Asian Journal of Applied Sciences (ISSN: 2321 – 0893) Volume 04 – Issue 02, April 2016 Asian Online Journals (www.ajouronline.com ) 256 Atmospheric Air Pollution and Roughness of Bark as Possible Factor in Increasing Density of Epiphytic Terrestrial Algae Asmida Ismail a* , Noor Akmal Abd Wahab a , Mohd Talib Latif b , Mohd Nizam Mohd Said b , Ahmad Ismail b , Amyrul Rafiq Zulkifli a , Ihsan Alwi a , Dzulsuhaimi Daud a & Fatin Normas Sulaiman a a School of Biology, Faculty of Applied Sciences, Universiti Teknologi MARA 40450, Shah Alam, Selangor, MALAYSIA b School of Environmental and Natural resource Sciences,Faculty of Science & Technology, Universiti Kebangsaan Malaysia 436000, Bangi, Selangor, MALAYSIA * Corresponding author’s email: asmida [AT] salam.uitm.edu.my _____________________________________________________________________________________________________________ ABSTRACT--- Air pollution released to the atmosphere due to anthropogenic source particularly of motor vehicles creates emissions that significantly affect not living organisms. Epiphytic terrestrial algae were known to have a tendency towards atmospheric gases due to its high sorption capability. Besides the pollutant, the different texture of the bark of the trees also plays an important role for the colonization of the algae. This present work studies on two parameters that canaffect the number of algal cells per unit area (density); the increased pollutants and tree bark texture. Sampling stations which represent the polluted and relatively unpolluted environment hasbeen chosen. Quadrat sampling method was used to estimate the density of algae on 30 random trees inhabiting 15 x 15 cm quadrat. Results showed that both polluted and unpolluted sites were dominated by the same algal species, the Coccomyxa confluens (Kützing) Fott. The polluted environment significantly support higher number ofepiphyticalgaeat 202 ± 37 x 10 4 cells/cm 2 compared to the unpolluted area at 63 ± 12 x 10 4 cells/m 2 . Similarly, trees with rough textures was found to sustain higher number of algal cell at 228 ± 52 x 10 4 cells/cm 2 compared to trees with smooth textures (187 ± 41 x 10 4 cells/cm 2 ). Higher concentration of carbon dioxide and/or carbon monoxide and nitrogenous gases in polluted area possibly enhanced the growth of epiphytic terrestrial algae.In conclusion, polluted environment and rough bark textures was found to positively support higher algal density. Keywords--- algae, air pollution, density, dominant species, bark _____________________________________________________________________________________________________________ 1. INTRODUCTION Air pollution is defined as the presence of foreign substances in the air or excessive amounts of certain impurities. Emissions from motor vehicles are the single most significant source of air pollution in many Malaysian urban areas (Waleed et al., 2013). As for the past years, motor vehicles remain the major contributor of air pollution especially in urban areas. In 2010, the number of registered car passengers increased by 7.16%, motorcycles by 5.61%, buses by 3.86%, goods vehicles by 3.20% and taxis by 6.96% compared to 2009 (Waleed et al., 2013). Up to end of 2011, there were 21,401,269 vehicles registered in Malaysia (Briggs, 2007). Significant quantities of pollutants such as carbon dioxide, carbon monoxide, sulfur oxides, nitrogen oxides, ammonia, particulate matter, volatile organic compounds and toxic metals such as leads are generated from great number of transportation.Air pollution from vehicles is split into primary and secondary pollution. Primary pollution is emitted directly into the atmosphere and become as precursors of secondary air pollutants. Meanwhile the secondary pollution results from chemical reactions between pollutants in the atmosphere. The combustion of fossil fuels is the most common source of air pollution (Afroz et al., 2003). Emissions from cars increase the levels of carbon dioxide (CO 2 ) and other greenhouse gases in the atmosphere. Malaysia produced 5.4 metric ton of CO 2 for the year 2000 exceeding the global average production of 3.9 metric ton per capita, and Asian average production of 2.2 metric ton per capita. Air pollutants particularly the nitrogen containing ones are known to affect vegetation indirectly either via chemical reactions in the atmosphere, or directly after being deposited on vegetation, soil or water (Frank, 2000). Therefore, vehicle exhaust emissions are a dominant feature causing detrimental effects on plants (Honour et al., 2009). Presence of anthropogenic pollutants and non-point source pollutants in the air caused air pollution which indirectly contributed towards the degradation of environment. The air pollutants especially those emitted by the vehicles, give negative impacts towards the population of epiphytic terrestrial algae. Since algae has been known as one of the bio-indicator for air pollution, the increasing or reducing number of algal population indicates the status of air pollution within the area. Several