SUSTAINABILITY COMES FIRST
Since 1948, sustainable management systems and modern technology have been adopted by high country farmers, leading to a restoration of many eco-systems and large increases in farm production. Photo copyright: Paul Collins
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.
Modern farming practices
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.
Feral Fallow deer amidst wilding pines on a formerly farmed block transferred to the Department of Conservation during tenure review. Wilding conifers pose a huge threat to our South Island tussock grasslands. Photo copyright: Norman Mackay
The biggest threats 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.