ISOSCAPES 2008Acquisition, analysis, and

application of spatially-explicit isotope data

Gabriel Bowen Jason West

Impetus for the meeting

New opportunities for:• Collaboration: A growing body of work

involving spatial isotope data in a range of fields makes this an opportune time to promote cross-disciplinary exchange

• Research Initiatives: New opportunities for spatial isotope monitoring and environmental data collection merit a discussion of how stable isotope research can and should be incorporated in and benefit from these programs

• Innovation: An increasing fluency in the language of isoscapes provides common ground for discussion on major, cross-cutting research challenges

What is an isoscape?

Quantitative representation of isotope distributions in space/time

Isoscapes integrate knowledge• Spatially resolved observations• Models of physical and biological processes

Isoscapes enable discovery• Data-model integration• Spatial tracing

Isoscapes facilitate communication• Homogeneous data

The underlying information

Isotopes “record” natural processes• Phase changes• Enzyme activity• Radioactive decay• Isotopic exchange• Movement & mixing• Reactant pool

Intensive mechanistic work is necessary• Metabolism• Transpiration• Biosynthetic pathways

Applications

Processes inferred from isotope

ratios• Water sources and transformations • Climate dynamics• Animal migration• Weathering• Biogeochemical cycling• Human impacts• Atmospheric transport

Isoscapes provide a framework for

addressing fundamental and applied

research questions at large scales

Grand Challenges inEnvironmental Sciences

Biological Diversity and Ecosystem Functioning

Biogeochemical cycles

Climate Variability

Hydrologic Forecasting

Infectious Disease and the Environment

Institutions and Resource Use

Land-Use Dynamics

Reinventing the Use of Materials

Climate change

From R. Dave Keeling (1998, AREE):

“It has been over 40 years since Roger

Revelle and Hans Suess pointed out that the

burning of fossil fuels was a large-scale

geophysical experiment... despite the

heightened political awareness of the

greenhouse problem indicated by the Kyoto

meeting last winter, most governments have

shown little interest in environmental

monitoring.”

Isotope data networks

Global Seawater Oxygen-18

GLOBALVIEW

Large-scale efforts

NEON: ...will gather long-term data on ecological

responses of the biosphere to changes in land use and

climate, and on feedbacks with the geosphere,

hydrosphere, and atmosphere...It will consist of

distributed sensor networks and experiments, linked by

advanced cyberinfrastructure to record and archive

ecological data for at least 30 years. Using standardized

protocols and an open data policy, NEON will gather

essential data for developing the scientific

understanding and theory required to manage the

nation’s ecological challenges.

neoninc.org

Large-scale efforts

WATERS: ... will transform our scientific

understanding of how water quantity, quality, and

related earth system processes are affected by natural

and human-induced changes to the environment. It will

accomplish this by enabling multi-scale, dynamic

predictive modeling for water, sediment, and water

quality by measuring or estimating fundamental

properties such as the flux, hydrologic flow paths,

residence times, and chemical/biological reaction rates

and include such capabilities as near-real-time

assimilation of data, prediction up to the national scale

and feedback to adjust community models and

observatory design and function. watersnet.org

Large-scale efforts

TRACE: …aims to improve the health and well-being

of European citizens by delivering improved traceability

of food products. The 5 year project sponsored by the

European Commission will provide consumers with

added confidence in the authenticity of European food

through complete traceability along entire fork to farm

food chains. TRACE will develop cost effective analytical

methods integrated within sector-specific and -generic

traceability systems that will enable the determination

and the objective verification of the origin of food.

Trace.eu.org

Meeting impetus Isoscape definition Big questions Data networks Large-scale efforts

Understanding 13C in tree

rings

"Blind monks examining an elephant" by Itcho Hanabusa

Blind monks…

13Ca in tree rings

“Briefly, the 13C/12C ratio of a plant constituent such as cellulose reflects the 13C/12C ratio of the atmosphere, but there is a temperature coefficient of 0.02‰ per °C. This is small enough to be of little consequence in this investigation.”

Wilson.1978.Nature

13Ca in tree rings

"Blind monks examining an elephant" by Itcho Hanabusa

“It seems clear that a resolution of the various parameters which may potentially affect atmospheric 13C will be forthcoming only after detailed study of tree-ring 13C/12C ratios before the onset of man’s major industrial and agricultural activities on a global scale and for a geographical area where lengthy direct temperature records are available.”

Farmer.1979.Nature

13Ca in tree rings

"Blind monks examining an elephant" by Itcho Hanabusa

“The differences between 13C/12C trends in trees from different regions, coupled with the differences between most 13C/12C trends in tree-rings representing the past 20 yr and the direct atmospheric measurement, seriously question the interpretation of any tree record in terms of global atmospheric behavior...A solution must be sought in the mechanism of fractionation in plants.”

Francey.1981.Nature

13Ca in tree rings

“Although the global atmospheric 13C/12C information in tree rings is often masked by a scatter which depends on local physical as well as climatological processes, it is, nevertheless, possible to infer past 13C/12C ratios of atmospheric CO2, if a larger number of free-standing trees from various parts of the world are measured...”

Freyer.1981.Nature

“Recent progress in understanding the mechanism of carbon isotope fractionation during photosynthesis suggests that anthropogenic influences on fractionation will occur on both local and global scales.”

Francey.1981.Nature

13Ca in tree rings

“The expression gives good agreement with 13

p measurements where independent information on ci exists, such as seasonal growth, growth low in the canopy and in conditions of low humidity. The expression provides possible explanations for two previously unexplained phenomena: the absence of anticipated changes due to fossil fuel-induced changes in 13

a, and regional differences

in 13p trends.”

Francey&Farquhar.1982.Nature

13p ≈ 13

a – a – (b – a)ci/ca

ci

ca

Isoscapes revealing“the elephant”

Components incorporated

• Plant physiology models• Observed meteorology• Satellite-derived data• Network data for model comparisons• Spatio-temporal synthesis

Suits et al.2005.GBC

Carbon isoscapesenabling discovery

• Spatial and temporal distributions of sources and

sinks

• Land versus ocean flux partitioning

• Underlying processes and response to change

• Comparison with observation (e.g., flux towers or

flask collection sites)

• Understanding biosphere-atmosphere

interactions

• Tracing movement of animals

Meeting goals

Communication

• Sharing of results within and across disciplines

• Exploration of insights from different approaches

Collaboration

• New connections promoting the integration of multiple isotope systems, and data- and knowledge-sharing

• New research and communication uniting instrument developers, empiricists, experimenters, modelers, and managers

Research Initiatives

• Improved understanding of community resource needs and appropriate mechanisms to fulfill them

Innovation

• New projects, applications, and research directions spawned from the merging of data and perspectives