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Criterion 1 Summary
Introduction
Forests are an integral part of Oregon’s natural, economic, and cultural landscape. Oregonians depend on forests for recreation and tourism, clean air and water, fish and wildlife habitat, and timber and wood fiber. Many different ecological processes have shaped Oregon’s forests, and they have a complex mix of plant and animal species that provide the range of values that Oregonians enjoy. Maintaining all the parts of these complex ecosystems is a goal that has been woven into many of Oregon’s policies and laws.
 
The ultimate goal of conserving biological diversity in Oregon’s forests is to ensure the long-term survival of all plant and animal species and the genetic variability within those species. Because different plants and animals are interdependent in many complex ways, biological diversity can be an excellent measure of total ecosystem health. The indicators of Criterion #1 can provide the structural framework needed to discuss biological diversity.
 
The first five indicators address ecosystem diversity and give a general overview of Oregon’s forests, the forest types, ownership, size, and management categories. Maps in Indicator #1 display the general pattern of forests and forest types across the state. Indicator #2 discusses the vegetative structure of these forests. Indicator #3 displays the complex mix of management and reserveed categories within the state. Indicator #4 combines the results of the first four indicators, and Indicator #5 discusses what we know about the effects of fragmenting the different forest types.
 
The species diversity indicators, #6 and #7, provide information about the number and characteristics of the vertebrate species that use Oregon’s forests and information about the status of individual species that are rare or endangered. Indicators #8 and #9, which look at genetic diversity, cover species that are in significant decline and discuss methods to develop models that would facilitate the consideration of wildlife in multidisciplinary natural resource assessments.

Ecosystem Diversity
Indicators #1 through #5 provide basic location, quantity, and quality information about Oregon’s forests and the different management designations for forest protection. Approximately 45 percent of Oregon is covered by forests. Forests are the dominant vegetation in Oregon’s four major mountain ranges: the Coast Range, Cascades, Siskiyous, and Blues. These forests are generally dominated by Douglas-fir, spruce, and hemlock west of the Cascade crest, and pine and mixed pine/fir stands in the dryer central and eastern part of the state.
 
Oregon’s forests fall into four major ownership categories. The federal government (U.S. Forest Service, Bureau of Land Management, and National Park Service) owns and manages 60 percent of Oregon’s forest land. Private owners, including both small woodland owners and large private corporations, own and manage 36 percent of Oregon’s forest land. The state of Oregon owns 2.6 percent of the forest land, and the various Native American tribes own a total of 1.4 percent of the forest land. Generally, private forest land is located in the valley bottoms and the lower elevations, and federal forest land is located at higher elevations.
 
The many ownership groups all have different goals for their land, creating a complex management situation for Oregon’s forests as a whole. Approximately 30 to 35 percent of Oregon’s forests have some formal management classification that protects wildlife, recreation, wilderness, or other non-market values, to some degree. The sizes of trees in Oregon’s forests depend on many factors including age, species, location, management, and history of disturbances. Since different species of wildlife prefer young and old forests, a healthy forest is made up of many different size classes. The size classes in the reserved areas are well-distributed across the entire range of sizes. About half of the reserved acreage is in the larger size classes, generally more than 100 years old.

Species Diversity
Indicator #6 contains a database of a total of 329 forest-dependent, vertebrate species in Oregon. Of these, 108 are mammals, 28 are amphibians, 171 are birds, and 22 are reptiles. The database provides managers a starting point for identifying species that use different forest structures and may be affected by various forest management practices. The data fields include information on: scientific name, common name, vertebrate type, general comments on preferred habitat and range, federal status, forest types used, and descriptions of specific forest structures that the animals might use (i.e., shrubs, cavities, down wood, deciduous trees, and riparian vegetation).
 
Indicator #7 lists forest-dependent species (including vascular plants and vertebrate animals) that are extirpated from the state, or listed as threatened or endangered at the state or federal levels, as well as sensitive species that have no formal listing but are of concern to biologists for a variety of reasons.

Genetic Diversity
Indicator #8 provides information on species that now occupy only a small part of their former range. The distribution of individual animals is important because it affects the likelihood that an individual will find a mate, the intensity of interspecific competition, and is ultimately related to the probability that a species will continue to exist. Shifts in a species’ range may indicate significant change in population size or habitat availability. After available data was reviewed, there was enough information to conclude that at least 11 forest-dependent species have been extirpated from a significant portion of their previous range since European-American settlement in Oregon.
 
Indicator #9 discusses population levels of representative species. If wildlife populations drop below a critical size they become vulnerable to extinction through the loss of genetic variability, which results in high mortality, low reproductive rates, and increased susceptibility to disease. Very little data exists that would allow biologists to conduct a Population Viability Analysis and project population size or likelihood of extinction for a species under particular circumstances. An alternative may be to create Habitat Suitability Models specifically developed to facilitate the consideration of wildlife in multidisciplinary natural resource assessments. The approach is based on deterministic models that link the availability of important habitat components and landscape characteristics to measures of carrying capacity for a given species or guild.

Data Needs
Data from the federal ground-based sampling systems (USFS, BLM, FIA) needs to be combined with the satellite image data used to calculate forest types and size classes (Indicators #1 through #4). It is important to know which forest types and size classes contain some of the habitat features referenced in the vertebrate database created for Indicator #6. The ground-based plot data contains information on snags, etc., while the satellite image data provides location information by mapping large areas for a relatively low cost. A merger of the two data systems would create information useful in answering many policy questions about wildlife and biodiversity.
 
Comprehensive databases for wildlife are extremely rare. Animal populations need to be monitored to allow early identification of species at risk of not maintaining viable populations. For species that are already at risk of not maintaining viable populations, thorough ongoing studies are warranted to identify management practices that can improve the outlook for the species’ survival.