Air pollution on highways and motorways perturbs carbon and nitrogen levels in roadside ecosystems

ABSTRACT

Vehicle emissions create corridors of increased carbon and nitrogen concentrations near highways that influence surrounding ecosystems. This study used the leaves of a variety of wild plant species and soil samples to examine the extent of total carbon (C) and total nitrogen (N) near highway M-2 and FSR in Punjab, Pakistan, in all four seasons of the year. Results showed significantly higher concentrations of C and N near roads in both plants and soils, indicating that a high proportion of vehicle derived C and N is deposited near roads. Compared to control samples, average soil C and N concentrations were increased by 174% and 519%, respectively, on the M-2 road. Similarly, 237% and 628% more C and N were measured in soil on FSR, respectively. The difference in mean concentrations of C and N among different seasons varied significantly. We inferred from these results that the level of C and N along roads depends upon the distance from the road, traffic volume, and seasonal variations. The raised level of C and N compounds could cause perilous impacts on the environment, especially to farmlands around major highways. Hence, farming activities like growing fruits and crops should be avoided near roads.

KEYWORDS:

• Air pollution
• Roadsides ecosystems
• C-N pollution
• Biomonitors

Acknowledgements

We are thankful to Katie Nigro (Colorado State University, Colorado, United States) for critically reviewing and language edition of our paper. We also acknowledge the help of Georgia Titcomb and Benjamin Boyce (University of California, Santa Barbara, United States) in laboratory analysis of samples, and Dr. Shaker ul Din Rahimoon (Lanzhou University, Lanzhou, China) for providing assistance in graphical representation of the study area. The authors also extend their deep appreciation to Deanship of Scientific Research, King Khalid University for funding through grant number R.G.P2/101/41.

Notes on contributors

Dr. Noreen Khalid is an Assistant Professor in the Department of Botany, Government College Women University Sialkot, Pakistan. She obtained her PhD in Ecology from University of Agriculture Faisalabad, Pakistan. She widely studied the impacts of vehicular emissions on roadside ecosystems in Punjab, Pakistan and California, USA.

Dr. Ali Noman is a faculty member at Department of Botany, Government College University Faisalabad, Pakistan. He has an experience on studying plant environment interactions. Currently his focus is upon environmental degradation and strategies to improve plant growth.

Dr. Atifa Masood is targeting upon plant environment relations under abiotic stress and currently working in Department of Botany, The University of Lahore.

Dr. Aasma Tufail working as an Assistant professor in the Department of Botany, University of Education, Lahore, Pakistan since 2016. Her Area of research is Plant Anatomy and Physiology.

Dr. Naila Hadayat is an Ecologist with expertise in plant survival and distribution in polluted soils and environments. She also studied the impacts of vehicular emissions on roadside ecosystems in Punjab, Pakistan and Florida, USA.

Dr. Ghalia S. H. Alnusairi is an environmentalist and has experience in teaching and research in arid environments of Kingdom of Saudi Arabia.

Prof. Dr. Saad Alamri is currently focusing on plant survival during abiotic stresses.

Prof. Dr. Mohamed Hashem is a professor Botany and Microbiology. His research includes plant environment interactions and growth dynamics during stress tolerance.

Mr. Muhammad Aqeel is a doctoral researcher of Ecology at School of Life Sciences, Lanzhou University, PR China. He studied impact of environmental hazards on plant functioning previously. Currently he is focusing on main natural plant communities’ structure, function and their driving factors across various climatic zones.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The authors also extend their deep appreciation to Deanship of Scientific Research, King Khalid University for funding through grant number R.G.P2/101/41.