阿克苏市郊柯柯牙防护林不同林龄新疆杨防风及土壤改良效应

Windbreak and Soil Improvement Effects of Different Aged Populus Bolleanain Kokyar Peri-urban Shelterbelt of Aksu City

新疆阿克苏市郊柯柯牙防护林绿化工程是干旱缺水环境下大面积人工植树造林的典范。以柯柯牙绿化工程中6年生、15年生和22年生的新疆杨人工林为研究对象,裸露沙地为对照,研究了不同林龄防护林0.5和2m高度的防风效果以及土壤改良效应。结果表明,新疆杨防护林防风效果明显,背风面防风效能在0.5m高度表现为:22年生>15年生>6年生,在2m高度表现为15年生>22年生>6年生。综合防风效能15年生和22年生的相近,均大于6年生。土壤容重明显降低,尤其表现在0—10cm的表层土。随着林龄的增大,土壤有机质和全氮含量不断增加,碱解氮、速效钾先增大后减少,有效磷含量则先减少后增大。

The Kokyar shelterbelt in the periurban area of Aksu in Xinjiang Wei Autonomous Region is a model project for large scale artificial afforestation in arid regions with extreme water shortage. Authors se lected Populus bolleana at three different stand ages（6, 15 and 9,2 year stand age, respectively） as a research object. Taking bare sand a control, the windbreak efficiency at the heights of 0.5 and 2.0 m and the soil im provement effects are analyzed. Results show that Populus bolleana shelterbelt had a very distinguished windbreak effect. Leeward windbreak efficiencies of different aged Populus bolleana at the height of 0.5 m were showed as the order of 22 year stand age 〉 15 year stand age 〉 6 year stand age, while at the height of 2.0 m, windbreak efficiencies were presented as the order of： 15 year stand age 〉 29. year stand age 〉 6 year stand age. The comprehensive windbreak efficiencies of 15 year and 29, year stand age Populus bolleana were very close, and both were better than 6 year stand age. Soil bulk density decreased significantly, espe cially within the 10 cm of topsoil. Soil organic matter and nitrogen content increased with the increasing stand age and available nitrogen, potassium content increased first and then decreased, while available phos phorus content deceased first and then increased.