Farming in the High Country
What is produced in the South Island High Country?
Until the 1950s, most High Country farming businesses relied almost solely on Merino wool for their income. Today, most have other sources of income including cattle and deer farming, trophy hunting and tourism.
Before human settlement, natural tussock grasslands covered a very limited area – roughly 5% of New Zealand. Most of this grassland was above the tree line where tall tussocks (Chionochloa spp.) predominated. At lower altitudes more than 85% of the country, including the South Island, was forested.
On the drier eastern side of the Main Divide of the South Island, most of the forests were dominated by either beeches (Nothofagus spp.) or native conifers such as totara or matai. Patches of tussock grasslands occurred within the forests. Red tussock (Chinochloa rubra) grew where poor drainage inhibited tree growth. Short tussocks (principally Festuca or Poa spp.) grew initially where landslides, windthrow or lightning strike had temporarily
cleared the forest.
In drier seasons in low rainfall areas, such as Central Otago, fire caused by lightning strike seems to have periodically destroyed large areas of forest or scrub. Grasslands colonised these burnt out areas, but over centuries forests regenerated, so long as fires did not recur.
Between 600 and 750 years ago, much of the forest in the drier eastern areas of New Zealand and in the central high country was removed by fires These were lit by Polynesians in the course of their travels or to hunt birds of the forest, especially the moa.
Most of the forests failed to recover because of repeated fires and the naturally slow regeneration of beech forest. Most of area burnt became occupied by bracken, shrubs and tussock grasses.
In the area we now call the high country, tall tussock grasslands (Chionochloa spp.) became widespread downslope from their natural environment in the high mountain zone. Short tussocks (Festuca, Poa spp.) and other grasses moved upslope from riverbeds and other disturbed sites. Red tussock (Chionochloa rubra) spread widely at lower altitudes from its niche in wetter soils within the forests.
Were it not for the recurrent lighting of fires by humans over the last 750 years, recovery of scrub or forest would have occurred everywhere except for the driest parts of Central Otago.
At the time of European settlement a mosaic of indigenous tall and short tussock grassland and shrubland (Dracophyllum, Discaria, Coprosma) was already established in the high country.
As they explored during 1850s, the Europeans brought sheep and some cattle onto burnt ground. In the 1860s they added deer, goats, hares and rabbits. Grazing pressure soon exceeded whatever effect birds, rats and invertebrates might have had before them.
Sheep numbers increased by more than 200% from 1861-71, reaching numbers that were far greater than the land could sustain. By 1890, sheep numbers on unimproved grasslands were declining, and continued to fall for 70 years in most areas.
Where tall tussocks were repeatedly burned and grazed they gave way to short tussocks and other plants. In drier areas, short tussocks were replaced by exotic grasses and weeds.
By 1900, under the impact of over-grazing, burning and rabbits, grasslands had been depleted to near-desert in North Otago, Central Otago, and drier parts of the Mackenzie Basin and Marlborough. Scabweeds (Raoulia spp.) became widespread in these areas.
During this period populations of deer, goats, Canada geese, pigs and tahr all grew rapidly, destroying vegetation, causing soil erosion and competing for livestock for feed in large parts of the high country.
As pastoral production declined, successive Governments tried to correct the problems, without understanding the ecological and other reasons for the land degradation.
The restoration, 1948 onward
The turning point in the history of the high country was in the years immediately following the Second World War. Aerial topdressing, mechanisation and the widespread application of scientific principles to farm management, came together with a growing awareness of the need for more sustainable management of hill and high country in both islands.
In 1948 the then Labour Government introduced the Land Act. Farmers were offered 33 year leases which could be renewed in perpetuity, in order to give them security of tenure and the incentive to invest in their farms.
At about the same time, 1080 poison was introduced and aerial spreading of poison on oats and carrots allowed rabbit numbers to be reduced and managed in all areas. Local Pest Destruction Boards carried out the work.
With track-making machinery and 4WD trucks to transport fencing materials and people, runholders started to subdivide blocks and develop improved pastures on their easier country using clovers and fertilisers.
By the 1970s, most livestock feeding was from improved pastures, with low-intensity grazing of higher altitude native grasslands in summer months only. Nevertheless, this access to native pasture remained — and still remains — vitally important to the management of the many high country farms that are prone to severe droughts on their lower country during summer and early autumn.
High Country farming today
Most farmers take great pride in their range management systems, in which weed control and the maintenance of good ground cover play important parts. These systems are based on experience, the results of scientific research and lessons learned from the mistakes of the past.
The biggest risks to the High Country environment today are invasive weed species, especially wildling conifers, scrub weeds and herbs of the hieracium family.
In recent decades, Douglas-fir and other wildling conifers have become recognised as a major problem, covering tens of thousands of hectares of grazing and conservation land in the high country of Marlborough, Canterbury, Otago and Southland. These northern hemisphere species out-compete native species and left unchecked have the potential to cover all tussock country including areas above the native bushline.
Some species of conifer are well controlled by stock grazed at medium to high intensity. In the low intensity grazing systems normal in tussock rangeland, only about 30% of wildlings are destroyed by stock, leaving large numbers of seedlings to be removed physically or by use of herbicides. This can become a major task and expense when a farmer is downwind of land where mature trees provide a seed source. The decision of the government to allocate more money to wildling control on conservation land in the high country is therefore welcomed by the Accord.
Broom and gorse are also major problems, especially where they have become established on public land in river beds, as they provide a seed source for weed spread to adjoining properties. Because broom and gorse seeds remain in soil for decades, the only realistic means of control once they have become established on large areas is through the development of improved pastures.
Because this is not practical in large areas of the high country, farmers are vigilant in their removal of outlier plants. Spraying and physical removal of broom, gorse and other scrub weeds is a major task on many properties.
Species of the introduced hieracium genus are problem weeds in low intensity grazing and conservation land in the high country. Two of these, mouse-ear and king devil, are among the most abundant plant species in tussock grasslands. Although they are eaten by stock, they are toxic to other plants and, on farms, reduce the total amount of feed available. Hieracium species are resistant to most herbicides and the main method of control is to develop land by application of fertiliser and oversowing. On unfertilised or poor sites, and in conservation areas, there are no effective control options.
In recent years the farmer-led Hieracium Control Trust has worked with MAF’s Sustainable Farming Fund and Landcare Research to study and introduce from Europe five insect species that attack hieracium. The effectiveness of these introductions will not be known for several years.