Plant dynamics of New Zealand tussock grassland infested with Hieracium pilosella. II. Transition matrices of vegetation changes.
The vegetation types in 1-m2 permanent quadrats were determined annually in 1975-82 on low and moderate productivity sites of improved or unimproved Festuca novae-zelandiae grassland differing in initial infestation with H. pilosella. The transition matrices of vegetation types showed the increase and relative stability of Hieracium spp., a decrease of F. novae-zelandiae with replacement by H. pilosella and H. praealtum on the low productivity site and a complex interaction following species introductions. The forward prediction indicated the following: all vegetation types would continue to occur; a high incidence of Hieracium spp. without sward improvement; a slow change to Trifolium hybridum or T. repens predominance on moderate productivity improved swards; equilibrium would be reached rapidly in both sites and treatments.