Kahikatea Dacrycarpus dacrydioides and Totara-Matai Podocarpus totara-Prumnopitys taxifolia forest patches in the agricultural landscape, Westland, New Zealand: representatives of a past and future condition

Abstract

Due to extensive clearance, podocarp forests on alluvial floodplains are under-represented, relative to their original extent, in the New Zealand agricultural landscape, and remnants are a priority for protection. This study uses a stand dynamics approach to 1) determine whether Kahikatea Dacrycarpus dacrydioides and Totara-Matai Podocarpus totara-Prumnopitys taxifolia forest patches in Westland, New Zealand, are remnants of pre-European forest, and 2) predict whether podocarp species will remain dominant in these patches. The majority of patches were initiated following European land clearance, with few being remnants of the original forest. Recruitment of podocarp seedlings and saplings into the canopy is no longer occurring in these stands, and over time they are likely to become dominated by angiosperm species. Within patch management may be an option to maintain podocarp dominance, while providing an economic return for landholders. While the forest types are representative of the original forest, the forest communities are not, with a lower ß diversity than in intact Kahikatea forest in the region. Planning for and managing patches as a shifting mosaic in the landscape is likely to be the most successful approach for maintaining their conservation value in the region.