Our Region
The Umpqua basin is dominated by the Klamath Ecoregion but includes portions of the Coast Range, Willamette Valley, and West Cascades ecoregions.
Oak and prairie. Credit: Sara Evans Peters
A unique landscape
A combination of geology and climate in the Umpqua Basin has created a unique landscape characterized by hills and valleys covered by oak savannas and woodlands mixed with oak-conifer forests and open grasslands bisected by the Umpqua River and its many tributaries. The landscape provides ranch lands, pastures, hay fields, woodlots, and habitat for native plants and wildlife.
Umpqua Bioregions
The Umpqua Bioregions hold some of the highest biodiversity of any terrestrial system in Oregon and contain some of the largest remaining landscape-scale examples of Oregon White Oak (Quercus garryana) forests and savannas in the Pacific Northwest (Umpqua Prairie and Oak Partnership Conservation Strategy, 2013). According to the Oregon Conservation Strategy, oak habitats also are known to be used by more than 200 species of native wildlife in addition to several invertebrates and plant species that are endemic to oak habitats.
Oak and grassland/prairie communities
Oak and grassland/prairie communities are very much a part of the region’s natural and cultural heritage, and Umpqua Basin tribes were the original land stewards of the habitats. The First Peoples of the Umpqua River Basin, including the Cow Creek Band of the Umpqua Tribe of Indians, used fire and other methods to manage open oak habitats that provided the tribal members with food, medicine, tools, home materials, decorations, and cultural needs. These open habitats provided habitat for hundreds of plant and animal species upon which the tribes depended and are still utilized and needed today.
Threats
Generally speaking, threats to oak habitat in the Umpqua that result in loss and degradation are due to conversion to intensive agriculture and commercial timber, fire suppression and exclusion, invasive species, rural and urban growth, and oak habitat encroachment.
Only 4-7% remaining habitats
Oak and prairie habitats are among the Pacific Northwest’s most threatened habitats with estimates as low as 4-7% remaining (ODFW 2006). And oak forests and prairies in the Basin are under the same human stresses found in other portions of Washington, Oregon, and California.
Conversion to Intensive Agriculture or Commercial Timber
The conversion of oak habitats to intensive agricultural practices and commercial timber has threatened oak habitats in the northwest for decades. While the frequency and scale of conversion have varied over the years, this threat remains a viable concern in the Umpqua. This threat is defined as any operations or land use practice that is established with proprietary interests in mind that could result in the loss or fragmentation of oak habitats on the landscape. Specific to agriculture, lands are cleared of oak habitats for crops or livestock, such as, but not limited to, vineyards, hemp, Christmas tree farms, sheep, cattle, and horses present a significant threat to the loss of oak habitats. Commercial timber conversion for alternate practices, such as but not limited to, forest conversion has historically posed a potential loss to oak habitats, however, this threat has been less prevalent in recent decades.
Oak Habitat Encroachment
Oak Woodlands are identified as a strategy habitat in the Oregon Conservation Strategy and are threatened by various forms of encroachment. Encroachment is the replacement of a desired species with a less-than-desirable species, often resulting in the suppression of the desired species or habitat (oak), thus reducing its native and/or historic range. Encroachment can occur with native and non-native species and is commonly referred to as fir encroachment in the Umpqua. We defined this threat to include, not only savanna and meadow habitats, but mixed conifer and hardwood habitats dominated by incense cedar, madrone, hawthorn, and conifers.
Fire Exclusion
Fire, natural and manmade, was once a regular occurrence on the landscape. For more than 100 years fire has been excluded from the landscape in efforts to prevent large catastrophic events and protect human life and infrastructure. This, along with the departure from traditional indigenous burning at low elevations in the spring and high elevations in the fall, has resulted in uncharacteristic levels of vegetation on the landscape, creating excessive fuel loads that have an ever-increasing potential for catastrophic wildfires. Fire exclusion is defined as any action that excludes, removes, or minimizes the positive effects of regular fire on the landscape which can have catastrophic negative impacts to the land, the ecosystem, and the people who inhabit it.
Non-Native/Invasive Plant Species
The Umpqua Basin hosts numerous plant species that are not native to the basin and directly compete with oaks, native understory, and historic ecosystem processes. Non-native and invasive species often out-compete native species and provide significant ladder fuels that can lead to catastrophic fires and habitat loss. Non-native species are defined as species that does not naturally occur in a specific area and has been introduced as a result of deliberate or accidental human activities. Invasive species are defined as aggressive and unwanted species whose introduction can cause economic losses to agricultural and horticultural industries, endanger native flora and fauna by encroaching in wildlands, hamper the enjoyment and full use of recreation sites, and are poisonous, injurious, or otherwise harmful to humans and animals.
Rural Residential & Urban Development
The development of our rural lands and the expansion of urban growth boundaries for residential purposes are a direct threat to oak habitats in the Umpqua Basin. Rural residential development is considered any development that occurs outside of the urban growth boundary and presents a potential loss and/or fragmentation of existing oak habitats. Urban development is considered any development that occurs inside the urban growth boundary or the threat of expanding the boundary into rural lands that contain oak habitats. Specific concerns include, but are not limited to: land partitioning, urban growth boundary expansion, zoning changes, and infrastructure changes (housing, land use reclassification, and development of agricultural lands).