Survey of ripgut brome and other species on Canterbury hill/high country roadsides

摘要

Ripgut brome is found in high country Canterbury pastures but little is known of its prevalence and distribution. In a 1020 km roadside vegetation survey, all exotic and native plant species within a 5 m x 5 m quadrat were identified at 10 km intervals. Ripgut brome (Bromus diandrus) was present in 11% of the 165 quadrats, which ranged from 40 to 950 m above sea level, occurring most frequently below 200 m. It was least often detected adjacent to intensive pastures (only 2% of quadrats). Agrostis capillaries (browntop) was present in 63% of quadrats, followed by Trifolium repens (white clover, 59%) and Dactylis glomerata (cocksfoot, 53%). The lowest number of exotic species was detected adjacent to intensive pasture (5.8) and highest adjacent to forestry (8.6 species). Highest numbers of native species were present adjacent to semi-improved pastures (1.7) and above 500 m (2.3 species). Species prevalent on roadsides were commonly grazed in hill/high country pastures rather than being pasture weeds.