1. WG II: Land use change and management effects on soil C stocks
639
WG II: Land use change and management effects on soil C stocks
Status report
Lars Vesterdal, Christopher Poeplau, Axel Don, Jens Leifeld, Bas van Wesemael (WG2)
Cost 639 MC meeting
University of Limerick
May 25, 2010

2. Data needs for reporting?
Too few data per country? Use IPCC default factors?
Recent efforts to review and summarize effects of land-use change and management, partly based on meta analyses of GLOBAL data:
e.g. Post & Kwon, 2000; Guo & Gifford 2002; Paul et al., 2002; Johnson & Curtis, 2001; Jandl et al., 2007
LUC and MC effects remain to be quantified
Need for summary of EU-specific knowledge
on LUC and management change –
tier 1 methodology for Europe?
-but in which form?

3. Environmental Management 33: 507-518 (2004)

4. Carbon response functions as a tool?
Example: afforestation of arable land
Mathematical function describing the response of a system
The response changes with time
West et al. 2004

5. Pros and cons of carbon response functions
WGIV meeting 2008
Represents temporal C dynamics better than IPCC factors
May not be the best solution in terms of transparency
A solution in terms of economy when used as an alternative to reporting based on systematic inventories.
Large variability in soils: systematic sampling may be preferable
CRFs may be a relevant alternative for a country with little variability in site conditions.
CRFs may also support reporting in cases where net emissions are around zero (i.e. go for cheap solution).

6. Pros of carbon response functions in Cost 639
Such functions will be valuable as
1) a synthesis tool
2) for management and planning guidelines
3) reporting of soil C change.

7. Time line of past activities
April 2007: Meeting in Vienna
Spring 2007: Questionnaire on LUC and MC interests/data
October 2007: Carbon Response Functions as a tool
Feb. 2008: Workshop Udine: Meta-database framework established
June 2008: Presentation at WGIV workshop for discussion relevance of CRFs
August 27, 2008: EuroSoil 2008 Vienna, workshop 9. Greenhouse gas budget of soils –hotspots of emission.

10. Time line of past activities
April 2007: Meeting in Vienna
Spring 2007: Questionnaire on LUC and MC interests/data
October 2007: Carbon Response Functions as a tool
Feb. 2008: Workshop Udine: Meta-database framework established
June 2008: Presentation at WGIV workshop for discussion relevance of CRFs
August 27, 2008: EuroSoil 2008 Vienna, workshop 9. Greenhouse gas budget of soils –hotspots of emission.
Nov. 2009: Expert meeting Copenhagen to set the scene for work in GHG-Europe/Cost639
February 2010: STSM/Expert meeting in Zürich for hard work
May 2010: WG2 meeting as side event at EGU for discussion of next steps. Poster with first results

11. Focus on LUC
European Environmental Agency (2005)

12. The Dataset Quality Criteria:
0<MAT<18, (temperate climate zone – defined by IPCC)
Chronosequence, paired plot, mono-site design
First hand data
At least roughly known land use history, soil information
Sampling by depth increments, not by horizons

13. The Dataset Author, Year, Journal Country, Location
MAT, MAP, Elevation, Soil type, Sand/Silt/Clay %
Sampling depth
LU1: type, age – LU2: type, age
Correction y/n
C (unit)
Bulk density
Number of replicates (n)
SD/SE
Comment (important details, e. g. forest floor y/n…)

14. The Dataset
n=101, n(europe)=33

15. The Dataset
n(data points) = 869

16. The Dataset Options for CRFs: Cropland to grassland and vice versa
Cropland to forest and vice versa
Grassland to forest
(Accumulation of forest floor)

17. Data corrections The studies differ widely in quality! Major problems:
Missing bulk density information to calculate stock [t/ha] from concentration [%]  PTF
When comparing stocks, the same soil mass has to be compared  Mass Correction

18. Significance? Carbon Response Functions Explaining factors: Age
Soil Texture
MAT
MAP
Sampling Depth
Significance?

19. Carbon Response Functions
Grassland to Cropland
MAT
MAP
Wet (>900 mm)
Intermediate ( mm)
Dry (<600mm)
Mean
Warm (>10° C)
Intermediate (7-10° C)
Cold (<7° C)
Mean

20. Carbon Response Functions
Cropland to grassland
Soils
Depth
0-20 cm
0~35 cm
0-70 cm
Subsoil (20 cm – bottom)

21. Carbon Response Functions
Forest to Cropland
Cropland to Forest
MAT
Soils
Warm (>10° C)
Intermediate (7-10° C)
Cold (<7° C)
Mean
Sandy soils
Loamy soils
Clay soils
Mean

22. Carbon Response Functions
Grassland to Forest

23. Mean sampling depth: ~30 (±4.7) cm, time: 100 years
Preliminary Conclusions
+25 t/ha (+68 t/ha)
+50% (+130%)
+5% (+40%)
+4 t/ha (+27 t/ha)
-45%
-66 t/ha
+59 t/ha
+120%
-54 t/ha
-36%
Mean sampling depth: ~30 (±4.7) cm, time: 100 years

24. Preliminary Conclusions
„Slow in, fast out!“
Site characteristics influence the change rate:
sand > loam > clay
warm > cold
wet > dry
topsoil > subsoil

25. Next steps – validation on Belgian LUC data
Land use history
Years
Source: Van Wesemael (2009)

26. Next steps
Validation of CRFs using Belgian regional datasets on LUC (Bas van Wesemael)
Writing journal publication (1 or 2) for GCB
Contributing to book - Chapter 2 on LUC and GHG dynamics