Climate Change Minister James Shaw is dousing farmer concerns that prime farmland is being bought for forestry.

Farmers are worried that more farms are being converted to forestry with planting estimates ranging up to to 70,000 hectares a year.

Shaw says only about 13,000 hectares were planted last year and deforestation is faster than new plantings.

James Shaw told Mike Hosking he concedes farmers are justified about being worried in some parts of the country.

"I'm not worried about the impact of food production, but I do know some communities are feeling like their world is being upended."

Farmers are frustrated the Government is focusing too much on tree planting to reach carbon zero targets,  instead of reducing fossil fuel consumption.