Abstract
Riparian buffer zones are viewed as an important management tool for waterway protection. However, little qualitative or quantitative assessment has been made of their dimensions or composition. We surveyed 88 small agricultural waterways within the Canterbury region to characterise the width and vegetative composition of riparian ‘buffer’ zones. Less than 20% of buffer zones were 10 m or wider and approximately 65% ≤ 5 m wide. Mean plant diversity was lowest in buffers ≤ 5 m (four taxa) and highest in buffers 25–30 m wide (11 taxa), although 98% of all taxa recorded in the survey occurred within 5 m of waterways. Exotic pasture grasses, weeds and adventive trees and shrubs dominated riparian areas at all distances from the ‐side. Furthermore, buffer width and vegetation type did not differ with adjacent land use despite regional efforts to plant native vegetation and regulatory emphasis on reducing water contamination from intensifying land use practices.