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Tall Chionochloa Tussock Grasslands
These grasslands are dominated by tussock forming Chionochloa grasses. Where undisturbed, some Chionochloa grasslands (e.g. C. rigida) can form dense stands with a thick layer of litter beneath. However, other herbs and grasses are usually found in the ground tier. The actual composition of the intertussock species depends on the geographic location, fertility and drainage of the site.
High altitude tall tussock grasslandsTall tussock grasslands found at high altitude occur above the natural tree limit, and are natural communities. They are generally stable, with a low incidence of weed species. However, these grasslands can be depleted by burning and grazing by stock, as well as by hares and feral deer, which selectively graze the more palatable Chionochloa species, leading to a dominance of shorter, less preferred plants. The proportion of herbs and small shrubs increases in open or disturbed areas, such as steep broken country, rocky areas and along streams. Mid altitude tall tussock grasslands
Tall tussock grasslands found at mid altitude have been induced as a result of historic burning of the original forest cover. There is therefore a tendency for shrubs to become prevalent in these grasslands, especially where soil fertility has been amended by aerial application of fertiliser. Woody plants can be native (e.g. matagouri, mingimingi, broom) or exotic (e.g. briar, gorse, broom, wilding pines). Grasslands at mid altitudes tend to be more modified than those at higher altitudes. In a pastoral system, it is desirable to keep tussock cover sufficiently open to promote the growth of palatable species in the intertussock spaces. In addition, if tussocks get too dense, stock have trouble travelling through the grasslands. Some farmers use fire to burn tussocks when the density of the tussock canopy precludes the intertussock species and/or stock. Some open tall tussock grasslands have subsequently been invaded by hawkweed species, and rabbits can locally be a problem. Low altitude tall tussock grasslands
Today, few examples of tall tussock grasslands are found at low altitudes. Land development for farming has removed much of the tussock cover, although small fragments can be found in areas which were e.g. too wet, dry or steep for farming purposes. E.g. copper tussock grasslands in Southland.