Biodiversity Guide - The Intertwine

egional conservation strategybiodiversity guideChapter 5 Fish and Wildlife of the RegionConservation Strategies: Habitat Needs ofInvertebratesAlthough the status of most of the region’sinvertebrates is unknown, residents can still takeaction to maintain and increase the diversity ofinvertebrates in both terrestrial and aquatic environments.A variety of native habitats will meetthe needs of many species. Planting native plantsin yards and parks and along streams, leavingareas “unmanaged,” and limiting the use of pesticidesall can have a positive impact. Managingfor healthy invertebrate populations can be doneby anyone—homeowners with only a small yard,business and industry, roadside managers, andpeople who care for parks and natural areas.Recognize HabitatInvertebrate habitat can be found anywhere, andeven small patches can contribute to supportingregionwide invertebrate populations. Forexample, warm, sunny habitat areas attract a goodvariety of invertebrates. Conserving the followingfeatures will benefit many invertebrates:n Natural or semi-natural grassland. Grasslandcan support a diverse native flora.n Hedgerows or small patches of shrub. Thesecan provide both habitat and connectivity tolarger habitat areas.n Roadsides. Carefully managed roadsides canprovide good herbaceous and shrub habitat forinvertebrates.n Urban gardens and parks. These areas provideimportant habitat in a fragmented landscape. Ifmanaged properly, they can serve as biodiversityreservoirs.n Stream, ditches, wetlands, and ponds. Allof these can be important in harboring invertebrates.Freshwater mussels inhabit many urbanwaterways. Although they are hard to see, theyare important in helping to keep these waterwaysclean.Protect Existing HabitatProtecting existing habitat and managing naturalareas with invertebrates in mind are primaryconservation activities. The Regional ConservationStrategy will help identify some key biodiversityhabitats, but there is more information aboutwoody habitats than grassland and prairie, whichare critical to a large group of invertebrates. It willbe important to identify, conserve and restoregrassland and prairie in future conservation workto protect butterflies and other species.Aquatic systems are vitally important to invertebrates.Maintaining all existing wetlands andephemeral, intermittent, and permanent streamsand streamside areas is vital to the maintenanceof a healthy aquatic invertebrate community.Enforcement of newer construction requirementsdesigned to protect waterways from harmfulsedimentation, maintain more natural hydrology,and protect riparian habitat can help preventfurther harm.habitat are too fragmented and widely spaced,they may not be able to support species whoseflight range is limited. The Backyard HabitatCertification program (a partnership betweenColumbia Land Trust and the Audubon Societyof Portland) encourages homeowners to helpbiodiversity; identifying gaps in connectivity forinvertebrates and other animals can help focusprograms such as these where they will be mosteffective. The following are some restoration principlesto consider for invertebrate conservation:n Control and remove invasive weeds.n Use native forbs and grasses to enhance thediversity of grasslands.n Use flowering native shrubs to create hedgerows,and lengthen the flowering period by usinga variety of species.n In urban parks and gardens, create flowerborders, ecolawns, and ornamental plantings thatfeature native plants.n Consider a green roof (i.e., an ecoroof) roof onbuildings and structures.n Relocate mussels found during aquatic restorationusing a standard relocation protocol (http://www.xerces.org/wp-content/uploads/2009/10/mussel-relocation-position-statement.pdf).Manage HabitatThe following techniques for managing habitatsare of particular relevance to urban areas:n Reduce pesticide use, consider less toxicalternatives, and implement an integrated pestmanagement (IPM) plan.system. This approach can be expensive but canhelp in developing targeted strategies.Mowing is a common practice in urban areas,usually to maintain the height of grasses in parksand lawns. Mowing should be avoided in areasthat offer insect habitat, such as those wherebees are actively foraging or nesting. Alternately,mowing can be conducted in the evening, wheninsects are less active. Other mowing techniquesthat help avoid harm to insect populationsinclude mowing only one part of the area peryear, leaving unmanaged areas for pollinators,avoiding mowing during major bloom periods,and allowing habitat to grow back between mowings.Questions, Unresolved Issues, and Data GapsMore systematic surveys of the greater Portland-Vancouver region are needed to better understandthe region’s fauna. One very useful exercisewould be to pull all of the information that isalready available into one place. Metro has implementedbutterfly surveys at several of its naturalareas. Surveys of the snail fauna of Forest Parkhave been implemented. The Xerces Society andlocal watershed groups are conducting musselsurveys across the Portland-Vancouver region.Unfortunately this information is not in anyone place and is hard to access. A clearinghousewhere all of this type of data can be house andeasily accessed would be ideal.For More Information:Kaufman Field Guide to Insects of North AmericaEric Eaton and Ken Kaufman. 2007. HoughtonMifflin Harcourt, New York.Restore HabitatRestoration in urban areas should include establishingnative flowering herbaceous plants, providingnesting materials for bees, and reducingpesticide use, to encourage bees and other insectsto colonize parks, gardens, and other urban areas.Pavement, buildings, and turf eliminate habitatfor ground-nesting insects and reduce the areaavailable for plants. If gardens and other potentialn Pesticides that are not allowed on bloomingcrops to protect beneficial insects may still beallowed on roadsides, gardens, and parks. Targetededucation can reduce these uses.n A chemical sampling protocol can be designedfor urban streams to determine what types andamounts of chemicals are entering the system.Once these chemical inputs have been determined,steps can be taken to limit them in theField Guide to Insects and Spiders of NorthAmericaArthur V. Evans. 2007. Sterling Publishing Co.,Inc., New York.Insects of the Pacific NorthwestPeter Haggard and Judy Haggard. 2006.Timber Press, Portland.76 77