Ken Sargent Three Parameter System Hydrology Soils Vegetation Checking for False Positives Ideally All 3 criteria hydrology soils and vegetation would change together if they are accurate indicators of the wetland boundary ID: 803825
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Slide1
Vegetation Criteria
How useful is it?
Ken Sargent
Slide2Three Parameter System
Hydrology SoilsVegetation
Slide3Checking 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.
Slide4What I did
Oregon Transportation Projects
20 ODOT wetland delineation reports (4 Delineators) thank you Allison, Ron and Jacob5 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
Slide5All Data
Upland Plots Only
Slide6Mountain vs Arid
Western
Mountains,Valley
and Coast
Arid West
% Meeting
Criteria
Upland Plots Only
Slide7Wetland Indicator Status
Obligate (OBL
). Almost always (99%) occurs in wetlands under natural conditionsFacultative 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.
Slide8Two Major Vegetation Criteria
Dominance TestPrevalence Index - PI
Slide9Dominance 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
Slide10Typically Distribution by WIS
Wetland Boundary
FAC
FACW
OBL
FACU
UPL
99%
67%
33%
1
%
Slide11Upland 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
Slide12Dominance test is whacked
Over 50% of upland sites meet wetland Wetland
vegetation critera.More accuracy from flipping coin in W
estern Oregon
Splitting
FACs
into two buckets (33-50% and 50-67%), Excluding
FAC
Dominants or dropping this test for wetland vegetation would be smart
Slide13Possible Direction 1.0
Evaluate Dominance Test Collect data on why the dominance test fails
Organize and present information to SWS
Slide14Prevalence Index
Weighted Mean
OBL(1), FACW(2), FAC
(3),
FACU
(4)
UPL
(5)
PI = or less than 3.00 meets the criteria
More accurate
Slide15False Positive by Test
% Meeting
Veg Criteria
Slide16Prevalence 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
Slide17FACULTATING of Grasses
Common Name
Scientific Name
1988 NW
2016 WMVC
Perennial Rye
Grass
Lolium
perenne
FACU
FAC
Tall Fescue
Schedonorus
arundinaceus
FACU
FAC
Kentucky Blue Grass
Poa
pratensis
FACU
FAC
Slide18Consistency with other Regions
Common Name
Scientific Name
2016 WMVC
Arid West
Atl
. Gulf
Coast
East Mount Pied
Great Plains
Mid
west
NC
/
NE
Perennial Rye Grass
Lolium
perenne
FAC
FACU
FAC
FACU
FACU
FACU
FACU
Tall Fescue
Schedonorus
arundinaceus
FAC
FAC
FACU
FACU
FACU
FACU
FACU
Kentucky Blue Grass
Poa
pratensis
FAC
FACU
FAC
FACU
FACU
FAC
FACU
Slide19Convert Common Grasses to FACU
4 Species
FAC
4 Species
FAC
U
% Meeting
Veg Criteria
Slide20NTCWV
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
Slide21Possible 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 pointsCollect New Data from re-evaluation of sites.
Organize and present information to
NTCWV
Additional sampling maybe necessary
Slide22Plant Distribution
Dry
Wet
Border
Count
Feet from Wetland Edge
Slide23Comments?
Does this make sense?Does anyone want to help? Where do I go for Funding?Cost - Benefit?