Campers wanting to get back to nature in the national forests could pay more for that privilege if Congress should agree to go along with a proposal to increase user fees there. Agriculture Secretary John R. Block told the American Recreation Coalition Roundtable yesterday that he is studying "who pays versus who benefits" from the use of the 4,582 campgrounds in the national forests.

The benefits go to the people who spent 2.83 billion hours in the forests in 1981. (The Forest Service doesn't count visitors, but visitor-days. Their 1981 figure is the equivalent of everyone in the country visiting a national forest for one 12-hour day.) The costs aren't so easily figured. The figures Block used--which the Forest Service's public affairs office could not confirm -- indicate that USDA spent nearly $75 million on its campgrounds in fiscal 1981. It received about $41 million in fees from campers, who are charged a fee in about 60 of the 155 national forests.

"To what extent should the people who have been enjoying free or subsidized benefits bear more of the costs of providing them?" Block asked. "Should we attempt to continue maintaining facilities where uses are limited and costs per visitor are high? We don't have pat answers to these questions, but I can assure you that simple economics will necessitate our doing more to recover some of the costs of providing the growing demand for recreational services."