determine the vegetation period and regional trends in germany wolfgang janssen...
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Determine the vegetation period and regional trends in Germany Wolfgang Janssen [email protected]. Phenology 2010, June. Background: different crops have different growth periods some issues need a general definition of the vegetation period impacts of climate change how to define? - PowerPoint PPT PresentationTRANSCRIPT
German Weather Serviceagrometeorological department
Determine the vegetation period and regional trends in Germany
Wolfgang [email protected]
Phenology 2010, June
German Weather Serviceagrometeorological department
Phenology 2010, June
Background:
- different crops have different growth periods- some issues need a general definition of the vegetation period- impacts of climate change
how to define?
good reproduction in past years?
any trends?
German Weather Serviceagrometeorological department
How to define? many different approaches with different results use only temperature as meteorological input link to definition of the phenological year
vegetation starts in early springwith plant stages:
forsythia, flowering (25.3.)gooseberry, leaf unfolding (27.3.)
vegetation stops at beginning of winter with plant stages: oak, leaf fall beech, leaf fall (27.10.)
Phenology 2010, June
German Weather Serviceagrometeorological department
large variation of phenological observations in small areas
most probable values by interpolation
58 stations with meterological and phenelogical observations
many different relations where tested not the best but simplest relation with good results was taken
Tsum = start day(Tmean day temperature – Treference temperature)
Phenology 2010, June
German Weather Serviceagrometeorological department
60 different start dates30 different ref. temp.(1800 cases)
for each case date reachingopt. temp. sum at 58 stations in 18 years
for each case optimal temp. sum for 58stations in 18 years
observed phenologicaldates of 58 stations in18 years
difference between observedand calculated dates =>dispersion for each case
Tsum = start date(Tmean day temperature – Treference temperature)
a simple methode to find the optimal start date and reference temperature
Phenology 2010, June
German Weather Serviceagrometeorological department
day of the year (start date)
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61
-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4,4-4,6 4,6-4,8 4,8-5 5-5,2 5,2-5,4 5,4-5,6 5,6-5,8 5,8-6 6-6,2 6,2-6,4 6,4-6,6 6,6-6,8 6,8-77-7,2 7,2-7,4 7,4-7,6 7,6-7,8 7,8-8 8-8,2 8,2-8,4 8,4-8,6 8,6-8,8 8,8-9 9-9,2 9,2-9,4
refe
renc
e te
mpe
ratu
re
start date = 49. day of year, reference temperature = 0 °C, sum = 164 °C
dispersion matrix for gooseberry (leaf unfolding)
Phenology 2010, June
German Weather Serviceagrometeorological department
Phenology 2010, June
a fixed start date or end of dormancy can‘t be correct ! start date must depend from weather situation made a test with the both coldest and warmest years
15 20 25 30 35 40 45 50 55 60-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
start date
refe
renc
e te
mpe
ratu
re7,2-7,47-7,26,8-76,6-6,86,4-6,66,2-6,46-6,25,8-65,6-5,85,4-5,65,2-5,45-5,24,8-54,6-4,84,4-4,6
15 20 25 30 35 40 45 50 55 60-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
start date
refe
renc
e te
mpe
ratu
re
4,7-4,94,5-4,74,3-4,54,1-4,33,9-4,13,7-3,93,5-3,73,3-3,53,1-3,32,9-3,12,7-2,92,5-2,72,3-2,52,1-2,31,9-2,1
warm years
cold years
same ref. temp. -2.5 °Cdifferent start days
German Weather Serviceagrometeorological department
determing for every year with a fixed reference temperature of -2.5 °Coptimal start date and optimum temperature sum (TScrop)
Phenology 2010, June
0
50
100
150
200
250
300
350
36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64
start date
optim
al te
mpe
ratu
re s
um
startdaycrop eTS *01962.053465
fitted dependence
observed
correlation 0.87
German Weather Serviceagrometeorological department
Phenology 2010, June
startdaycrop eTS *01962.053465
Calculation cheme:• starting at 1.1.• for every following day• calculating TScrop
• calculate TSlimit
TS > TSlimit ?
as start date is earlier, a higher temperatur sum is required (small chilling)as start date is later, a lower temperatur sum is required (large chilling)
plant state reached
yes
no
itcropit TSTSTSTS limlim ,min
60
70
80
90
100
110
60 70 80 90 100 110
calculated
obse
rved
correlation of 0,90dispersion of 4.3 days
startday temprefTTMTS ..
German Weather Serviceagrometeorological department
calculated phenologicalplant state in 2009
in mean +0,8 days differencePhenology 2010, June
observed phenologicalplant state in 2009
German Weather Serviceagrometeorological department
160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235 24025
27
28
30
31
33
34
36
37
39
40
5,5-5,7 5,7-5,9 5,9-6,1 6,1-6,3 6,3-6,5 6,5-6,7 6,7-6,9 6,9-7,1 7,1-7,3 7,3-7,5 7,5-7,77,7-7,9 7,9-8,1 8,1-8,3 8,3-8,5 8,5-8,7 8,7-8,9 8,9-9,1 9,1-9,3 9,3-9,5 9,5-9,7 9,7-9,9
day of the year (start date)
start date = 214. day of year, reference temperature = 30 °C, sum = -1383 °C
refe
renc
e te
mpe
ratu
re
dispersion matrix for beech (leaf fall, 300. day of year)
Phenology 2010, June
German Weather Serviceagrometeorological department
determing for every year with a fixed reference temperature of 30 °Coptimal start date and optimum temperature sum (TScrop)
Phenology 2010, June
startdateTScrop *25,134265
fitted dependence
observed
correlation 0.99
-2000
-1800
-1600
-1400
-1200
-1000
-800
-600
-400
-200
0
170 180 190 200 210 220 230 240 250 260 270 280
start date
optim
al te
mpe
ratu
re s
um
German Weather Serviceagrometeorological department
Phenology 2010, June
Calculation cheme:• starting at 180. day • for every following day• calculating TScrop
• calculate TSlimit
TS < TSlimit ?
with high temperatures end of vegetation is laterlatest possible end is 18.11. (322. day of year)
plant state reached
yes
no
),max( limlim itcropit TSTSTSTS
275
285
295
305
315
325
275 285 295 305 315 325calculated
obse
rved
correlation of 0,60dispersion of 5,1 days
startdateTScrop *25,134265 startday temprefTTMTS ..
German Weather Serviceagrometeorological department
in mean +0,4 days differencePhenology 2010, June
calculated phenologicalplant state in 2007
observed phenologicalplant state in 2007
German Weather Serviceagrometeorological department
Phenology 2010, June
Comparison between observed and calculated mean values for Germany
70
75
80
85
90
95
100
105
110
1961
1966
1971
1976
1981
1986
1991
1996
2001
2006
years
day
of th
e ye
ar
270
275
280
285
290
295
300
305
310
calculated begin observed begin calculatetd end observed end
German Weather Serviceagrometeorological department
time series for mean vegetation period in Germany
Phenology 2010, June
185
190
195
200
205
210
215
220
225
230
1961
1966
1971
1976
1981
1986
1991
1996
2001
2006
years
perio
d in
day
s
calculated period observed period running average
1980 1991period 1 period 28 days longer
German Weather Serviceagrometeorological department
Phenology 2010, June
calculated vegetationperiod 1961 - 1980
calculated vegetationperiod 1991 - 2009
trend
German Weather Serviceagrometeorological department
optimal parameter for other plant stages
phenological plant stage ref. temp. correlation dispersion
grasland, start of greening (19.3.) -2.5 0.89 4.5
dandelion, flowering (14.4.) -2.5 0.89 4.1
apple, flowering (28.4.) 1.0 0.90 3.7
Phenology 2010, June
German Weather Serviceagrometeorological department
Phenology 2010, June
begin greening of grasland
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
day of the yearre
fere
nce
tem
pera
ture
in °C
6-6,2 6,2-6,4 6,4-6,6 6,6-6,8 6,8-7 7-7,2 7,2-7,4 7,4-7,6 7,6-7,8 7,8-88-8,2 8,2-8,4 8,4-8,6 8,6-8,8 8,8-9 9-9,2 9,2-9,4 9,4-9,6 9,6-9,8 9,8-10
German Weather Serviceagrometeorological department
Phenology 2010, June
ref. Temp. = -2,5 °Cstartday
crop eTS *01962.060035
0
50
100
150
200
250
300
350
400
450
500
20 25 30 35 40 45 50 55 60 65
correlation 0,84
55
60
65
70
75
80
85
90
95
100
105
110
115
55 60 65 70 75 80 85 90 95 100 105 110 115
calculated
obse
rved
correlation 0,89mean dispersion 4,5 days
German Weather Serviceagrometeorological department
Phenology 2010, June
21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66 69 72 75 78 81
-10-9-8-7-6-5-4-3-2-1012345
start day
refe
renc
e te
mpe
ratu
re in
°C
4,8-5 5-5,2 5,2-5,4 5,4-5,6 5,6-5,8 5,8-6 6-6,2 6,2-6,4 6,4-6,6 6,6-6,86,8-7 7-7,2 7,2-7,4 7,4-7,6 7,6-7,8 7,8-8 8-8,2 8,2-8,4 8,4-8,6 8,6-8,88,8-9 9-9,2 9,2-9,4 9,4-9,6 9,6-9,8
flowering of dandelion
German Weather Serviceagrometeorological department
Phenology 2010, June
ref. Temp. = -2,5 °Cstartday
crop eTS *01.071515
0
100
200
300
400
500
600
700
20 25 30 35 40 45 50 55 60
correlation 0,81
70
80
90
100
110
120
130
70 80 90 100 110 120 130
calculated
obse
rved
correlation 0,89mean dispersion 4,1 days
German Weather Serviceagrometeorological department
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100-5-4-3-2-1012345678910
3,8-4 4-4,2 4,2-4,4 4,4-4,6 4,6-4,8 4,8-5 5-5,2 5,2-5,4 5,4-5,6 5,6-5,8 5,8-6 6-6,26,2-6,4 6,4-6,6 6,6-6,8 6,8-7 7-7,2 7,2-7,4 7,4-7,6 7,6-7,8 7,8-8 8-8,2
apple, flowering
Phenology 2010, June
always 24.2. for start day, ref. temp. of 1 °C, temp. sum of 361 °C
correlation of 0,90 and 3,7 days deviation
German Weather Serviceagrometeorological department
Phenology 2010, June
Thank you for your attention!