Long-term impacts of grazing on indigenous forest remnants on North Island hill country, New Zealand

摘要: Small isolated patches of native forest surrounded by extensive pastoral grasslands, characteristic many New Zealand rural landscapes, represent an important reservoir lowland biodiversity. Improved management them is a major focus biodiversity conservation initiatives in Zealand. We quantified the long-term impacts grazing on indigenous remnants hill country at Whatawhata, western Waikato, North Island. Structure and composition were compared between fragments grazed for >50 years nearby ungrazed continuous forest. Grazed had shorter less shady canopies, sparser understoreys, tree populations with larger mean diameters, ground layers lower cover litter higher vegetation bare soil than Fragments also indigenous-plant species richness, especially sapling seedling populations, almost no palatable shrubs, terrestrial orchids, ferns that require high humidity (e.g. Hymenophyllum spp.), but contained adventive herbaceous species. A transition appears to be occurring from tall, long-lived trees like Beilschmiedia tawa Dysoxylum spectabile short shorter-lived Kunzea ericoides, Melicytus ramiflorus, Dicksonia squarrosa. Because inhibits most regeneration processes, unfenced conifer–broadleaved are unlikely maintained pasture long term. ___________________________________________________________________________________________________________________________________