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Vegetation Criteria How useful is it? Ken Sargent
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Three Parameter System Hydrology Soils Vegetation
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Checking for False Positives Ideally All 3 criteria (hydrology, soils and vegetation) would change together if they are accurate indicators of the wetland boundary. Upland sites sometimes meet one wetland criteria ( false positive) Is one parameter lagging – less consistent at accurately identifying wetland boundary.
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What I did Oregon Transportation Projects 20 ODOT wetland delineation reports (4 Delineators) thank you Allison, Ron and Jacob 5 consultant reports(5 Delineators) 184 upland datasheets Quick review/no double checks Mostly in the Western Mountains -159 Only some in Arid West – 25 Checked for false positive criteria
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All Data Upland Plots Only
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Mountain vs Arid Western Mountains,Valley and CoastArid West % Meeting Criteria Upland Plots Only
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Wetland Indicator Status Obligate (OBL). Almost always (99%) occurs in wetlands under natural conditions Facultative wetland (FACW). Usually (67% – 99%)occurs in wetlands, but occasionally found in uplands. Facultative (FAC). Equally (34% – 66%) likely to occur in wetlands or uplands. Facultative upland (FACU). Usually (67% – 99%)occur in uplands, but occasionally found in wetlands. Upland (UPL). Occur almost always (estimated probability > 99% in uplands under natural conditions.
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Two Major Vegetation Criteria Dominance Test Prevalence Index - PI
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Dominance Test Criteria - Greater than 50% of the dominant vegetation is FAC, FACW or OBL FAC plants are equally likely to occur in wetlands or uplands Since FAC plants are found equally on both sides of the wetland boundary they are not really reflective of wetlands
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Typically Distribution by WIS Wetland Boundary FAC FACW OBL FACU UPL 99%67% 33%1%
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Upland Plant Communities Meeting Wetland Vegetation Criteria More FAC than FACU dominants – example - 33% FAC, 33% FAC and 33% FACU FAC Dominant with FACU subdominants – example - 80% FAC, 5% FACU, 5% FACU, 5% FACU
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Dominance test is whacked Over 50% of upland sites meet wetland Wetland vegetation critera. More accuracy from flipping coin in Western Oregon Splitting FACs into two buckets (33-50% and 50-67%), Excluding FAC Dominants or dropping this test for wetland vegetation would be smart
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Possible Direction 1.0 Evaluate Dominance Test Collect data on why the dominance test fails Organize and present information to SWS
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Prevalence Index Weighted Mean OBL(1), FACW(2), FAC (3), FACU (4) UPL (5) PI = or less than 3.00 meets the criteria More accurate
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False Positive by Test % Meeting Veg Criteria
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Prevalence Index (PI) better--Partial Whackage Roughly 25% of the time a false positive Even if we just used PI for vegetation it still would not be very accurate
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FACULTATING of Grasses Common NameScientific Name1988 NW2016 WMVC Perennial Rye GrassLolium perenneFACUFAC Tall FescueSchedonorus arundinaceusFACUFAC Kentucky Blue GrassPoa pratensisFACUFAC
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Consistency with other Regions Common NameScientific Name 2016 WMVC Arid West Atl. Gulf Coast East Mount Pied Great Plains Mid west NC/ NE Perennial Rye GrassLolium perenneFACFACUFACFACU Tall FescueSchedonorus arundinaceusFAC FACU Kentucky Blue GrassPoa pratensisFACFACUFACFACU FACFACU
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Convert Common Grasses to FACU 4 Species FAC 4 Species FACU % Meeting Veg Criteria
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NTCWV Nation Technical Committee for Wetland Vegetation (2007) Regional Subcommittees (Corps, EPA, NRCS and USFWS) establish WIS ratings by consensus Regional Subcommittees will accept data and recommendations for changes
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Possible Direction 2.0 Determine if WIS rating is appropriate Collate % cover data from report data sheets to evaluate distribution of grass species on upland versus wetland sampling points Collect New Data from re-evaluation of sites. Organize and present information to NTCWV Additional sampling maybe necessary
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Plant Distribution DryWet Border Count Feet from Wetland Edge
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Comments? Does this make sense? Does anyone want to help? Where do I go for Funding? Cost - Benefit?
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