Stream Community Structure: An Analysis of Riparian Forest

Buffer Restoration in the Chesapeake Bay Watershed

Leslie Orzetti, PhDEcosystem Solutions, Inc.

Outline

Background Forest Buffer Zones Benthic Macroinvertebrates Chesapeake Bay

Hypotheses Methods Results Discussion

What is a forest buffer? Chesapeake Bay Program Definition

Areas of trees, shrubs and other vegetation, that are adjacent to a body of water, that are managed for several purposes

Benthic Macroinvertebrates: Nature’s Water Quality Indicators

What are they? Why do we want to use bugs? What affects them?

Water quality Habitat

How do we use them? Metrics

Benthic Macroinvertebrate Metrics

Composition Tolerance Feeding Habit

% EPT

% Plecoptera

% Ephemero

% Trichoptera

EPT/Chiro

Taxa Richness

No. intolerant families

% Tolerance

% Dominance

FBI

% Scrapers

% Predators

% Gatherers

% Filterers

% Shredders

Scraper/Filter

% Burrowers

% Clingers

% Climbers

% Sprawlers

% Skaters

% Swimmers

• Does stream water quality and habitat improve with relative age of restored forest buffer?

• Does stream benthic community increase in diversity and richness with age of restored buffer?

• Does stream benthic community diversity and richness increase with improved ambient water quality and habitat?

Hypotheses

Sites

• How big are they?– First order streams

• Where are they?– Piedmont physiographic

region– Frederick, Carroll,

Loudon, Fauquier, Fairfax, Prince William Counties

Okajangus, 1982

Sites with no buffer

Garrett

Wacopin

Sites 1-2 Years Old

Harbaugh

Stull

Sites 4-6 Years Old

FriendRoyer

Sites Older than 10 Years

Monocacy NRMA

Johnny Moore

Control SitesPrince William Forest Park

Field Methods

• 150 m reach in buffer zone

• In situ water quality– DataSonde Hydrolab

• Water samples

• Benthic invertebrate collection

• Habitat characterization

• Landuse characterization

Laboratory Methods

• Nutrient analysis– Nitrogen– Phosphorus

• Solids analysis

• Benthic invertebrate analysis– Identification– Metrics

RESULTS

Habitat Results

0 10 20 30 40 50 60Buffer Age (years)

50

100

150

200

Hab

i tat

score

Buffer Age Class

50

100

150

200

Hab

i tat

Sc o

re

Habitat

Popes Head

Catharpin

Water Quality PCA: Age

PCA Axes 1 and 3: Suite 1 Water Quality by Age

B

BBB

B

B

B

B

B

A

AAA

AA

A

A

AAA

AAA A

A AAA

A AA

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

-0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2

Axis 1

Axis

3

A = Under 10 Years OldB= Over 10 Years Old

Water Quality PCA: Landuse

PCA Axes 1 and 3: Suite1 Water Quality by Landuse

P

P

F

R

F

A

P

R

A

S

S

F

P

F

PP

SR S

A

F

P

P

PP

P

PSS

R

S

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2

Axis 1

Ax

is 3

R = RuralP = PastureA = AgricultureF = ForestS = Suburban

Water Quality PCA: Buffer Width

PCA Axes 1 and 3: Suite 1 Water Quality by Buffer

O

O

U NU

O

N U

U

U

OO

UO

N

U N

O

O

O

U

N

O

O

O

O

U

O

O

O

O

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2

Axis 1

Ax

is 3

N = No bufferU = Under 50 feetO = Over 50 feet

Water Quality Discriminant Analysis

Less th

an 10

Over 1

0

Buffer Age Class

-4

-3

-2

-1

0

1

2

3

Can

onic

al S

cor e

Composition and Tolerance PCA: Age

PCA Axes 1 and 2 Benthic Macroinvertebrates by Age

AA

AAAA

A AAA BAAA

AAAA A

AA A

A

B

B

B

BB B

B

B-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

-0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2

Axis 1

Ax

is 2

A = Under 10 Years OldB= Over 10 Years Old

Composition and Tolerance PCA: Landuse

PCA Axes 1 and 2: Benthic Macroinvertebrates by Landuse

S

R

PS

PP

P R

P

PPF

A

S

S

FP F

S

S

A

RAP

FP

R

F

PP S

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

-0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2

Axis 1

Axis

2

R = RuralP = PastureA = AgricultureF = ForestS = Suburban

Composition and Tolerance PCA: Buffer Width

PCA Axes 1 and 2: Benthic Macroinvertebrate by Buffer Width

O

O

OU

OUOUNUU

O

O

N

OO O

U

N

O

OO-O

OU

O

O

U U NN

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

-0.6 -0.1 0.4 0.9

Axis 1

Axis

2

N = No bufferU = Under 50 feetO = Over 50 feet

Discriminant Analysis:Composition and Tolerance Metrics

Less th

an 10

Over 1

0

Age Class

-3

-2

-1

0

1

2

3

4

5

Can

oni c

al S

core

Abundance PCA: Age

PCA Axes 1 and 2: Significant Abundance by Age

AAAAA AAAAB

A AAAA A

A AA

A

AB

B

B

B

BAA

B

B

B

-0.4

-0.2

0

0.2

0.4

0.6

0.8

-1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4

Axis 1

Axi

s 2

A = Under 10 Years OldB= Over 10 Years Old

Discriminant Analysis:Abundance Data

Less th

an 10

Over 1

0

Age Class

-4

-3

-2

-1

0

1

2

Can

oni c

al S

core

Conclusions

• Habitat improved with age of buffer

• Water quality improved with age of buffer

• Benthic macroinvertebrate diversity and richness improved with age of buffer

• Benthic macroinvertebrate diversity and richness improved with ambient water quality and habitat

Conclusions

• Physical, chemical and biological components of a stream ecosystem are intrinsically linked

• Younger buffered sites have the capacity to improve with time

• Managers should see improvements within 5-10 years post restoration

Forest Buffers on DoD Installations

• DoD Legacy funded study

• Year 1 – Visited 15 field sites on 8 installations– Collected samples from 11 sites

• Benthic macroinvertebrates

• Water Quality

• Habitat

– 4 Sites unsampleable

Status of Buffers on DoD Installations

• Several installations have well maintained restored buffer areas

• Many installations have intact buffers without restoration

• Natural Resource Manager turnover and loss of restored buffer information

• Reporting of buffer miles

NRL Chesapeake

Recommendations and Future Considerations

• In-stream improvements

• Monitoring plantings

• Continued stream monitoring (every 2-3 years post restoration)

• Stream corridor preservation

• Increase buffer zone width

• Redefine forest riparian buffer zone for reporting restored buffer miles

Acknowledgements

• George Mason University

• Virginia Department of Forestry

• Maryland Department of Forestry

• Prince William Forest Park

• Lab and Field Crews