Discovery Park MGIS Capstone 2018 Vegetation Monitoring and Mapping Project
Sample Plot moisture indexes give an obligate wetland species a numeric rank of 1,
a facultative-wet wetland species a numeric rank of 2, a facultative wetland species
numeric rank of 3, a facultative-upland species a numeric rank of 4, and an upland
species a numeric rank of 5. Aggregated plant sample plot moisture index scores
close to one indicate hydrophytic plants adapted to low oxygen in their root zones
typically due to saturation by a high water table. Scores closer to 5 indicate
plants with low tolerance to low oxygen from high water and that are typically
found in much drier site conditions.
Discovery Park Ecosystem Services
The Discovery Park Moisture Index
Browse Discovery Park Ecosystem Services Vegetation Monitoring and Mapping Web Pages
The Discovery Park Vegetation Monitoring and Mapping Website Main Page
The Discovery Park Credit / Debit Calculator
The Discovery Park Weed Index Surface
The Discovery Park Plant Community
The Discovery Park Bird Use of Plant Community
Discovery Park - Multiple Ecosystem Services at Multiple Scales
The Discovery Park Worldwide Web Map
Other Resources
Discovery Park Predicted Moisture Index Surface
Moisture Index
Calculating a Sample Plot Moisture Index
The table below demonstrates how a moisture index for a plant sample plot is calculated. The percent cover of each species in the sample plot is multiplied by their respective moisture indexes to derive a weighted percent cover. Both the percent cover and weighted percent cover columns are totaled. Then the total weighted percent cover is divided by the total unweighted percent cover (625 / 220) to derive the sample plot moisture index of 2.84
Example Sample Plot 2 Moisture Index Calculation
Species
Percent Cover
Moisture Index
Weighted Percent Cover
Oemleria cerasiformis
1
4
4
Ilex aquifolium
<
1
4
4
Hedera helix
<
3
5
15
Rubus spectabilis
<
75
3
225
Polystichum munitum
<
7
5
35
Thuja plicata
<
20
3
60
Rubus armeniacus
<
7
4
28
Unknown moss
<
3
3
9
Lysichiton americanus
<
20
1
20
Oenanthe sarmentosa
<
15
1
15
Alnus rubra
<
40
3
120
Equisetum telmateia
<
4
2
8
Pteridium aquilinum
<
10
4
40
Urtica dioica
<
10
3
30
Athyrium filix femina
<
4
3
12
Totals:
<
220
625
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Hypothetical Wetland Mitigation Bank Management Unit A Credit Release Based on One Component (Moisture Index 1 = OBL, 2 = FACW. low, 3 = FAC, 4 = FACU, 5 = UPL) of Vegetation Performance - based on assumption of Credit Value at $75,000.00
MoistureClass
MIndexRange
Acres
PotCredits
Penalty
AvaiCredits
CreditValue
1
1 – 2
18.91
9.455
0
9.455
$709,125.00
2
2 – 3
11.14
5.57
0
5.57
$417,750.00
3
3 – 4
3.56
1.78
1.0
0
$0
4
4 – 5
0.71
0.355
1.0
0
$0
Total
34.32
17.16
15.025
$1,126,875.00
Note: Vegetation threshold of Moisture Index <= 3 for jurisdictional wetland only meets one of three criteria the site must meet for credit release. The site must also have hydric soils and wetland hydrology. In addition, depending on the target wetland type, other hydrology standards may also need to be met.
John Marshall
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