Viikki Urban Tree Laboratorio

Doc. Eero Nikinmaa,MSc Anu Riikonen

Aims of the study• Improve knowledge base of urban tree management

– How quickly tree recover from planting shock? what is suitable irrigation frequency?

– Do the aereation tubes in soil have positive impact on street tree development?

– How different surface material used on pavements impact on trees?

• To test the growing properties of load bearing soils – Can LBS be used to increase root growing space in northern environment

(aereation, water holding capacity, heat capacity & transfer)– What soil substrate structure is optimal for aeration / water holding in

street conditions– Can clay/ organic matter guarantee sufficiency of nutrients, when, how

and what fertilizers are needed?

• To charecterise the growing environment of trees on streets– Air and soil temperature, light climate, evaporative demand

Experimental streets: Normal modern streets in Helsinki

• Narrow alleys• Limited growing space• High mechanical

damage risk• De-icing

Testing different technical solutions

• Aereation pipes• Concrete and natural

stones• Different joint

width

Load bearing soil• 3 types• Load bearing sceleton:

(d 32-64mm) or (d 64-140mm) granite rocks

• 50 - 55% rocks and 40 - 45% soil + air (volumetric)

• Soil variation:– org. matter content (5-

20%)– variation in sand content

(pF curves)– fertilized (N,P) and non-

fertilized

• Load bearing properties passed laboratory tests

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 5 10 15 20 25

Volumetric moisture content %

pF

Soil 1

Soil 2

Soil 3

Soil nutrient analysisExperimental street - SOIL ANALYSIS, LOAD BEARING SOILS 2003

Soil type

Organic matter

johto-luku pH Ca P K Mg S B Cu Mn Zn NO3-N

NH4-

N Fe Cl Mo Na Cd Cr Ni Al

Kekkilä1 HkMr vm 15.2 7.3 4000 10 91.1 274 111 1.0 2.9 6.7 1.47 350 4 274 140 0.11 164 <0.05 87 48 90401 hkKHt m 14.8 7.3 3790 9.6 88.1 251 102 1.0 2.7 6.8 1.58 320 4 256 120 0.08 168 0.05 19 19 89001 HkMr vm 12.8 7.3 4220 10 88.5 253 103 1.0 2.9 6.6 1.29 310 4 241 120 0.07 148 . . . .1 HkMr vm 13.8 7.3 4500 13 105 268 129 1.0 3.7 7.3 2.58 320 4 298 140 0.11 159 . . . .1 HkMr vm 13.5 7.3 4190 10 92.6 253 109 0.9 3.2 7.0 2.11 320 6 284 103 0.08 169 . . . .keskiarvo 14.0 7.3 4140.0 10.5 93.1 259.8 110.8 1.0 3.1 6.9 1.8 324.0 4.4 270.6 124.6 0.1 161.6 0.1 53.0 33.5 8970.0Yit2 HtMr rm 10.4 6.6 3910 86 454 286 174 1.2 14.0 17.0 37.20 140 37 1570 75 0.15 171 0.1 49 35 112002 HtMr rm 7.0 6.7 3080 110 553 292 83 1.2 7.6 13.0 29.10 42 36 888 73 0.11 209 0.08 130 71 127002 HtMr rm 8.3 6.6 3140 86 496 268 94 1.1 9.6 15.0 30.70 84 33 1150 63 0.13 172 . . . .2 HtMr rm 8.6 6.5 3110 93 551 282 98 1.3 8.3 16.0 26.60 60 44 995 73 0.08 194 . . . .2 HtMr rm 9.5 6.6 2860 100 561 295 102 1.3 7.2 15.0 27.00 58 48 858 84 0.09 208 . . . .keskiarvo 8.8 6.6 3220.0 95.0 523.0 284.6 110.2 1.2 9.3 15.2 30.1 76.8 39.6 1092.2 73.6 0.1 190.8 0.1 89.5 53.0 11950.0Yliop.3 HkMr m 2.6 8.0 3290 39 188 142 36 0.8 3.8 7.6 5.33 14 3 508 15 0.04 36.2 <0.05 160 74 90803 HtMr m 3.1 7.8 3500 42 199 143 44 0.8 3.8 8.1 5.14 15 3 524 19 0.05 38.5 0.05 50 24 88703 HtMr m 3.0 7.9 3120 41 180 131 39 0.8 3.5 7.7 4.79 15 2 509 17 0.05 35.9 . . . .3 HkMr vm 2.4 8.0 3160 41 183 129 35 0.8 3.8 7.6 5.23 12 2 527 14 0.05 35.1 . . . .3 HtMr m 3.2 8.0 3240 40 192 135 41 0.8 3.5 7.3 4.93 21 2 503 19 0.06 37.4 . . . .keskiarvo 2.9 7.9 3262.0 40.6 188.4 136.0 39.0 0.8 3.7 7.7 5.1 15.4 2.4 514.2 16.8 0.1 36.6 0.1 105.0 49.0 8975.0

ViljavuusluokkaleimatBadFairly BadAcceptableSatisfactoryGoodHighQuestionably high

Monitoring as a method

By monitoring the growing conditions and the response of trees to them we gain rapidly information of the causal reasons for tree preformance in the urban environment.

Set up of monitoring• 2 Streets• 3 Load bearing soil types /

street• Alnus glutinosa & Tilia

vulgaris• ~5-6 trees/treatment

/street• 3 intensively monitored

points/ street (High temporal resolution)

• 9 points of manual monitoring/ street (Spatial resolution)

Manual measuring point

Intensive monitoring

Soil types

Street II

Street I

Monitoring-Intensive every 10 min

- Manual every 2 - 3 weeks

Growing conditions• Soil Profiles

– Temperature– Volumetric – Gas concentrations

• Above ground– PAR– Air temperature

• Meteorological information from nearby weather station

Tree• Intensive

– Sap flux (2 methods )– Growth

• Manual– Gas exchange +

fysiological measurements (Fluorosence)

– Nutrients contents– Structure– Root sampling (sampling

wells 4 distances from trees)

Installation of sensors

SoilTemperature

Gas

WeatherPAR

Air Temp

Tree

Sap-fluxHeat dissipation

Sap-fluxDiam. variation

Datamanagement

GSM

Office

Street 2

Street 1

Manual measurements

Street as a growing site

Irradiation and air temperature 18.7.2004

5

10

15

20

25

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00

Time

Tem

pera

ture

, d

eg

rees C

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

PA

R m

mo

l/m

-2 s

-1

Norkkokuja lpt

Pasteurinkatu, lpt

norkkokuja, PAR

Pasteurinkatu, PAR

Min. and Max Temperatures at the two streets 15.-31.1. 2005

-15

-13

-11-9

-7

-5

-3

-11

3

5

15.1

.

16.1

.

17.1

.

18.1

.

19.1

.

20.1

.

21.1

.

22.1

.

23.1

.

24.1

.

25.1

.

26.1

.

27.1

.

28.1

.

29.1

.

30.1

.

31.1

.

Date

Tem

per

atu

re,

deg

rees

C

Min. and Max Temperatures at the two streets 15.-31.8. 2004

0

5

10

15

20

25

15.8

.

16.8

.

17.8

.

18.8

.

19.8

.

20.8

.

21.8

.

22.8

.

23.8

.

24.8

.

25.8

.

26.8

.

27.8

.

28.8

.

29.8

.

30.8

.

31.8

.

Date

Tem

per

atu

re,

deg

rees

C

Air temperature at the two streets 15.8.-1.9.2004

0

5

10

15

20

25

Päivämäärä 19.8. 23.8. 27.8. 31.8.

Air

tem

per

atu

re, d

egre

es C

norkkokuja

pasteurinkatu

Soil: Annual cycle of temperature, Sufficiency of water

Soil temperatures, different streets

0

5

10

15

20

25

30

26 31 36 41 46 51 4 9 14 19 24 29 34 39 44 49

Week #

So

il te

mp

era

ture

, de

gre

es

C

Norkkokuja

Pasteurinkatu

Soil Temperature Pasteur Street, 2003-2004

0

5

10

15

20

25

30

26 28 30 32 34 36 38 40 42 44 46 48 50 52 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50

Week nro

Tem

per

atu

re

Kekkilä

YIT

YO/TTKK

Volumetric Water content: Norkkostreet 2003-2004 10 cm depth

0

25

50

75

100

26 30 34 38 42 46 50 2 6 10 14 18 22 26 30 34 38 42 46 50Week #

Pro

po

rtio

n o

f po

re v

olu

me

Volumetric water content: Pasteur street 2003-200430 cm depth

0

25

50

75

100

26 30 34 38 42 46 50 2 6 10 14 18 22 26 30 34 38 42 46 50Week #

Pro

po

rtio

n o

f po

re v

olu

me

Surface pavement material

Concrete stone

Granite”dice”

Impact of pavement on soil gas concentrations ?

CO2 concentrations under different pavement types, both streets 2004

0

5000

10000

15000

20000

25000

10granitepasteur

30 60 10concrete

30 60 10granitenorkko

30 60 10concrete

30 60

CO

2 co

nc.

pp

m

Permeability to precipitationSoil moisture content development july 2004

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0.350

0.400

0.450

0.500

1.7. 4.7. 7.7. 10.7. 13.7. 16.7. 19.7. 22.7. 25.7. 28.7. 31.7.

Vo

lum

etr

ic w

ate

r co

nte

nt

%

10 cm

30 cm

Too much water can be a problem!

Volumetric water content: Pasteur street 2003-200430 cm depth

0

25

50

75

100

26 30 34 38 42 46 50 2 6 10 14 18 22 26 30 34 38 42 46 50Week #

Pro

po

rtio

n o

f po

re v

olu

me

CO2 different streets 2004

-10000

0

10000

20000

30000

40000

50000

7.5. 31.5. 21.6. 12.7. 2.8. 16.8. 6.9. 27.9. 18.10. 16.11. 2.12.

norkkokuja

pasteurinkatu

versokuja

Methane, different streets, 2004

0.1

1

10

100

1000

7.5. 31.5. 21.6. 16.8. 6.9. 27.9. 18.10. 16.11. 2.12.

norkkokuja

pasteurinkatu

versokuja

Soil Co2 and max photosynthesis, Pasteur street july-04

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

p2 p5 p8 p12 p15

Tree

Pn

an

d s

oil

CO

2 %

max.fotos.

Hiilid.

Soil Co2 and max photosynthesis, Pasteur street august-04

01

234

567

89

p2 p5 p8 p12 p15

Tree

Pn

an

d s

oil

CO

2 %

Pn

Hiilid.

Aereation pipes are beneficial!

Significance of aereation on different soils

0

2000

4000

6000

8000

alusta 1 alusta 2 alusta 3

CO

2 co

nte

nt

pp

m

ei ilmastoitu

ilmastoitu

CO2 content 2004 in aereated and non-aerated soils

0

2000

4000

6000

8000

7.5. 31.5. 21.6. 12.7. 2.8. 16.8. 6.9. 27.9. 18.10. 16.11.

CO

2 p

pm

ilmastointi -10

ilmastointi -30

ilmastointi -60

ei ilmastointia -10

ei ilmastointia -30

ei ilmastointia -60

Soil organic matter reflects on gas concentrations!

Soil Temperature vs. CO2, Norkko street

y = 690.43e0.0909x

R2 = 0.6058

y = 439.25e0.1791x

R2 = 0.5887

y = 521.22e0.0721x

R2 = 0.5882

-5000

5000

15000

25000

35000

45000

55000

0 5 10 15 20 25

Soil temperature, degrees C

CO

2 co

nte

nt,

pp

m

alusta 1

alusta 2

alusta 3

Expon. (alusta 1)

Expon. (alusta 2)

Expon. (alusta 3)

Soil Temperature vs. CO2, Pasteur street

y = 704.66e0.0892x

R2 = 0.6335

y = 2666.1e0.0893x

R2 = 0.5521

y = 5547.9e0.0678x

R2 = 0.231

-5000

5000

15000

25000

35000

45000

55000

0 5 10 15 20 25 30 35

Soil Temperature, degrees C

CO

2 co

nte

nt

pp

m

alusta 1

alusta 2

alusta 3

Expon. (alusta 1)

Expon. (alusta 2)

Expon. (alusta 3)

Variation in factors influencing photosynthetic production

Max photosynthetic rate, different times and different soils. 2004

0

2

4

6

8

10

12

14

16

June July August

Pn

n1

n2

n3

Stomatal conductance, different soils and times of the year, 2004

0

50

100

150

200

250

300

350

400

450

June July August

GS

, m

ikro

mo

lm2s

-1

n1

n2

n3

O2 content and fluorosence

0.65

0.7

0.75

0.8

0.85

5 8 12 15

Tree

Fv/F

m

150000

160000

170000

180000190000

200000

210000

220000

230000

O2,

pp

m

Pasteurinkatu 2005

0.70

0.72

0.74

0.76

0.78

0.80

0.82

0.84

0.86

0.88

1 2 3 4 5 6 8 12 15

Tree No.

Fv

/Fm

June13

July13

August24

Differences in Photosynthetic production

Net assimilation vs. internal CO2 in Norkkokuja, August 2005

0

100

200

300

400

500

0 5 10 15 20 25

Net assimilation µmol/m2/s

Inte

rnal

CO

2, p

pm

1.2

1.4

2.2

2.5

3.2

3.4

Net assimilation vs. internal CO2 in Pasteurinkatu, August 2005

0

100

200

300

400

500

0 2 4 6 8 10 12 14

Net assimilation µnol/m2/s

inte

rnal

CO

2, p

pm

1

2

4

5

7

8

10

Net assimilation and light, Norkkokuja, August 2005

-5

0

5

10

15

20

25

1500 600 300 150 75 0

light, µmol/m2/s

ne

t a

ss

imila

tio

n µ

mo

l/m2

/s

1.2

1.4

2.2

2.5

3.2

3.4

Net assimilation and light, Pasteurinkatu, August 2005

-2

0

2

4

6

8

10

12

14

1500 600 300 150 75 0

light, µmol/m2/s

net

assim

ilati

on

µm

ol/m

2/s

1

2

4

5

7

8

10

Canopy conductance is linked to light and soil (example 2003)

Volumetric moisture content

0.135

0.140

0.145

0.150

0.155

0.160

0.165

0.170

time

Light and canopy conductance july 2003

0.000000

0.000100

0.000200

0.000300

0.000400

0.000500

0.000600

0.000700

0.000800

time

0

100

200

300

400

500

600

700

800

900

Growth differences

Shoot growth in different parts of crown, Tilia, 2004

0

40

80

120

160

1S1

2 4S2

5 7S3

8

Av.

sh

oo

t le

ng

th,

cm

Upper crown

Middle crown

Shoot growth in different parts of crown, Alnus, 2004

0

100

200

300

3S1

4 2S2

6 2S3

4

Av.

sh

oo

t le

ng

th,

cm

Upper Crown

Middle Crown

Conclusions• Irrigation after plantation was sufficiient• Loosely positioned granite ”dices” allow air

penetration, tight granite rock considerably less• Aeration pipes improve situation• Surplus water produced adverse conditions, draught

problem not yet observed. Aereation of pores more critical than water holding capacity in the souther boreal city of Helsinki?Climate change scenarios suggest increasing storm water loads!

• Excees organic matter a risk factor, rapid decomposition eats O2 + soil properties change

• As O2 dropped below 18% (>2% CO2), tree physiology changed