美国黄松在陕西黄土丘陵山地引种效果分析

麟游秦家沟地处陕西黄土丘陵山地,具有与美国落基山黄松原产地相似的生态条件。10年的引种生长效果表明,美国黄松在引种地能正常生长发育,适应性强且无任何病害,初步显示出其速生潜力。与黄土高原的延安树木园和榆林黑龙潭树木园比较,陕西麟游秦家沟的美国黄松具有较大的生长量:10年生树高年生长量21.4cm,胸径年生长量达到0.359cm;与本地乡土树种油松比较,美国黄松胸径生长量显著大于油松,树高接近油松。同一坡向不同部位栽植的美国黄松生长差异较大,台地上最好,坡面次之,沟间地生长不良。

Introduction of Pinus ponderosa and their growing effects in Linyou county of Shaanxi Provine

The ecological condition is similar between introducing region in Linyou county of Shanxi and original region of P.ponderosa var.scopulorum.The result of ten-year introduction indicates that P.ponderosa grow well with relatively strong adaptability to local climate and ecological environment,not injured by freeze,without plant diseases and insect pests.It also begins to show its potential of rapid growth.The growth in the region is better obviously than Yanan arboretum on the Loess plateau and mountainous region in Yulin Heilong pond.The 10 year-old plants has an annual height growth of 21.4 cm and diameter growth 0.359 cm.Compared with the native Pinus tabulaeformis,the diameter growth of Pinus ponderosa young plants is obviously faster,the height growth of which is close to that of Pinus tabulaeformis.Different planting positions have great effect on the growth of P.ponderosa.It is best to select mild slope with thicker soil layer,enough light and better water condition as afforestation site in mountainous area.