盐池县沙地白榆低产林改造效果研究

文章分析了宁夏盐池县白榆纯林及宽幅林带形成低产林和＂小老头树＂的原因,并采取强度间伐、实施抚育管理、加强有害生物的防治等措施进行改造。结果表明：①间伐对白榆树高长生影响不显著;②间伐对白榆树直径生长影响显著,且随着间伐强度的加大,直径生长也加大;③在白榆同龄林中,间伐后不同密度的林分,单位面积上的蓄积量及其增长率是不同的;密度为1 620株/hm2的林分蓄积量最大,2010年时蓄积量为47.3 m3/hm2;密度为470株/hm2的林分蓄积量最小,为27.4 m3/hm2;蓄积增长率则与间伐强度呈正相关。

Effect of Low-yield Forest Siberian Elm Reconstruction in Sandy Soil of Yanchi County

The article analyzed the causes of forest low-yield and short trees of pure forest and its forest belts of Siberian Elm,and introduced the artificial tending techniques in Siberian Elm through experiments,such as intensity intermediate felling, tending management and pest control. The results showed that there was not significant effect of intermediate felling on tree height and growth;There was a significant effect of intermediate felling on breast-height diameter. The greater the intermediate felling, the larger the diameter; Stand volume of per unit area and increasing rate of forest stand with various intensity after felling among the forest of same age was different. The stand stocking volume was the highest with intensity of 1 620 trees/hm^2 and was of 47.3 m^3/hm^2 in the year of 2010, while that was the lowest with intensity of 470 trees/hm= and was of 27.4 m^3/hm^2. There was a positive correlation between increasing rate and intermediate felling intensity.