CONCORD, New Hampshire — The state has rejected a proposal by the owner of New Hampshire’s largest private single-tract forest to reduce logging there and sell more credits on the carbon stored in the trees, saying the plan violates a conservation easement. The New Hampshire Department of Natural & Cultural Resources said the 10-year management plan proposed for the 146,000-acre Connecticut Lakes Headwaters Forest, located mostly in the Coos County town of Pittsburg, defies the easement’s stated purpose — to ensure the North Country parcel “largely remains an undeveloped productive working forest.” “Responsible forestry play a large part in New Hampshire’s long and proud tradition of environmental stewardship,” Gov. Chris Sununu said in a statement. “As proposed, the plan would have detrimental impact on the traditional forest use, conservation of wildlife habitat and take a serious economic toll on the North Country.