河北坝上地区柠条平茬试验研究

Effects of Stubble on the Growth of Caragana korshinskii in Bashang Region of Hebei Province

柠条以其根系发达、耐旱、耐寒、耐风沙等强大的生态适应性,特别适宜河北坝上地区干旱、半干旱的气候条件和沙质土壤条件,是当地主要的造林树种之一。然而随着柠条林龄的增加,在坝上地区种植较早的柠条相继出现了生长衰退、枯死等现象,生态效益显著下降。该研究通过柠条平茬试验及分析,旨在达到规范柠条平茬作业、促进柠条生长、加速衰退柠条更新、减少因柠条平茬而造成的风蚀沙化的目的。研究结果表明:平茬可促进柠条生长和新梢萌生,平茬后地上部生长量显著增加,以距地表5cm处平茬效果较好,不仅可最大限度地促进柠条生长、更新,同时也可减少风蚀的发生。11a生中龄柠条平茬后效果最佳。从有利于更新复壮的角度考虑,柠条最适平茬时期是10~15a;从促进生长和开发利用角度考虑,平茬也可在6~10a进行。

As one of the main local afforestation species in Bashang region of Hebei province with its developed root system, drought resistance, cold resistance, strong barren sandadaptability, Caraganakorshinskii is especially suitable for arid and semi-arid climate and sandy soil conditions of Bashang region of Hebei province.However,C.korshinskiiwhich had been planted earlier appeared of growth decline and death inthis area with the increase of tree age,Which made the ecological benefits of C.korshinskii decreased significantly.The aim of this study is to standardize the operation of stubble on C.korshinskii, promoting the growth of trees, accelerating the renewal of C.korshinskii, and reducing the wind erosion and desertification caused by the stubble of C.korshinskii. The results showed that the stubble could promote the growth and shoot initiation of C.korshinskii with their aboveground biomass increased significantly.Stubble with 5 cm height from ground may reduce the occurrence of wind erosion,promote the growth and the regeneration of C.korshinskii. The stubble of 11 year old tree may have the best effect of growth.The most suitable stubble period of C.korshinskii is from 10 to 15 years of agefrom the point of rejuvenation.Stubble can also be carried out in 6 to 10 years of tree ageconsidering the promoting growth and development. In order to ensure that the wind speed below 10 classdoesn＇t afford the sand, the width of stubble belt is had better not more than 15 m.