water source utilization and nutrient status in tree islands in shark river slough, everglades...

Water source utilization and nutrient status in tree islands in Shark River Slough,

Everglades National Park

Tree island sites

Profile of a tree island

Vegetation zones on a tree island - Chekika

Emergent Hardwoods

Floodtolerant veg.

Sawgrass/Slough

Wet season: Two POSSIBLE water sources in tree islands

1. Soilwater – rain trapped in leaf litter – NUTRIENT RICH2. Regional surface/groundwater – NUTRIENT POOR

These two sources can be ISOTOPICALLY DISTINCT

Evaporating pool of water = enriched in heavy isotopeAllows for differentiating pools of water

Water(H2O):

Hydrogen has 2 isotopes – 1H (lighter) and 2H (heavier)

Oxygen has two major isotopes -- 16O (lighter) and 18O (heavier)

Stable isotopes of water

10001‰)(tan

xR

R

dards

sample

dD

(o

/oo

) W

AT

ER

d18O (o/oo) WATER

dD=(8*d18 O)+10 M

eteoric W

ater

Soil Water

Wet

Dry

WetDry

Fig 3b. Blue dots indicate sampling stations on tree island.Yellow and orange dots represent actual trees sampledaround station.

ENP Tree Islands - sites and methods

• Nutrient sampling: every 2 months for 1 year

• Foliar N and P

• Water sampling: for 1 year

-Rainwater on Grossman Hammock

-Soil water (organic horizon) ( every 2 months )

-Plant stem water ( every 2 months )

• Cryogenic distillation of soil and stem water

• Isotopic analysis on mass spectrometer

Chekika – airboat/helicopterSatinLeaf – airboat/on footGrossman Hammock – car/foot

Per island:

20 upland plants

30 lowland plants:1. Sawgrass-flooded ecotone

2. Flooded – hammock ecotone

Results so far… Chekika

nov plant stem waters

-50.0

-40.0

-30.0

-20.0

-10.0

0.0

10.0

20.0

30.0

-8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0

O18

2H

SL1 flooded

SL2 f looded

upland hardw oods

rain

met w ater line

acknowledgements

Leo Sternberg - advisorFernando Miralles-Wilhelm (FIU) – PI on NSF Biocomplexity ProjectMike Ross (FIU) – collaboration and logistics on tree islands

Fieldwork and LabworkPablo Ruiz, Mike Klein, Brooke Shamblin, Daniel Gomez, Diane, Jeanette, Astrid, Anita , Daniel Ramirez, John Cozza, Eric, Hao, Patrick Ellsworth, Xin Wang, Patricia, Maria Camila Pinzon, Cassandra

My committee – Don DeAngelis, David Janos, Leo Sternberg, Fernando Miralles-Wilhelm

Funding: NSF Biocomplexity in the Environment project