The Department of Conservation’s latest report on timber supply in Maine could not be more plain: The harvesting practices for both large and small landowners are not sustainable and will lead long-term to a widespread decline of Maine’s forests. That’s the bad news. The good news is that something can be done about it.

The department’s report, called “Timber Supply Outlook for Maine: 1995-2045,” is an excellent base from which to find out what that something should be. The report’s own recommendation to increase yield — primarily with better partial-harvesting practices but also through increased herbicide spraying, pre-commercial thinning and plantations — offers a few of the possible solutions, just as they present difficulties because of cost and public reaction. But the report is important because no matter how complicated the eventual mix of solutions because the situation in the woods is simple.

This is how simple: In 1972, the Maine woods grew nearly 7.5 million cords of wood with 3.5 million cords harvested. In 1996, it grew 4.9 million cords with 6.5 million cords harvested. The earlier numbers are not considered quite as reliable as those after 1985 so the difference may not be as dramatic as they suggest, but even the approximate disparity in the amount grown and the amount harvested in those years explains why people lament that the forest isn’t as they remembered it. They’re right. It isn’t.

What currently exists is a forest, on average, in decline because of the way it has been cut. Assuming a steady demand for wood and an absence of natural disasters, the report predicts the amount of wood in the forest will drop year after year, slowly at first then a bit more steeply after 50 years. Even after 90 years, the wood supply doesn’t disappear altogether, but the forest is diminished by 30 percent.

The public, however, is not likely to wait around for that to happen. Long before the gap between the amount harvested and the amount growing widens considerably, legislation — by lawmakers or through citizen initiative — will require that it be closed. This will not merely be a mandate on private property but a way to protect the state’s interest in its wildlife, its waters and the health of its future.

One of the more encouraging plans by the Conservation Department will have it collecting forest data annually and reporting on it every two years, rather than every decade or so. The fresh information should improve the quality of the debate around the forests, although the Legislature would provide a service to the state if it directed the department to distinguish between landowners doing sustainable cutting and those who are not. Identifying specifically where problems exist in the forest would help suggest the sort of solutions needed.

The good news is that, old growth aside, Maine’s forests can grow back and that careful stewardship can yield both a vigorous forest and a sound timber industry. But as the report demonstrates, Maine landowners eventually will lose both unless they change the way they are harvesting trees.