Deschutes & Ochoco National Forests
Crooked River National Grassland

Wildlife Habitats Unique combinations of food, climate and shelter define wildlife habitats. There are five distinctive habitats in Central Oregon, with micro habitat conditions within each of them. This diversity in landscape supports the diversity of wildlife who live here year round or visit seasonally. Current conditions of habitats are influenced by some of the following factors: Edges The place where plant communities meet or successional stages come together is called edge. Edge effect describes the increased diversity of plants and animals due to the mingling of two adjoining communities or successional stages. Some wildlife species associate with edge because of the close proximity of food, shelter, and other habitat components. As examples, the mule deer commonly grazes in openings but hides or rests in dense cover. The northern goshawk typically nests within dense forest next to a small wetland seep.   Alpine Forest Shrub/ Grassland Wetlands Rock Outcrops

VIEW SITES WILDLIFE HABITAT Alpine Forest Shrubland/Grassland Wetlands Rock Outcrops IMAGE GALLERY FOR KIDS LINKS/CONTACTS

Weather

Periodic extremes of dry or wet climate may allow plant species to enlarge or shrink their distribution. For instance, as a wet meadow dries from extended drought, coniferous trees from adjacent uplands may pioneer and alter the new site through water consumption and shading. Conversely, sites which are normally too dry for conifers can moderate sufficiently after years of copious or timely precipitation to allow tree seed germination and seedling survival.

It takes a hardy plant to survive the root-wrenching topsoil upheaval during Central Oregon's freeze-and-thaw spring season. In addition, an accumulation of heavy snow can break or deform even the strongest tree. Trees toppled in windstorms cause openings in the forest canopy where seedlings can germinate on the forest floor, although massive accumulations of woody debris can actually delay seedling establishment.

Fire

Until the early-1900's, wildfire regularly burned across Central Oregon. Depending on the kind of habitat or subhabitat, the time between fires averaged 8 to 100 years. These fires - usually of low intensity because fuels didn't accumulate - pruned or cropped aerial growth instead of killing plants. With the arrival of European settlers and the establishment of public wildland reserves, energetic fire suppression became a common practice. As a result, habitats - especially forest - accumulated fuel in such great amounts that today's ignition burns hot enough to cover massive areas and to kill vegetation. While cool ground fires release nutrients stored in soil humus, hot fires can destroy soil microorganisms that help make these nutrients available to plants.

Insects/Disease

Small mammals, insects, and microorganisms are essential processors of the nutrients in dead vegetation. At an endemic level, insects and diseases kill some plants in a natural thinning process, freeing adjacent vegetation to grow fast and abundant. However, insects or disease can proliferate to weaken or kill vegetation - especially trees - when there is too much plant?life for the moisture, sunlight, or nutrients available.

Animal Use

Animals, whether wild or domestic, exert a significant effect on vegetation. Rodents and birds spread seeds or vegetative parts that sprout new plants. They crop, injure, or kill vegetation for food or construction materials. Grazing can retard or halt tree seedling regeneration in either conifer or hardwood forests. Conversely, grazing can stimulate growth in some lethargic plants that evolved from natural cropping by fire or native grazers.

Human Activity

Human carelessness or excessive use may compact soil, disrupt animal or plant behavior, ignite wildfire, and introduce environmental contaminants such as foreign species or chemical pollutants. Vegetative manipulation - timber management, prescribed burning, or plantings, etc. - can change the direction and speed of succession.

Succession

Ecological succession is the orderly change in vegetation and animal life that takes place over time as a tract of land evolves from bare ground to a highly stable condition. Each of several plant communities that follow one another in sequence is called a seral stage. You might visualize this by picturing the advance of a forest following wildfire, where bare ground is colonized or resprouts with grasses, forbs, or shrubs. In turn, those plants are overgrown by tree seedlings that progress to saplings, poles, and mature trees. Generally, species diversity increases as succession advances, with the most diverse communities being the most stable.

USDA Forest Service - Deschutes & Ochoco National Forests
Last Modified: Friday, 19 March 2004 at 18:47:28 EDT