South Asian Nitrogen Hub, University of Peradeniya and Dilmah Tea share outcomes of the project at knowledge sharing event
The Dilmah Conservation “Lichens: Nature’s Air Quality Sensor” event, held on 3rd October 2024, highlighted research on nitrogen pollution’s impact on biodiversity and ecosystems in Sri Lanka and South Asia. The event presented the findings of a five-year study led by the South Asian Nitrogen Hub (SANH), the University of Peradeniya, and Dilmah Conservation, focusing on the Rilagala forest near Dilmah’s Climate Change Research Centre. This study is the first to gather high-frequency high-quality continuous ammonia and meteorological data set in Sri Lanka. Another highlight is that the research uses lichens as bioindicators to monitor nitrogen pollution in tropical forests. The research fills a significant gap in understanding nitrogen pollution’s effects, supporting more effective nitrogen management, vital for preserving tropical ecosystems. The event, held at the Genesis Dilmah Centre in Maligawatte, featured regional experts like Dr. Gothamie Weerakoon, Prof. Sarath Nissanka, Prof mark Sutton and Dr. Ajinkya Deshpande, who shared insights from the study.
Dr Gothamie Weerakoon (left) on Lichens and Dr Ajinkya Deshpande (right) on the details of the Ammonia Enhancement Project that uses lichens as bioindicators to measure nitrogen pollution
Professor Mark Sutton, Director, SANH, joined online from the UK to speak on the global nitrogen pollution problem. He explained that only 20% of nitrogen used in agriculture (from fertiliser and livestock) is efficiently absorbed, with the rest contributing to pollution. Sutton highlighted that nitrogen waste represents both an environmental and economic issue
He said, ‘If we take the total value of nitrogen wasted in air and water, which is about 200 million tonnes, and multiply that by USD 1.50 per kilogram of nitrogen, we get approximately USD 300 billion worth of wasted nitrogen resources. In the Colombo Declaration of 2019, the Sri Lankan government committed to the ambition of halving nitrogen waste by 2030. At today’s prices, this would save around USD 150 billion worth of resources each year.’
Sri Lanka’s nitrogen management needs improvement, as noted by Prof. Nissanka, who revealed that the country ranks 131st out of 181 nations in sustainable nitrogen management. One key outcome of SANH’s research was a comprehensive review of Sri Lanka’s nitrogen-related policies, leading to the creation of the National Nitrogen Policy Report. This along with data findings can be used to begin dialogue with different sectors towards setting Nitrogen emissions controls policies.
Dr Ajinkya, Environmental Ecologist, UK Centre for Ecology & Hydrology (UKCEH) said, “There is a combined effect of a changing climate and increasing air pollution and these two have a negative impact on sensitive organisms like lichens and moss which would lead to a widespread loss of these species and be extremely harmful for a biodiversity hotspot such as Sri Lanka. So all this put together creates the need for high quality measurements to start seeing what the impacts are and how we can mitigate them.”
Dr. Gothamie Weerakoon, Lichen specialist, Natural History Museum, UK explained why lichens are excellent air quality sensors. She pointed out that lichens predate dinosaurs, having appeared over 600 million years ago, and are capable of starting ecological succession. As some of the slowest-growing organisms on Earth, with some specimens as old as 11,000 years, lichens offer valuable long-term insights into environmental changes.
Dr. Weerakoon added, “Lichens can tell us what has happened, how temperature has shifted, and how humidity levels have changed.”
Buddhika Weerakoon, PHD candidate, University of Peradeniya shared that the research identified around 150 lichen species within the sampling plot, noting significant responses from lichens to elevated ammonia levels. This highlights the rich biodiversity of the area and demonstrates the ability of lichens to act as bioindicators, effectively monitoring air quality and nitrogen pollution.
Additionally, research coordinator Tharindu Prabashwara discussed the various challenges and achievements encountered during the project, while field assistants Thathsarani Hemapala, Chamara Udayanga, and Sanjaya Karunarathna shared their hands-on experiences and contributions to the research.
