Woody encroachment on pastures in Western Canada

Abstract

Brush encroachment is a serious problem on pastures in Western Canada. It results in a loss of productivity and habitat for wildlife. Sixty-seven pastures were visited in Manitoba, Saskatchewan and Alberta. Approximately half were privately owned lands and the remainder were public lands. Each field sampled was divided into grass, shrub and forest strata, within each stratum vegetation cover was noted and biomass and soil samples were taken. A historical reconstruction was created using aerial photos dating back to the 1940s up until most recent photos available. Six cover classes were delineated and patch statistics were calculated. Information on historical management practices were obtained also. It was determined that woody encroachment is occurring on pastures, but no significant trends found between environmental factors and encroachment. Therefore it was concluded that management probably has the greatest impact on the occurrence and extent of woody encroachment.