# Presentation: 440611

## Development of Multi-tiered Wetland Assessment Methods for Monitoring Wetland Condition

- Amy Deller Jacobs
- DE 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

## Delaware Wetland Status and Trends

- From 1982-1992
- 	Delaware lost
- 	2000 acres

***Delaware Wetland Status and Trends***

## Slide 4

## Slide 5

## 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

## Multiple Levels of Assessment

- GIS Platform
- No Fieldwork
***LEVEL 2***
- Rapid Assessment
- Some Fieldwork
***LEVEL 3***
- Intensive Field Sampling

- Level of Effort Increases

- Level of Detail Decreases

***Multiple Levels of Assessment***

## Nanticoke Wetland Study

***Nanticoke Wetland Study***

## Slide 9

## Overall Success RatePermission for Access

***Overall Success Rate******Permission for Access***

**N = 446**

**45%**

**17%**

**Granted**

**No Contact**

**Denied**

**38%**

**No Contact**

**Granted**

**Denied**

**38%**

**44%**

**18%**

**N = 321**

***TNC***

***STATE***

## Success Rate with Contact	Excluding Public Lands

***Success Rate with Contact******	******Excluding Public Lands***

**N = 227**

**Percent**

**67%**

**33%**

## Slide 12

## Hydrogeomorphic Models

- Data

- Variable

- Variable

- Variable

- Variable

- Variable

- Function

- Function

## HGM Function Wildlife Habitat

- (Vdisturb + ((Vtba + Vtden)/2) + Vshrub + Vsnag)/4

- Results are between 0 and 1

## Total Effort

***24 man-hours***** **

## Slide 16

## 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

- 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)***

## Habitat Category

|  |
| --- |

|  |
| --- |

|  |
| --- |

|  |
| --- |

| 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***

## Total Score

***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

- 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***_

## Slide 23

## Multiple Levels of Assessment

- GIS Platform
- No Fieldwork
***LEVEL 2***
- Rapid Assessment
- Some Fieldwork
***LEVEL 3***
- Intensive Field Sampling

- Level of Effort Increases

- Level of Detail Decreases

***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

**Notes:**
Sign (+,-) indicates whether variable is positively or negatively related to the HGM function

Variable names
ex100—length of excavated stream channel (ditches or channelized streams) in 100 m circle around sample point
nat1000--length of natural stream channel in 1000 m circle around sample point
nimpound1000—number of stream impoundments within 1000 m
DEVTOT100—proportion of total developed land (low+high intensity) in 100 m circle aroung sample point
FOREVER—evergreen forest
FORDEC—deciduous forest
FOREST—total forest

## Slide 28

## Monitor to Determine Progress and Reassess Priorities

- Determine Stressors

**Notes:**
Report on condition after the first box but this doesn’t improve the resource

## Slide 30