不同树种幼林生长差异及对土壤营养的影响

通过调查不同树种新造林树高生长量及其林地土壤有机质和速效氮、磷、钾含量,研究其生长及对土壤营养的影响.结果为：光皮桦、四川桤木、楸树、栾树、湿地松6年生树高分别为8.2、7.7、7.4、7.0、5.3 m;不同树种造林后对土壤营养物质含量的提高有明显差异,5个树种造林后效果排序的先后次序为光皮桦、四川桤木、栾木、楸树、湿地松;新造林均表现为造林当年土壤营养含量明显下降,第2年起逐年增加,第3～5年超过造林前水平.

Different tree species growth and its effects on soil nutrient

Through the investigation on height growth of different tree species and woodland soil organic matter content and available N, P, K content, the growth of different tree species and its effect on soil nutrient were researched. The results showed that, the 6 years old tree height of Betula luminifera, Alnus eremastogyne, Catalpa bungei, Koelreuteria paniculata, Pinus elliottii were 8. 2 m, 7.7 m, 7.4 m, 7.0 m and 5.3m respectively. There was significant difference in the increase of soil nutrients among different tree species, 5 species sorting for Betula luminifera, Alnus cremastogyne, Koelrenteria paniculata, Catalpa bungei, Pinus elliottii. New afforestation showed that soil nutrient content decreased significantly in the first year of afforestation, then increased year by year since the second year, exceeded the level before afforestation from third to fifth year.