Old-Growth Forests and Deforestation

Old-Growth Forests Characteristics Ex: Pacific Northwest Trees at least 250 years old Multi-level canopy Standing dead trees and fallen logs Ex: Pacific Northwest Noted for Douglas Fir trees that are hundreds of year old, but still have trees of all species and sizes

Old-Growth Forests Variety of tree species and sizes help to make a healthy ecosystem Healthy mature trees Produce seeds to grow new trees and provide food Dead and dying trees play an important role

Old-Growth Forests Snags Standing dead or dying trees When snags topple over, it opens up a canopy letting sunlight through Fallen trees provide habitats for smaller organisms Nurse logs Young seedlings take root and grow Provide evidence of natural recycling process

Logging Forests Forests regulate climate by recycling water and carbon dioxide. On hot days a large tree may absorb 5.5 tons of water from the soil and release it into the atmosphere through its leaves in a process called transpiration.

FORESTRY PRACTICES Forests are logged by two different methods: CLEAR CUTTING – every tree is cut down whether it has value or not and the unnecessary trees are left SELECTIVE CUTTING – only certain trees are cut down depending on what they are needed for ( firewood, paper, furniture or lumber)

EVALUATING A CLEAR-CUT Company’s point of View 1. Less expensive – provide timber or pulp at a more competitive price 2. Company can choose which trees to plant – get better price for when the area is logged again in the future.

EVALUATING A CLEAR-CUT Ecological Point of View 1. Soil erosion and runoff into local streams increases – increasing growth of algae 2. Eroded soil forms sediment in streams, affecting spawning areas of fish. 3.Removal of vegetation on the ground exposes the soil, increasing the warming of the area in summer and cooling in winter Exposure also increases water loss from the soil.

EVALUATING A CLEAR-CUT Clear-cut creates completely different abiotic and biotic conditions in the area. Ecosystem must change – therefore the community must change. Loss in forest plants – loss of forest animals

DEFORESTATION Is any removal of trees from the area of land. Deforestation affects the environment in many ways: 1. Erosion – tree roots hold soil in place during heavy rains 2. Nutrient Loss – nutrients are washed away with the rain instead of being absorbed by the trees

DEFORESTATION 3. Temperature Change – the ground will absorb more energy and affect organism functions 4. Carbon Cycle Change - no trees to take in CO2 and to make O2 5. Food Web Changes – less producers at the beginning of food chains 6. Habitat loss – nesting areas and ground cover disappears

A logger would say that this tree was overmature A logger would say that this tree was overmature. What would an ecologist say?

Multiple Use Management Most old-growth timber on private land is already gone Nearly all old-growth wood is in National forests and managed by government U.S. Forests service can sell permits to log these areas

Multiple Use Management There are roughly 191 million acres in our national forests Law requires national forests to be managed for multiple uses Timber Mining Watershed protection Grazing Recreation Fish and wildlife habitats

Multiple Use Management Local economy can be tied to “uses” permitted on federally owned land Conflicts often occur with these multiple uses Water quality can be damaged by improper disposal during oil and gas production Critics of the Forest Service say timber harvest is given priority over other uses

Conflict in the Northwest Logging is most controversial environmental issue in this area Ecologists believe wood should stay in the forest No such thing as waste in the forest Death and decay of Douglas Fir tree provide life for other organisms Foresters, hired by commercial timber companies consider these forests to be “overmature” To foresters, timber is a crop and is ready for harvesting Believe it is wasteful to allow valuable timber to decompose on forest floor

How much is enough? National Forest Management Act (1976) Requires management plans to be made for every national forest Timber companies were logging old-growth timber at a rate of 60,000 acres per year, in 1987 Court ruled service plans for Pacific Northwest were inadequate and logging was stopped

How much is enough? Northwest Forest Plan was adopted in 1994 Based on ecosystem management approach Requires government agencies to survey and manage these forests Permits logging only in areas that do not disrupt habitat of ecologically important organisms