Fire Project Update:Fire Project Update:

Mass and nutrient loss of cattail communities in WCA 2A in response to

prescribed firesprescribed fires Quarterly Communications Meeting on the

Long Term Plan for Achieving Water Quality GoalsLong-Term Plan for Achieving Water Quality Goalsfor Everglades Protection Area Tributary Basins

September 29 2009September 29, 2009

ShiLi Miao (PI)Cassondra Thomas

Amy Farrell

Management objectiveA h th lti l f fi l t thAssess whether multiple surface fires accelerate the recovery of the nutrient-enriched areas now dominated by cattails in WCA 2Ay

Research objectivesj• Determine ecological effects of multiple surface fires on critical wetland ecosystem structure, function, and processes in nutrient-enriched areas

• Examine natural recovery pattern in WCA 2A

Conceptual model for Fire ProjectConceptual model for Fire Project

1. Release and Return

P1

1.2.3.

Release and ReturnSurface WaterSoil

Ash Ash

P1.4. Vegetation

Water Flow PP P

P

PP

2.

4.

Species Species other other than than

cattailcattail

PP

P

Soil PSoil P

Competition for Nutrients

PPDecompositionDecomposition

3.Competition for Nutrients

SedimentSediment

ObjectivesObjectives

• Quantify mass and nutrient loss and• Quantify mass and nutrient loss and return

• Examine factors that affect mass and nutrient loss and return

• Assess ash chemistry and its impacts t liton water quality

Fire Project Design

WCA-2A

Fire Project Design

WCA 2AWaterDepth

Date Type (cm)Highly P-enriched

(1000 -1200 mg/kg)

Moderately P-enrichedH2H1

Highly enrichedJuly 2006 Prescribed 10July 2008 Prescribed 43

Moderately P enriched(600 -1000 mg/kg)

Reference(< 600 mg/kg)

Rs

M2M1 Moderately enriched

February 2006 Wildfire 19August 2008 Prescribed 32

RcRs

Fire ImplementationFire Implementation

A Bi d N t i tAverage Biomass and Nutrient Loss

800

1000

7 008.009.00

7357.3

g/m

2 )

600

800

g/m

2 )

4 005.006.007.00735

Loss

(g

400

Loss

(g

0.75

1.004.00

351

0

200

0 00

0.25

0.500.4

Mass Carbon0

Nitrogen Phosphorus0.00

Average Biomass and NutrientAverage Biomass and Nutrient Loss

40

50

g/m2 40

50

ss (%

)

30

40

ss (%

)

30

40

Los

10

20 Los

20

M C b0

10

Ni Ph h0

10

Mass Carbon Nitrogen Phosphorus

Biomass & Nutrient Loss atBiomass & Nutrient Loss at Different Habitat & Burns

Habitat Fire # Nutrient loss (%)Mass Carbon Nitrogen P

Highly-enriched 1 62 62 62 502 44 43 58 49

Moderately-enriched 1 49 62 63 412 28 25 28 30

Highly-enriched plot post-fire, 2006

Combusted mass•62% of total mass

Nutrients released m-2

• 585 g C 0 7 P• 78 % of dead litter

layer• 24 % of live leaves

• 0.7 g P• 11 g N

Highly-enriched plot post-fire, 2008

Combusted mass•44% total mass

63 % f d d litt

Nutrients released m-2

• 379 g C• 63 % of dead litter

layer• 10 % of live leaves

• 0.6 g P• 10 g N

post-fire - February 21, 20061 dayModerately-enriched plot post-fire, 2006

Combusted mass•49% total mass

59 % f d d litt

Nutrients released m-2

• 424 g C • 59 % of dead litter layer

• 19 % of live leaves

g C• 0.1 g P• 10 g N

Moderately-enriched plot post-fire 2008

Combusted mass•28% total mass

Nutrients released m-2

• 195 g C28% total mass• 33 % of dead litter

layer• 17 % of live leaves

195 g C• 0.2 g P• 3 g N

Mass Loss and Pre-Fire MassMass Loss and Pre Fire Masss

(%)

100y = 0.02X + 4.02 Highly enriched 1st Fire

Moderately enriched 1st Fire

ss L

oss

80

yr2 = 0.28p = 0.05

Moderately enriched 1st FireHighly enriched 2nd FireModerately enriched 2nd Fire

nd m

as

40

60

vegr

oun

20

40

0 500 1000 1500 2000 2500 3000

Abo

v

0

Pre-fire Aboveground mass (g/m2)

Mass Loss and Water DepthMass Loss and Water Depths

(%)

80

100 y = -0.854x + 63.59r2 = 0.27

p = 0.056

mas

s Lo

s

60

80

egro

und

m

40

Abo

ve

0

20 Highly-enriched 1st Fire Moderately-enriched 1st FireHighly-enriched 2nd FireModerately-enriched 2nd Fire

Water Depth (cm)0 10 20 30 40 50

Mass Loss and Temperaturep

(%)

80

100

120

Cattail

Mas

s Lo

ss

20

40

60

80

SawgrassRegression line95% Confidence intervalHighly enriched 1st FireModerately enriched 1st FireHighly enriched 2nd Fire

0

oss

(%)

60

80

100

120

g yModerately enriched 2nd Fire

TN L

o

0

20

40

60

120

C L

oss

(%)

40

60

80

100

Temperature (oC)0 100 200 300 400 500 600

T

0

20

Mass Loss and SpeciesMass Loss and SpeciesCattail Sawgrass

AirTotal C

(351 g/m2)(40%)

Total N(7.3 g/m2)

(47%) Particulate P(0.36 g/m2)

Aboveground Mass(1681 g/m2)

C N P & Metals

(40%)( g )

(40%)

C,N,P & Metals(810 g C/m2, 14.0 g N/m2, 0.8 g

P/m2)A. Release

All %s in A. are based on pre-mass

Ash Collection DesignAsh Collection Design

Nutrient Return to the SystemNutrient Return to the System

AshLeaf fragmentsg1.4%1.4%

Sediment

Water

Sediment

Ash Return to the SystemAsh Return to the System

Ash return % pre-fire % burnedAsh return % pre-fire % burned

Mass 0.6 1.4

Ash TN 0.5 0.9

Ash TC 0.4 1.0

Ash TP 4.0 8.9

Air

Ash(10.6 g/m2)

(1.4%)

B. Return

Water

MetalsTN

(0.06 g/m2)(0.9%)

TC(3.4 g/m2)

(1.0%)

TP(0.03 g/m2)

(8.9%)

PO4(0.9 mg/m2)

NH4(0.5 mg/m2)

NO3(0.1 mg/m2)

Soil( g )

(0.25%)(0 5 g/ )

(0.007%)(0 g/ )

(0.001%)

All %s in B are based on burned mass or nutrient content

Ash Chemistry with Varying Temperatureg/

g re

sidu

e)

500

600

700

mg/

g re

sidu

e)

30

40

al C

arbo

n (m

200

300

400

al N

itrog

en (m

10

20

Temperature (οC)150 250 350 450 550As

h To

ta

0

100

Temperature (οC)150 250 350 450 550As

h To

ta

0

mg/

g re

sidu

e)

12

14

16

Cattail LiveCattail DeadSawgrass LiveSawgrass Dead ho

spho

rus

(m

4

6

8

10

Sawgrass Dead

Temperature (οC)

150 250 350 450 550

Ash

Tota

l P

0

2

Surface Water pH Response to Ash Additionp p

8.6

pH

8.2

8.4

8.6Highly enriched 1st Fire Highly enriched 2nd Fire Moderately enriched 2nd Fire

face

wat

er p

7 6

7.8

8.0

Surf

7.2

7.4

7.6

Time 06:00 10:00 14:00 18:00 22:00

7.0

Ash Deposition and Water Depth onAsh Deposition and Water Depth on SWTP

AirTotal C

(351 g/m2)(40%)

Total N(7.3 g/m2)

(47%) Particulate P(0.36 g/m2)

Aboveground Mass(1681 g/m2)

C N P & Metals

(40%)( g )

(40%)

C,N,P & Metals(810 g C/m2, 14.0 g N/m2, 0.8 g

P/m2)A. Release

Ash(10.6 g/m2)

(0.6%)

B. Return

Water

MetalsTN

(0.06 g/m2)(0.5%)

TC(3.4 g/m2)

(0.4%)

TP(0.03 g/m2)

(4.0%)

PO4(0.9 mg/m2)

NH4(0.5 mg/m2)

NO3(0.1 mg/m2)

Soil( g )

(0.1%)(0 5 g/ )

(0.004%)(0 g/ )

(0.001%)

All percentages are based on pre-fire mass or nutrient content

Major ConclusionsMajor Conclusions• Prescribed fires were an effective way to quickly remove nutrients as approximatelyquickly remove nutrients, as approximately 1% of N and C and < 8% of P of burned nutrients was returned as ash.nutrients was returned as ash.• Pre-fire mass and water depth at the time of fire were the main factors determining massfire were the main factors determining mass and nutrient loss.• Water depth and fire temperature both• Water depth and fire temperature both directly (release) and indirectly (ash effect on water quality) affected ecosystem q y) ynutrient concentration.

Management ImplicationsManagement Implications

• Two years were required for fuel loads to return for repeated fire but more time may be required for additional fires

A N l d d l t d

may be required for additional fires.

• As more N was released and less returned in ash than P, repeated fires can lead to a more N limited system and therefore caremore N-limited system, and therefore care must be taken when considering prescribed fires in N-limited systems.es ted syste s

Management ImplicationsManagement Implications• Water depth is a key management

id i i h l l b 10 dconsideration with levels between 10 and 40 cm resulting in successful surface firesfires.

• The lower end is good for maximizing nutrient lossut e t oss

• The upper end is good for minimizing water quality changes.

• High water levels also reduce fire temperature, creating ash with lower pH, TP p , g p ,and soluble P concentrations.

CardoTBE Scheda EcologicalBEM S tSFWMD

AcknowledgementsCardoTBECassondra ThomasChris EdelsteinDean Monette

Scheda Ecological AssociatesErik SindhojLili CarpenterJ if Zi

BEM SystemsSusan CarstennWendy SoteraElsa Krauss

SFWMDRobert JohnsonBen Gu

Dean MonetteAmy FarrellDavid CoxChristina Stylianos

Jennifer ZimmermanJosh CreasserManuel Tapia

yAndy SteinerDan Pisut Birkitt

Environmental ServicesServicesHongjun Chen Damien CondoDan Salembier

Project Publications• Miao and Carstenn 2006. A new direction for large-scale experimental design and analysis. Frontiers in Ecology and the Environment 5: 227Frontiers in Ecology and the Environment 5: 227.

• Miao et al. 2008. Allometric relationships of field population of two clonal species with contrasting life histories, Cladium jamaicense and Typha domingensis. Aquatic Botany 88: 1-9.

• Gu et al. 2008. Effects of a prescribed fire on dissolved inorganic carbon dynamics in a nutrient-enriched Everglades wetland. Fundamental and Applied Limnology 171:263-272.

• Miao and Zou, 2009. Seasonal variation in seed bank composition and its interaction with nutrient enrichment in Everglades wetlands Aquatic Botany 90:157-164nutrient enrichment in Everglades wetlands. Aquatic Botany 90:157 164.

• Qian et al. 2009. Effects of burn temperature on ash nutrient forms and availability from cattail and sawgrass in the Florida Everglades. J. Environ. Qual. 38: 1-15.

Qi t l 2009 E ti ti f tfi t i t l i th Fl id E l d J E i Q l• Qian et al. 2009. Estimation of postfire nutrient loss in the Florida Everglades. J. Environ. Qual. 38: 1812-1820.

• Thomas et al. 2009. Environmental factors affecting temporal and spatial patterns of soil redox potential in Florida Everglades wetlands. Wetlands 29:1133-1145. p g

•Miao et al. 2009. Real World Ecology: Large-scale and Long-Term Studies and Methods. Springer

pdf request to “smiao@sfwmd.gov”

Thank You