陕西陇县引种美国黄松生长调查

对陇县3个林场的美国黄松引种育苗、造林效果进行了调查研究.结果表明,美国黄松(Pinus ponderosa)苗期生长量大于油松.八渡林场、龙门洞林场和陇县苗圃的黄松高生长量分别是油松的108.8、105.5和123,陇县苗圃的黄松与油松有极显著差异,而且黄松苗木根系发达,适应性强.陇县八渡林场7 a生美国黄松幼树,平均高为1.21 m,平均地径生长量为3.69 cm,与本地相同立地条件下生长的油松比较,树高生长量小12.4,地径生长量大27.6.与省内其他引种地比较,八渡林场黄松的高生长量明显大于榆林黑

A Study on the Growth of Introduced Pinus ponderosa in Longxian County of Shaanxi

The nurserying and effectiveness of afforestation of introduced Pinus ponderosa were investigated in 3 forest farms in Longxian county. The results show that P. ponderosa has higher growth quantity than P. tabulaeformis in seedling stage. The growth quantity of P. ponderosa is 108.8%, 105.5% and 123% respectively of P. tabulaeformis in Badu forest farm, Longmen forest farm and Longxian nursery, and there are marked difference on growth quantity between P. tabulaeformis and P. ponderosa in Longxian nursery. The seedlings of P. ponderosa has developed roots and shown high adaptability. The young tree of 7 year P. ponderosa in Badu forest farm, the growth of height is 1.21 m, 12.4% smaller than P. tabulaeformis, and the growth of base diameter is 3.69 cm, 27.6% higher than P. tabulaeformis in the same growth site. Compared with other introduced P. ponderosa in Shaanxi, the growth of height in Badu forest farm is marked higher than in Heilongtan of Yulin, botanical garden of Yan'an, Qinjiagou of Linyou County and Houzhenzi of Zhouzhi county.