Title: Myakka
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Permanent Link: http://ufdc.ufl.edu/UF00089449/00020
 Material Information
Title: Myakka
Series Title: Myakka
Physical Description: Serial
Creator: Department of Soil and Water Science. Institute of Food and Agricultural Sciences. University of Florida.
Publisher: Department of Soil and Water Science. Institute of Food and Agricultural Sciences. University of Florida.
Publication Date: Summer 2007
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Bibliographic ID: UF00089449
Volume ID: VID00020
Source Institution: University of Florida
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LA Soi an Wae Scec Deatmn Publ--icatio

lI Volume 7 Number 2 Institute of Food and Anricultural Sciences

Summer 2007



Soils as Reservoirs of Carbon
Biochar as a Soil C Amendment
in the Amazon
Soil Spectral Sensing for
Prediction of Soil Carbon Pools
-Santa Fe River Watershed
Rapid Assessment and
Trajectory Modeling of
Changes in Soil Carbon
Influence of Water Le"els on
Subsidence of Organic Soils in
the St Johns Riter Basin

Controls on Methanogenesis in
the Florida Everglades

Carbon Sequestration of
Agroforestry Systems
Soi0l ccretion Dynamics in the
Flonda E"erglades
Lo' Impact De"elopment
Faculty. Student Et Staff Ne' 's
Dr Earl Le' 'is Stone

Susan Curry

Dr. Vimala Nair
Dr. Nicholas Comerford


iThe major challenges for Florida's landscapes are:
(1) meeting critical environmental regulations
2 related to water quality while maintaining
economic productivity, (2) decreasing the rate of
soil degradation and ameliorating degraded soils,
and (3) protecting the quality of natural resources.
SSoils function as sinks or sources for various
.... : contaminants including: nutrients, trace metals,
3 human and animal pathogens, pesticides, and other
S toxic organic compounds of agricultural and
industrial origin. Land use changes and alterations
4 in management practices have significant impacts on soil quality and ultimately affect
the quality of groundwater, adjacent streams, wetlands, takes, and estuaries. In
addition, land use changes and other human activities also are altering the chemical
4 composition of the atmosphere through enhanced production of greenhouse gases such as
carbon dioxide, methane, and nitrous oxide. On a positive note, soils are known to be
effective in carbon sequestration and serve as major reservoirs for carbon.
Given the unique landscape, climatic/hydrologic and land use conditions, Florida soils
have a larger carbon sequestration potential than most other states. Thus, it is critical to
6 assess soil carbon stocks across Florida and their carbon sequestration potential to
provide input for evolving carbon trading systems and markets. Recently, Governor Crist
6 provided leadership in signing an executive order to set targets of reducing Florida's
greenhouse gas emissions, setting new standards for use of renewable energy sources,
7 and considering a system allowing entities emitting greenhouse gases to buy credits from
entities that are reducing emissions. Florida soils could be such an entity to sequester
8 carbon thereby offsetting rising global carbon dioxide emissions. We are challenged to
develop a Florida carbon budget and gain a better understanding of carbon cycling across
Florida's complex soil-landscape.

The research and educational activities of the Soil and Water Science Department (SWSD)
have broad applications to water quality, carbon sequestration, and climate change. Our
faculty are taking a holistic, integrated approach to research and education to address
broader issues related to soil and water quality, carbon sequestration, and production of
greenhouse gases. In this newsletter, we highlight some of the research and education
activities related to carbon sequestration. A core group of SWSD faculty have formed a
working group to review current research on soil's role in carbon sequestration and
explore potential funding opportunities. The efforts of this group are led by Nick
Comerford, who has a long track record of studying carbon sequestration in forested

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A Soils as Reservoirs of Carbon

Florida has the highest soil carbon density (g C km 2) in the continental United
States and ranks near the top among all states in its total soil carbon storage.
Even with these impressive metrics, SWSD researchers are working to better
document and predict the soil carbon storage, sequestration and mineralization
from molecular scale to soil pedon to the landscape. These activities, while
focused on Florida, also include research extending to Europe, Southeast Asia,
and Brazil.

One of the SWSD's long-term goals is to measure the soil carbon change in the
landscape. Practically speaking, that means that the carbon change in the
landscape must be large in comparison to measurement error. Therefore,
accurate measurement of soil carbon is necessary; or those soil carbon pools
that are most sensitive to change must be identified, isolated and measured. -
Total carbon is fast and easy to measure in many of Florida's soils, but small .- -
changes can be difficult to document. In upland soils, soil carbon is ... ..
sequestered by interaction with clay, occlusion within soil aggregates,
deposited or added in forms that are recalcitrant, completed with aluminum Central Ridge. Soil Carbon below the
and/or movement to depth were there is reduced decomposition. Sandy surface 2 m profile is not sampled during
surface soils have little clay and do not have macroaggregation. the soil survey. (Photo Credit: Willie Harris)

It is also known that much of Florida's soil carbon is not in the sandy surface soil, but found in the subsoil. A significant
question remains: How much soil carbon is stored below the soil depths we typically measure? That question is best
illustrated with a picture of a central ridge soil. The soil depth that is typically described and where soil carbon is
measured, the surface 2m, is above the large soil carbon accumulation one sees in the subsoil of this landscape. So how
much do we really know about carbon storage in Florida's soils? For additional information, contact Nick Comerford at

Biochar as a Soil Carbon Amendment in the Amazon of Brazil

The use of charcoal made from plant material (biochar) is an application of relatively recalcitrant carbon to soil for
the dual purpose of sequestering carbon in the soil and increasing crop growth. Nicholas Comerford, a collaborator on
the research team of Dr. Newton Falcao, scientist from the National Institute of Amazonian Research (Manaus,
Brazil), has been involved in cooking at the phosphorus sorption issue. This team, through the efforts of graduate
students and international collaborators, has documented the significant P sorptive capacity of biochar and shown
that the phosphorus sorption capacity of recently produced biochar is superior to the biochar found in Dark Earth soils
(Terra Preta do Indio) of the Amazon. For additional information, contact Nick Comerford at nbc@ufl.edu.

Join us at ..
The 8th Annual Soil and Water Science Research Forum
The 8th Annual Soil and Water Science Research Forum (http://soils.ifas.ufl.edu/forum/) is scheduled for September 14,
2007, in Gainesville, Florida. The forum is designed to bring together representatives from state and federal agencies as
well as private industry, faculty and graduate students, and prospective students interested in soil and water science. The
forum will provide an opportunity for all those interested in soil and water science to interact with our students, faculty,
and administrators on campus. This year, Dr. Kenneth Nealson, Wrigley Professor of Geobiology, Department of Earth
Sciences, University of Southern California is the featured keynote speaker at the forum. We look forward to your
participation in the forum. If you are planning to attend, please register at http://soils.ifas.ufl.edu/forum/. For additional
information, contact Lena Ma at Lqma@ufl.edu.


Soil Spectral Sensing for Prediction of Soil Carbon Pools I
in the Santa Fe River Watershed

Soil spectral sensing for prediction of soil carbon pools is currently being evaluated in
the Santa Fe River watershed. Funding for this project is provided by Natural
Resources Conservation Service (NRCS) Cooperative Ecosystem Study Unit (CESU)
with S. Grunwald, N.B. Comerford, and J.O. Sickman as the investigators. In this
project a quantitative geospatial framework is being used to assess soil carbon pools
(total, mineralizable, hydrolysable, hot water extractable and recalcitrant), their
linkages to mineralizable nitrogen and phosphorus and environmental landscape
properties. The carbon, nitrogen and phosphorus pools are being integrated into a
holistic soil-landscape model cutting across a variety of ecosystem types in the Santa
Fe River Watershed. Site-specific observations are being upscaled to the watershed
scale (3,585 km2) using GIS and advanced geostatistical methods and synergized into a
Geospatial Soil Knowledge Management System.

A spectral library in the visible/near-infrared range for various soil properties has
been developed for the Santa Fe River Watershed. The spectral library can be used for
rapid, accurate predictions of soil properties that are cheaper than conventional Lab
analysis. The potential application of cost-effective spectral mapping of large soil-
landscapes is tremendous.

Aja Stoppe, graduate student
in the Forest Soils Laboratory,
soil sampling for C in the
Santa Fe River Watershed

The project has also looked at the mineralizability of soil carbon in soil size fractions and shown that land use
(vegetation x management interactions) has a noteworthy influence on the ability of soil carbon; with soil carbon
under annual cropping systems being almost two times more mineralizable per gram of carbon than that under
forested ecosystems. These studies are providing us with a better insight into how land management can protect soil
carbon from decomposition and what are the labile pools of carbon in our unique soils.

For additional information, contact: Sabine Grunwald at sabgru@ufl.edu.

Rapid Assessment and Trajectory Modeling of Changes in Soil Carbon across Florida

c / I

Soil Organic Carbon (kg/m2) 1z
9 0o (AFISOLSo
16 37 *( OLISOL)
60 94 (HSTOSQLS)

-- ----

Soil Organic Carbon Distribution
Flnrila (r. AA Vacn uec and r runn

SWSD faculty were recently awarded a USDA-NRI grant to investigate the Rapid
Assessment and Trajectory Modeling of Changes in Soil Carbon across
Florida. The investigators are S. Grunwald, N.B. Comerford, W.G. Harris and
G.L. Bruland (University of Hawaii). The goal of this research is to assess the
effects of land cover/land use (LC/LU) change on carbon stocks giving special
attention to translating site-specific carbon pools (labile, recalcitrant and total
carbon) to landscape scales. Study objectives are comprehensive and range
from, but not limited to: determining soil carbon pools in various ecosystem
types across a large southeastern landscape (Florida); to investigating the
strength and magnitude of relationships between environmental landscape
properties and corresponding carbon pools within a GIS; upscaling soil carbon
S pools to the landscape scale by modeling spatial autocorrelations and
/ covariations with environmental landscape properties. The studies data base
will be comprehensive, including historic (-1,300 soil samples) and
reconnaissance (-1,000) soil samples taken from throughout the state.
%A12 Ir'

S-- The story of soil carbon in Florida is not complete without considering the
Everglades. In addition to the abundant historic data already published by the Wetlands Biogeochemistry Laboratory in
the SWSD, a new project will be looking specifically at soil carbon in the floc/detritus and topsoil of parts of the
Everglades. The project, Remote-sensing Supported Digital Soil Mapping in South Florida, is being funded by NRCS-
CESU with S. Grunwald and N.B. Comerford as investigators. This study will add to the comprehensive inventory of soil
carbon in a vast portion of the Everglades that has already been the subject of research within our department and
incorporate Remote-sensing in the upscaling of the results. For additional information, contact: Sabine Grunwald at







Influence of Water Levels on Subsidence of Organic
Soils in the Upper St. Johns River Basin

The accumulation of the characteristic organic soils of the Upper St. Johns
River Basin (USJRB) has taken several thousand years. The stability of these
soils is highly dependent on hydrology as their formation is due to the
historically extended hydroperiod of the USJRB floodplain wetlands. In some
regions of the USJRB, the hydrology of the floodplain has been dramatically
altered, resulting in substantial loss of organic soil. The main goal of this
research was to determine the minimum water levels in wetlands needed to
prevent net loss of organic soils that eventually leads to subsidence of soils in
the Blue Cypress Marsh (BCM) of USRB. This was achieved by investigating the
effect of water drawdown on soils with different vegetation type, temperature
and nutrient levels. The effect was determined by measuring microbial
activities such as aerobic and anaerobic respiration, methane production,
phenol oxidase activity and p glucosidase enzyme activities. This research was
supported by the St. Johns River Water Management District. The investigators
are: Matt Fisher, Kanika Inglett, Todd Osborne, and K. Ramesh Reddy.

Matt Fisher from the St. Johns River
Water Management District, collecting
soil cores at the Blue Cypress Marsh site.

Results of this study showed that organic soils in the BCMCA are subject to impact with respect to water level
drawdown. Carbon dioxide flux studies suggest that the surface 10 cm of soil is the most reactive and requires
protection from subsidence due to oxidation when water levels are low. Soils in the BCMCA are also
characteristically variable with respect to soil ability, dominant vegetation type, and site nutrient status, therefore
responses to subsidence inducing low water events is site dependant. Microbially mediated oxidation is the primary
driver of organic soil subsidence, and while shrinkage and compaction due to dewatering can have an effect, the
long term losses of organic carbon due to oxidation are the most critical threat. This study provides evidence that
suggests any drawdown even resulting in water levels below the soil surface can result in increased soil organic
matter losses to oxidation and that these losses will be variable across the landscape given variation in soil nutrient
availability and organic matter quality. For additional information, contact: K. Ramesh Reddy at krr@ufl.edu.

Controls on Methanogenesis in the Florida Everglades

Freshwater wetlands are among the most productive ecosystems in the
Near inf terior world and provide a range of vital ecosystem services, including habitat
for diverse plant and animal species and processes related to water
quality and carbon storage. The terminal process of the carbon cycle is
Smineralization to either carbon dioxide or methane, and the specific
routes through which carbon is funneled to these end products may be
complex and linked to other cycles, such as the sulfur cycle. Both
carbon dioxide and methane are green house gases, with methane being
most potent of the two. Natural wetlands account for over 20% of global
methane produced, such that a detailed understanding of the pathways
leading to methanogenesis, and of the mechanisms through which
Everglades Water Conservation Area-2A Ecosystem eutrophication impacts these pathways, is crucial to understanding the
Alteration impact of nutrient enrichment on ecosystem processes in wetlands and
to developing ecosystem and global models of methane flux.

Results of a recently completed NSF funded project (Andy Ogram and K. R. Reddy) showed that ratios of rates of potential
hydrogenotrophic methanogenesis to potential acetoclastic methanogenesis rates are much higher in the nutrient enriched
soils than in the oligotrophic soils. Most probable numbers of hydrogenotrophic methanogens are over 1000 times greater
than acetoclastic methanogens in nutrient enriched soils, and less than 100 times greater in oligotrophic soils. In addition,
the dominant microbial groups controlling fermentation, methanogenesis and sulfate reduction exhibit different
physiological characteristics with regard to acetate metabolism in the different soils, strongly suggesting different
pathways for consumption of acetate and routes for methanogenesis as a function of nutrient enrichment. Results of this
study have major implications on pathways and microbial communities involved in methane emissions from eutrophic
wetlands. For additional information, contact: Andy Ogram at aogram@uft.edu.


.do& -






Carbon Sequestration of Agroforestry Systems

Carbon sequestration potential of agroforestry systems is
attracting worldwide attention following the recognition of
agroforestry as an activity for carbon sequestration under the
Kyoto Protocol. This is a major theme for the research team of
Vimala Nair (SWSD) and P.K. Nair (School of Forest Resources and
Conservation, affiliate SWSD faculty). Through their collaboration
with graduate students and overseas scientists, the widely
believed, but largely untested, premise that agroforestry systems
will retain more stable soil carbon than arable copping and
pasture systems is being investigated. The systems under
investigation include silvopastoral agroforestry systems in Florida;
traditional and improved agroforestry systems in Mali, West
Africa; homegarden systems in Kerala, India; and extensive ,
(existing) as well as intensive (experimental) silvopastoral ..
systems in northern Spain. .,"
systems in northern Spain. Carbon sequestration studies at a silvopastoral site
at the Range Cattle Research and Education Center
in Ona, Florida (Photo credit: Solomon Haile)

Soil carbon storage in different particle-size fractions at varying
depths is being investigated, and wherever appropriate, the
carbon source is being identified as being from the tree or the
crop/grass (herbaceous) through the use of 13C/12C isotopic
ratios. Additional investigations of this nature are planned for
2007 2008 from the silvopastoral system in the Cerrado region
and the multistrata agroforestry system in the humid tropical
lowlands, both in Brazil, through the involvement of visiting
Brazilian scientists. For additional information, contact: Vimala
Nair at vdn@uft.edu .
Carbon sequestration studies at a Faidhelbia
albida dominant parkland system in Mali, West
Africa (Photo credit: Asako Takimoto)

Carbon sequestration studies in a homegarden in
Kerala, India (from left to right: Subharjit Saha, two
of the owners of the homegarden, and Dr. Kumar,
local host in Kerala, India
Vimala Nair discussing the potential for carbon
sequestration studies with host Dr. Mosquera-Losada
at the forestry experimental site in Lugo, Spain.



Soil Accretion Dynamics in the Florida Everglades


Findings from a 3-year investigation of Shark River Slough in the Florida
Everglades suggest a complex relationship between C assimilation and litter
decomposition rates that regulates local soil elevation differences. Most
changes in soil elevation of this area are due to an accumulation of organic
plant litter and inorganic calcium carbonate in the form of Mart. It was first
hypothesized that soil accretion rates would be greater on ridges than that
on lower elevation sloughs. It was found that biomass production was
greater and plant litter quality more recalcitrant (tissue C:N and
lignin:cellulose ratios) on sawgrass dominated ridges than in stoughs
suggesting a greater accretion rate of soils on ridges. However, due to the
higher elevation of ridges, soils are exposed to the atmosphere more
frequently and for longer periods increasing decomposition rates. As a
result, although Litter input was greater and more recalcitrant on ridges,
Graduate Student Chris Lewis prepares
greater decomposition rates appear to result in Long-term soil accretion on samples after being dropped off by helicopter
ridges being almost equal to that of adjacent sloughs. This suggests that a within Everglades National Park.
dynamic equilibrium exists between C input potential and the duration of
flooding, where periods of greater soil accretion on ridges can occur when hydrologic conditions allow (wet years).
However, ridge elevation can only get so high relative to slough bottoms due to hydrologic feedback mechanisms causing
ridge tops to become exposed and undergo decomposition. As long as the ridge community maintains a greater potential
for soil accretion than that of sloughs, some relative difference in elevation between ridges and sloughs can occur.
Maintaining differences in soil elevation are fundamental to preserving the ridge slough vegetative mosaic, a critical
habitat and landscape feature of the Florida Everglades. For additional information, contact: Mark Clark at

Low Impact Development Training

The Low Impact Development Training Initiative received a Promising
Practice award from the Council for Sustainable Florida in June
2007. This award acknowledges innovative programs that "create a
sustainable economic, environmental, and social future for
Florida." The award was presented to Mark Clark representing the
Program for Resource Efficient Communities (PREC) along with Linda
Burnette and Gene Caputo both from the St. Johns River Water
Management District. The Low Impact Development Training Initiative is
a 6-hour workshop targeting local county governments to raise
awareness of development impacts and provides guidance on more
sustainable development alternatives. The Program for Resource
Efficient Communities is a multidisciplinary effort of UF faculty from 5
departments that was initiated and is coordinated by the Florida Energy
Extension Service, Directed by Pierce Jones. For additional information,
contact: Mark Clark at clarkmw@ifas.ufl.edu or go to http://
www. buildgreen.ufl.edu

SWS Alumni

In our newsletter, we would like to
include news from our alumni and
their success stories and
accomplishments. Please provide
highlights of your current activities,
so we can include them in future
SWSD newsletters. Please e-mail
information and a photograph to
Susan Curry at: scurry@ufl.edu.




Faculty, Students Et Staff News

PURC Water Utility Benchmarking in Mexico

Julie Padowski delivered an
invited presentation, "Survey
of Benchmarking
Methodologies: Improving[
Water Utility Efficiency" this
summer at the "Seminario
International de Gesti6n y
Regulaci6n de los Servicios de
Agua Potable y Saneamiento:
La Experiencia Mexicana e
International" in Mexico City in
coordination with the Public
Utility Research Center at UF. Her talk emphasized the
need for improved efficiency within water utilities and a
stronger link between water resource managers and water
utility managers in order to promote long-term sustainable
water use. The event was organized by local institutions
and organizations and attracted water utility managers,
consultants, academics and regulators from Mexico and
around the world to share ideas and discuss problems
associated with the legal and institutional framework of
water and sanitation services.

( Congratulations... Summer 2007
Daniel Herrera, Advisor, W. Harris
Kamal Mahmoud, Advisor, P. Nkedi-Kizza
Daniel Perkins, Advisor, J. Jawitz

Erin Atkinson, Advisor, J. Jawitz
Miguel Mozdzen, Advisor, P. C. Wilson

The following students were awarded Grinter Fellowships
for their PhD programs:
Edmund Azah (L. Ma)
Alex Cheesman (K. R. Reddy)
Augustine Obour (M. Silveira and G. O'Connor)
Shiny Mathews (L. Ma)
Augustine Muwamba (P. Nkedi-Kizza)

Debolina Chakraborty (V.D. Nair) and Gustavo Vasques
(S. Grunwald) were awarded Alumni Awards to pursue

Welcome... Incoming Students

Fall 2007

Rotem Shahar, MS, T. Obreza
Augustine Obour, PhD, M. Silveira/G. O'Connor
Debolina Chakraborty, PhD, V. Nair
Edmund Azah, PhD, L. Ma
Ronald Gonzalez, PhD, J. Sartain
Shawna Loper, MS, A. Shober
Xiaolin Sui, MS, M. Silveira
Lori Clark, MS, T. Obreza
Matthew Wilson, MS, E. Hanlon
Stephen Hanks, MS, C. Fitz

Pauric Mc Groary, PhD, G. Snyder
Neil Young, MS, G. Snyder
Erin Yancey, MS, J. Thomas
Melinda Hooper, MS, L. R. Ellis
Laura Sadowski, MS, J. Sartain
Daniel Moura, MS, M. Silveira/G. O'Connor
Tanya Scheff, MS, L. R. Ellis
Kristin Wheeler, MS, S. Newman
Marti Occhipinti, MS, G. Toor
R. Drew Lindemann, MS, S. Daroub

Robert Compitello, MS, T. Osborne






In Memoriam


Earl Stone, 92, passed away July 23, 2007 in Gainesville, FL. He was born July 12,
S1915 in Hinmansville, NY. He received his BS in forestry from the New York State
College of Forestry at Syracuse in 1938, and his MS in soil science from the University
of Wisconsin in 1940. He then worked as a forester with the US Forest Service. From
1942 to 1945 Dr. Stone served with the 8th Photographic Reconnaissance Squadron, 5th
Air Force, in the SW Pacific. He received his PhD in soil science from Cornell
University in 1948, and was appointed to the Charles Lathrop Pack professorship in
forest soils in the Department of Agronomy at Cornell. Dr. Stone conducted research
and teaching on effects of soil properties on forest type and growth; tree root
mycorrhizae; soil fertility and forest ecology; element accumulation under forests;
and ecology of the forest floor.
Upon retiring from Cornell in 1979, Dr. Stone joined the University of Florida as adjunct professor of soil science,
with an affiliate appointment in UF's School of Forest Resources and Conservation. He remained active in research,
writing, and mentoring of graduate students until 2002.
Dr. Stone took on numerous scientific/professional assignments during his career, including visiting associate
professor of forestry at the University of the Philippines; Fullbright senior research fellow at the Forest Research
Institute, Rotorua, NZ; visiting professor (Thailand) for Oregon State University; consultant to the National Institute
of Biology, Bogor, Indonesia; consultant to the President's Advisory Panel on Timber and the Environment; and
member of the Bikini Atoll Rehabilitation Committee. Dr. Stone was widely published and much sought-after as a
keynote speaker and writer of comprehensive articles. He was a Fellow of the American Association for the
Advancement of Science, the Society of American Foresters, SSSA, and ASA. He twice served as chair of Division S-7,
and served on numerous editorial panels.
Dr. Stone was predeceased by his wife of 56 years, Margaret H. Stone, and by his second wife, Jean LaChance Stone.
He is survived by a brother, three children, and five grandchildren. Contributions may be sent in memory of Earl
Stone to the Charles Lathrop Pack Forestry Trust, PO Box 2600, Ithaca, NY 14850. Sympathies may be conveyed to
Earl Stone III, 911 Grants Pkwy, Arlington, TX 76014.

Plan to attend...
University of Florida and Progress Energy partner to host the
First UF Water Institute Symposium

SSustainable February 27-28, 2008
e Hilton University of Florida
Water Resources Conference Center
FhalGAe Q ge. 1 U Gainesville, Florida

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