Biodiversity Guide - The Intertwine

egional conservation strategybiodiversity guideChapter 6 Important Issues and Conceptsn Prioritize and reconnect isolated habitats byacquiring strategic properties and removingbuildings, impervious surfaces, berms, levees, andfloodwalls.n Retrofit developed areas for stormwater detention;develop and implement strategies to reducethe area of effective impervious surfaces andincrease vegetation cover.n Increase riparian corridors and stream channelcomplexity through plantings, maintenance ofnative vegetation on stream and riverbanks, andthe addition of large woody debris.n Engage in projects that help mimic naturalflow conditions—e.g., “sustainable flow” dammanagement, water conservation, and purchaseof floodplain easements and water rights forinstream use.n In upper and middle watershed areas, useforest practices that leave riparian areas intact,reduce habitat fragmentation, and reduce sedimentand chemical loads.n In mid-elevations, implement strategic land useplanning and work with rural landowners, ranchers,and farmers to implement best managementpractices to increase vegetation and the width ofriparian corridors, and to reduce the effects ofagriculture on streams, rivers, and floodplains.Stream and floodplain restoration can be complicatedin human-influenced landscapes. Takingthese approaches can add up over time to helpstabilize hydrology and improve stream andfloodplain conditions.For More InformationEcological Issues in Floodplains and RiparianCorridorsS.M. Bolton and J. Shellberg. 2001. WA-RD 524.1.Olympia, WA, Research Office, Washington StateDepartment of Transportation.Urban Stream Rehabilitation in thePacific NorthwestD.B. Booth, J.R. Karr, S. Schauman, C.P. Konrad,S.A. Morley, M.G. Larson, P.C. Henshaw, E.J.Nelson, and S.J. Burges. 2001. EPA GrantNumber R82-5284-010. Seattle, WA, Universityof Washington.“An Ecosystem Perspective of Riparian Zones”S.V. Gregory, F.J. Swanson, W.A. McKee, andK.W. Cummins. 1991. BioScience 41:540-551.The Flood Pulse Concept in River-floodplainSystemsW.J. Junk, P.B. Bailey, and R.E. Sparks. 1989.Canadian Special Publications in Fisheries andAquatic Sciences, Paper #106.The Natural Flow RegimeN.L. Poff, J.D. Allan, M.B. Bain, J.R. Karr, K.L.Prestegaard, B.D. Richter, R.E. Sparks, and J.C.Stromberg. 1997. BioScience 47:769-784.Disturbance and Recovery of Large FloodplainRiversR.E. Sparks, P.B. Bayley, S.L. Kohler, and L.L.Osborne. 1990. Environmental Management14:699-709.“Flood Disturbance in a Forested MountainLandscape. Interactions f Land Use and Floods”F.J. Swanson, S.L. Johnson, S.V. Gregory, and S.A.Acker. 1998. BioScience 48:681-689.“Stream Restoration in Urban Catchmentsthrough Redesigning Stormwater Systems:Looking to the Catchment to Save the Stream”C.J. Walsh, T.D. Fletcher, and A.R. Ladson. 2005.Journal of the North American BenthologicalSociety 24:690-705.Pollinators and PollinatorConservationMace Vaughan, Xerces SocietyPollination is the transfer of pollen within orbetween flowers, resulting in the production ofseeds. In most cases pollen transfer is accomplishedeither by the wind or by an animal. Morethan 75 percent of plant species require insectsto successfully move pollen between plants. Thenon-native European honey bee (Apis mellifera)is the most well-known insect pollinator,yet North America is home to more than 4,000species of native bees, along with countless otherpollinators such as butterflies, various beetles,flies, solitary wasps, hummingbirds, and otheranimals. Of these species, bees are consideredamong the most important to temperate NorthAmerican terrestrial ecosystems.Importance of Protecting PollinatorsPollinators are essential to our environment andeconomy. The ecological service that pollinatorsprovide is necessary for the reproduction ofnearly 75 percent of the world’s flowering plants.Fruits and seeds that are derived from insectpollination are a major part of the diet of approximately25 percent of birds and mammals, fromred-backed voles to bears. In addition, insect pollinatorsare direct food for other wildlife species;for example, more than 90 percent of bird speciesrequire insects as a primary food source duringat least one stage of their life. The conservationof biological diversity benefits from a frameworkthat guides conservationists to work at multiplelevels of the food chain. Pollinator conservationprovides such a framework by focusing onthe foundational elements of all terrestrial foodwebs—i.e., native plants and invertebrate communities.Pollinators also play a key role in agriculture,enabling production of more than two-thirds ofthe world’s crop species, whose fruits and seedstogether provide more than 30 percent of ourfoods and beverages. The United States alonegrows more than 100 crops that either require orbenefit from pollinators. The economic value ofinsect-pollinated crops in the United States wasestimated to be $20 billion in 2000. Oregon andWashington are among the world’s largest producersof insect-pollinated crops, such as berries,tree fruit, alfalfa seed, and vegetable seed.In many places, the essential service of pollinationis at risk. Pesticide use and the loss, alteration,and fragmentation of habitat contribute topollinator declines, especially in landscapes withhigh levels of urban or agricultural development.On October 18, 2006, the National Academy ofSciences released the report Status of Pollinatorsin North America, which called attention to thedecline of pollinators and urged nonprofit organizationsto collaborate with land managers topromote and sustain these important species.Native Pollinators in the RegionLocated at the north end of the Willamette Valleyand the south end of Puget Trough, the greaterPortland-Vancouver region is home to at least250 native bee species. Declines of a few of thesespecies are well documented. The western bumblebee (Bombus occidentalis)—formerly one of themost common bumble bee species in Oregon—has declined dramatically in recent years and nowis at immediate risk of extirpation throughout thewestern United States. Although an exotic diseasehas been implicated in the decline of the westernbumble bee, pollinator biologists also recognizeother factors, such as pesticide use and theloss, fragmentation, and degradation of naturalhabitat.Beyond bees, the greater Portland-Vancouverregion is home to other imperiled pollinators,such as the Fender’s blue butterfly (Icaricia icarioidesfenderi), whose dependence on the threatenedKincaid’s lupine (Lupinus sulphureus subspkincaidii) makes it critically vulnerable to extinction.(The lupine’s range has become restrictedto a handful of locations in western Oregon and114 115