ministerium für umwelt und naturschutz, landwirtschaft und verbraucherschutz des landes...
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Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Modelling of the carbon accumulation in beech forests based upon inventory data
and with regard to the biomass and nutrient export through an intensified harvesting
Rainer Joosten
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
General Situation
NRW Climate protection through forestry 1. Carbon sequestration 2. Biomass energy
Political demands: Forest protection Increase the forest cropping (EU: +160 Mio m³ = > 50%)
Issue to quantify: carbon storage maximise the biomass harvest
Nutrient export through full tree harvesting
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Situation in North Rhine - Westphalia
Area: 34,000 km² 18 Mio People = 527 per km² primary energetic consumption: 4,100 PJ Green energy: <1% (45% coal) CO2-emission: 16.8 t per capita
880,000 ha forest 1.1 Mio additional energy wood resources (77% hardwood) = 0.2% of the primary energetic consumption
Cologne
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Aim of the study
Beech forests are the most important hardwood forests in NRW ( Developing of reliable functions for beech stands
Biomass Carbon Main-Nutrients (Ca, Mg, K , P)
connecting these functions with the inventory data on tree level
Inventory: 1 x 1 km² Tree level variables: DBH, Height Sample plot variables: Altitude, precipitation, temperature
NRW: 20 – 800 m above sea level, 550 – 1500 mm, 5° - 10,5° C
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
116 Sample trees from four growing regions
80 cm
40 cm
40 m
20 m
dbh height
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Predicted and observed ln-transformed functions
R² = 0.995; AIC: -86.1 R² = 0.996; AIC: -100.2
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Error of carbon prediction
Relative prediction error: at tree-level:
16 % At plot level
< 10 % Whole NRW (≈ 1500 inentory plots)
< 2 % Stock changes (presupposing remeasurement)
1 %
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
-4
-2
0
2
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6
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-4 -2 0 2 4 6 8
ln C (kg) observed
lnC
(kg
)p
red
icte
d
-4
-2
0
2
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6
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-4 -2 0 2 4 6 8
ln C (kg) observed
lnC
(kg
)p
red
icte
d
(1 ) P e llin e n . (2 ) P re tz sc h1 :1 1 :1
Comparing with six reference studies (ln C kg)
North Germany North Germany
Pre
dic
ted
(g)
Observed (g)
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Comparing with six reference studies
Austria (Vienna) South Sweden
-4
-2
0
2
4
6
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-4 -2 0 2 4 6 8
ln C(kg) observed
lnC
(kg
)p
red
icte
d
-4
-2
0
2
4
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-4 -2 0 2 4 6 8
ln C (kg) observed
lnC
(kg
)p
red
icte
d
(3 ) H o c h b ic h le r1 :1 1 :1
Pre
dic
ted
(g)
Observed (g)
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Comparing with six reference studies
North Spain USA
-4
-2
0
2
4
6
8
-4 -2 0 2 4 6 8
ln C (kg) observed
lnC
(kg
)p
red
icte
d
-4
-2
0
2
4
6
8
-4 -2 0 2 4 6 8
ln C (kg) observed
lnC
(kg
)p
red
icte
d
(6 ) S c h ro e d e r e t a l .(5 ) S a n ta R e g in a e t a l .
1 :1
Pre
dic
ted
(g)
Observed (g)
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Estimation of aboveground Ca and Mg
0
2500
5000
7500
10000
0 2500 5000 7500 10000
g e m e s s e n e r W e rt C a in g
bere
chne
terW
ertC
ain
g
R ²= 0 ,979
0
500
1000
1500
2000
2500
0 500 1000 1500 2000 2500
g e m e s s e n e r W e rt M g in gbe
rech
nete
rWer
tMg
ing
R ²= 0 ,985
Pre
dic
ted
(g)
Observed (g)
Ca Mg
d-h-alt-temp(y) d-h-temp(v)
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
0
1000
2000
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4000
5000
6000
0 1000 2000 3000 4000 5000 6000
g e m e s s e n e r W e rt K in g
bere
chne
terW
ertK
ing
R ²= 0 ,984
0
100
200
300
400
500
600
0 100 200 300 400 500 600g e mes s en er W ert P in g
ber
ech
net
erW
ert
Pin
g
R²= 0,981
Estimation of aboveground K and PP
red
icte
d (
g)
Observed (g)
K P
d-h-alt-temp(y) d-h-preci.
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Estimation of nutrient export realising the allowable yield cut of the FI
Merchantable wood (> 7 cm) : Volume: 11,2 m³ ha
–1 a-1
Biomass 6,6 Mg ha –1 a-1
Ca: 13,75 kg ha –1 a-1
Mg 2,45 kg ha –1 a-1 K 6,24 kg ha
–1 a-1 P 0,60 kg ha
–1 a-1
Branches ≤ 7 cm Volume: 2,0 m³ ha –1 a-1
Biomass 1,18 Mg ha –1 a-1 + 18 %
Ca: 5,53 kg ha –1 a-1 + 40 % Mg 0,56 kg ha –1 a-1 + 23 % K 1,49 kg ha –1 a-1 + 24
% P 0,32 kg ha –1 a-1 + 53
%
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Abb. 4:
TDAC: 2,7 – 4,15 kmolc/ha*J
Verwitterung*): 0,2 – 1 kmolc/ha*J
Rei(K+Ca+Mg): 0,37 kmolc/ha*J Dh(K+Ca+Mg): 1,05 kmolc/ha*J
TD(K+Ca+Mg): 0,34 – 0,60 kmolc/ha*J
Simplified acid-base-balance in beech forests
Total deposition (TD)acid
K+Ca+Mg
weathering
Wood ≤ 7 cm
Wood > 7 cm
Ministerium fürUmwelt undNaturschutz,Landwirtschaft undVerbraucherschutzdes LandesNordrhein-Westfalen
Conclusions
NFI provide statistically reliable data Connecting tree-level data with biomass functions should be preferred Implementing site specific variables improve the reliability Periodical remeasurement of sample plots decrease the error The application of biomass functions of foreign regions is questionable
Depending upon site and climatic conditions
Neither renunciation on full tree harvesting nor mechanical barking will balance the nutrient budget for annual depositions
Compensation only through fertilisation On fertilised sites harvest restrictions are unnecessary