1. R. Comolli
Earth and Environmental Sciences Dept.
Milan Bicocca University
Milan
SOIL MONITORING
PRELIMINARY RESULTS IN ITALY
MILAN, 17 JUNE 2014
LIFE+ 10 ENV/IT/399
Final conference
FORESTE URBANE – IL RESPIRO DELLE CITTÀ

2. Soils and forests
Natural forest (Bosco Fontana) UPF (Bosco di Maristella)
Aims
• Characterization of UPF soils
• Soil modifications owing to UPF
implantation
• Evaluation of UPF soils (chemical
and biological fertility, water
retention, etc.)
• Soil-vegetation relationships
Soil

3. Soilscapes of the study plots
1. Parco Nord Milano: coarse LGM fluvioglacial
deposits
2. Boscoincittà: hydromorphic LGM fluvioglacial
deposits
3. Bosco di Maristella: LGM fluvial deposits
4. Bosco Fontana: fluvial terraces
5. Foresta di Carpaneta: hydromorphic LGM
fluvioglacial deposits

4. Soil types
Plot Soil type (WRB 2006)
Parco Nord Milano 23B Haplic Luvisol (Humic, Endoskeletic, Chromic)
Parco Nord Milano 2A_nd Luvic Phaeozem (Endoskeletic)
Parco Nord Milano 18C Haplic Luvisol (Humic, Epidystric, Endoskeletic)
Parco Nord Milano 25A Haplic Luvisol (Humic, Epidystric)
Parco Nord Milano 2A Cutanic Luvisol (Humic, Epidystric, Endoskeletic)
Parco Nord Milano 9A Luvic Phaeozem (Endoskeletic, Endoarenic)
Parco Nord Milano 1D Haplic Luvisol (Humic, Endoskeletic, Chromic)
Parco Nord Milano 28C Haplic Luvisol (Humic, Epidystric, Endoskeletic, Chromic)
Parco Nord Milano 1A Haplic Luvisol (Humic, Endoskeletic, Chromic)
Parco Nord Milano 14A Haplic Luvisol (Humic, Epidystric, Endoskeletic)
Boscoincittà Haplic Umbrisol (Humic, Endoeutric)
Foresta della Carpaneta Endopetric Hypocalcic Vertic Calcisol
Bosco di Maristella Haplic Cambisol (Humic, Hypereutric, Siltic)
Bosco Fontana Petric Luvic Calcisol (Skeletic, Endoarenic, Chromic)

5. Soil types
Plot Soil type (WRB 2006)
Parco Nord Milano Luvisol (Phaeozem)
Humic, Epidystric, Endoskeletic, Chromic
Boscoincittà Umbrisol
Humic, Endoeutric
Foresta della Carpaneta Calcisol
Endopetric Hypocalcic Vertic
Bosco di Maristella Cambisol
Humic, Hypereutric, Siltic
Bosco Fontana Calcisol
Petric, Luvic, Skeletic, Endoarenic, Chromic

6. Soil types
Parco Nord Milano
The soils are about 1.5 m deep, moderately acid, have generally sandy loam texture, and some of them have
compacted subsurface horizons. The main pedogenetic process is clay illuviation.

7. Soil types
Bosco Fontana
The soils have thick organic surface horizons, are strongly acid in the topsoil, but alkaline in the subsoil, with
hard petrocalcic horizons and a large amount of rock fragments. The main pedogenetic processes are clay
illuviation and calcification.

8. Soil spatial variability
Examples of topsoil and subsoil pH maps (referred to 1A study area in Parco Nord Milano):
for both of them, it can be noted a positive pH gradient from north-west to south-east.
pH maps
For each plot, topsoil and subsoil pH maps were obtained by applying geostatistic procedures: pH reveals
strong variability in some plots, but greater uniformity in others.

9. Organic surface horizons
Organic horizons
Dry weight of the soil
organic horizons (litter)
related to the forest type
of each study area.

10. Soil biological quality index (QBS)
QBS-ar is based on microarthropod groups present
in a soil sample. Each biological form found in the
sample receives a score from 1 to 20
(EcoMorphological Index, EMI), according to its
adaptation to soil environment.
QBS method is based on the assumption that there
is a direct correlation between soil quality and
microarthropod groups well adapted to edaphic life.
Soil samples for QBS calculation
were taken from the surface layer,
up to 10 cm depth, using a known
volume sampler, to determine also
soil bulk density and water content.
Determination of biological forms and calculation of QBS Index
Berlese-Tullgren
extractor

11. Bait-lamina test
The feeding activity of soil animals was determined by the Bait-lamina
Test, through insertion into the ground of drilled strips, filled with an
organic bait, and their subsequent extraction after 14 days: the biological
activity, at different depths, was expressed as percentage of empty holes
on the total of the holes.

12. Forest and meadow soils
To assess the soil changes as a
result of land use change (from
arable or meadow to forest), we
studied soils that retained the
land use preceding the planting
of the wood.
In these comparison soils, field
observations with auger were
executed, together with topsoil
and subsoil sampling.
forest soil meadow soil for comparison

13. Biological indices
The edaphic community of the woods shows
a greater diversification compared to that of
the meadows.
The Bait-lamina Test proves that the biological activity is greater in
the meadow (22% of organic bait consumed) than in the wood
(16%), contrary to what happens with QBS values, generally greater
in the wood.
QBS Index vs Bait-lamina Test
Tests were taken both in the forest areas and in adjacent soils maintained with the former land use
(arable or meadow).

14. Soil modifications
pH H2O
Aree Confronto Boschi
0
1
2
3
4
5
6
pH
Mean: 5.84 ± 0.09 5.62 ± 0.04 Mean: 56.22 ± 4.08 25.77 ± 2.23
P value: 0.0360* P value: <0.0001***
Tasso Saturazione in Basi
Aree Confronto Boschi
0
10
20
30
40
50
60
70
TSB
pH H2O Base Saturation
UPFsComparison plots UPFsComparison plots
BS(%)
pH

15. Soil modifications
Soil pH (H2O) vs. Forest age
Age of the forest (years)
Topsoil
R2=0.0836
0-10 cm layers
R2=0.296
A horizons
R2=0.566

16. Soil modifications
Carbonio organico
Aree confronto Boschi
0.00
0.25
0.50
0.75
1.00
1.25
C%
Capacità di Scambio Cationico
Aree confronto Boschi
0
10
20
CSC(cmol(+)/kg)
Soil Organic Carbon Cation Exchange Capacity
Mean: 1.05 ± 0.16 0.98 ± 0.08 Mean: 12.10 ± 1.27 15.53 ± 0.72
P value: 0.6987 P value: 0.0165*
UPFsComparison plots UPFsComparison plots
SOC(%)
CEC(cmol(+)kg-1)

17. Soil modifications
Soil Organic Carbon vs. Forest age
Topsoil
R2 = 0.111
0-10 cm layers
R2 = 0.400
A horizons
R2 = 0.656
Age of the forest (years)
SoilOrganicCarbon(%)

18. Soil monographs
Photographs of the soil profile
The soil of each study area was described in a specific monograph.

19. Soil monographs
Horizon Depth Description
Ah 0 - 7 cm dry; matrix color 10YR 3/2; silty loam; very little few rock fragments, not weathered; large granular structure, strongly
developed; abundant roots, from very fine to medium; no effervescence to HCl; abrupt wavy lower boundary
A1 7 - 25 cm dry; matrix color 10YR 3/3; loam; common rock fragments, fine and very fine, not to low weathered; large subangular blocky
structure, moderatately developed; common roots, from very fine to medium; no effervescence to HCl; little brick fragments;
gradual smooth lower boundary
A2 25 - 40 cm dry; matrix color 10YR 3/3.5; silty loam; common rock fragments, fine and very fine, not to low weathered; large subangular
blocky structure, moderately developed; moderately compacted; common roots, from very fine to medium; no effervescence
to HCl; little brick and plastic fragments; clear smooth lower boundary
Btd 40 - 58 cm slightly moist; matrix color 7.5YR 3/4; sandy loam; abundant rock fragments, fine and very fine, medium weathered; fine
angular blocky structure, slightly developed, tending to massive; heavy compaction (possibly plow sole); few roots, from very
fine to medium; no effervescence to HCl; clear wavy lower boundary
Bt 58 - 80 cm slightly moist; matrix color 7.5YR 3/4; sandy loam; abundant rock fragments, fine and very fine, medium weathered; medium
subangular blocky structure, moderately developed; few roots, from very fine to medium; no effervescence to HCl; clear wavy
lower boundary
Description of the soil profile (by horizons)
Etc.

20. Soil monographs
Analytical data of the soil profile (by horizons)
Horizon
Depth
pH H2O pH KCl tot. CaCO3 %
org. C tot. N
C:N
avail. P mg
kg-1cm % %
Ah 0 - 7 6,5 5,7 0,00 4,254 0,262 16,21 18,23
A1 7 - 25 5,3 4,3 N.D. 1,138 0,084 13,49 21,87
A2 25 - 40 5,4 4,2 N.D. 0,988 0,092 10,73 23,09
Btd 40 - 58 5,4 4,1 N.D. 0,520 0,060 8,65 10,69
Bt 58 - 80 5,3 4,0 N.D. 0,409 0,043 9,56
BC 80 - 95 5,9 5,1 N.D. 0,269 0,033 8,25
CB 95 - 130 7,9 7,1 1,62 0,289 0,030 9,58
C 130 - 160 8,3 7,8 26,23 0,124 < 0,001 -
Horizon
Depth Cation exchange complex (cmol(+) kg-1) BS
cm CEC Ca2+ Mg2+ Na+ K+ %
Ah 0 - 7 20,53 13,70 2,53 0,02 0,32 80,73
A1 7 - 25 15,83 2,58 0,53 0,07 0,08 20,59
A2 25 - 40 14,03 2,46 0,42 0,05 0,06 21,31
Btd 40 - 58 15,44 4,18 0,71 0,07 0,15 33,10
Bt 58 - 80 11,56 3,41 0,52 0,06 0,14 35,74
BC 80 - 95 12,29 5,20 0,72 0,09 0,07 49,46
CB 95 - 130 9,90 7,52 0,56 0,00 0,02 81,79
C 130 - 160 6,63 6,23 0,46 0,05 0,01 100,00

21. Soil monographs
Vertical trend
of pH, organic C and C:N
ratio in the soil profile

22. Soil monographs
Soil classification
Diagnostic horizons (WRB, 2007):
• umbric = 0-40 cm
• argic = 40-80 cm
WRB (2007) classification:
Haplic Luvisol (Humic, Epidystric, Endoskeletic)
Soil Taxonomy (2010) classification:
Typic Hapludalf, loamy-skeletal, mixed, mesic
Réferéntiel Pédologique (2008) classification:
NÉOLUVISOL oligosaturé, compacté
Topsoil depth: 0-40 cm
Subsoil depth: 40-80 cm

23. Soil monographs
Point Horizon Depth
(cm)
Rock
fragments
(class)
Effervescence
to HCl
(class)
Color Notes
T1 A
AB
B
0-12
12-45
45-83
0
1
1
0
0
0
10YR 3/3
10YR 3/3,5
10YR 3/6
T2 A
AB
Bt1
Bt2
0-11
11-35
35-59
59-80
0
0
0
0
10YR 3/3
10YR 3/3,5
9YR 3/4
9YR 3/4
40 cm: brick
fragments
T3 A
AB
Bt1
Bt2
0-11
11-38
38-60
60-80
1
1
1
1
0
0
0
0
10YR 3/3
10YR 3/3,5
7,5YR 3/4
7,5YR 3/4
50 cm: brick
fragments
T4 A
AB
BA
B
0-11
11-25
25-38
38-57
1
1
2
3
0
0
0
0
10YR 3/3
10YR 3/4
10YR 3/4
10YR 3/6
T5 A
AB
BA
C?
0-12
12-25
25-35
35-59
3-4 0
0
0
0
10YR 3/3
10YR 3/3,5
10YR 3/3,5
7,5YR 3/4
brick fragments
Etc.: T6-T15
Description of the
observations with soil
auger

24. Soil monographs
Analytical data
(pH in H2O and KCl)
for topsoil and subsoil samples
collected from the observations
with auger
pH in H2O pH in KCl
Punto Topsoil Subsoil Punto Topsoil Subsoil
T3 5,1 5,3 T3 4,1 4,2
T4 5,2 5,3 T4 4,2 4,3
T5 5,6 5,5 T5 4,5 4,3
T6 5,2 5,4 T6 4,2 4,3
T7 5,4 5,4 T7 4,2 4,2
T8 5,0 5,3 T8 3,9 4,1
T9 5,1 5,0 T9 4,0 3,9
T10 5,0 5,3 T10 4,0 4,1
T11 5,0 5,3 T11 4,0 4,2
T12 5,2 5,3 T12 4,1 4,2
T13 4,9 5,1 T13 4,0 4,1
T14 5,1 5,3 T14 4,0 4,2
T15 5,0 5,2 T15 4,0 4,2
P 5,5 5,3 P 4,5 4,0
Mean 5,09 5,27 Mean 4,08 4,16
St. dev. 0,22 0,12 St. dev. 0,17 0,11
min. 4,8 5,0 min. 3,9 3,9
max. 5,6 5,5 max. 4,5 4,3

25. Soil monographs
Maps of pH H2O of the plot

26. Soil monographs
Layer
Depth
pH H2O pH KCl tot. CaCO3 %
org. C tot. N
C:N
av_P
mg kg-1cm % %
Topsoil 0 - 40 5,3 4,2 0,0 1,22 0,10 12,12 22,69
Subsoil 40 - 80 5,5 4,3 0,0 0,59 0,06 9,11 17,23
Layer
Depth Cation exchange complex (cmol(+) kg-1) BS
cm CEC Ca2+ Mg2+ Na+ K+ %
Topsoil 0 - 40 15,31 1,50 0,26 0,08 0,09 12,61
Subsoil 40 - 80 12,88 2,37 0,37 0,06 0,09 22,43
Layer
Depth Particle size %
Text. class
USDA
cm Coarse
sand
Fine sand
Total
sand
Coarse silt Fine silt Total silt Clay
Topsoil 0 - 40 29,3 12,3 41,6 17,4 31,7 49,1 9,3 Loam
Subsoil 40 - 80 26,0 14,6 40,6 14,1 28,0 42,1 17,3 Loam
Analytical data for topsoil and subsoil (mixed samples)

27. Principal Component Analysis (PCA)
Relationships between topsoil parameters of
the 14 study plots:
• there are strong relationships between
exchangeable bases (Ca, Mg, Na, K) and
pH;
• bulk density and soil organic matter are
opposite;
• bulk density and age of the wood are
opposite;
• the litter weight and the age of the
wood are related;
• the organic C content is related to the
age of the wood.
PCA for topsoil parameters
(with the addition of the plot age)

28. PCA for topsoil cases (study plots)
Principal Component Analysis (PCA)
• There is great similarity
between the soils of the
Parco Nord Milano (except
the plot 9A)
• Bosco Fontana soils and
Bosco di Carpaneta soils are
very different from each
other and from Parco Nord
Milano soils

29. Correlations
pH
H2O
pH
KCl
CaCO3 SOC Tot N C:N Av P CEC Ca Mg K BS Clay Sand Litter QBS BD Age
pH H2O 1,00
pH KCl 0,98 1,00
CaCO3 0,81 0,85 1,00
SOC -0,35 -0,23 -0,16 1,00
Tot N -0,24 -0,12 -0,04 0,98 1,00
C:N -0,65 -0,55 -0,59 0,68 0,53 1,00
Av P -0,10 -0,21 -0,28 -0,22 -0,17 -0,18 1,00
CEC 0,50 0,59 0,69 0,46 0,59 -0,26 -0,19 1,00
Ca 0,91 0,94 0,88 -0,05 0,08 -0,57 -0,25 0,76 1,00
Mg 0,86 0,88 0,83 -0,04 0,12 -0,57 -0,07 0,75 0,97 1,00
K 0,72 0,70 0,72 0,04 0,22 -0,61 -0,08 0,76 0,85 0,87 1,00
BS 0,91 0,90 0,73 -0,17 -0,06 -0,55 -0,17 0,53 0,93 0,92 0,78 1,00
Clay 0,76 0,72 0,81 -0,49 -0,34 -0,90 0,09 0,52 0,73 0,72 0,70 0,61 1,00
Sand -0,57 -0,47 -0,50 0,76 0,64 0,87 -0,25 -0,10 -0,43 -0,43 -0,41 -0,42 -0,78 1,00
Litter -0,38 -0,30 -0,29 0,58 0,48 0,49 -0,39 0,16 -0,18 -0,25 -0,21 -0,25 -0,36 0,54 1,00
QBS 0,43 0,54 0,60 0,46 0,49 0,11 -0,45 0,72 0,63 0,56 0,47 0,46 0,23 0,10 0,36 1,00
BD 0,40 0,25 0,16 -0,93 -0,88 -0,72 0,21 -0,37 0,10 0,06 0,10 0,23 0,51 -0,82 -0,52 -0,40 1,00
Age -0,65 -0,55 -0,33 0,72 0,64 0,67 -0,42 0,03 -0,38 -0,39 -0,23 -0,46 -0,60 0,83 0,52 0,13 -0,76 1,00
Statistical correlations
between parameters of the topsoil samples
Marked correlations are significant at p < 0,050 - N=14

30. Future monitoring
Sample plot
Confidence interval
75% 85% 95%
Parco Nord Milano – 23B 2 2 4
Parco Nord Milano – 1A 10 15 27
Parco Nord Milano – 1D 2 3 5
Parco Nord Milano – 2A 2 2 4
Parco Nord Milano – 2A_nd 7 11 19
Parco Nord Milano – 14A 1 2 2
Parco Nord Milano – 9A 1 1 2
Parco Nord Milano – 18C 2 2 4
Parco Nord Milano – 28C 1 1 2
Parco Nord Milano – 25A 1 1 2
Boscoincittà 2 3 5
Bosco di Maristella 1 1 1
Foresta di Carpaneta 1 1 1
Bosco Fontana 1 1 2
Number of samples for future soil monitoring
It was calculated the minimum number of soil subsamples to be collected for each plot in a future monitoring program in order to apply
significantly sound statistics oriented to highlight a defined change in soil pH.
The table shows the number of future samplings necessary to
highlight, in a few years, a possible variation of ± 0.3 pH
points, according to the confidence interval.
The minimum number of future soil subsamples (n) to be
collected in different areas was obtained using the following
equation:
• Фα is the critical value at the probability level α
• s2 is the observed variance
• D is the defined change in soil pH
2 2
2
s
D
 n =
s2
where:

31. Conclusions
 The 14 studied plots have soil well differentiated from each other.
 In some plots, pH has a great spatial variability, while it’s rather homogeneous in
others.
 Soil parameters: there is strong correlation between the age of the UPF and some
soil parameters (pH, SOC, total N, bulk density).
 The number of future soil samplings is in inverse relation to the variance of the
parameter: therefore, plots with a higher variability will require a greater number of
samplings than more uniform areas.
 The QBS Index has higher values ​​in forest soils, intermediate values in meadow soils
and lower values in arable soils; the biological quality tends to increase with the age
of the forest.
 Soil properties are modified by the UPF implantation, at first in the topsoil: the main
processes are acidification and SOM accumulation. Their intensity is directly
correlated with the age of the UPF.

32. Thank you
for your attention!