C N P Fluxes in the Coastal Zone

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C N P Fluxes in the Coastal Zone
The LOICZ Approach to Budgeting and Global
Extrapolation S. V. Smith U. Hawaii March 2000

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What is the role of the coastal ocean in global
CNP cycles?

• Easier to quantify globally than locally
• Via global loading budgets
• Little understanding of distribution or controls.
• Function of biota and inorganic reactions
• Function of environmental conditions
• F(land inputs, oceanic exchanges)
• F(human pressures)
• F(regional, global environmental change).
• An environmentally important question that can be
  approached via geochemical reasoning.

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General Background
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Global Elevation
Only a small portion lies in the LOICZ domain.
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Coastal Zone (200 to 200 m)
This domain is nominally 200 m to -200 meters,
orabout 18 of global area.
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Coastal Ocean (0 to 200 m)
The coastal ocean, being budgeted by LOICZ, is
about 5 of global area.
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The Global Coastal Ocean A Narrow, Uneven,
Chemically Reactive Ribbon
This ribbon is 500,000 km long and averages
about 50 km in width.
Most materials entering the ocean from land pass
through this ribbon.
Most net biogeochemical reaction is thought to
occur in the landward, estuarine, portion of the
ribbon.
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LOICZ and IGBP

• IGBP is the International Geosphere-Biosphere
  Programme.
• http//www.igbp.kva.se/
• Part of ICSU, the International Council of
  Scientific Unions
• LOICZ is Land-Ocean Interactions in the Coastal
  Zone.
• http//kellia.nioz.nl/loicz
• A key project element of IGBP

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IGBPInternational Geosphere-Biosphere Programme

• IGBP aim --To describe and understand the
  interactive physical, chemical and biological
  processes that regulate the Earth System, the
  environment provided for life, the changes
  occurring in the system, and the influences of
  human actions.
• LOICZ aim -- About the same as IGBP aim for the
  coastal zone.

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Alphabet Soup of the IGBP

• JGOFS Joint Global Ocean Flux Studies
• IGAC International Global Atmospheric Chemistry
• GCTE Global Change and Terrestrial Ecosystems
• BAHC Biospheric Aspects of the Hydrological Cycle
• PAGES Past Global Change
• LOICZ Land-Ocean Interactions in the Coastal Zone
• LUCC Land Use and Cover Change
• GLOBEC Global Ocean Ecosystem
  Dynamics_________________________________________
  _________
• GAIM Global Analysis, Integration and Modelling
• START System for Analysis, Research, and Training
• DIS Data and Information System

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LOICZBudgeting Background
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Develop a Globally Applicable Method of Flux
Estimation

• Ability to work with secondary data
• Minimal data requirements
• Widely applicable, uniform methodology
• Robust
• Informative about processes of CNP flux.

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LOICZ Budgeting Procedure

• Conservation of mass is one of the most
  fundamental concepts of ecology and geochemistry.

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Water, Salt, and Stoichiometrically Linked
Nutrient Budgets

• Water and salt budgets are used to estimate water
  exchange in coastal systems.
• Departure of nutrient budgets from conservative
  behavior measures system biogeochemical fluxes.
• Nonconservative DIP flux is assumed proportional
  to (primary production respiration).
• Mismatch from Redfield expectations for DIP and
  DIN flux is assumed proportional to (nitrogen
  fixation denitrification).

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Water and Salt Budgets

• Water budget
• Freshwater flows known.
• System residual flow (VR) conserves volume.

• Salt budget
• Net flows known.
• Mixing (VX) conserves salt content.

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Nutrient Budgets

• Nutrient (Y) budgets
• Internal dissolved nutrient net source or sink
  (?Y) to conserve Y.

• Calculations based on simple system stoichiometry
• Assume Redfield CNP ratio (106161)
• (production - respiration) -106 x ??DIP
• (Nitrogen fixation - denitrification) ??DINobs
  - 16 x ?DIP

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LOICZ Strategy

• Develop a global inventory of these budgets.
• Guidelines, a tutorial, and individual site
  budgets at http//data.ecology.su.se/MNODE/
• Under direction of S. V. Smith, F. Wulff
• Major emphasis of this presentation.
• Use typology (classification) techniques to
  extrapolate from budgeted sites to global coastal
  zone.
• Under direction of R. W. Buddemeier
• Tools and examples available athttp//www.palanti
  r.swarthmore.edu/maxwell/loicz/(B. Maxwell)

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LOICZ Budgeting Research

• New, or primary, data collection is not a
  primary aim of LOICZ budgeting research.
• There is heavy reliance on available secondary
  data to insure widespread (global) coverage.
• Workshops and information sharing via the World
  Wide Web are the major tools for adding
  information to the LOICZ budgeting data base.
• Funding for workshops has come from UNEP/GEF,
  LOICZ, WOTRO, local sponsorship.
• Develop analytical tools to assist in budgeting.

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LOICZ budget workshops to date

• September 1995Guidelines Development
• (Halifax, Canada)
• December 1995Introduce guidelines to SWOL
• (Penang, Malaysia)
• October 1996LOICZ/JGOFS Continental Margins
• (Lagos, Nigeria)
• June 1997Mexico lagoons
• (Ensenada, Mexico)
• October 1997LOICZ/JGOFS Continental Margins
• (Texel, The Netherlands)

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LOICZ budget workshops, cont.

• October 1998Australasia estuaries
• (Canberra, Australia)
• January 1999Mexico, C. America lagoons II
• (Merida, Mexico)
• July 1999South China Sea estuaries
• (Manila, Philippines)
• November 1999South America estuaries
• (Bahia Blanca, Argentina)
• February 2000South Asia estuaries
• (Goa, India)

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The Global Environment Facility (GEF) of the
United Nations Environment Programme (UNEP) has
funded LOICZ to conduct a series of local budget,
regional typology and global synthesis workshops.
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LOICZ-UNEP/GEF Tentative Workshop Schedule

• July 1999 Budget--South China SeaNovember
  1999 Budget--South AmericaFebruary
  2000 Budget--South AsiaJune 2000 Budget--East
  AsiaSeptember 2000 BudgetAfrica.
• November 2000 RegionalAsiaMarch
  2001 RegionalAmericasMay 2001 RegionalAfri
  ca/Europe.
• November 2001 Global Synthesis.
• One more, as needed.

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LOICZ Biogeochemical Modelling Web Page
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http//data.ecology.su.se/MNODE/
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Preliminary Budgeting Results
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LOICZ Budget Sites to Date
gt100 sites so far gt 200 sites desired.
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Latitude, Longitude of Budget Sites

• Present site distribution
• Poor cover at high latitudes (N S).
• Poor cover from 10?N to 15?S.
• Poor cover in Africa.
• S. Asia sites not yet posted.

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Nutrient Load v Latitude

• Load variation most obvious with DIP.
• High loads near 15?N are in SE Asia.
• High loads near 30?S are in Australia

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Internal Nutrient Flux v Latitude

• ?DIP response to load may differ in the N and S
  hemispheres.
• ??DIN response to load seems weaker than DDIP.

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?DIP, DDIN v DIP Load

• ??DIP and DDIN both increase ( or -) at high DIP
  loads.
• Responses more prominent for DIP than for DIN.

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?DIP, DDIN v DIN Load

• No clear effect of DIN load on DDIP.
• ?DIN appears to become negative at high DIN load.

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Net Ecosystem Metabolism(production
respiration)

• Remember Rates are apparent, based on
  stoichiometric assumptions.
• No clear overall trend most values cluster near
  0.
• Extreme values (beyond ? 10) are questionable.

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(Nitrogen Fixation Denitrification)

• Although values cluster near 0, clear dominance
  of apparent denitrification.
• Apparent N fixation gt5 seems too high.

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Some Cautionary Notes

• Individual budgets may suffer from data quality
  or other analytical problems.
• Stoichiometry is apparent, and not always
  reliable.
• Simple averaging of budgets is not a legitimate
  estimate of global average performance the
  coastal zone is too heterogeneous and sampling is
  too biased for such averaging.
• Also, system size, or relative geographic
  importance, not accounted for in simple
  averaging.
• Upscaling must take these factors into account.

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Introduction to Typology
DEFINITION
Typology The study of types, as in systematic
classification.
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e. g., N. American Budget Sites and River Flow
There are many considerations in developing a
coastal zone typology.

• It is important to relate sites to
  characteristics of freshwater inflow.
• Most of coastline characterized by small coastal
  watersheds.

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Natural and Anthropogenic Controls on Fluxes to
the Ocean
What is carried in river inflow, and why?

• Other Factors
• Population density
• Economic drivers
• Fertilizer use
• Atmospheric deposition
• Et cetera.

Land use, vegetation type, and budget sites
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Statistical Clustering of Types in the Global
Coastal Zone
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Example of newly developed statistical
clustering techniquesAustralasia10 Clusters
Distinguish separate clusters
Emphasize similar clusters
OR
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What is the link between typology and the budgets?
How do budget characteristics conform with
clusters?
and compare with
Budget Sites
We tune the
with
Expert typology
Similar clusters
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Conclusions and Commentsabout Budgeting and
Typology

• We are accumulating coverage of global CNP fluxes
  in much of the coastal zone.
• Some trends are beginning to emerge.
• Extrapolating from individual budget sites to the
  global coastal zone remains a challenge.
• This extrapolation is being approached via a
  global typology.
• Natural influences and human dimension must be
  addressed by both budgets and typology.

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Need help or advice about biogeochemical
budgeting or setting up a budgeting workshop?

• Stephen Smith
  svsmith_at_soest.hawaii.edu 
• Fred Wulff
  fred_at_system.ecology.su.se
• Vilma Dupra
  vdupra_at_soest.hawaii.edu
• Dennis Swaney
  dennis_at_system.ecology.su.se
• Victor Camacho
  vcamacho_at_bahia.ens.uabc.mx
•  Malou McGlone mcglonem_at_msi01.cs.upd.e
  du.ph
•  Laura David
  ldavid_at_msi01.cs.upd.edu.ph
• LOICZ International Project Office
  loicz_at_nioz.nl
•  Biogeochemical Modeling Web Page
  http//data.ecology.su.se/MNODE/

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Thank you!
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