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为评价我国北方大规模人工造林对土壤磷素转化及磷素有效性的影响,对半干旱沙地樟子松人工林和天然植被(疏林草地)不同层次(0~5cm,5~20cm)土壤中不同形态磷组分和磷酸单酯酶活性进行了比较。结果表明:除人工林土壤中活性有机磷不受土壤深度影响外,各样地表层土壤中各种磷素含量和酶活性均显著高于低层土壤,但分层效应在人工林中低于疏林草地;与疏林草地土壤相比,除Al-P外,人工林土壤中各种磷素绝对含量和酶活性均显著降低,总有机磷和Ca-P在全磷中的比例显著下降,而活性磷,Al-P和Fe-P占全磷的比例增加。可见表层土壤是磷素转化最活跃的区域,凋落物分解是土壤磷的主要来源;用樟子松进行人工造林促进了有机磷的矿化和Ca-P的溶解,提高了土壤磷素的有效性,同时导致土壤总磷库逐渐耗竭。要维持该人工防护林功能和稳定性,必须对地被物予以保护,并进行适当施肥。
In order to evaluate the effects of large-scale afforestation on soil phosphorus conversion and phosphorus availability in northern China, the effects of different afforestation (0 ~ 5cm, 5 ~ 20cm) of Pinus sylvestris var. Mongolica and semi-arid land on natural vegetation (sparse grassland) Different forms of phosphorus in soil and phosphate monoester enzyme activity were compared. The results showed that all kinds of phosphorus and enzyme activities in surface soils were significantly higher than those in lower soils, except that the active organic phosphorus was not affected by soil depth in the plantations. However, Forest grassland. Compared with sparse grassland soil, except for Al-P, the content of all kinds of phosphorus and enzyme activity in the soil of plantation decreased significantly, the proportion of total organic phosphorus and Ca-P in total phosphorus decreased significantly, The ratio of active phosphorus, Al-P and Fe-P to total phosphorus increased. It can be seen that the topsoil is the most active area for phosphorus transformation, and litter decomposition is the main source of soil phosphorus. Artificial afforestation with Pinus sylvestris var. Mongolica promoted the mineralization of organic phosphorus and the dissolution of Ca-P, and increased the availability of soil phosphorus At the same time, it leads to the gradual depletion of soil total P store. In order to maintain the function and stability of the artificial shelter forest, the ground cover must be protected and proper fertilization applied.