Brush control on sandy rangelands in Central Alberta.

摘要: Balsam poplar, aspen, and willows that had invaded subirrigated sandy rangeland were treated with (1) prescribed spring burning, (2) the herbicide 2,4-D ester, (3) burning followed by ester. After 5 years, spraying reduced brush most. Brush reinvasion was occurring rapidly on all areas. Stand openings of about one quarter hectare in an 8 meter high poplar forest resulting from these treatments did persist for at least years. Treatments effective enough to lower cover some cases increase forage production. Repeated substantially density reinvading woody suckers. The presence plants has long been concern land managers interested increasing Woody species encroachment attributed fire control, overgrazing, farm abandonment (Friesen et al. 1965) although climatic cycles have also influential (Bailey Wroe 1974). Forage production could be increased if vegetation reduced. depressing effect grasses demonstrated 1974; Whysong Bailey 1975). Methods control focused upon mechanical means, herbicides, or combination these. Mechanical removal aspen replacement forages not always successful arresting suckering (Pringle 1973). Burning --cover is because discontinuous coverage fuels difficulty obtaining suitable conditions (Perala A single fails (Horton Hopkins 1966). However under appropriate conditions, conjunction spraying, may range improvement tool. Foliar applications herbicides used Authors are professor research associate, Department Plant Science, University Alberta, Edmonton, Alberta. This supported Alberta Agricultural Research Trust grant a National Council Canada senior author. Manuscript received July 19, 1977. success western 1972; Bowes 1976) indicating usefulness continued this area. experiments reported here designed determine magnitude duration effects treatment, two composition, stems, herbage mix poplarwillo,w (Populus-Salix) which encroached ranges dominated baltic rushKentucky bluegrass (Juncus balticus1Poa pratensis) grassland.