global change

Natural grasslands are among the most threatened biomes on Earth. They are under pressure from land cover change including afforestation, farming intensification, invasive species, altered fire regimes, and soil amendments, all of which impact native biodiversity and ecosystem functioning. In Aotearoa New Zealand, tussock-dominated native grasslands expanded due to increased fire activity during waves of human settlement. These areas have subsequently been maintained as modified grasslands by agricultural pastoral land management practices and effects of introduced feral mammals.

While global climate change is impacting biota across the world, New Zealand’s maritime climate is highly variable and relatively mild, so climate change is sometimes seen as a minimal threat to species and ecosystems especially in comparison to the more immediate threat of invasive species. However, climate change will alter rainfall patterns, increase the incidence and severity of extreme events, and gradually increase temperatures which will all modify terrestrial, freshwater, and marine systems.