Assessment of Physical Damage and Recovery of Native Understorey Species Following the Experimental Pine Felling at Karori Wildlife Sanctuary, Wellington, New Zealand

Abstract

The study assessed the physical damage and the recovery of understorey species Macropiper excelsum, Brachyglottis repanda, Melicytus ramiflorus and the tree fern species Cyathea medullaris and C. dealbata following experimental pine felling in early January 1999 at Karori Wildlife Sanctuary in Wellington, New Zealand. Considerable damage resulted from the pine felling operation. However, eighty-seven percent of all the plants of all the species assessed survived the damage and 81% showed signs of recovery by producing sprouts or fronds (in the case of tree ferns) by March-April. Survival and recovery of the plants were mainly related to the species and the size of the plant and the intensity of damage suffered. Survival and recovery among Melicytus ramiflorus plants was the highest (100%) among all the species whereas 94% Macropiper excelsum survived and 88% resprouted. Among Brachyglottis repanda plants survival and recovery was 77% and 67% respectively. Ten (80%) tree ferns (Cyathea medullaris and C dealbata) survived but only 58% developed new fronds. Melicytus ramiflorus plants produced the highest mean number of sprouts (52 ± 28.8) and the longest (29.8 ± 14.8cm) sprouts among all sprouting species, whereas sprouting Brachyglottis repanda was lowest. Seventy-eight percent of all the plants that died suffered heavy damage. Among Macropiper excelsum, height assumed by plant after damage and among Brachyglottis repanda, the basal area of the plant were the best predictors of total sprouts and leaves. Light level and the location of the plant within the gap were not significantly related to the sprout numbers.