distribution and biomass of macrophytes growing near streams

Distribution and Biomassof Macrophytes Growing Near Streams

North End

Graywood

U.S.D.A. Project Macrophyte Study SitesExperimental Controls

Beds dominated by

milfoil near stream outlets

Eagle Point

Long Point

Old Orchard Point

McPherson Point

Sand Point

McPherson Point Gully

Long Point

Long Pt. Cove

Hartson Point

Cottonwood Cove

Sutton Point

Macrophyte Studies Project Goals:

• Monitor changes in biomass and standing crop, focusing on areas dominated by Eurasian watermilfoil near streams.

• Establish the relationship between nutrient loading, macrophyte biomass and standing crop

• Characterize changes in areas associated with control and experimental watersheds to determine the effectiveness of BMPs in reducing plant growth.

Graywood Gully

#1

#2

Transects #3

• 2-4 quadrat samples collected by divers at 1, 2, 3, 4 m

• Swimmer tracks the perimeter of the milfoil while boat with Trimble GPS operator follows

• Plants are separated by species and weighed

August 2003 Average and S.D. for all sites. Each number is average of 2-4 quadrats.

Tran Latitutde DepthLocation # (minutes) 1 m 2 m 3 m 4 m

1 44.459 N 31 + 29 199 + 130 61 + 45 12 + 10Sutton Point 2 44.511 N 17 + 11 113 + 38 60 + 32 9 + 8

3 44.563 N 39 + 22 270 + 25 103 + 60 4 + 31 45.441 N 32 + 21 154 + 10 121 + 89 18 + 8

Cottonwood Gully 2 45.496 N 32 + 2 160 + 53 123 + 56 11 + 33 45.544 N 72 + 17 128 + 40 171 + 7 141 46.598 N 13 + 2 169 + 65 247 + 45 11 + 5

McPherson's Point 2 46.654 N 29 + 12 609 + 13 295 + 24 45 + 533 46.692 N 6 + 4 128 + 66 98 + 41 9 + 41 46.497 N 19 + 11 89 + 5 135 + 35 18 + 6

Long Point Cove 2 46.552 N 25 + 9 --- 126 + 68 ---3 46.584 N 45 + 37 301 228 + 85 ---

Long Point 1 46.778 N --- 204 + 18 75 + 31 ---1 47.173 N 28 + 10 --- --- ---

Sand Point Gully 2 47.21 N 36 + 8 346 + 150 234 + 140 21+ 153 47.242 N 36 + 23 245 + 30 335 + 168 50+ 211 48.552 N 69 + 49 107 + 12 81 + 15 36 + 24

Graywood Gully 2 48.614 N 40 + 24 204 + 126 133 + 72 95 + 603 48.652 N 69 + 33 80 + 33 81+ 3 178 + 83

Comprehensive data set now includes four summers.

Average Surface StandingBiomass Area Crop

Location Year grams . m-2 m2

Kg Dry WeightSutton Point 2000 184 + 43 --- --- +++ 2001 467 + 183 8,592 4,017 * 2002 71 + 40 3,688 262

x 2003 138 + 92 11,819 1631

Cottonwood Gully 2000 193 + 85 --- --- ++ 2001 373 + 168 9,387 3,501 *** 2002 316 + 134 7,360 2,326

2003 146 + 41 3,750 548

McPherson's Point 2000 262 + 134 23,192 6,192 +++ 2001 459 + 202 25,783 11.834 ** 2002 151 + 74 12,004 1,813

x 2003 237 + 106 19,760 4,683

Long Point Cove 2000 252 + 35 --- --- ++ 2001 303 + 164 26,498 8,026 ** 2002 247 + 140 26,093 6,444

x 2003 195 + 85 24,554 4,788

Long Point ** 2002 212 + 159 3,123 662 x 2003 140 + 68 1,440 202

Sand Point Gully 2000 212 + 29 9,535 2, 021 +++ 2001 484 + 300 9,781 4,730 *** 2002 325 + 82 7,354 2,390

x 2003 290 + 120 5,310 1,540

Graywood Gully 2000 238 --- --- +++ 2001 412 + 162 36,148 14,897 ** 2002 193 + 123 6,703 1,294

x 2003 131 + 76 14,186 1,858

0

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0 100 200 300 400 500 600 700 800

2001 Macrophyte Dry Weights (g . m-2)

R2 = 0.04 p = 0.26

0

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0 100 200 300 400 500 600 700 800

2002 Macrophyte Biomass (g/ m sq.)

20

03

Macro

ph

yte

Bio

mass (

g/

m

sq

.)

Comparison of August Biomass Over Last Three Years

2001 vs. 2002

2002 vs. 2003

2001 vs. 2003

Changes in the distribution of

Eurasian Watermilfoil

within individual beds

such as Graywood gully

0

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% E

urasia

n W

aterm

ilfo

il 0

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% E

urasia

n W

aterm

ilfo

il

1m 2m 3m 4m Stream

1m 2m 3m 4m Central

1m 2m 3m 4m North

Stations are 100-150 m apart along

shore

NM = no milfoil

0

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20000

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30000

35000

40000B

ed

Su

rface

Are

a (

sq. m

)

20002001

20022003

ND NDND ND

Annual Changes in Milfoil Bed Surface Area

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ed

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rface

Are

a (

sq. m

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Annual Changes in Bed Surface Area

W 2001

W 2001

W 2001

W 2001

W 2002

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Sta

nd

ing

Cro

p (

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DW

)

20002001

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Annual Changes of Standing Crops in Milfoil Dominated Areas

W 2001

W 2001

W 2001

W 2001

W 2002

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20000

0.0001 0.001 0.01 0.1 1Loading Total Phosphorus (Kg/day) Sept - Dec

Conesus LakeMacrophyte Standing Crop vs. Stream Loading

of Total Phosphorus

R2 = 0.93p = 0.035

JJ

J

J

JJ

R2 = 0.79p = 0.019

2001

2002

2000R2 = 0.83p = 0.012

Relationship of Macrophyte Standing Crop to Average Daily Loading for USDA watersheds

Eagle Point

Long Point

Old Orchard Point

McPherson Point

Sand Point

Loading Prediction Curves for Long Point Cove and North Gully

y = 0.1001x

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.0000 0.1000 0.2000 0.3000 0.4000 0.5000

North McMillan (Kg)

Nor

th G

ully

TP

(Kg)

Relationship of Standing Crop to Total Phosphorus Loading by Streams, Summer

2003

R2 = 0.9251p< 0.01

0

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6000

0 0.05 0.1 0.15 0.2 0.25 0.3

Kg Total Phosphorus/ Day(Nov 1 2002 to Oct 31 2003)

Sta

nd

ing

Cro

p (

Kg

)

Progress:

• Better understanding of dynamic nature of milfoil growth

• Established possible cyclical pattern of bed growth

• Loading prediction curve for Long Pt. Cove

• Continued to document statistically significant relationship between stream loading of TP and standing crop

Goals for 2004:

• North McMillan loading prediction curve

• Refine estimates of standing crops

• Comparison of trends in experimental and control beds

• Seasonal changes in sediment nutrient levels