impacts of the drought and heat in 2003 on forests · fir (abal) elztal. the regression model shows...

Impacts of the Drought

and Heat in 2003 on ForestsScientific Conference 17 – 19 November 2004

Freiburg, Germany

Working Group 5: Forest Growth

Impacts of Drought and Heat on Tree and Forest Growth

A Synthesis of Studies on Short-, Medium- and Long-term Effects Observed under Temperate Climatic

Conditions

Hans-Peter Kahle, Institute for Forest Growth, University Freiburg

Questions addressed:

Was Tree Growth Affected by the Heat and Drought in 2003?

- To which Extent? (% of “normal”)

- Most affected Species (on the same site): Beech vs. Spruce

- Most affected Sites: Elevation and Aspect

- Most affected Stands: dense vs. open

- Most affected Crown Class: dominant vs. intermediate.

Drought 2003Working Group 5: Forest Growth

Scaling issues addressed:

Short-term effects on growth? Effects in 2003? (% of “normal”)

Medium-term consequences?Effects during the next 5 years?

Long-term consequences?Effects beyond the next 5 years?


Weather Conditions in 2003at two meteo stations in Baden-Württemberg:

- Karlsruhe (DWD): 112 m asl

- Schauinsland (UBA): 1205 m asl


high elevation

(Data source: DWD 2004, UBA 2004)

Weather Conditions in 2003: Air Temperature

low elevation

Weather Conditions in 2003: Air Temperature Anomalies


rKA/SC = 0.9135

Weather Conditions in 2003: Precipitation


low elevation

high elevation


Weather Conditions in 2003: Precipitation Anomalies

rKA/SC = 0.7607

Mean air temperature 1994-2002 and 2003

02468

10121416182022

11,4 18,1 6,0 11,7

Jan-Dec May-Sep Jan-Dec May-Sep

Karlsruhe Schauinsland

Tp (°

C)


(112 m) (1205 m)

Mean air temperature 1994-2002 and 2003

02468

10121416182022

11,4 11,9 18,1 20,3 6,0 7,2 11,7 14,8



Tp (°

C)

+ 0,5°C + 2,2°C + 1,2°C + 3,1°C

+ 4,4 % + 12,2 % + 20,2 % + 27,0 %


(112 m) (1205 m)

Precipitation sum 1994-2002 and 2003

0

500

1000

1500

2000

2500

813 352 2142 894



Pr (m

m)


Precipitation sum 1994-2002 and 2003

0

500

1000

1500

2000

2500

813 561 352 245 2142 1488 894 532



Pr (m

m)

- 252 mm- 107 mm

- 654 mm

- 362 mm

- 31 %

- 31 %

- 31 %

- 40 %


240 mm

211 mm

376 mm

344 mm

(Data source: DWD 2004)

21.5 °C23.8 °C

16.4 °C 17.8 °C

11.6 °C 12.3 °C

23.0 °C25.5 °C

17.9 °C 19.4 °C

13.0 °C 13.9 °C

Climate Trends at Karlsruhe: Temperature & Precipitation

(Data source: DWD 2004)

Climate Trends at Karlsruhe: Climatic Water Balance

- 71 mm

-135 mm

111 mm

50 mm

-127 mm

-208 mm

(Station Karlsruhe, Data source: DWD 2004)

Weather in Selected Warm and Dry Years in 1895-2004

Temperate oceanic forestTemperate continental forestBoreal coniferous forestTemperate mountain systemSubtropical dry forestSubtropical mountain systemTemperate steppeBoreal mountain system

Weather Conditions in Selected Years in Europe (Ecozones according to FAO classification)

(Map source: FAO 2002)

Subtropica

l dry

forest

Subtropica

l mountai

n system

Temperate oce

anic

forest

Temperate co

ntinental

fore

st

Temperate steppe

Temperate m

ountain sys

tem

Boreal

conife

rous fo

rest

Boreal

mountain sys

temPolar

-70

-60

-50

-40

-30

-20

-10

0

Prec

ipita

tion

(Mai

-Sep

)(d

evia

tion

in %

of 1

975-

2002

)

194719762003

(Data source: New et al. 1999, 2000, 2002)

Subtropica

l dry

fore

st

Subtropica

l mountai

n syste

m

Tempera

te oce

anic

fore

st

Tempera

te co

ntinental

fore

st

Tempera

te ste

ppe

Tempera

te m

ountain sys

tem

Boreal

conife

rous fo

rest

Boreal

mountai

n syste

m

Polar

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

Tem

pera

ture

(May

-Sep

) (d

evia

tion

in K

of 1

975-

2002

)

194719762003

(Data source: New et al. 1999, 2000, 2002)

Radial Growth by Species and Elevation

- Dendrometer studies


Point Dendrometer Mounted on a Beech Stem (Hauser 1999)

Stainless steel body with displacement transducer

Sensor head

5 cm

Black Forest Vosges Mountains Rhine Valley

Dendrometer Measurements - Field Sites

Günterstal: 450 m aslHeibrain: 750 m asl

Schauinsland: 1250 m asl

Dietenbach: 220 m asl

Beech Low Elevation (220 m asl) Oak

Spruce Low Elevation (450 m asl) Beech

22.05.xx

06.05.03

08.04.xx

01.04.03 06.10.xx

23.06.xx

02.06.03

02.08.0303.04.03

08.04.xx

26.06.03

29.09.xx

27.10.03

Spruce Medium Elevation (750 m asl) Beech

Spruce High Elevation (1250 m asl) Beech

020406080

100120140160180200

450 750 1250

FASY FASY FASY

GUE HEI SCHnu

mbe

r of g

row

ing

days

1999-20022003

Number of GrowingDays derivedfromDendrometerData

Beech

020406080

100120140160180200

450 750 1250

PCAB PCAB PCAB

GUE HEI SCH

num

ber o

f gro

win

g da

ys

1999-20022003

Spruce

Occurrence of may shoot of Norway spruce at Schauinsland (1250 m asl)

120130140150160170

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

year

day

of y

ear

(Data source: Henhappl 2004)

Radial growth in 2003

0

20

40

60

80

100

120

140

0 500 1000 1500

Altitude (m asl)

ir 20

03 (I

ndex

200

2=10

0)

BeechOakSpruceLinear (Spruce)Linear (Beech)

Radial growth in 2004

0

20

40

60

80

100

120

140

0 500 1000 1500

Altitude (m asl)

ir 20

04 (I

ndex

200

2=10

0)

BeechOakSpruceLinear (Spruce)Linear (Beech)

Rate of radial displacement of European Beech(expressed in % of the maximum rate during the period 1999-2002)

220 m asl

450 m asl

750 m asl

1250 m asl

Radial Growth and Aspect of the Site


Radial Growth of European Beech at Möhringen (750 m asl)

Aspect: north-east south-west


• level of growth larger on north-east facing slope!• growth reduction smaller on south-west facing slope!• recovery faster on south-west facing slope!

Radial Growth and Stand Density


Radial growth of European Beech at Möhringen (760 m asl)

control basal area 15 m² basal area 10 m²

control BA 15 m² BA 10 m²

Rate of radial displacement of Beech at Möhringen(expressed in % of the maximum rate during the period 2001-2002)


• the lower the stand density the higher the level of growth!• no clear difference in growth reduction in 2003!• no clear difference in recovery in 2004!

Radial Growth and Crown Class



dominant codominant intermediate

• the higher the crown class the higher the level of growth!• intermediate trees show larger growth reduction in 2003!• no clear differences between crown classes in recovery

in 2004!


Restrospective Growth AnalysesTwo sites in the Black Forest:

- Municipal forest of Freiburg (Dist. I/Abt. 23, 650 m asl)

- Community Forest Elzach (Elztal, 400 m asl)


Annual Radial Increment, Black Forest, 650 m asl. (I/23)

Norwayspruce (PCAB)

Silver fir(ABAL)

Douglas fir (PSME)

European beech (FASY)

2003

Standardized Annual Radial Increment, Black Forest, 650 m asl. (I/23)

2003

Annual Radial Increment of Beech in Relation to Spruce(Black Forest I/23, 650 m asl.)

Annual Radial Increment of Dead and Alive Norway Spruce

Annual Radial Increment of Dead vs. Alive Norway Spruce

Detail: stem cross section Norway spruce (Elztal, Tree no. 6, Radius 2)

2002 2001 2000 1999 1998 19972003

2004 1996

grey value profile

Annual Radial Increment of Dead and Alive Silver Fir

Annual Radial Increment of Dead vs. Alive Silver Fir

Annual Radial Increment of Norway Spruce and Climatic WaterBalance during July-August of the Five Preceeding Years

Annual Radial Increment of Silver Fir and Climatic Water Balance during July-August of the Five Preceeding Years

Development of radial increment after extreme growth reduction versus the time in years passed since the reduction occurred

Spruce PCAB: left, Fir ABAL: right. The analysis refers to the time period 1936-2002. Only events where radial increment is within the 1-10- (red line), 11-20- (blue) and 21-30-percentile (green) of the ir-index distribution were selected. The annual radial increment data have been standardised into ir-indices using cubic smoothing splines with 50% frequency cut-off of 30 years and normalised to a mean of zero and a standard deviation of one. The lines are the regression models together with the 95% confidence belts (dotted lines).

Development of radial increment after extreme growth reduction

Spruce (PCAB) Elztal. The regression model shows the development of radial increment after extreme growth reduction versus the initial intensity of growth reduction and the time in years passed since the growth reduction occurred. Further explanations see previous figure. Surface plot (left) and corresponding contour plot (right).

Development of radial increment after extreme growth reduction

Fir (ABAL) Elztal. The regression model shows the development of radial increment after extreme growth reduction versus the initial intensity of growth reduction and the time in years passed since the growth reduction occurred. Further explanations see previous figure. Surface plot (left) and corresponding contour plot (right).

Norway Spruce: Terminal Shoot of a 32 m tall Tree.(photo: 28.09.2004, Elzach, Brand)

2002

2003

2004• shoot length reduced• needle number reduced• needle density increased• needle length reduced

Normalstate

Stress Recovery

Func

tiona

lst

ate

Prod

uctio

n

Return to normal state

short-termmedium- to long-term

(acc. to Larcher 2003)

Stress concept: temporary stress, elastic response

time

?

Conclusions: Radial Growth Reduction in 2003 Elevation: low elevation > high elevation

Aspect: north-east > south-west


Conclusions: Radial Growth Reduction in 2003 Species: Spruce > Beech

Recovery: Beech > Spruce

Spruce > Fir

Crown Class: intermediate > dominant

Density: no (clear) difference


Acknowledgment:Felix Baab, IWW, D

Matthias Dobbertin, WSL, CH

Albert Fehrenbach, IWW, D

André Granier, INRA, F

Stephan Raspe, LWF, D

Rüdiger Unseld, IWW, D


Thank you

for your attention!

impacts of the drought and heat in 2003 on forests · fir (abal) elztal. the regression model shows...

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