altered hydrology & vegetation: effects on the transport and breakdown of organic matter in...

Altered Hydrology & Vegetation: Effects on the Transport and Breakdown of Organic Matter in Urban Streams

Kenneth T. Belt1, Christopher Swan2, Richard Pouyat1, Sujay Kaushal3, Peter Groffman4, Istvan Turcsanyi5, William Stack6, and Gary Fisher7

1 USDA Forest Service, 2 UMBC Dept. of Geography and Environmental Systems3 UMCES Appalachian Lab, 4 Institute of Ecosystem Studies, 5, UMBC Center for Urban Environmental Research & Education, 6 Baltimore City

DPW, 7 USGS

BES Annual Meeting, Baltimore, UMBC, October 19, 2006

UMBCUMBC

Outline

•Urban Drainage Networks•Leaf Breakdown•DOC Export (preliminary)•POM Export (preliminary)•Ongoing Work

Support…

•Phyl (my wife)…arthritic bag making sessions, field work…putting up with me.

•Rich Pouyat (USFS)…Guidance, encouragement, bag making…field work (the infamous blind rainstorm drive)

•Chris Swan (UMBC GES)…guidance, encouragement, nutrient analysis, bug picking support

•Sujay Kaushal (UMCES)…guidance, encouragement, DOC analyses

•Peter Groffman/Dan Dillon, Gio et al. (IES)…sampling support, nutrient data; loan of an “ISCO”

•Claire Welty (CUERE)…facilities, guidance; loan of 2 “ISCOs”

•Istvan Turcsanyi (CUERE)…guidance and endless filtering and weighing

•UMBC GES interns: Bill Greenwood, Yaakov Birnbaum, Heather Modic

•All those technicians & colleagues…..

Motivation

•Leaves (and breakdown products & leachate) in streams are an important energy (food) source

•They also are habitat

•They are important in a variety of BGC reactions and pathways

•They also likely carry significant, not heretofore considered, elemental/pollutant loads

•Urban Drainage Networks

Buried Urban Streams

Increased Effective Drainage Density in Urban Streams

Curb & GutterNetwork

“Upland Riparian” Streams…

….Deliver Particulate & Dissolved Loads to Streams

Urban Landscapes & Organic Matter Transport

The Gutter Subsidy

Estimate of Baltimore Gutter Leaf Loads (whole Catchment Area Basis; Error Bars Show Range of Estimate)

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

Pond

Baism

an

Glyndon

Delig

ht

Red R

un

Horseh

ead

Villa

Nova

Scotts

Lev

el

Dead R

un

Owings

Mill

s

Catchment

Cat

chm

ent

An

nu

al C

urb

Lea

f L

oad

(Kg

Dry

Mas

s/h

a)

0

10

20

30

40

50

60

70

80

90

100

Ro

ad D

ensi

ty (

km/s

q k

m)

CatchmentRoad Density

Civil Infrastructure and Organic Matter

POM

Pollutants

OutputsTo Stream

OutputsTo Stream

Forest Stand Urban Landscape

Leaf Breakdown

How quickly do leaves breakdown in the stream benthic environment?

Mass Loss from Leaf Bags

Mass Remaining Baismans Run (Forested Catchment)

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 20 40 60 80 100

Days

Ma

ss

Re

ma

inin

g

GS F

GU F

LS F

LU F

RD F

RP F

RS F

RU F

Collection Dates:1st Jan 3 2nd Jan 203rd Feb 34th Mar 35th Mar 30

Bags installed on Dec 24 2004

Breakdown Rates: Mass Loss Coefficients

Exponential decay model:

Wt W0-1 = e-kt

•W0 = the initial leaf mass (g)

•Wt is the mass (g) remaining on day t

•k is the rate of breakdown (day-1)

Leaf Breakdown: Basic Questions…Streams, Sources &

Landscape Position

1. Do leaves breakdown faster in suburban than in forested streams?

2. Do leaves from upland portions of the urban landscape breakdown faster than riparian leaves?

3. Do leaves from gutter sources break down faster than leaves from higher points in the landscape and riparian leaves?

4. Do riparian leaves from different locations along the urban-rural gradient differ in their breakdown rates?

Stream Study Sites

Baismans Run(Forested)

Gwynns FallsAt Gwynnbrook

(Suburban)

10 kilometers

Leaf Litter Breakdown Study Streams

Baltimore City

Gwynns Falls at Gwynnbrook(Suburban)

Baismans Run(Forested)

Baismans Run

Gwynns Falls at Gwynnbrook

Study Stream Catchments

Riparian Source Sites(Sycamore)

Distal Riparian (rural)

Suburban Riparian

Urban,Riparian

ProximalRiparian(rural)

Suburban Landscape

UrbanLandscape

Urban,Gutter

Suburban, Gutter

Lawn (“Landscape”) & Gutter Source Sites(Planetree)

Sycamore Leaf Mass Loss Rates: Different Spatial Sources

Leaf Breakdown Rates in Forested and Suburban Streams

-0.009

-0.008

-0.007

-0.006

-0.005

-0.004

-0.003

-0.002

Pla

tan

acea

e*

Su

bu

rban

Gu

tter

Urb

anG

utt

er

Su

bu

rban

Lan

dsc

ape

Urb

anL

and

scap

e

Rip

aria

nR

ura

l(D

)

Rip

aria

nR

ura

l(P

)

Rip

aria

nS

ub

urb

an

Rip

aria

nU

rban

Mas

s L

oss

Co

eff.

(m

ass

loss

per

day

)

Fast

(>0.010 day-1)

Slow

(< 0.005 day-1)

* Webster (1986) (14 estimates)

Forested Stream(Baismans Run)

Suburban StreamG.Falls Gwynnbrook)

Gutter Landscape RiparianSuburb Urban Suburb Urban Rural Rural Suburb Urban (Distal) (Prox)

*

``

Study Streams: Light Green- Forested, Dark Green- Suburban

Suburban Stream

Forested Stream

Leaf Mass Loss Rates

(Sycamore)(Planetree)Litter Sources

Urban Streams… Faster

Mass Loss: Urban vs. Suburban Streams



-0.009

-0.008

-0.007

-0.006

-0.005

-0.004

-0.003

-0.002

Pla

tan

acea

e*

Su

bu

rban

Gu

tter

Urb

anG

utt

er

Su

bu

rban

Lan

dsc

ape

Urb

anL

and

scap

e

Rip

aria

nR

ura

l(D

)

Rip

aria

nR

ura

l(P

)

Rip

aria

nS

ub

urb

an

Rip

aria

nU

rban

Mas

s L

oss

Co

eff.

(m

ass

loss

per

day

)

Fast

(>0.010 day-1)

Slow

(< 0.005 day-1)





*

``


Riparian sources Slower

Mass Loss Rates: Upland vs. Riparian



-0.009

-0.008

-0.007

-0.006

-0.005

-0.004

-0.003

-0.002

Pla

tan

acea

e*

Su

bu

rban

Gu

tter

Urb

anG

utt

er

Su

bu

rban

Lan

dsc

ape

Urb

anL

and

scap

e

Rip

aria

nR

ura

l(D

)

Rip

aria

nR

ura

l(P

)

Rip

aria

nS

ub

urb

an

Rip

aria

nU

rban

Mas

s L

oss

Co

eff.

(m

ass

loss

per

day

)

Fast

(>0.010 day-1)

Slow

(< 0.005 day-1)





*

``


“Gutter”… about the same as “Landscape”

Litter Sources: Gutter vs. Landscape



-0.009

-0.008

-0.007

-0.006

-0.005

-0.004

-0.003

-0.002

Pla

tan

acea

e*

Su

bu

rban

Gu

tter

Urb

anG

utt

er

Su

bu

rban

Lan

dsc

ape

Urb

anL

and

scap

e

Rip

aria

nR

ura

l(D

)

Rip

aria

nR

ura

l(P

)

Rip

aria

nS

ub

urb

an

Rip

aria

nU

rban

Mas

s L

oss

Co

eff.

(m

ass

loss

per

day

)

Fast

(>0.010 day-1)

Slow

(< 0.005 day-1)





*

``


Urban… Much faster than Suburban

No Effect for Riparian Leaves?

The Riparian Urban-Rural Gradient

Sycamore Leaf Mass Loss Rates: The Urban-Rural Gradient

Leaf Breakdown Rates in Forested & Suburban Streams-0.009

-0.008

-0.007

-0.006

-0.005

-0.004

-0.003

-0.002

-0.001

0.000

Pla

tan

acea

*

. R

ura

l-

.R

ipar

ian

(D

)

. R

ura

l-

.R

ipar

ian

(P

)

. Su

bu

rban

- .

. G

utt

er

.

. Su

bu

rban

- .

. Lan

dsc

ape-

. Su

bu

rban

- .

. R

ipar

ian

.

. U

rban

-

..

Gu

tter

.

. U

rban

-

.. L

and

scap

e-

. U

rban

-

..

Rip

aria

n

.

Lo

ss C

oef

fici

ent

(mas

s lo

ss p

er d

ay) Fast

(> 0.010 day-1)

Slow

(< 0.005 day-1)




Rural Suburban Urban Riparian Gutter LScape Riparian Gutter LScape Riparian (Distal) (Prox)


DOC Export

DOC Export in Urban Streams

1. How do urban DOC concentrations and export rates compare to “natural” systems ?

2. How much does DOC transport vary temporally (seasonal); how important is hydrology (storms)?

3. Is drainage density (and its attendant features) important?

Preliminary DOC & Flow Data

•8 of 13 sites•15 to 20 samples at each site•July to November 2005•Grab sampling…every few weeks

•Mostly dry weather•Some with recent storm runoff activity (within days)

Gwynns Falls at Gwynnbrook Avg Daily Flow & DOC Concentration

1

10

100

1000

7/17/2005 8/6/2005 8/26/2005 9/15/2005 10/5/2005 10/25/2005 11/14/2005

Av

g D

ail

y Q

(c

fs)

0

1

2

3

4

5

6

7

8

DO

C c

on

c (

mg

/l)

Q cfs

GFGB (Suburb)

DOC Concentration vs. Flow Ratepreliminary data

y = 1.6357Ln(x) + 0.7348

R2 = 0.624

y = 2.6863x0.2266

R2 = 0.1683

0.1

1

10

100

0.1 1 10 100 1000

Avg Daily Flow (cfs)

DO

C (

mg

/l)

DRKR

GFGB

Log. (GFGB)

Log. (DRKR)

Average Daily Flow Rate vs. Impervious Cover(8 catchments, July - Nov 2005

0.0

0.5

1.0

1.5

2.0

2.5

-5 5 15 25 35 45 55

Catchment Impervious Surface Cover (%)

Avg

Dai

ly F

low

(m

m/d

)

Forested & Agric Sites

More Urbanization

More ISC…More Runoff

Average DOC Concentration vs. Impervious CoverJuly - Nov 2005, 8 catchments, N = 15 to 20 (each)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

-5 5 15 25 35 45 55


Avg

DO

C C

on

c (m

g/l)


More Urbanization

More ISC…Higher DOC Conc

Average DOC Areal Loading Rate vs. Impervious CoverJuly - Nov 2005, 8 catchments, N = 15 to 20 (each)

0

20

40

60

80

100

120

140

-5 5 15 25 35 45 55


DO

C L

oad

ing

(g

/ha/

day

)


More Urbanization

More ISC…Higher Catchment DOC Exports

DOC Areal Load vs Areal Flow Rate(8 catchments, 15-20 samples each, July-Nov 2005)

0.1

1

10

100

1000

0.01 0.10 1.00 10.00 100.00Areal Avg Daily Flow (mm/d)

DO

C A

real

Lo

ad R

ate

(g/d

/ha)

PBDOC_ALd

MDDOC_ALd

BRDOC_ALd

GBDOC_ALd

VNDOC_ALd

GLDOC_ALd

CPDOC_ALd

DRDOC_ALd

Power (DRDOC_ALd)

Forested &Agricultural Sites(Green Triangles)

Dead Run Trendline(Power Function)

Urban catchments…High DOC exports at higher flows

Urban catchments produce large DOC loads…including at elevated flows

And these loads may be related to to impervious area cover & infrastructure…?

POM Export

POM Export in Urban Streams

1. How do urban POM concentrations and export rates compare to “natural” systems ?

2. How much does POM transport vary temporally (seasonal); how important is hydrology (storms)?

3. Is drainage density (and its attendant features) important?

AFDM & TSS at 3 SitesBaismans R, GFalls at Gwynnbrook, Dead R; Apr to Sep 2006

Gwynns Falls at Gwynnbrook AFDM & TSS(GFGB) Spring-Summer 2006

0.1

1.0

10.0

100.0

24-Mar 13-Apr 3-May 23-May 12-Jun 2-Jul 22-Jul 11-Aug 31-Aug 20-Sep

AF

DM

& T

SS

(m

g/l

)

AFDM50 (mg/l)

TSS105 (mg/l)

Avg: 39% Organic Matter

Suburban

Baismans Run AFDM & TSS(BARN) Spring-Summer 2006

0.1

1.0

10.0

100.0


AF

DM

& T

SS

(m

g/l

)

AFDM50 (mg/l)

TSS105 (mg/l)

Forested

Avg: 31% Organic Matter

Dead Run AFDM & TSS (DRKR) Spring-Summer 2006

0.1

1.0

10.0

100.0


AF

DM

& T

SS

(m

g/l

)

AFDM50 (mg/l)

TSS105 (mg/l)

Avg: 52 % Organic Matter

Urban

% Organic Matter

Forested: 31 % Suburban: 39 %Urban: 52%

% Organic MatterApr-May Jun-Sep

Forested: 40 % 29 % Suburban: 50 % 37 %Urban: 42 % 54%

TSSAFDM

Forested

Suburban

Urban

AFDM & TSS11 Sites; Spg-Sum 2006 (+/- Std Dev)

0.1

1.0

10.0

100.0

1000.0

POBR BARN MCDN GFGB GFGL MNBK GFVN GFCP DRKR MAWI GRGF

AF

DM

(m

g/l)

Avg AFDM

Avg TSS

Increasing Urbanization

Reference Sites

Highly Urban Sites

AFDM & TSS at 11 SitesSpg-Sum 2006

Ongoing/Future Work

Organic Matter…the Urban Dilemma

•Urban streams: faster particle breakdown …greater export rates from the benthic ecosystem…carbon poor benthos

But….

•Higher urban imports (gutter subsidy)?

•Smaller particles?

•Leached loads (DOC)?

Organic Matter in Streams:Types of OM

DOC- dissolved OM FPOM- fine particulate OMCPOM- coarse particulate OM

Organic Matter in Streams:Basic Transport Pathways

DOC

CPOM

FPOM

Groundwater

Surface &

Shallow

Groundwater

Leaching

Surface

WatersDOC

Riparian & Upland Litterfall

•13 gauged BES catchments…an urban-rural gradient

•Storm and dry weather sampling

•Intensive sampling with auto samplers at 3 catchments

•Particulate and dissolved organic matter

•Urban hydrology approach

•Sediment exports (% organic matter)

Basic Approach

Bridge

Dry Weather Flow

StormFlow

Discrete Storm FPOM Samples

Discrete Storm CPOM Samples

24 hr CPOM Sampler (Dry

Weather Flow)Whole Storm

CPOM Sampler

Peak Storm Flow CPOM Sampler

(stationary)

Intensive Site Sampling Conceptual Scheme

Automated Sampler

FPOM Grab (Dry Weather Flow)

USGS Stage

Recorder

Gwynns FallsMain Channel Stream Sites

Small Headwater Stream Sites

Subcatchment Stream Sites

BaismansRun

GwynnsFalls

BES Stream Sites: Routine & Intensive

GFGB

GFVN

GFCP

BARNPOBR

DRKR

3 IntensiveMonitoringSites

13 Routine Sampling Sites:

Gwynns FallsMain Channel Stream Sites

Small Headwater Stream Sites

Subcatchment Stream Sites

BaismansRun

GwynnsFalls

BES Stream Sites: Auto Storm Composites

GFGB

GFVN

RGHT

BALT &LANV

7 Auto SamplerStormCompositeSamplers

(including the 3 OM intensive Sites)

13 Routine Sampling Sites:

A Multidisciplinary, Cooperative Effort…

US Forest ServiceUMBC Geography & Environmental SystemsUMCES Appalachian LabCenter for Urban Environmental Research and EducationBaltimore Ecosystem Study/Institute of Ecosystem StudiesCity of Baltimore DPWUS Geological Survey

…and more partners to come

altered hydrology & vegetation: effects on the transport and breakdown of organic matter in...

Documents

urban landscape breakdown

riparian leaves

breakdown of organic

urban streams kenneth

forested streams

rate of breakdown day

gutter sources

breakdown products leachate