摘要
报告了河北坝上地区青杨、榆树、柽柳、柠条、沙棘等５个优良饲料用树种的发芽期、展叶期和落叶期等物候特征，观测了它们的年生长进程，并提出了合理的收割时间为８月１０～２０日；各树种饲料产量差别很大，其中榆树产量最高。而且，所有树种产量均比天然草场产量高；各个树种在根量、根幅和根系分布深度方面也存在明显的差别，并由此把它们划分为主根发达型、侧根发达型及主侧根均衡发育型３种根型。
The phenological dates of sprouting, leaf developing and leaf abscission of five fod- der trees in Bashang region, Hebci were observed. Based on their annual growth rhythm,Au-gust 10～20 was proposed. The 5 tree speeies yielded more as the optimum period for havest-ing fodder than natural meadow, with the Ulmus pumila as the best.The signifieance differ-enees in root biomass,horizontal and vertieal distribution of root system were found amongthe 5 tree speeies ,and could be divided into three types:tap root type,lateral root type,andeven-developed root type.
关键词
饲料林
根系类型
河北坝上地区
fodder forest
root type
Bashang region of Hebei
