Ecological indices based on macrobenthos:
the case of AMBI and M-AMBI in assessing
seafloor integrity status
Dr Angel BORJA
Marine Research Division
aborja@azti.es
Introduction





Advantages
Ecological theory
Development
Validation
Applications (response to pressures)
Ecological status (M-AMBI)



M-AMBI
Disadvantages
Introduction: Impacts on benthos
AMBI (AZTI’s Marine Biotic Index) as indicator
of impact


AMBI
Reference conditions and status
Response to pressures
Advantages and disadvantages
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Impacts on benthos
• Advantages of using it as indicator:
–
–
–
–
–
Real affection to biota (species-community level)
Global indicator of pollution
Integrated information through time
Short life-span species: fast recovery (good change indicators)
Easy-work ecosystem component
• Disadvantages as indicator:
– Taxonomists are needed
– High economic cost
– Slow delivery of results
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Impacts on benthos
Which kind of biological approaches can be used?:
 Qualitative values: cover (for macroalgae), etc.
 Basic variables: taxonomy lists, richness, density,
biomass, diversity and evenness
 Different analyses: ABC curves, MDS, Canoco,
Primer, multimetric approaches, etc.
 Biotic indices: old methods, but recently refreshed
by new indices.
 In our case, the AMBI (AZTI Marine Biotic Index) and
M-AMBI (multivariate AMBI).
 They can be used in the MSFD for 2 of the indicators
of seafloor integrity: sensitive/opportunistic species
(AMBI) and multimetric indices (M-AMBI)
Introduction
AMBI
M-AMBI
Advantages
Impacts on benthos
Developing an index
Borja, A., D. Dauer, 2008. Ecological Indicators, 8: 331-337.
Disadvantages
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
• Adaptive strategies
– Reproductive (r): short
life-cycle, fast growth,
early sexual maturity,
larvae through the year
and direct development =
opportunists
– Competitive (k): long lifecycle, slow growth, high
biomass.
– Tolerant (T): species not
affected
– Not viable: azoic situation
PEARSON & ROSENBERG (1978)
MODEL
Peak of opportunistic species
Richness
Biomass
Abundance
+
ORGANIC MATTER ENRICHMENT
-
Borja, A., J. Franco, V. Pérez, 2000. Marine Pollution Bulletin, 40(12): 1100-1114.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
• Initial State = Normal zone
– Rich biocenosis in individuals and species
– Many species exclusive from the biocenosis, linked to grain-size
– High diversity
• Slight unbalance = Ecotone I = Disequilibrium zone
– Exclusive species decrease in number and abundance
– Tolerant species proliferate, pioneer species appear
– Diversity decreases
• Pronounced disequilibrium = Disequilibrium zone =
Polluted
– Representative species disappear, opportunists dominate
– Diversity very low
– In extreme cases presence of 1 or 2 species
• Fauna disappears = Azoic Zone
Borja, A., J. Franco, V. Pérez, 2000. Marine Pollution Bulletin, 40(12): 1100-1114.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
- Group I: Species very sensitive to disturbance, present under
unpolluted conditions (initial state): specialist carnivores, some depositfeeding tubicolous polychaetes.
- Group II: Species indifferent to disturbance, present in low densities,
non-significant variations with time (from initial state, to slight
unbalance), suspension feeders, less selective carnivores, scavengers.
- Group III: Species tolerant to excess organic matter enrichment. They
occur under normal conditions, but are stimulated by organic enrichment
(slight unbalance situations), surface deposit-feeding species, as
tubicolous spionids.
- Group IV: Second-order opportunistic species (slight to pronounced
unbalanced situations). Mainly small sized polychaetes: subsurface
deposit-feeders, such as cirratulids.
- Group V: First-order opportunistic species (pronounced unbalanced
situations). These are deposit-feeders, which proliferate in reduced
sediments.
Borja, A., J. Franco, V. Pérez, 2000. Marine Pollution Bulletin, 40(12): 1100-1114.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
Borja, A., J. Franco, V. Pérez, 2000. Marine Pollution Bulletin, 40(12): 1100-1114.
Normal
Unbalanced
Polluted
Very polluted
Group I
Sensitive
Group II
Indifferent
Group III
Tolerant
Group IV
Opportunistic
Group V
Opportunistic
© AZTI-Tecnalia
Increasing gradient of impact or disturbance
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI =
((0 * %GI) + (1.5 * %GII) + (3 * %GIII) + (4.5 * %GIV) + (6 * %GV))/100
Dominating
Ecological Group
I
PERCENTAGE OF GROUPS
100
Biotic
90
AMBI
Coefficient
80
0.0 < AMBI
BC
70  0.2
60  1.2
0.2 < AMBI
BC
50  3.3I
1.2 < AMBI
BC
40
3.3 < AMBI
BC
 4.3
30
4.3 < AMBI
BC
20  5.0
10  5.5
5.0 < AMBI
BC
5.5 < AMBI
BC0 0 6.0
Azoic
WFD
III
III
IV-V
1
UNPOLLUTED
V
Azoic
II
2
5
Benthic Community Health
6
Site Disturbance
Classification
AZOIC SEDIMENT
1
0
POLLUTION
BIOTIC AMBI
COEFFICIENT
2
3
4
Normal
V Undisturbed
Impoverished
Unbalanced
Slightly disturbed
Transitional to pollution
Meanly disturbed
IV
Polluted
Transitional to heavy pollution
Heavily disturbed
Heavy3 polluted 4
5
6
7
BIOTIC INDEX
Azoic
Extremely disturbed
SLIGHTLY POLLUTED
MEANLY POLLUTED
HEAVILY
`POLLUTED
EXTREM.
POLLUTED
HIGH
GOOD
MODERATE
POOR
BAD
STATUS
STATUS
STATUS
STATUS
STATUS
INCREASING POLLUTION
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
•
•
You can consult our web page (http://ambi.azti.es) and obtain our free
AMBI software to calculate and represent the index.
This approach includes the classification of 6,500 species from the
Atlantic, Mediterranean, Pacific, etc. (it is updated regularly).
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
3006
200
5
(ml.l -1)
POTENCIAL
REDOX
(m V)
OXYGEN
DISSOLVED
OXÍGENO
DISUELTO
(mV)
POTENTIAL
REDOX
4007
100
4
0
3
-100
2
-200
0
0
1
1
2
2
3
3
4
4
5
5
AMBI
ÍNDICE
BIÓTICO
6
6
7
7
BIÓTICO
ÍNDICEAMBI
Borja, A., J. Franco, V. Pérez, 2000. Marine Pollution Bulletin, 40(12): 1100-1114.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
100
300
800
250
90 2,0
25080
700
LEAD
Pb
Cr
CHROMIUM
CADMIUM
Cd
ZINC
Zn
COPPER
Cu
200
600
70
1,5
200 500
60
150
400
15050
1,0
40 300
100
10030 200
20 0,550
50
10
0
0
100
00
0,0
0
0
00
0 1
1
11
1 2
2
2
33
44
55
3
4
5
3
4BIÓTICO
2 ÍNDICE
3 BIÓTICO
4 5 5
ÍNDICE
AMBI
AMBI
ÍNDICEAMBI
BIÓTICO
ÍNDICE
BIÓTICO
ÍNDICE
BIÓTICO
AMBI
AMBI
66
6
6 6
77
7
7 7
Borja, A., J. Franco, V. Pérez, 2000. Marine Pollution Bulletin, 40(12): 1100-1114.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
%ERL-Hg
PORCENTAJE
PERCENTAGE
PORCENTAJE
PERCENTAGE
PORCENTAJE
PERCENTAGE
PERCENTAGE
PORCENTAJE
100100
%ERL-Ni
%ERL-As
100
%ERL-Cr
100 90 90
%ERL-Cd
%ERL-Pb
90
%ERL-Cu
80
90 80 80
70
80 70 70
60 60
60
70
50
50
50
40
60
40
30
50 30 40
20
40 20 30
10
30 10 20
0
0
1
2
3
4
5
6
20 0 10
0 0
1
2
3
4
5
10
INDICEAMBI
BIÓTICO
0
1
2
3
4
5
AMBI
INDICE
BIÓTICO
0
0
1
2
3 AMBI
4
5
ÍNDICE
BIÓTICO
%ERL-DDT
%ERL-PAH
%ERL-PCB
7
6
7
6
6
7
7
AMBI
INDICE
BIÓTICO
Borja, A., J. Franco, V. Pérez, 2000. Marine Pollution Bulletin, 40(12): 1100-1114.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
Applications: submarine outfall (Barcelone)
Cardell, M. J. (1996). Estructura y dinámica de la macrofauna bentónica en
sedimentos
marinos sometidos a vertidos domésticos e industriales: Efecto de las
SPAIN
aguas y lodos residuales de Badalona
la planta depuradora de Sant Adrià de Besòs
(Barcelonès). Ph.D. Thesis, Universidad de Barcelona, 450 pp.
Ros, J., Cardell, M.J., Alva, V., Palacín, C. & Llobet, I. (1990). Comunidades
sobre fondos blandos afectados por un aporte masivo de lodos y aguas residuales
33
(litoral frente a Barcelona, Mediterráneo Occidental): Resultados
preliminares.
Actas VI Simposio Ibérico de Estudios del Bentos Marino, Palma de Mallorca, 1,
407-423.
Besòs River
32
11
27
8
28
26
Barcelona
4
25
21
34
1 36
37
2
5
20
38
14
3
35
30
22
19
24
18
15
40
31
39
23
16
13
17
12
29
0
1
2
3
4
5
6
7
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
Applications: Nervión estuary (Spain)
Adapted from Borja et al., 2006 (MEPS)
7
90%
6
70%
5
60%
4
50%
40%
3
30%
2
20%
1
10%
IV
III
II
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
AHV
closed
Water treatment
started
V
1994
1993
1992
1991
0
1990
0%
Biological
treatment
I
AMBI
Oxygen sat.
AMBI
80%
1989
Oxygen Saturation
Ecological Groups
100%
AMBI v
4
3
Introduction
2
1
0
0
200
400
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI
600 validation
800
1000
1200
1400
Applications:
drill-cuttings (North Sea)
DISTANCE (m)
Beryl B
7
7
5
4
3
2
1
0
0
AMBI values
AMBI
values
AMBI
AMBI values
6
Beryl B
HD
2
MD
y = 0.5707Ln(x) - 0.8734
5
76
4
6
3
5
5
2
R = 0.8351
SD
44 1
UD
0
3
5000 3000 1000 500
3
2
12 7
01 6
5
2000
950 500 130
0 4
AMBI values
7
ED
6
3
2000
1
2
1
4000
10
250
250
500
1000 3000 5000
ED
250
500
850
MD
SD
UD
HD
1200 2000 3000 5000
80001000 10000 10000
12000
SD
DISTANCE
(m)
TOTAL ORGANIC
CARBON
TOTAL
HYDRO
CARBON
UD
0
500
HD
MD
6000
100
5000 3000 1000
ED
250
250
500
1000 3000 5000
Muxika, I., A. Borja, W. Bonne, 2005. Ecological Indicators, 5: 19-31.
100000
Introduction
AMBI
M-AMBI
Advantages
Ecological theory of AMBI
AMBI development
AMBI validation
Applications: fish farm (Greece)
7
6
5
4
3
2
1
0
0
5
Cephalonia
10
25
Ithaki
C
Sounion
Muxika, I., A. Borja, W. Bonne, 2005. Ecological Indicators, 5: 19-31.
Disadvantages
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
Applications: aquaculture
Dependent variable
Abundance
Richness
Diversity AMBI
-2
log(ind. m ) (nr. of taxa) (ind. bit-1)
intercept
4.2703645
-7.524
1.774
4.496
De=Depth (square root (meters))
8.402
0.397
-0.0486
C=Current speed (log(cm s-1))
-1.072
-1.615
P=Production (t year-1)
-0.000335
-0.000599
-0.00104 0.000665
Di=Distance to cages (log(1+meters))
3.514
0.534
-0.593
0.226
0.252
0.413
0.451
Multiple R-squared
<0.001
<0.01
<0.001
<0.001
p-value
Borja, A., J.G. Rodríguez, K. Black, A. Bodoy, C. Emblow, T.F. Fernandes, J. Forte, I.
Karakassis, I. Muxika, T.D. Nickell, N. Papageorgiou, F. Pranovi, K. Sevastou, P.
Tomassetti, D. Angel, 2009. Assessing the suitability of a range of benthic indices in the
evaluation of environmental impact of fin and shellfish aquaculture located in sites
across Europe. Aquaculture, 293: 231-240.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
Applications: aquaculture
AMBI
5
4
5
d = 15 m
s = 3 cm s-1
1500
3
4
100
2
100
5
AMBI
3
100
4
1500
3
200
300
5
800
3
4
100
2
10
20
30
1500
50
5
4
100
150
1500
3
0
10
20
30
50
100
distance to cages (m)
150
100
0
10
3
1500
800
800
1
0
10
20
distance to cages (m)
Borja et al., 2009. Aquaculture, 293: 231-240.
30
30
1500
2
100
20
d = 60 m
s = 14 cm s-1
4
1
0
800
5
d = 60 m
s = 8 cm s-1
2
1
30
1
3
100
2
20
1500
2
100
4
800
10
d = 40 m
s = 14 cm s-1
3
800
5
d = 60 m
s = 3 cm s-1
0
4
1
0
100
5
d = 40 m
s = 8 cm s-1
2
1
800
1
0
d = 40 m
s = 3 cm s-1
1500
2
1
0
d = 15 m
s = 14 cm s-1
4
800
2
1
AMBI
1500
3
800
5
d = 15 m
s = 8 cm s-1
0
10
100
20
distance to cages (m)
30
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Ecological theory of AMBI
AMBI development
AMBI validation
Applications: harbour (Spain)
5
Blanes
3 4
6
2
7
GIRONA
C oeficiente B iótico (B C )
6
Río
Tordera
S ta tio n 1
S ta tio n 2
S ta tio n 3
S ta tio n 4
S ta tio n 5
S ta tio n 6
Highly disturbed
5
Moderately disturbed
4
3
Slightly disturb
2
1
1
Undisturbed
0
Mar
A pr
May
J un
J ul
A ug
S ep
Oct
Nov
D ec
Jan
Feb
Mean
Introduction
AMBI
M-AMBI
Advantages
Reference conditions and status
Reference Variation
Ecological Status
None or
small
High
Slight
Good
Moderate
Moderate
Important
Poor
Strong
Bad
Disadvantages
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Reference conditions and status
Stretches
Oligo/Mesohaline
Polyhaline
Euhaline

Type I
Type II
Type III
Type IV
C. edule-S. plana
C. edule-S. plana
C. edule-S. plana
V. fasciata/P. arenarius
V. fasciata
A. alba/P. arenarius
A. alba
T. tenuis-V. fasciata
We use diversity,
richness and AMBI in
assessing quality =
M-AMBI.
SYSTEMS SIZE SAMPLE Nº REPLICATES SIEVE
Coastal
0.1 m2
3
1 mm
Estuarine
0.25 m2
3
1 mm
High status
Indicator
Richness (nr sp.)
Diversity (bit.ind-1)
AMBI
C. edule-S. plana
13
2.5
2.8
4
V. fasciata
32
3.8
2
P. arenarius
9
2
1
Richness 13
A. alba
40
3.5
2.1
T. tenuis-V. fasciata
42
4
1
Bad status: all 0, except AMBI= 6
Muxika, I., A. Borja, J. Bald, 2007. Marine Pollution Bulletin, 55: 16-29.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Factor 2
Reference conditions and status
2
Ecological Quality Ratio (EQR) or MAMBI: between 0 and 1, depending on
boundaries between quality classes,
the ecological status is assessed
r3
A : High status
R: 13
H’: 2.5
AMBI: 2.8
to
Fac
1
R: 4
H’: 1.6
AMBI: 3.3
H
Factor 1
G
M
P
B : Bad status
B
R: 0
H’: 0
AMBI: 6
Muxika, I., A. Borja, J. Bald, 2007. Marine Pollution Bulletin, 55: 16-29.
3
Introduction
AMBI
M-AMBI
Advantages
Reference conditions and status
Borja, A., D. Dauer, A, Grémare, 2012. Ecological Indicators, 12: 1-7.
Disadvantages
Introduction
AMBI
M-AMBI
Advantages
Reference conditions and status
Disadvantages
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Reference conditions and status
Response of M-AMBI to pressures
M-AMBI
20 km
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1994
H
G
M
P
B
1996
1998
2000
E-N20
2002
2004
2006
2008
E-N30
Borja, A., I. Muxika, J.G. Rodríguez, 2009. Marine Ecology, 30: 214-227.
Introduction
AMBI
2001
M-AMBI
Advantages
Disadvantages
2002
2005
Reference conditions and status
Response of M-AMBI to pressures
2006
M-AMBI
20 km
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1994
H
G
M
P
B
1996
1998
2000
E-O5
2002
E-O10
2004
2006
2008
E-OI10 Introduction
100
E-OI15
AMBI
M-AMBI
Advantages
Disadvantages
Reference conditions and status
Response of M-AMBI to pressures
E-OI20
80
60
40
20
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1994
20 km
2006
2006
2005
2004
2003
2003
2002
2001
2000
2000
1999
1998
1997
1997
1996
1995
1994
0
M-AMBI
OXYGEN SATURATION (%)
120
H
G
M
P
B
1996
1998
2000
E-OI10
2002
E-OI15
2004
2006
2008
E-OI20
Borja, A., I. Muxika, J.G. Rodríguez, 2009. Marine Ecology, 30: 214-227.
s
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Reference conditions and status
Response of M-AMBI to pressures
Pressure/Action
Discharge removal
Sediment disposal
Discharge removal
Before Pressure or Action
Years
MAMBI±SD
1996 to 2001
0.34±0.13
1995, 1997, 1998,
1999, 2000
0.80±0.04
2002
1995 to 1997
0.66±0.02
Dredging
1999, 2000, 2001
0.81±0.02
Dredging
1997, 1998, 2001,
2002, 2005
0.55±0.07
1998, 1999, 2000,
2001
Land reclamation
1999, 2000, 2001
Marina construction
2004, 2005
Dredging
After Pressure or Action
Years
MAMBI±SD
2002 to 2007
0.85±0.13
1996, 2001,
2002, 2003
0.53±0.11
2003, 2004
1998 to 2001
0.79±0.03
2002
0.50±0.06
2002, 2003
1995, 1999,
2000, 2003,
0.39±0.04
2004
t-Student
Significance
-6.56
p<0.005
5.53
p<0.005
-7.84
p<0.005
8.50
p<0.005
4.28
p<0.005
0.84±0.16
2002, 2003
0.38±0.16
3.44
p<0.05
0.48±0.02
0.59±0.07
2002, 2003
2006, 2007
0.32±0.06
0.48±0.07
3.93
1.63
p<0.005
NS
Borja, A., I. Muxika, J.G. Rodríguez, 2009. Marine Ecology, 30: 214-227.
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Reference conditions and status
Response of M-AMBI to pressures
Borja et al., 2011. Marine Pollution Bulletin, 62(3): 499-513..
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Reference conditions and status
Response of M-AMBI to pressures
Callier, M. D., M. Richard, C. W. McKindsey, P. Archambault, G. Desrosiers,
2009. Responses of benthic macrofauna and biogeochemical fluxes to
various levels of mussel biodeposition: An in situ "benthocosm" experiment.
Marine Pollution Bulletin, 58: 1544-1553.
Introduction
AMBI
AMBI
M-AMBI
Advantages
Disadvantages
Reference conditions and status
Response of M-AMBI to pressures
AMBI & M-AMBI use
AMBI and M-AMBI
Denmark
Germany
Netherlands
UK
Ireland
France
Spain
Portugal
Italy
Slovenia
Greece
Cyprus
Bulgaria
Romania
AMBI
X
X
X
X
X
X
X
X
X
X
O
O
X
X
M-AMBI
X
O
X
X
O
X
X
X
X
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
AMBI and M-AMBI can be used with density and biomass
Cai, W., Á. Borja, L. Liu, W. Meng, I. Muxika, J.G. Rodríguez (in press). Assessing benthic
health under multiple human pressures in Bohai Bay (China), using density and biomass in
calculating AMBI and M-AMBI. Marine Ecology
0.9
y = 0.8576x + 0.0227
R² = 0.8114
M-bAMBI
0.7
0.5
0.3
0.1
Bad
-0.1
-0.1
0.1
Poor
Moderate
0.3
0.5
M-AMBI
Good
0.7
High
0.9
Introduction
(i)
AMBI
M-AMBI
Advantages
Disadvantages
AMBI and M-AMBI have been validated with a large set of environmental
pressures and impact sources (near 300 and 70 references, respectively).
(ii) AMBI and M-AMBI are easy to use, having freely-available software, with
an updated species list with 6,500 taxa (http://ambi.azti.es)
(iii) AMBI has guidelines for use (Borja & Muxika, 2005. Mar. Poll. Bull).
(iv) AMBI and M-AMBI are efficient in detecting time and spatial impact
gradients.
(v) AMBI is insensitive to seasonal variability (in absence of external impacts)
(vi) AMBI is independent from sample size
(vii) AMBI and M-AMBI have been verified in a very large number of
geographical areas.
(viii) AMBI and M-AMBI are useful in advising policy-makers (comprehensive
pictures for non-scientists).
(ix) M-AMBI has been intercalibrated within the Water Framework Directive.
Introduction
(i)
AMBI
M-AMBI
Advantages
Disadvantages
The robustness of AMBI is reduced with low number of taxa (1 to 3) and/or
individuals (including naturally-stressed locations).
(ii) AMBI does not work well with physical impacts: sand extraction, fish
trawling, etc. (but, M-AMBI works in some of these cases)
(iii) In order to avoid ambiguous results, calculate the AMBI values for each of
the replicates, then to derive the mean value.
(iv) Be careful with high unassigned percentage of taxa (>20%) in AMBI.
(v) The assignation of taxa to the ecological groups, together with taxonomy
problems (synonyms, etc.) could lead to misclassification problems. The
assignation requires some consensus between the scientific community.
(vi) M-AMBI needs clear sampling protocols, since diversity and richness
depend on sample size
(vii) The status assessment depends on the boundaries set in the AMBI and
M-AMBI scale values. Changing the boundaries would alter the final
classification (as in other methods).
(viii) It is better to use M-AMBI with a minimum of 50 stations
Introduction
AMBI
M-AMBI
Advantages
Disadvantages
Final comments
(i)
Algorithms of M-AMBI: each software uses different algorithms when
calculating Factor Analysis, producing different M-AMBI values. Use AMBI
software.
(ii) For M-AMBI: derive always adequate reference conditions for each
ecotope/type
(iii) Both methods are practical and pragmatic, easy to understand by the
society
(iv) AMBI software runs only in PC
(v) Finally, if you know a method working anywhere, under all pressures, all
circumstances, etc., please, let me know!!!
Dr Ángel Borja (aborja@azti.es)
FP7 DEVOTES Project: www.devotes-project.eu
ResearchGate Profile: https://www.researchgate.net/profile/Angel_Borja/
Linkedin: www.linkedin.com/profile/view?id=245091062&trk=tab_pro