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FOREST ECOLOGY. “Conservation is a state of harmony between men and land.”. “A Sand County Almanac” Aldo Leopold - 1949. WHAT IS A FOREST?. Only trees? A community? An ecosystem? Includes animals? Fish? Streams & lakes? Houses? How big of an area?
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FOREST ECOLOGY “Conservation is a state ofharmony between men and land.” “A Sand County Almanac” Aldo Leopold - 1949
WHAT IS A FOREST? Only trees? A community? An ecosystem? Includes animals? Fish? Streams & lakes? Houses? How big of an area? Regeneration areas? Plantations? Christmas tree farm? Ecological processes like nutrient or energy cycling? “That portion of a geographically large area dominated by trees. As an ecosystem, it is meant to include all plants and sometimes the animals dependent upon the trees and plants. Smaller area of largely homogenous tree compositions are called stands”.
FOREST ECOLOGY BASICS COMPOSITION STRUCTURE FUNCTION
COMPOSITION Genetic Diversity - Gene Pools Species, Number of Species & Species Abundance Populations of Animals & Plants Species Associations & Community Diversity Ecosystem Diversity
STRUCTURE Vertical & Horizontal Spatial Heterogeneity & Density Edge Effect Islands & Fragmentation Dead Trees & Snags Micro-Environments Appearance
VERTICAL STRUCTURE Dominant Co-Dominant Co-Dominant Intermediate Intermediate Suppressed Shrubs Ground Cover Vertical structure refers to the “ladder-like” arrangement in a forest. Adapted from Baughman, et al., 1993. Woodland Stewardship. P. 17.
HORIZONTAL STRUCTURE Stand density and crown cover within timber stands and across the landscape is horizontal structure. 40% 80% 100% Adapted from Baughman, et al., 1993. Woodland Stewardship. P. 20.
EDGES, SNAGS, ANDFRAGMENTATION Edge Effect Large Snags Forest Fragmentation Green. 1995. Birds and Forests. P.55. UM-Cartography Lab.
FUNCTION Energy Capture & Trophics Weathering Mineral & Nutrient Cycling Water Movement Temperature & Humidity Succession & Disturbance
ENERGY CAPTURE 10% Energy Capture Trophic Levels
CYCLING Ecosystem Gains Losses Nutrient, Mineral, and Water Cycling
SUCCESSION Grasses & Forbs Shrubs & Saplings Young Forest Mature Forest Old Forest Wisconsin DNR, 1995. Wisconsin’s Biodiversity as a Management Issue. P. 22.
DISTURBANCE Forested ecosystems are dependent upon disturbance for renewal and to provide biological diversity. The plants and animals in a forest don’t know whether the disturbance is caused by natural events or human-caused events. Natural Events Fire Wind Animals Flooding Diseases/Insects Human-Caused Events Fire Harvest Pollution Development Exotic Introductions
FORESTRY AND WILDLIFE Woodland wildlife is managed by manipulating the forest to provide the kind and variety of habitat needed. • Forestry practices in the U.P. have many effects: • encourages plant diversity • encourages forest regeneration • causes multiple age distributions • provides “edge” • creates horizontal and vertical structure • adds more micro-environments • accelerates system metabolism & nutrient cycling
IDEAS FOR YOUR LAND In most parts of the country, forest is a small part of the landscape. In the U.P., forest is the dominant cover type. This causes resource managers to rearrange priorities for habitat management that differ from the general opinion. 1. Modify timber harvests (time & space). 2. Leave large snags & large fallen logs. 3. “Create” future tree cavities. 4. Construct brush piles. 5. Mix areas of varying vertical structure. 6. Create small openings.