Air pollution assessment using lichen biodiversity index (LBI) in Shah Alam, Selangor / Nurul Adibah Mokhtar

Biomonitoring technique was frequently used to monitor air pollution level. Lichens are
the commonly used biomonitor since it has the ability to absorb toxic materials into
their thallus system. A study was conducted in Shah Alam, Selangor to determine the
species composition of lichen, to assess the air pollution status according to Lichen
Biodiversity Index (LBI) and to quantify the effect of motor vehicle frequency on the
LBI value and species composition of lichens. This study also aimed to identify the
most tolerant and the most sensitive lichen species in the study area. A total of 21
sectionsin central Shah Alam were studied with 52 sampling stations were chosen based
on the presence of Roystonea regia as the host tree for lichen. Frequency of lichen was
collected using quadrat with a dimension of 10 x 50 cm2

and lichens found within the
quadrat were collected for species identification purpose. Frequency of motor vehicles
on the traffic road of each sampling station in the study area was counted and recorded
to determine the influence of phytotoxic gaseous released by motor vehicles on lichens
in the study area. From morphological analysis conducted on the lichen samples,
thirteen species of lichen from nine genus and seven family were recorded. Air pollution
status of each sampling station was calculated based on LBI to determine the air
pollution status in central Shah Alam. Two sections showed high alteration of air, six
sections showed moderate alteration of air, eight sections showed low alteration of air
but with low naturality, four sections showed moderate naturality of air and one section
showed high naturality of air. Section 10, 19 and 21 were omitted due to the absence of
the host tree. Section 10 and Section 19 have been developed as a private property area
while Section 21 have been developed as cemeteries area. According to the LBI
standard, this study area is considered as slightly polluted since 38.10% of the study
area showed condition above moderate pollution level (low alteration/low naturality)
while only 23.81% of the study area showed condition below moderate pollution level.
Regression analysis showed a negative linear relationship between LBI value and
frequency of motor vehicles with R

2 = 0.652. Air pollution caused by motor vehicles
also negatively affected the species composition of lichen in this study area where there
is also a negative linear relationship with R

2 = 0.596. Pyxine cocoes was identified as
the most tolerant lichen species since it was found in all 21 sections while Parmotrema
praesorediosum was identified as the most sensitive lichen as it was only found in
Section 6 and Section 12 that possessed the highest LBI value. Principal Component
Analysis (PCA) was also conducted to determine the correlation of various lichen
species and study area. From the analysis, PCA plot indicated that the lichen species
were correlated with sections that comprised of mostly moderate and less polluted
sampling stations which are Section 1, 6, 7, 8, 9, 16, 17, 18, 20 and 23. The most
sensitive lichen species; Parmotrema praesorediosum showed a high correlation with
Section 6 and 12 while the most tolerant lichen species; Pyxine cocoes showed a high
correlation with Section 7 and 9. From the result, this study has proven that lichen is
very suitable to be used as biomonitoring tool for air pollution and air quality
assessment. Therefore, it should be widely used in the future study since it may indicate
a direct effect of the pollution towards living organisms.