methodologies for estimating forest soil carbon stocks using … · 2006-04-20 · forest soil...

Methodologies for estimating forest soil carbon stocks using annual forest inventory data

Charles H. (Hobie) PerryNorthern Research StationUSDA Forest ServiceImage courtesy USDA NRCS

Northern Research StationUSDA Forest Service

Outline

1. Goals of USDA Forest Inventory & Analysis Program

2. Sampling Design and Estimation

3. Analysis & Reporting4. FIA and the Broader Soils

Community


1 National program goals


Context

There are many challenges topopulation estimation.• Logistically difficult• Risky and expensive• Limited utility of existing data

(incl., STATSGO & SSURGO)– Infrequent sampling– Traditional agricultural emphasis

FIA designed as part of an

integrated monitoring

system

Source: FIA Fact Sheet Series


The role of FIA

• The extent (area) of forest land;• The volume, growth, and removal of

forest resources; and• The health and condition of the

forest.

To conduct forest inventories of the United States to estimate:

Image creditUSDA NRCS


Strategic Objectives

• National plot configuration, sampling design, variables and measurement protocols

• Estimation using standardized formulae• Data released at prescribed intervals• A national database with user-friendly access• Nationally consistent reports (5 years)• Peer review/publication of outputs/procedures


1a Monitoring questions for the Soil Quality Indicator

More than a soil carbon inventory…

http://forest.moscowfsl.wsu.edu/engr/roadph.html

Soil erosion?

Changes in soil physical properties?

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ce: O

’Nei

ll et

al.

2005

.

Changes in other soil chemical properties?

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ce: M

cWilli

ams

et a

l. In

pre

p.


2 Sample design & estimation


Sampling and estimation occurs in three phases

Phase 1

Phase 2

Phase 3

Remotely sensed data used to obtain initial plot land cover observations and to stratify land areas with the objective of increasing precision

Field crews visit to locations of plots with accessible forest to measure traditional suite of mensurational variables

Measurement of an additional suite of variables related to the health of the forest on a 1:16 proportion of Phase 2 plots


What do these phases look like?

Sour

ce: O

’Nei

ll et

al.

2005

.

38 800 ha2 425 ha


Hexes are assigned to panels,and plots are located in hexes


FIA definitions split the landscape into “forest” and “non-forest”

Accessible forest land• Timberland • Pastured

timberland • Plantations• Wide windbreaks• Wooded pasture• Urban forest land

Non-forest with trees• Cropland with trees• Pasture and

rangeland with trees

• Wooded strip• Narrow windbreak• Shelterbelt• Urban and other

with trees


Basic plot design includesfour subplots


Soils sampling scheme

9 7 5 3 1 2 4 6 8

Soil Sampling Points

Soil sampling line (point sample)

4 3

1

2Erosion and 24.0 ft radiuscompaction

Annular plot 58.9 ft rad ius

Subplot

9 7 5 3 1 2 4 6 8


9 7 5 3 1 2 4 6 8


Soil sampling line (point sample)Soil sampling line (point sample)Soil sampling line (point sample)

4 3

1

2Erosion and 24.0 ft radiuscompaction

Annular plot 58.9 ft rad ius

Subplot

Soil measurements are collected on the subplots and within the annular plots. Soil samples are collected from within the annular plots 2, 3, and 4 only.

Adap

ted

from

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eill

et a

l. 20

05.

We measure, then sample…

Litter layer

Organic layer

Mineral soil

RestrictiveLayer (?)

N

W

S

E30.5 cm

12

3

50 cm

0 cm

10 cm

20 cm

Top view

Side View


Measured soil attributes include…

• Erosion assessment– % bare soil

• Soil compaction assessment– % area compacted– Compaction type

• Soil sampling– Forest floor and litter thickness– Forest floor sample collection– Depth to restrictive layer– Mineral soil sample collection

• 0 – 4 in• 4 – 8 in

– Soil texture

• Forest floor– Physical properties:

• Bulk density• Water content

– Chemical properties:• Total carbon (organic)• Total nitrogen

• Mineral soil– Physical properties:

• Bulk density• Water content• Coarse fragments (> 2 mm)

– Chemical properties:• Organic and inorganic carbon• Total nitrogen• pH• Exchangeable cations (Na, K, Mg,

Ca, Al), metals (Mn, Ni, Cu, Zn, Cd, Pb), sulfur and phosphorus

Fiel

d M

easu

rem

ents

Lab

Mea

sure

men

ts


2a Estimation units:the other challenge

STATSGO/SSURGO


3 Analysis and reporting


We report at many scales

• National FHM report

• Regional studies

• State reports

• Where is international reporting?

National FHM report

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ce: P

erry

and

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r. In

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ss.

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and

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Regional carbon studyforest floor

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ce: P

erry

et a

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Regional carbon studymineral soil (0-20 cm)

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ce: P

erry

et a

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State reporting

0

1

2

3

4

5

6

7

8

9

Aspen / birch Maple / beech /birch

Oak / hickory Spruce / fir White / red / jackpine

Forest Type Group

Fore

st fl

oor t

hick

ness

(cm

)

Source: Miles et al. In press.

0

5

10

15

20

25

30

35

40

45

50

Aspen / birch Maple / beech /birch

Oak / hickory Spruce / fir White / red / jackpine

Forest type groupFo

rest

floo

r car

bon

cont

ent (

%)

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ce: M

iles

et a

l.In

pre

ss.


4 Data dissemination

FIA Reports

http://ncrs.fs.fed.us/pubs/3513


Individual Data Requests

• Joint Research

• Specific Data Needs

• Limited


5 FIA & the broader soils community


How does FIA fit?

Fitting in• Rolling annual

inventory• Filling gaps with

forest soils sampling• Sharing data with a

cyber-infrastructure

Falling short• Only on “forestland”• Limited soil sampling• Continuing struggle

with appropriate estimation units


What are the limitations to the current inventory?

• Requirements• Focus on traditional resources

– P3 sampling intensity

Definition-oriented and thus tied directly to the original purpose of the program

Moving to an all-tree inventory


Take-home messages

• FIA is a statistically-sound forest resource inventory with a national mandate.

• There is room for improvement,

• and that’s where you come in!

fincontact: [email protected]+1 651 649 5191

methodologies for estimating forest soil carbon stocks using … · 2006-04-20 · forest soil...

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