【摘要】 樟子松是我国"三北"地区主要的固沙造林树种,探讨其生长过程中对风沙土肥力变化的影响具有现实意义。本文选取8年、15年、30年、36年、42年、49年和56年林龄的樟子松固沙林样地,采用常规分析方法测定了不同林龄下土壤养分含量和酶活性变化。结果表明:随林龄的增长,土壤全钾、全磷、全氮、有机质、速效钾、速效磷、速效氮含量均逐渐提高,并在42年后缓慢下降;土壤脱氢酶、过氧化物酶和磷酸酶活性同样随林龄的增长而增加。土壤养分含量和土壤酶活性变化的总体特征为42年>36年>30年>56年>8年>49年>15年。此外,随着土层深度的增加,樟子松固沙林土壤养分含量以及酶活性均下降。0～2 cm土层全磷、全氮、有机质、速效钾、速效磷、速效氮含量以及脱氢酶和磷酸酶活性均最高,分别为0.30 g·kg^-1、1.10 g·kg^-1、36.50 g·kg^-1、165.00 mg·kg^-1、0.80 mg·kg^-1、85.00 mg·kg^-1、7.04μg·h^-1·g^-1和0.59 mg·2 h^-1·100 g^-1。不同林龄以及不同土层的樟子松固沙林土壤养分以及酶活性差异明显,浅层土壤肥力更高,造林42年对沙区土壤的改良效果最佳。更多还原

【Abstract】 Pinus sylvestris var. mongolica is the main sand-fixing afforestation tree species in the Three North region of China. It has practical significance to discuss the effects on fertility of sandy soil. Some sand-fixed forest plots of 8 a, 15 a, 30 a, 36 a, 42 a, 49 a and 56 a have been selected to determine the soil nutrient content and enzyme activity of different stand age. The results show that soil total potassium, total phosphorus, total nitrogen, organic matter, available potassium, available phosphorus and available nitrogen have increased with the increase of stand age, and slowly decreased after 42 a. Soil dehydrogenase, peroxidase and phosphatase activities have increased with the increase of stand age. The changes of soil nutrient content and soil enzyme activity are 42 a>36 a>30 a>56 a>8 a>49 a>15 a. Furthermore, with the increase of depth of soil, the values of total phosphorus, total nitrogen, organic matter, available potassium, available phosphorus, available nitrogen, dehydrogenase activity and phosphatase activity of 0-2 cm soil layer are the highest, with 0.30 g·kg^-1, 1.10 g·kg^-1, 36.50 g·kg^-1, 165.00 mg·kg^-1, 0.80 mg·kg^-1, 85.00 mg·kg^-1, 7.04 μg·h^-1·g^-1 and 0.59 mg·2 h^-1·100 g^-1 respectively. The soil nutrient content and enzyme activity of Pinus sylvestris var. mongolica sand-fixing forest with different stand age and soil layers are significantly different, upper soil fertility is higher, and soil improvement can be the best after afforestation for 42 a.更多还原