What Challenges Do Our Forests Face?
the Maine forest is healthy. Still, natural and human induced
disturbances pose challenges. These include land development, the
introduction of exotic plant species that threaten native tree
populations, insects and disease, and atmospheric threats like acid
precipitation and climate change. Each of these disturbances has the
potential to create a decline in biological diversity, or the
decline in the total number of plant and animal species including small
mammals, grasses, flowers, fungi and soil bacteria.
How Land is Used
Maine’s population increased 83% from 694,466 people in 1900 to 1,274,923 people in the year 2000. Most of the increase occurred in the first half of the 20th century. In the last 20 to 40 years some
moved out of the state and others moved in, but the net population
stayed about the same.
What has changed dramatically is where people choose to live. People left northern and Down- east Maine and moved to urban areas. Since the early 1980’s, the fastest growing towns are within 10 to 25 miles of metropolitan areas. Small towns have become suburbs. Between 1982 and 1997, the population of the greater Portland area grew 17% and continues to grow rapidly today. Housing is expensive and hard to find. Farms and forests are converted into residential and commercial development almost overnight; land use changes increased by 108% in the fifteen years between 1982 and 1997 when land was converted to house lots, roads and stores.
developments break up forest habitat. While deer, chickadees, bluejays
and raccoons thrive on patchy woods between houses, many wildlife --
like bobcat, some owls and hawks, and many songbirds -- need extensive
stretches of undeveloped forest in order to successfully raise a family.
Small patches of woods, or fragmented forest areas, don’t
provide either enough food or enough protection from predators.
Land use planning that takes
wildlife habitat into consideration can reduce the negative impacts of
development without compromising economic value or the aesthetics of the
Gypsy moth caterpillars defoliate trees, bitter-sweet vines strangle native trees, and brown-tail moths pose threats both to trees and human health. Hemlock woolly adelgids, recent exotic insects that are a serious threat to eastern hemlock, are spreading through southern New England and have been found in nursery stock shipped into Maine. Quarantines of hemlock nursery stock and outright refusal to allow stock into the state may halt it before it gains a foothold in the state.
Acid rain, snow, fog, and other airborne pollutants such as low-level ozone and sulfur dioxide weaken trees, thus making forests more susceptible to insect infestation and disease. Acid precipitation appears to interfere with absorption of soil nutrients, resulting in stunted tree growth. Acid fog is a particular concern on some Downeast islands.
The effects of global climate change are difficult to measure, but increasing evidence suggests that warmer temperatures could change the mix of tree species in the state and introduce new insect pests and tree diseases.
We Can Work it Out
CD-ROM: Using Remote Sensing to Address Coastal Management Issues – The Maine Project (Available from the Maine State Planning Office)
www.seec.scarborough.me.us/tour teachers, community members and research professionals work together designing investigations relevant to the community.