2C N P Fluxes in the Coastal Zone The LOICZ Approach to Budgeting and Global ExtrapolationS. V. SmithU. HawaiiMarch 2000
3What 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.
5Only a small portion lies in the “LOICZ domain.” Global ElevationOnly a small portion lies in the “LOICZ domain.”
6Coastal Zone (+200 to –200 m)This domain is nominally m to -200 meters, or about 18% of global area.
7Coastal Ocean (0 to –200 m)The coastal ocean, being budgeted by LOICZ, is about 5% of global area.
8The Global Coastal Ocean: A Narrow, Uneven, Chemically Reactive “Ribbon” LANDOCEANThis 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.
9LOICZ and IGBPIGBP is the “International Geosphere-Biosphere Programme.”Part of ICSU, the International Council of Scientific UnionsLOICZ is “Land-Ocean Interactions in the Coastal Zone.”A key project element of IGBP
10IGBP: International 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.
11Alphabet Soup of the IGBP JGOFS Joint Global Ocean Flux StudiesIGAC International Global Atmospheric ChemistryGCTE Global Change and Terrestrial EcosystemsBAHC Biospheric Aspects of the Hydrological CyclePAGES Past Global ChangeLOICZ Land-Ocean Interactions in the Coastal ZoneLUCC Land Use and Cover ChangeGLOBEC Global Ocean Ecosystem Dynamics __________________________________________________GAIM Global Analysis, Integration and ModellingSTART System for Analysis, Research, and TrainingDIS Data and Information System
13Develop 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.
14LOICZ Budgeting Procedure Conservation of mass is one of the most fundamental concepts of ecology and geochemistry.
15Water, 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).
16Water and Salt Budgets Water budget Salt budget Freshwater flows known.System residual flow (VR) conserves volume.Salt budgetNet flows known.Mixing (VX) conserves salt content.
17Nutrient Budgets Nutrient (Y) budgets Internal dissolved nutrient net source or sink (Y) to conserve Y.Calculations based on simple system stoichiometryAssume Redfield C:N:P ratio (106:16:1)(production - respiration) = -106 x DIP(Nitrogen fixation - denitrification) = DINobs - 16 x DIP
18LOICZ Strategy Develop a global inventory of these budgets. Guidelines, a tutorial, and individual site budgets atUnder direction of S. V. Smith, F. WulffMajor emphasis of this presentation.Use “typology” (classification) techniques to extrapolate from budgeted sites to global coastal zone.Under direction of R. W. BuddemeierTools and examples available at (B. Maxwell)
19LOICZ 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.
20LOICZ budget workshops to date September 1995—Guidelines Development(Halifax, Canada)December 1995—Introduce guidelines to SWOL(Penang, Malaysia)October 1996—LOICZ/JGOFS Continental Margins(Lagos, Nigeria)June 1997—Mexico lagoons(Ensenada, Mexico)October 1997—LOICZ/JGOFS Continental Margins(Texel, The Netherlands)
21LOICZ budget workshops, cont. October 1998—Australasia estuaries(Canberra, Australia)January 1999—Mexico, C. America lagoons II(Merida, Mexico)July 1999—South China Sea estuaries(Manila, Philippines)November 1999—South America estuaries(Bahia Blanca, Argentina)February 2000—South Asia estuaries(Goa, India)
22The 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.
23LOICZ-UNEP/GEF Tentative Workshop Schedule July Budget--South China Sea; November Budget--South America; February Budget--South Asia; June Budget--East Asia; September Budget—Africa.November Regional—Asia; March Regional—Americas; May Regional—Africa/Europe.November Global Synthesis.One more, as needed.
28LOICZ Budget Sites to Date >100 sites so far; > 200 sites desired.
29Latitude, Longitude of Budget Sites Present site distributionPoor cover at high latitudes (N & S).Poor cover from 10N to 15S.Poor cover in Africa.S. Asia sites not yet posted.
30Nutrient Load v Latitude Load variation most obvious with DIP.High loads near 15N are in SE Asia.High loads near 30S are in Australia
31Internal Nutrient Flux v Latitude DIP response to load may differ in the N and S hemispheres.DIN response to load seems weaker than DDIP.
32DIP, DDIN v DIP LoadDIP and DDIN both increase (+ or -) at high DIP loads.Responses more prominent for DIP than for DIN.
33DIP, DDIN v DIN Load No clear effect of DIN load on DDIP. DIN appears to become negative at high DIN load.
34Net 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.
35(Nitrogen Fixation – Denitrification) Although values cluster near 0, clear dominance of apparent denitrification.Apparent N fixation >5 seems too high.
36Some Cautionary NotesIndividual 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.
37Introduction to Typology DEFINITIONTypology:The study of types, as in systematic classification.
38e. g., N. American Budget Sites and River Flow There are many considerations in developing a “coastal zone typology.”e. g., N. American Budget Sites and River FlowIt is important to relate sites to characteristics of freshwater inflow.Most of coastline characterized by small coastal watersheds.
39Natural and Anthropogenic Controls on Fluxes to the Ocean What is carried in river inflow, and why?Other FactorsPopulation density;Economic drivers;Fertilizer use;Atmospheric deposition;Et cetera.Land use, vegetation type,and budget sites
40Statistical Clustering of “Types” in the Global Coastal Zone
41Example of newly developed statistical clustering techniques Australasia—10 Clusters Distinguish separate clustersOREmphasize similar clusters
42What is the link between typology and the budgets? How do budget characteristics conform with clusters?and compare withBudget SitesWe tune thewithExpert typologySimilar clusters
43Conclusions and Comments about 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.
44Need help or advice about biogeochemical budgeting or setting up a budgeting workshop? Stephen SmithFred WulffVilma DupraDennis SwaneyVictor Camacho Malou McGlone Laura DavidLOICZ International Project Office Biogeochemical Modeling Web Page