林业科学2016，Vol.52Issue(5)：9-16,8.DOI:10.11707/j.1001-7488.20160502
陕北半干旱黄土区沙棘人工林的死亡率及适宜地形因子
Mortality and Appropriate Topographical Conditions of Seabuckthorn Plantation in Semi-Arid Region of Loess Plateau in North Shaanxi,China
摘要
Abstract
[Objective]Determining the appropriate topographical conditions of seabuckthorn ( Hippophae rhamnoides) plantations in semi-arid region of Loess Plateau in north Shaanxi could provide a basis for the stable construction and sustainable management of the plantation forest in this area. [Method] Seabuckthorn plantations with different topographical conditions were surveyed in Wuqi County,Yan’an City,Shaanxi Province using the method of sampling plots. The mortality of seabuckthorn plantations in different topographical conditions were analyzed by correlation analysis and single factor variance analysis from slope position, slope direction, and gradients. [Result]The mortality of seabuckthorn plantations increased firstly and then decreased from the top to the bottom of slopes. Non-significant differences of mortality were showed among the slope positions,although it is 38% at the top,47% at the middle and 31% at the bottom of slopes. The mortality of seabuckthorn plantation at shady slope was the lowest among all the slope directions,with the maximum value of 21% and the average of 4%. The highest mortality occurred on sunny slope,with the minimum of 33% and the average of 63%. The mortalities of semi-shady and semi-sunny slopes were between those of shady and sunny slopes,and the average mortality of seabuckthorn plantations was lower on semi-shady slope than on semi-sunny slope. There were significant differences (P <0. 05) between the shady slope and semi-shady slope,semi-sunny slope and sunny slope. The mortality of seabuckthorn plantations on different slopes rose with increasing gradients. On shady slope,the growth was not obvious. The variation of mortality with gradients was logarithmic on semi-shady slope,linear on semi-sunny slope and exponential on sunny slope. The morality of seabuckthorn plantations had non-significant correlation with the slope position,but significant ( P <0. 01 ) with the slope direction and the gradient. Moreover,the effect of gradient to the mortality was stronger than that of slope aspect. Seabuckthorn forests on shady slope presented a slight degradation ( mortality 0% -30%) . Seabuckthorn plantations on semi-shady slope and semi-sunny slope were the same,of which the flat slope (5° -15°) and the gentle slope (15° -25°) displayed slight degradations, the steep slope (25° -35°) and the extremely steep slope (35° -45°) showed moderate degradations ( morality 30% -70%) . Seabuckthorn plantations of the extremely steep slope on sunny slope showed a severe degradation,and other three gradient sections had moderate degradations ( morality 70% -100%) . [Conclusion]In the semi-arid region of Loess Plateau in north Shaanxi where the average annual precipitation is less than 500 mm,the main cause for death of seabuckthorn plantations was lack of water. Suitable topographical conditions were shady slopes,semi-shady and gentle slopes,semi-shady gentle slope,semi-sunny flat slopes,and semi-sunny gentle slopes.关键词
沙棘人工林/衰退/坡位/坡向/坡度/半干旱区Key words
seabuckthorn plantation/degradation/slope position/slope aspect/gradient/semi-arid region分类
农业科技引用本文复制引用
陈文思,朱清科,刘蕾蕾,马欢,赵维军,王瑜..陕北半干旱黄土区沙棘人工林的死亡率及适宜地形因子[J].林业科学,2016,52(5):9-16,8.基金项目
国家“十三五”科技支撑计划课题“困难立地植被恢复技术研究与示范”(2015BAD07B02)。 （2015BAD07B02）
