Transcript The National Inventory of Down Woody Materials: Methods

Estimating Dead Wood during National
Forest Inventories
A review of national forest inventory methodologies
and suggestions for harmonization
Chris Woodall
Jacques Rondeux
Northern FIA
St. Paul, USA
Gembloux Ag. Univ.
Gembloux, Belgium
Hans Verkerk
Göran Ståhl
European For. Inst.
Joensuu, Finland
Swedish Univ. Ag. Sci.
Uppsala, Sweden
Outline
•
•
•
•
Background
Objectives
Survey
Results
–
–
–
–
Current Status
Variables Measured
Sample Techniques
Harmonization Possibilities
• Conclusions
Background
• Carbon stocks
36%
51%
• Biodiversity
Trees
Understory
1%
Forest floor
9%
3%
• Fuel loading
Down and
dead wood
Forest soils
US Forest Carbon Stocks
• Wildlife habitat
Background
• Climate Change
– UN Intergovernmental Panel
on Climate Change
• European Union
– ComMon Project
– SENSOR Project
• Land use sustainability
– MCPFE
• Ministerial Conference on
Protection of Forests in Europe
– COST Action E43
UN Framework Convention on
Climate Change
• Changes in carbon
stocks by component
every year
• Assess impacts of
climate change
• Suggest adaptation
and mitigation
“ComMon” Project
• Comparison and evaluation of methods for
monitoring of dead wood, vegetation, lichens, and
stand structure in European forests
• Pilot countries: Austria, Belgium, Spain, Sweden
• Harmonization of basic inventory principles
• Evaluation and development of indicators
Europe vs. Rest of World
Study Goal
“Look at dead wood inventories
around world...compare in context of
harmonization”
Objectives
1) to describe the current status (e.g., year of first
inventory)
2) to broadly describe the dead wood components and
attributes measured (e.g., standing dead trees),
3) to broadly describe the DW sample techniques (e.g.,
fixed area), and
4) to suggest opportunities for international
harmonization
Survey
• Current Status of
Inventory
• Components
Measured
• Sample Methods
• Dimension Thresholds
Survey
Countries Contacted
Dozens of countries contacted…many did not
respond…either had no inventory, did not care to
respond, or language barrier
Respondents
Argentina
Austria
Australia
Belgium
Bosnia/Herzegovina
Brazil
Canada
China
Czech Republic
Estonia
Finland
France
Germany
Greece
Hungary
Israel
Italy
Latvia
Lithuania
Luxembourg
Mexico
Netherlands
New Zealand
Norway
Poland
Romania
Russia
Slovakia
Spain
Serbia
Sweden
Switzerland
Ukraine
United Kingdom
United States
Results
Current Status
•
•
•
•
•
Year national inventory began?
Number of plots sampled?
Frequency of remeasurement?
Is data publicly available?
National analysis/report produced?
Start of Last Cycle
14
Number of Countries
12
10
8
6
4
2
0
<2000
2000-2003
Year
2004-present
Sample Intensity
Number of Countries
12
10
8
6
4
2
0
<1,000
1,000-9,999
10,000 +
Sample intensity (forested ha/plot)
Cycle Length (Remeasurement)
Number of countries
25
20
15
10
5
0
0-4
5-10
Cycle length (years)
11 +
Data/Report Publicly Available
Yes
No
30%
45%
55%
Data Publicly Available?
70%
Yes
No
Public Report Produced?
Components Measured/Sample
Methods
•
•
•
•
•
Standing dead trees?
Down and dead trees?
Stumps?
Logging residue piles?
Fine woody debris (diameters < 7 cm)?
Dead Wood Attributes Measured?
• Almost all countries
with a deadwood
inventory …
inventoried both
standing dead and down
dead trees (CWD)
How about other Components?
Yes
No
39%
Yes
27%
No
52%
Yes
No
61%
73%
Stumps
Residue Piles
48%
Fine Woody Debris
Number of Decay Classes
9
Number of countries
8
7
6
5
4
3
2
1
0
1-4
5
Number of decay classes
6+
Sample Methods
• For standing dead
trees … almost all
countries used fixedarea plots
Dead and Down Sample Methods
17%
4%
Ocular Estimation
Fixed-Area
Line-Intersect
17%
Variable Radius
62%
Dimension Thresholds
•
•
•
•
•
•
Standing dead trees?
Down and dead trees?
Stumps?
Logging residue piles?
Fine woody debris (e.g., diameters < 7 cm)?
Number of CWD decay classes?
Attribute Thresholds
• Almost all countries
had diameter
thresholds … roughly
half had height and
length thresholds (1 to
1.3 m)
Standing Dead Tree Thresholds
Number of countries
12
10
8
6
4
2
0
0.0-5.0
5.1-9.9
Standing dead tree DBH (cm)
10.0+
Down Dead Thresholds
Number of countries
12
10
8
6
4
2
0
0.0-7.0
7.1-9.9
Down and dead tree DBH (cm)
10.0 +
Stump Thresholds
Number of countries
12
10
8
6
4
2
0
0.0-5.0
5.1-9.9
Stump diameter (cm)
10.0+
Fine Woody Debris Thresholds
Number of countries
4
3
2
1
0
0.0-7.0
7.1 +
Fine woody debris diameter (cm)
Harmonization
Similarities
• Standing dead and down dead measured in unison
• Diameter, species, and decay attributes measured for trees
• Recent inventories
• Fixed-radius predominant sample method for standing dead
• Most did not have official summaries/reports
• Cycle length
Differences
• Definitions: different thresholds for CWD and FWD creates different
populations
• Number of dead tree attributes (sometimes just standing dead)
• Standing versus down dead delineations
• Decay classes
• Sample methods (Fixed vs variable vs LIS) for down and dead
• Sample intensity
• Inventory purpose: biodiversity versus fire (hollow)
Differences
In United States…
18% of tallied CWD
have large-end
diameters below 10
cm
Suggestions for Harmonization
• Common variable definitions and/or
database/estimation flexibility
• Publish monitoring reports
• Communication
• Common thresholds…common thresholds…common
thresholds
• Sample intensity
[email protected]