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.
Although a cover of grasses and legumes may be established on exposed mountain subsoils through seeding and the use of a complete fertiliser, this cover is not likely to last for more than a few years without the application of more fertiliser. Native tussock species once established in the protection of other low-growing species might persist and provide stability over a longer period.