The greatest threat to the sustainability of this country’s forests and probably the number one challenge for land managers is not forest fires, as may be perceived by the public, but insect infestations and the spread of disease. Insects and disease do not get the media coverage that fires do, but the National Report on Sustainable Forests-2010 (http://www.fs.fed.us/research/sustain/national-report.php) identified pest infestations as the largest disturbance process affecting forest health. These pest issues actually may be contributing to conditions that will create larger, more intense forest fires.
Current forestry management methods have changed vastly from those previously used, issues used to be all about harvest i.e., when can we harvest and how much can be taken without depleting resources? Forest area has become relatively stable over the past century and, in fact, the volume of wood produced within forested areas has increased, the problem facing those attempting to manage forests sustainably has become much more complex. Human influences, pests and disease are substantially affecting forests now, and these effects will most likely continue into the future. So the question becomes how can our actions be used to limit damage to forest ecosystems and, possibly, magnify benefits derived from them.
The USDA Forest Service’s Forest Health Protection unit (FHP), in cooperation with state, local and private partners, collects and compiles forest health data acquired through ground surveys, aerial surveys and remote sensing to aid in the development of forest management plans. Information from their study indicates that pest related tree mortality has increased threefold from the findings of the 2003 Sustainability Report. These results should be used to inform changes to management methods. However, pest issues vary seasonally and regionally; bark beetles in the western part of the country prey on trees already weakened by drought, gypsy moth populations are kept in check when spring is especially wet and the habits and preferences of emerald ash borer are still being studied but it is rapidly spreading.
Management strategies have to be developed with regionally specific problems in mind, they also need to be living documents, able to easily adapt and change with conditions. Additionally, although there may be a small public voice that believes systems should be left to care for themselves, ecosystems that have already been altered due to human impacts, climate change, invasive species, novel pathogens and fire suppression cannot be expected to manage on their own. A large portion of forested land has been altered in some way and letting nature run its course without intervening to quarantine pests, stop the spread of invasive species, manage insect issues and, at the very least, consistently monitor consequences could be catastrophic. Sustained, collaborative efforts of multi-level government and stage agencies, municipalities, nonprofit groups and other stakeholders to sustain and conserve natural resources and processes can yield long-term, positive results for trees everywhere.
The definition and objective of sustainability may, itself, change over time as human influences, needs and desires change. Reversing negative impacts and returning natural spaces to their previous states, even from just a couple hundred years ago, may not actually be realistic. However, conservation of forest resources is crucial to air and water quality and so these standards must be managed for even as desirable characteristics and landscape values change with time.