Establishing an evidence-based framework for the systematic conservation of New Zealand's terrestrial ecosystems

Although New Zealand's 2020 biodiversity strategy, Te Mana o Te Taiao, places a high priority on protecting indigenous ecosystems, it provides minimal detail on how this will be accomplished. Using spatial data and a conservation prioritisation tool we demonstrate the implementation of a comprehensive framework for the systematic conservation of New Zealand's terrestrial ecosystems, as proposed in a pioneering paper by Kelly (1980). Working within the Horizons Region (Manawatu-Whanganui, lower North Island), we analyse the extent of losses of 65 terrestrial ecosystems since human settlement by combining maps of their potential distribution and current land cover. Two-thirds of the original indigenous cover has been lost, with lowland ecosystems suffering greatest losses; much surviving cover is substantially modified. Our prioritisation analyses identify various options for siting conservation management to maintain the integrity of a full range of indigenous ecosystems in a highly modified landscape, given varying degrees of constraint on the availability of land for conservation. Restricting management to DOC-administered land would severely constrain ecosystem representation, but dramatic improvements in ecosystem representation would result from protecting and managing a relatively small number of sites on land of other tenures, mostly at lower elevations. Results such as these could play a crucial role in supporting achievement of New Zealand's high-level goals for ecosystem conservation and meeting international conservation obligations. They could be used to (1) assess the conservation status of individual terrestrial ecosystems, (2) develop national and regional policies specifically targeting protection of at-risk ecosystems, (3) design and implement strategies that explicitly target management across a full range of ecosystems, (4) support processes designed to coordinate management among different conservation actors, and (5) inform individual landowners of the conservation value of indigenous ecosystems on their land. Obstacles to implementing such an approach include a range of technical, institutional, and social factors.