GLOBE Carbon Cycle: Modeling Forest Ecosystems

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GLOBE Carbon Cycle Modeling Forest Ecosystems

• Sarah Silverberg, Rita Freuder
• University of New Hampshire

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Outline

• The GLOBE Carbon Cycle Project
• Modeling
• Biomass Accumulation Model
• Modeling with iSee Systems
• Activity Run the model
• Learn about one activity that can be done using
  this model
• Activity Comparing Collected Data with Model
  Results

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Carbon Cycle Project Goals

• Students will
• Learn why carbon is an important element in
  ecosystems, and how it cycles through ecosystems.
  
• Gain skills in current carbon cycle research
  techniques.
• Increase their ability to critically think about
  problems.
• Understand the nature of science research.

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Proposed Activities to Meet Goals

• 4 Major Categories
• Modeling
• Classroom Experiments
• Field Measurements
• Remote Sensing Toolkit

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Modeling

• Introduces students to the use of models in
  science
• Learn how carbon is stored and transferred at the
  ecosystem and global level
• Understand ways that carbon can change with a
  change in environmental conditions
• Connection to field collected data

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Website Updates and Information
globecarboncycle.unh.edu
Email globecarboncycle_at_globe.gov
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What is a Model?
The American Heritage Dictionary of the English
Language, Fourth Edition model  (n). 1. A
small object, usually built to scale, that
represents in detail another, often larger
object. 2. A preliminary work or construction
that serves as a plan from which a final product
is to be made. 3. A schematic description of a
system or phenomenon that accounts for its known
or inferred properties and may be used for
further study of its characteristics. 4. One
that serves as the subject for an artist,
especially a person employed to pose for a
painter, sculptor, or photographer. 5. A person
employed to display merchandise, such as clothing
or cosmetics.
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Better Working Definitions
The most useless scale for a road map is 11
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Why Use a Model?

• Synthesize existing knowledge in ways not
  possible using human CPU (Cranial Processing
  Unit).
• Forecast future conditions, often with policy-
  relevant goals.
• Examine the fundamental behavior of a system.
• Identify gaps in current knowledge and to guide
  future research.
• Generate hypotheses (as opposed to predictions).
• The purpose of models is not to fit the data but
  to sharpen the questions. -S. Karlin

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Models Dont Need to be Complex to be Useful
A Box and Arrow or Pool and Flux model
Residence Time the amount of time material
remains in a pool Turnover Rate the fraction of
material in a pool that enters or leaves in a
specified amount of time
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1 Box Forest Biomass Model

• OUTPUT (?)
• 2 per year
• (Current Biomass 0.02)

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1 Box Forest Biomass Model

• Remember 45-50 of biomass by weight is carbon!!!

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1 Box Forest Biomass Model
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1 Box Forest Biomass Model
WoodBiomass(t) WoodBiomass(t - dt) (WoodNPP -
WoodLitter - Harvest) dtINIT WoodBiomass
0 INFLOWS WoodNPP 3.9 200Foliar_Nitrogen O
UTFLOWS WoodLitter WoodBiomass
WoodLoss Harvest IF (TIME HarvYear) then
(WoodBiomass HarvIntens) ELSE
(0) BiomassIncrement WoodNPP - WoodLitter
Foliar_Nitrogen 2 HarvIntens 0 HarvYear
0 WoodLoss .02
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iSee Systems
http//www.iseesystems.com/
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iSee Systems isee player
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iSee Player Tutorial

• Step by step instructions for how to use the isee
  player
• Meant for first time users and as a refresher
• Uses the 1 box forest biomass model as the
  example
• Currently available as a presentation or
  printable pdf

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To get started Open the program isee player OR
Stella From the menu bar at the top of the page
select File--gtOpen In the open screen navigate
to your CD (found under my computer. Once in
the CD Select the modeling folder Select
the Biomass Accumulation Folder Select
BiomassAccumulation2.4.STM Read the story (more
science) by clicking the green arrow Run the
model by clicking the red arrow Check out the
isee player tutorial.ppt for more info about
running the model (also in the modeling folder on
your CD)
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Forest Carbon Stocks in NH a comparison of the
US Forest Service State-level Carbon report with
estimates from the Stella Biomass Accumulation
Model In this activity, we use data on the
acreage of different forest types, and mean
foliage N, to run the Stella Biomass
Accumulation Model, generating an estimate of
forest carbon stocks in NH. We then compare our
model estimates to the values reported by the
USFS, which are based on extensive field sampling
and allometry.
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Collected data are part of the Forest Inventory
Analysis program run by the US Forest Service.
Data for forest resources by state in
Excel http//www.fs.fed.us/ne/global/pubs/books/e
pa/index.html
Go to the link Excel Spreadsheet of regional
and state totals Also available on
CD FIATablesForStateTotals.xls
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http//serc.carleton.edu/eet
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Learning Goals

• After completion of this activity students will
  be able to
• Describe how forest biomass generally changes
  over time
• Understand how forest biomass relates to carbon
  storage
• Run the STELLA Biomass Accumulation Model using
  the iSee Player
• Assess similarities and differences between field
  measured data and model outcomes

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Open Files CarbonStockScenario_template.xls FIATa
blesForStateTotals.xls Biomass Accumulation2.4.STM
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STEP 1 The FIA Carbon Data File

• View FIATablesForStateTotals.xls
• Notice the tabs at the bottom
• Data is broken down by region (7 total)
• After each region there is a separate tab for
  each state in the region
• Use the scrolling arrows to view all tabs
• Select the New Hampshire (NH) tab for this
  exercise

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STEP 2 Examine FIA Carbon Data
Area of Forested Land
Total C Stock
Biomass Fraction of Total C Stock
Biomass Fraction 153.6/521.7 0.29
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STEP 3 Using the Carbon Data

• View CarbonStockScenario_template.xls
• Notice the tabs at the bottom
• Templates for
• Region 1 East and Central US
• Region 2 Rocky Mountains and Pacific
• A tab for NH is already filled in with FIA Carbon
  Data

Table 2
Table 3
Table 4
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STEP 4 Converting Total C Stock to the
Aboveground Forest Biomass Component (The largest
tree component comparable to model results)
Both are automatically calculated in the excel
sheet
2. Multiply the biomass C stock by 87. This is
the proportion of tree biomass found aboveground
(Bolte et al. 2004).
1. Multiply total C stock by the biomass fraction
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STEP 5 Foliar Nitrogen by Forest Type
For more information about where the foliar N
values come from check out the foliar N
worksheets in this file
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STEP 6 Run the Biomass Accumulation Model Using
Foliar N
OPEN MODEL
Enter foliar N, then click Run
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STEP 7 Record Model Data into Scenario Template
Use the model graph or table to find carbon
storage by year (50, 80, 100, 150, 250)
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STEP 8 Convert gC/m2 to million metric tons of
carbon (MMTC) The model automatically calculates
this so FIA State Carbon Values can be compared
to model output values
Acres 4046m2/acre gC/m2 kgC/1000gC
MTC/1000kgC MMTC/1x106 MTC MMTC
From column C (initially table 2)
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STEP 9 Compare FIA C storage to model C storage
Notice the FIA measured carbon storage lies
within the range of carbon storage values
produced by the model. Based on the FIA
carbon data and biomass model output we could
estimate that in 1997(the FIA data collection
year) New Hampshire forests were approximately
140 years old.
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STEP 10 Data Analysis - Some Potential Questions
What do the data mean? Are forests in New
Hampshire really 140 years old? What are some
potential reasons for disagreement between
measured and modeled data? How does the model
help us better understand forest carbon
storage? What is the future of carbon storage in
New Hampshire forests? (How long will forests
continue to increase their carbon storage?)