development of multi-tiered wetland assessment methods for monitoring wetland condition
DESCRIPTION
Amy Deller Jacobs DE Department of Natural Resources and Environmental Control. Development of Multi-tiered Wetland Assessment Methods for Monitoring Wetland Condition. Delaware Wetland Status and Trends. 54% lost since 1780’s Most of loss due to ditching and channelization and - PowerPoint PPT PresentationTRANSCRIPT
Development of Multi-tiered Wetland Assessment Methods for Monitoring Wetland Condition
Amy Deller JacobsDE Department of Natural Resources and
Environmental Control
Delaware Wetland Status and Trends
• 54% lost since 1780’s
• Most of loss due to ditching and channelization and
direct conversion to ag of nontidal wetlands
•From 1986-1997 there was an 80% reduction in loss from previous decade•From 1982-1992
Delaware lost 2000 acres
Delaware Wetland Status and Trends
Why Monitor Condition?• Evaluate what functions are being performed and at what level
• Determine stressors
• Gain information to guide restoration and enhancement
• Meet requirements of TMDL lawsuit/ Required under Clean Water Act
LEVEL 1GIS PlatformNo Fieldwork
LEVEL 2Rapid AssessmentSome Fieldwork
LEVEL 3Intensive Field Sampling
Level of Effort IncreasesLe
vel o
f Det
ail D
ecre
ases
Multiple Levels of Assessment
Nanticoke Wetland Study
10,000Meters
EMAP sample points
Overall Success RatePermission for Access
N = 446
45%
17%
Granted
No Contact
Denied
38%
No Contact
Granted
Denied
38%44%
18%
N = 321
TNC STATE
020406080100
Yes No
Success Rate with ContactExcluding Public Lands
N = 227
Perc
ent 67%
33%
Hydrogeomorphic Models
Data
Variable Variable VariableVariableVariable
Function Function
HGM Function Wildlife Habitat(Vdisturb + ((Vtba + Vtden)/2) + Vshrub + Vsnag)/4
Results are between 0 and 1
Total EffortTotal Effort6%
2%
2%
6%65%
1%3% 2%
13%
Printing of Map
Reviewing Map/ enter indatabaseLooking up landownerinformationEnter in database andSend letterFollow-up phone call
Initial Site Visit
Field Crew Preparation tosampleSampling Site
Sending Thank you letterupdating database24 man-hours
Rapid Assessment (Level II)Development of a Rapid Assessment Method• Evaluates condition and can distinguish
various levels • Requires a site visit• No detailed data collected
• Based on HGM models and field experience• Evaluates stressors present at a site• Weights stressors according to their impact
on 4 categories (hydrology, habitat, biogeo cycling, and landscape)
• Provides one overall score of the condition of the wetland
Rapid Assessment (Level II)
Mowing -3
Farmed -9
Grazing -3
Forest harvesting (>50% of stand)
Recovered 0
Recovering -5
Recent -7
Cleared not recovering -7
Excessive herbivory
Presense of invasive spp.
Dominate the site -7
Do NOT dominate the site -2
Chemical defoliation -3
Managed or converted to pine -5
Burned -3
Trails -1
Garbage/ isolated dumping -1
Other
Subtotal Habitat Community 10 + sum of above, if score <0 record 0
Habitat Category
Rapid Assessment (Level II)
Total Score
(Hydrology/10) + (Hydrology/10)*(Biogeo/10)) + (Habitat/10) + ((Habitat/10)*(Landscape/10))
Current projects• Validating with HGM (level III)• Determining sensitivity of methods• Evaluating transferability to other areas of
the state
Rapid Assessment (Level II)
Comparison of Effort to sample 50 sites
• 4 hours/ site• 4 person crew• 25 days(2 sites/day)• 100 person-days• Several hours office
work
• 2 hours/ site• 2 person crew• 12.5 days (4 sites/ day)• 25 person-days• Minimal office work
Level III Level II
LEVEL 1GIS PlatformNo Fieldwork
LEVEL 2Rapid AssessmentSome Fieldwork
LEVEL 3Intensive Field Sampling
Level of Effort IncreasesLe
vel o
f Det
ail D
ecre
ases
Multiple Levels of Assessment
Landscape Level Assessment (I)
• Inventory – status and trends• Updated wetland maps
– Including HGM modifiers – Provide additional information
• Landscape analysis– Inferring condition based on indicators in
surrounding landscape
Stepwise multiple regression results for flat HGM functions
Variables
Function No. Names r2 *
Biogeochemistry 5 ex100 –ex500 –FOREVER100 –GRASS1000 FOREST1000
0.44
Habitat 5 +nat100 –nimpound1000 –FOREVER 100 –GRASS1000 FOREST1000
0.35
Hydrology 3 -ex100 –nat1000 +FORDEC1000 0.43
Plant 2 -ex1000 +FORDEC100 0.17
*n=89, p<0.0001 for all models
Stepwise multiple regression results for riverine HGM functions
Variables
Function No. Names r2 *
Biogeochemistry 3 -ex100 +nat1000 –DEVTOT100 0.51
Habitat 2 -ex100 +nat1000 0.42
Hydrology 5 -ex100 +nat1000 +FOREST100 +FOREST1000 -FORDEC1000
0.70
Landscape 6 -ex100 –ex1000 +nat1000 –CROP100 –DEVTOT1000 +FOREVER1000
0.70
Plant 2 -ex500 –DEVTOT100 0.31*n=54, p<0.0001 for all models
Assess loss and
condition by subclass
Determine Spatial Need to
Restore Function
Prioritize Restoration and
Protection Projects
Monitor to Determine Progress and Reassess Priorities
Determine Stressors