The success of three restoration plantings at Kennedy's Bush, Port Hills, Canterbury, New Zealand

Abstract

This study presents the results of an investigation into the success of three different aged (10, 30 and 35 years) restoration plantings at Kennedy's Bush, Port Hills, Canterbury, New Zealand. Vegetation and ground invertebrates from the three restoration study plots were compared with mature and naturally regenerating forest remnants, and a tussock grassland study plot using ordination techniques and a variety of diversity indices. Both vegetation and invertebrate communities displayed a developmental sequence from the grassland to the mature forest study plots, suggesting that as the restorations aged they became more similar to the mature forest study plot. Restoration success is described as a continuum from the recolonisation and establishment of species to the restoration of all ecosystem attributes, including structure, composition and function. The later stages of the continuum cannot occur in the absence of success in the initial stages. Initial species composition at planting and the presence of fruit for attracting birds, features often regarded as essential for early restoration success, did not appear to be critical in this study. All three restoration plantings at Kennedy's Bush successfully facilitated the recolonisation of native forest plants and ground invertebrates. While the older restoration plantings have restored ecosystem function, all plantings have failed to restore ecosystem structure and composition, suggesting restoration has not successfully restored ecosystem structure and function yet. However, the future of the plantings looks promising. It is suggested that as the plantings age they will more closely resemble the mature forest community at Ahuriri Scenic Reserve and should successfully restore ecosystem structure as well as function, indicating that future restoration projects in the study area are likely to be successful.