Farmers develop area the size of Rarotonga
‘‘It’s not a choice between bio-diversity and farming. The two can co-exist and do co-exist.’’
Kate Cocks
Mt Nicholas Station farmer
Farmers in the Canterbury high country have developed an area the size of Rarotonga in just 20 years, a new report shows.
Environment Canterbury’s report into agricultural land use change in the MidCanterbury hill and high country showed 6800 hectares was converted into pasture between 1990 and 2019.
Presented by Philip Grove at the Environmental Defence Society in Christchurch yesterday, the report said the development had resulted in direct loss of habitat for indigenous species and had likely reduced the populations of many species.
Development generally happened on flat or gently sloping landforms, including the beds and margins of braided rivers.
Most of the development happened on private freehold land, but a significant portion was on Crown pastoral and University of Canterbury lease land.
The largest development was in the Waimakariri catchment, where there had been a 57 per cent increase (3124ha), while the Rakaia catchment had sliced off a quarter of its high country (19,570ha).
The study also found more than 744 hectares had been lost from areas recommended for protection after ecological surveys in the 1980s.
As well as habitat reductions, the study identified adverse effects on wetlands from higher levels of nutrients, sediments and microbial contamination associated with land use intensification.
The development expansion would result in increased greenhouse gas emissions, particularly nitrous oxide and methane, the report found.
Grove said intensification in the high country was ongoing and the study suggested a more co-ordinated approach between management agencies was required.
Landcare Research programme leader Dr Susan Walker said agricultural intensification of the Mackenzie basin had caused a major decline in indigenous biodiversity. Five times as many freshwater fish specific were considered threatened than in 2002.
Walker warned the problems would not level off even if intensification stopped now.
Wilderness Lodge Arthur’s Pass founder and former pastoral lessee Dr Gerry McSweeney said intensification was destruction. Farmers had taken an ‘‘incredibly’’ diverse landscape and turned it into something resembling the Canterbury plains.
He believed it was critical to work out who had the power to stop the clearance of habitat on high country farms.
Merino NZ markets and sustainability general manager Dave Maslen said New Zealand was sitting on the cusp of a remarkable opportunity as Covid-19 had ‘‘awakened’’ consumers to the environmental footprint of their products.
‘‘What if we could generate value from less impact.’’
Mt Nicholas Station farmer Kate Cocks said she worked closely with the Department of Conservation. ‘‘It’s not a choice between bio-diversity and farming. The two can co-exist and do co-exist.’’