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,01/,20/95 10:46 •- 503 231 6195 PTLD. FIFLD STA. VI004 <br /> in Willamette Valley grasslands in mid - April mid- May(Kagan 1980)•: :Flowers <br /> - are produced on umbels. Each plant usually produces:one,•sgmetimes.two,. -- <br /> umbelsper plant. Kagan (1980) found that'approximately 90: of'the flowers` • . <br /> • produced -are male.with'some plants producing hermaphroditic.umbels,.usually <br /> the second umbel produced on a plant. He -also found that more than half' <br /> .. (50:9 *)• of the plants observed at Willow Creek Preserve:in Eugene, Oregon were <br /> sterile . -.. . <br /> L. bradshawii reproduces only by seed. Pollination method is.•not entirely <br /> known but may be. through insects, self- poll.ination, wind -and rain. 'Kagan <br /> • (1980) observed few pollinators, and data suggested that the plants observed <br /> were often_ "self - pollinating ".• Fruits are present from late.Mayto. early. June. • , <br /> (Kagan '1980) and•are dropped upon maturity.. Seeds fall to the.:ground.andmay <br /> be' distributed- by flood waters, but tlis not been confirmed. <br /> More 'detailed information regarding the life history of L. bradshawii can be <br /> found in Kagan (1980) and the Recovery Plan '(USFWk 1993).'• <br /> status .. <br /> There are currently - a total of approximately 14 distinct populations of L. <br /> • bradshawii in four areas of the' Willamette: Valley . ( USFWS•1993). It Is <br /> estimated that less than 0.1% of the historic populations of L.' bradshawii <br /> • remain (USFWS•'1993). In addition, the LaCamas Lake .population in Washington is <br /> another site not included in the Recovery Plan. This -population . is• - important <br /> • because it is the largest known population and is outside • <br /> historic range of the species. . <br /> As described in, the final rule. to list-L. bradshawii as endangered (53 FR <br /> 38451; September 30, 1988) and Recovery Plan (USFWS- 1993), threats.to. the L. • <br /> ' • bradshawii include: -(1) loss of habitat; (2) disease; and (3) reproductive <br /> strategy -of the species combined with other stressors. <br /> Habitat has been lost by succession of habitat, changes in hydrology, and'loss <br /> of habitat to urban,or agricultural development. Willamette. Valley - : wet. <br /> prairies continue to undergo succession and invasion by trees. and shrubs. <br /> This succession was once naturally controlled by widespread `f.looding,.browsing <br /> animals, and fire. Flood control projects' in the••upper Willamette baiin,• <br /> urbanization, land use practices; and fire suppression. have altered the • . <br /> historic processes which, maintained native. grasslands. L. bradshawii can <br /> survive some shading, but cannot survive under a or shrub canopy. , <br /> • <br /> Flood control has also affected L. bradshawii by reducing available habitat • <br /> and, possibly, seed dispersal•..'Flood control reduced the area.and abundance <br /> of seasonally Wet prairies throughout the Willamette Valley. Since ` L. . <br /> bradshawii is dependent on.wet areas, often within•the floodplain of a creek, <br /> - or small river, hydrologic changes have drastically•reduced habitat available <br /> to the plant. L. bradshawii seeds have also'been - found to have some buoyancy, <br /> and dispersal may be increased by flooding (USFWS 1993). If dispersal is <br /> enhanced by flooding, it is'likely that the hydrologic changes have reduced <br /> dispersal quantity and'distance -- - <br /> ' Most of_the habitat for L. bradshawii occurs in and Around °and• - <br /> Corvallis, Oregon (USFWS 1993). These undeveloped, flat grasslands are often <br /> primary targets for urban development. : Eugene- has developed a West Eugene • <br />