The Institute for Business Research found that covenanting land owners, the majority of whom are farmers, are together spending an estimated $25 million of their own money every year to protect native species, forests, wetlands and other special areas in their QEII covenants.
In total, the land owners have made a financial commitment of between $1.1-$1.3 billion in direct or lost opportunity costs establishing and maintaining land under covenant since the QE II Trust twas set up in 1977.
"The land surrounding 69 per cent of covenanted sites is used for grazing. While not all of the covenanted land would be suitable for farming, it's no surprise to us that thousands of farmers have voluntarily opted to permanently protect important wetland, bush and landscape sites, and to forgo revenue from it," Mr Allen says.
"These special sites have even more protection than national parks. The QEII covenants cannot be revoked by subsequent land owners."
The study said that loss of potential income from other alternative uses of land under covenant is estimated to be between $443-$638 million since 1977.
Farmers and other land owners pitch in with environmentalists, volunteers and council staff to carry out planting, pest control, fencing and other work on the covenanted sites.
"The philosophy of the late Gordon Stephenson - who was the national chairman of Federated Farmers' dairy section in the mid 1970s - was that kaitiakitanga, or guardianship, of the land for future generations was an honour rather than a chore.
"The fact is, that's an approach that is followed by farmers up and down New Zealand," Mr Allen says.