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4 <br /> urbanization, land use practices, and fire suppression have altered the <br /> historic processes that maintained native grasslands. L. bradshawii can <br /> survive some shading, but cannot survive under a tree or shrub canopy. <br /> Flood control has also affected L. bradshawii by reducing available <br /> habitat and, possibly, seed dispersal. Flood control reduced the area <br /> and abundance of seasonally wet prairies throughout the Willamette <br /> Valley. Since L. bradshawii is dependent on wet areas, often within the <br /> floodplain of a creek or small river, hydrologic changes have <br /> drastically reduced habitat available to the plant. L. bradshawii seeds <br /> have also been found to have some buoyancy, and dispersal may be <br /> increased by flooding (USFWS 1993). If dispersal is enhanced by <br /> flooding, it is likely that the hydrologic changes have reduced <br /> dispersal quantity and distance. <br /> Most of the habitat for L. bradshawii occu s and around Eugene and <br /> Corvallis, Oregon (USFWS 1993). Thes��,,un•, oped, flat grasslands are <br /> often primary targets for urban deve,6imenj�'� ugen has developed a <br /> West Eugene Wetland Plan (City of Eu•ene £99 ,o tegorize developable <br /> and protected areas in the West Eugi - rea, bsi this plan has not been <br /> submitted for consultation under the The impact of development in <br /> the Eugene area on L. bradshawii ha= n• ern analyzed. <br /> Outside urban areas, habitat in th net by agricultural and <br /> residential development. Ag r 1cu ra • evelopment not only directly <br /> 1 <br /> destroys habitat, but activ t ,associated with agriculture also affect <br /> L. bradshawii and , its ha• m at 4v s pray and leaching of herbicides, <br /> grazing, and the ' troda,tion non- native plants can kill plants or <br /> degrade suitable h � itat '4 In ,addition, hydrologic changes associated <br /> with irrigation and food ce trol in agricultural areas have reduced <br /> available habita , IF '''„!) <br /> fz <br /> B. Overuti izatio for commercial. recreational. scientific. or <br /> educatialurposes . <br /> There is no known overutilization of this plant for commercial, <br /> recreational, or scientific purposes. <br /> C. pisease or predation. <br /> Besides habitat alterations, disease may also be influencing L. <br /> bradshawii, particularly the smaller populations. A fungus that causes <br /> a brown spot disease occurs sporadically within a population, destroying <br /> the aboveground portions of the plants. Aphids and spittle bugs also <br /> parasitize L. bradshawii. These parasites were found exclusively on <br /> plants with seeds (Kagan 1980). The seed on fungus- infected plants <br /> seldom reached maturity before the plant died back. Parasitized plants <br /> had a significantly higher incidence of aborted fruits. Parasitization <br /> and resulting fruit abortion can severely reduce the survival of a small <br /> population. <br />