reconciling podzolic and redoximorphic responses to seasonal saturation willie harris, rex ellis,...

Reconciling Podzolic and Redoximorphic Responses to

Seasonal SaturationWillie Harris, Rex Ellis, Wade Hurt, Chumki Banik, Scarlett Balboa,

Travis Richardson, Chad Rischar, Ashley Phillips

Acknowledgments:

We thank Mr. Kafui Awuma and Ms. Kimberly Johnson for assistance with various field and laboratory aspects of this project. We also thank the following students for their help in the field with well installation, surveying, photography, etc.: Jeff Brantley, Luke Gommermann, Will Mahler, and Alexandra Rozin.

Funding from USDA-NRCS and McIntire-Stennis

Podzolization• Pedogenic translocation & joint accumulation of C & metals• Produces Bh horizon in FL • Well expressed Bh = Spodic horizon & Spodosol soil order

– Eluviation – • loss

– Illuviation –• gain

A

E

Bh

Florida Spodosol

“Podzolic” relates to …

Spodosol distribution worldwide

Commonly well drained

Mainly restricted toimperfectly-drained sites

What is the role of the water table (WT) in fostering Spodosol formation in Florida?

Randy Schaetzl

“Seasonal High Water Saturation” (SHS)

A

E

Bh

Florida Spodosol

SHS commonly about here

“Redoximorphic” relates to …

Images from page 18 of "Field Indicators of Hydric Soils"ftp://ftp-fc.sc.egov.usda.gov/NSSC/Hydric_Soils/FieldIndicators_v7.pdf

DepletionsConcentrations

Redoximorphic features: • Features associated with wetness – SHS indicators• Result from alternating periods of reduction & oxidation of Fe

& Mn in soils

Main Objectives

• Address uncertainties of redoximorphic–podzolic morphological effects along hydrologic gradients

• Test idea that Fe depletion along hydrologic gradients is a factor explaining association of Florida Spodosols with fluctuating WT

Approach

• Evaluate hydropedological trends along sandhill-flatwood-wetland transitions

• Install wells along 4 transects (23 total)

• Have local experts make SHS calls

• Monitor WT over a 2-year period

• Described and sample soils at each well site

• Determine Al, Fe, and C distribution by horizon

Transect Site Locations – Alachua Co.

20 km12.4 miles

Austin Carey Memorial Forest (ACMF) – 2 sites

Longleaf Flatwoods Reserve (LFR) – 2 sites

Transect Site Plant Community Transition

Marginal “sandhills” Flatwoods bordering wetland

Example:“sandhills” to flatwoods @ site 3

Bunk! That’s not redox! Oh, yeah!

Come over here and say

that!

What are we “reconciling”? …

Jeff Locuta’s image – Pedology class 2012

What are we “reconciling”? … (cont.)• Overlapping morphological effects of both processes along

transition from Spodosols to better-drained soils

• Evidence of process linkage through redox influence on Fe

“Sandhills” “Flatwoods”AA

What are we “reconciling”? … (cont.)• Schematic cross section of transition

• Soils shown were along transition

• Note trend in water table and degree of podzolization

• Note “cross-over” between SHS and Bh

• How are SHS indicators (redox features) affected by Bh?

Findings

A. WT & SHS indicator correspondence

y = 0.5754x + 20.255R² = 0.7644

0

20

40

60

80

100

120

0 20 40 60 80 100 120 140 160

Mea

n SH

S (c

m)

Mean Water Table Depth, (cm) 8/15 to 9/7/2012

SHS calls vs. WT• Late summer• Water in all wells• Water table fluctuating

27

28

29

30

31

32

0 10 20 30 40 50 60 70 80 90 100 110 120 130

5/30/12 Observation Depth

Ground surface

Fluctuating water table

Average SHS call

Elev

ation

(m

NAD

88)

Distance along transect (m)

1-1 1-2

1-31-4

1-5

1-6Road?


1-1 1-2

1-31-4

1-5

1-6

Concentrations Depletions(aka “stripping”)

Transect 1 - LFR

27

28

29

30

31

32

0 10 20 30 40 50 60 70 80 90 100 110 120 130


Ground surface


Average SHS call

Elev

ation

(m

NAD

88)


1-1 1-2

1-31-4

1-5

1-6Road?


1-1 1-2

1-31-4

1-5

1-6

27

28

29

30

31

32

0 10 20 30 40 50 60 70 80 90 100 110 120 130


Ground surface

Series7

Average SHS call

Elev

ation

(m

NAD

88)


1-1 1-2

1-31-4

1-5

1-6Road?


1-1 1-2

1-31-4

1-5

1-6

27

28

29

30

31

32

0 10 20 30 40 50 60 70 80 90 100 110 120 130


Ground surface


Average SHS call

Elev

ation

(m

NAD

88)


1-1 1-2

1-31-4

1-5

1-6Road?


1-1 1-2

1-31-4

1-5

1-6

27

28

29

30

31

32

0 10 20 30 40 50 60 70 80 90 100 110 120 130


Ground surface

Series7

Average SHS call

Elev

ation

(m

NAD

88)


1-1 1-2

1-31-4

1-5

1-6Road?


1-1 1-2

1-31-4

1-5

1-6

27

28

29

30

31

32

0 10 20 30 40 50 60 70 80 90 100 110 120 130


Ground surface


Average SHS call

Elev

ation

(m

NAD

88)


1-1 1-2

1-31-4

1-5

1-6Road?


1-1 1-2

1-31-4

1-5

1-6

Conclusions –WT & SHS calls

• Strong relation between SHS & mean WT depth during periods of fluctuation

• Highest WT shallower than SHS calls, especially on wettest end

• Predominant indicator was depletion

• Depletions were indicators for SHS calls in Bh

Thanks!Questions?

reconciling podzolic and redoximorphic responses to seasonal saturation willie harris, rex ellis,...

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