Changes in the tussock grasslands in the central Waimakariri River basin, Canterbury, New Zealand, 1947–1981

Abstract

Abstract Seven mid-altitude grazed tussock grassland transects in the central Waimakariri River basin were repeatedly surveyed between 1947 and 1981. Proportions of living vegetation, dead material, and bare ground were obtained using the point-intercept method, annually from 1947 to 1963 and in 1980 and 1981. Plant species were recorded in 1956, 1959, 1962, and 1980. The vegetative cover was discontinuous, covering between 20% and 80% of each transect. For combined transects the proportion of living vegetation declined from 1947 to 1953 at a rate of 2.29% yr-1. Between 1954 and 1981 the vegetation cover increased at a rate of 0.56% yr-1. Over the full period there was no overall significant change in the total extent of living vegetation cover. However, the extent of living vegetation increased on well vegetated sites and declined on poorly vegetated sites. The extent of living vegetation also increased in years with wetter springs, on transects at the lowest altitudes, and on sites dominated by Chionoch...