108
assisted by using ecological indicator values (e.g., Nimis and Martellos 2001, 2003)
and a numerical analysis of a matrix of species (Gombert et al. 2004; van Haluwyn
and Lerond 1988).
4.3 Method for the Calculation of the Value of Atmospheric
Purity
One of the most commonly used methods of using lichen as a bioindicator for the
biological indication of air quality is the index of atmospheric purity (IАP).
This method involves a quantitative approach to air quality assessment that combines the number, frequency, and coverage of each lichen species in a particular
study area (Kricke and Loppi 2002).
Тhere are 20 different formulas for calculating the IAP (Conti and Cecchetti
2001). One of the most commonly used formulas for calculating the index of atmospheric purity is:
IAP
u
¦
1
10 1
n
Q f
(4.2)
where n is the number of lichen species found at a given station, Q is factor for
accompanying species, and f is cover and frequency of each species.
The value for Q × f is divided by 10 to give a more manageable number (Johnsen
and Søchting 1973).
Factor Q is calculated as follows:
Q
S
m
j
m
i
n
ij
¦¦
1 1
(4.3)
where n is the number of species, m is the number of stations where the species of
interest are present, and S ij equals 1 if species i is present at station j (De Sloover and
LeBlanc 1968).
This formula is still widely used in recent air quality assessments based on the
calculation of IAP values, which is carried out in many research papers (Jayalal
et al. 2017; Das et al. 2013; Attanayaka and Wijeyaratne 2013; Biazrov 2002).
However, it has been shown that a simple method can very easily predict pollution
levels with a certainty of over 97% (Gottardini et al. 1999).
Over time, many modifications involving various parameters like vitality and
damage were developed. IAP values can be calculated using different equations:
IAP
u
¦
1
n
Q C
(4.4)
S. Ristić et al.
assisted by using ecological indicator values (e.g., Nimis and Martellos 2001, 2003)
and a numerical analysis of a matrix of species (Gombert et al. 2004; van Haluwyn
and Lerond 1988).
4.3 Method for the Calculation of the Value of Atmospheric
Purity
One of the most commonly used methods of using lichen as a bioindicator for the
biological indication of air quality is the index of atmospheric purity (IАP).
This method involves a quantitative approach to air quality assessment that combines the number, frequency, and coverage of each lichen species in a particular
study area (Kricke and Loppi 2002).
Тhere are 20 different formulas for calculating the IAP (Conti and Cecchetti
2001). One of the most commonly used formulas for calculating the index of atmospheric purity is:
IAP
u
¦
1
10 1
n
Q f
(4.2)
where n is the number of lichen species found at a given station, Q is factor for
accompanying species, and f is cover and frequency of each species.
The value for Q × f is divided by 10 to give a more manageable number (Johnsen
and Søchting 1973).
Factor Q is calculated as follows:
Q
S
m
j
m
i
n
ij
¦¦
1 1
(4.3)
where n is the number of species, m is the number of stations where the species of
interest are present, and S ij equals 1 if species i is present at station j (De Sloover and
LeBlanc 1968).
This formula is still widely used in recent air quality assessments based on the
calculation of IAP values, which is carried out in many research papers (Jayalal
et al. 2017; Das et al. 2013; Attanayaka and Wijeyaratne 2013; Biazrov 2002).
However, it has been shown that a simple method can very easily predict pollution
levels with a certainty of over 97% (Gottardini et al. 1999).
Over time, many modifications involving various parameters like vitality and
damage were developed. IAP values can be calculated using different equations:
IAP
u
¦
1
n
Q C
(4.4)
S. Ristić et al.