行带式柠条锦鸡儿林在内蒙古四子王旗退耕还草工程中的应用

Optimal Structures of Caragana korshinskii Belts to Make Grassland from Farmland in Siziwang Banner,Inner Mongolia

为改善温带草原区的退耕还草技术,以内蒙古中部四子王旗退耕农田为例,研究行带式柠条锦鸡儿林对草本群落的修复能力。结果表明:1)林带间距的宽窄影响林带间隙草本群落的恢复过程,过窄或过宽的带间距都不利于林带间隙草本群落的恢复进程;2)当退耕地与林带的距离适当时,林带能明显促进草本群落的恢复,使草本的盖度和物种数目明显提高,当距离过大或过小时,这种促进作用显著减弱;3)林带间隙内不同距离草本群落的恢复效果符合高斯模型;4)根据高斯回归模型推算,当林带间距介于16～28m时,林带对草本群落的修复作用能够达到最佳状态。研究结果对优化温带草原区退耕地促草型灌木林的结构具有参考价值,就行带式柠条锦鸡儿林来说,最好将林带间距控制在16～28m之间。

Main aims of this study are to investigate effects of shrubs on vegetation restoration of grassland from previous farmland,and then to optimize management measures to build the grassland.The study site was in Siziwang Banner,central Inner Mongolia,where the local vegetation is temperate and arid grassland.The followings are our main findings.1）Grassland restoration depends on width between neighboring shrub belts.If the width is within appropriate distance,land between the belts will be restored with grasses well,otherwise not.2）If a distance from an abandoned farmland to its nearest shrub belt is moderate,the land will be restored with grasses effectively,with better coverage vegetation and rich grass species,and otherwise less effectively.3）Gaussian mathematic model well fits the relationship between restoration degrees of grassland and the distances from abandoned farmland to shrub belts.4）According to the fitted model,shrub belts can promote grassland restoration well if the distances between the belts are in a range of 16-28 m.This study is helpful to optimize the structure of shrub belts in dry abandoned farmland such as in Siziwang Banner.As for the genera of Caragana korshinskii,the optimal width of belt-gap is found being between 16-28 m.