杉木纯林,分析了不同林分菌根侵染率与孢子密度及部分土壤养分因子(全磷、速效磷、全钾、速效钾)的关系。结果表明:(1)菌根侵染率与孢子密度均呈现出随林龄增大而增大的趋势,pH随林龄增大而减少的趋势;(2)根际土中磷的含量总体偏低,而且受到土壤酸化流失和丛枝菌根真菌积累的双重影响呈现出先减少后增加的趋势;(3)虽然有效钾含量随林龄变化趋势不显著,但丛枝菌根真菌能促进土壤钾的积累。因此,丛枝菌根真菌能有效调控根际土的养分动力学特征,减缓土壤酸化造成的养分流失。更多还原

【Abstract】 Arbuscular mycorrhizal fungi(AMF) are important beneficial fungi that colonize plant roots through soil and mutually coexist with host plants. Exploring the changes in soil nutrients and mycorrhizal colonization status of Chinese fir forests of different ages could be benefit for in-depth understanding of the interactions between nutrients and mycorrhizal fungi in fir forest, providing suggestions for the improvement of soil fertility and promoting sustainable management of Chinese fir forest. In this study, 10-year-old(10 a), 25-year-old(25 a), and 45-year-old(45 a) pure Chinese fir forests were selected, and the relationships between mycorrhizal colonization rate, spore density and rhizosphere soil nutrients(total phosphorus, available phosphorus, total potassium, and available potassium) were analyzed. The results showed that:(1) Both mycorrhizal colonization rate and spore density increased with forest age, while pH decreased with forest age.(2) The content of phosphorus in the rhizosphere soil is low. With the effects of soil acidification and arbuscular mycorrhizal fungal accumulation, rhizosphere phosphorus exhibited a trend of U shape.(3) Although the content of available potassium did not change with stand age significantly, the arbuscular mycorrhizal fungi promoted the accumulation of potassium in the rhizosphere soil. Therefore, arbuscular mycorrhizal fungi can effectively regulate the nutrient dynamics of rhizosphere soil and slow down the nutrient loss caused by soil acidification.更多还原