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Let’s not miss the grasses for the trees: In conversation with Mahesh Sankaran

Yashada Kulkarni

Mahesh Sankaran is Professor at the National Centre for Biological Sciences (NCBS), Bengaluru where he heads the Community and Ecosystems Ecology lab. He is the recipient of the Infosys Prize 2021 for Life Sciences, the first ecologist to have won this prestigious award. In this interview, he talks about his work on grasslands and climate change, and on winning the Infosys Prize. The interview has been edited for clarity and brevity.

Mahesh Sankaran [Source: ISF]
Mahesh Sankaran [Source: ISF] 

You were recently awarded the Infosys Prize for Life Sciences for your pioneering work on tropical savanna ecosystems and for research that permeated into policy. Can you tell us about your experiences on this path?

I worked in the computer science field for a couple of years before I realised I did not want to pursue it as a career. Since there were very few places in India that offered degrees in ecology at that time, I did my Master’s at Auburn University in the US in Wildlife Biology and PhD from Syracuse University. The fieldwork for my PhD was in the amazing ecosystem of Kalakad Mundanthurai Tiger Reserve in southern India. This was my first serious exposure to fieldwork. My postdocs were in the UK and the US, with fieldwork in the savanna ecosystems of Africa. I moved to India in 2009, where my work expanded from grassland ecosystems to forests. Some long-term research continues in Africa. 

Around 2015 – 16, I got involved with the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). Later, I was also a reviewer-editor for the Intergovernmental Panel on Climate Change (IPCC). Last year, I was part of a one-of-its-kind joint workshop of IPBES and IPCC. This workshop highlighted the link between biodiversity and ecosystem services and why we need to consider them in dealing with climate change. 

When we think of India’s natural landscapes, the word forest’ may come to mind, but not so much the words savanna’ and grassland’. Can you tell us something about these tropical grassy biomes in India and how they differ from forests?

Tropical grasses are C4 grasses, that is, they use a different photosynthetic pathway than trees. Savanna’, as is currently defined in literature, is a system where trees are interspersed in a C4 grass matrix. 

Grasslands and savannas were classified from a forest perspective by colonial foresters in India in the 1800s. Many are wrongly called dry thorn scrubs, open or dry deciduous forests. In India, majority of these biomes today have been transformed to other land uses and are facing many challenges since they are easy to clear and some of them are quite fertile. 

Overall, people seem to value forests more than grasslands. There is a term for this – biome awareness disparity. But grasslands are biomes in their own right and support many charismatic megafauna such as the great Indian bustard. Nearly 1/​5th of the world’s population depends on them.

What is the connection between grassy biomes and climate change?

Less than 5% of the plants on Earth are C4 grasses. While they occupy a very small fraction of plant diversity, they contribute to almost 25% of the global carbon cycle. Droughts, which are predicted to become more frequent due to climate change, cause trees to die and release carbon into the atmosphere. Since most of the carbon is below the ground in grasslands, during a drought, it stays below ground. It is argued that grasslands are thus more consistent and reliable carbon stores. Climate mitigation ventures such as tree plantation activities on grasslands can sometimes harm the ecosystem and be counter-productive. When it comes to their role in the carbon cycle, policy managers need to see what is below the ground and not just focus on above-ground carbon.

What would you put in your wishlist for policy changes in India for grassland conservation? 

My wishlist would include a greater appreciation of grasslands, recognition of the ecosystem services they provide and greater protection for them. Protection does not always mean designating grasslands as Protected Areas, such as National Parks, where human activities, fire and grazing are banned. Protection can also mean restoring grasslands and not allowing ill-conceived tree planting activities. 

You are the first scientist from the ecological sciences to have been awarded the esteemed Infosys Prize. What are your thoughts on the recognition of Indian ecological research outside academia and in mainstream society? 

It was an honour to receive the Infosys Award and gratifying to know it was given to somebody from the ecological sciences. Ecology is still a niche field in India and although there are more ecologists today, the number is still small. Hopefully, this recognition will make people aware that there are opportunities in ecology, climate and sustainability science. In terms of awareness outside academia, I think scientists need to do more to communicate their research, on more accessible platforms, particularly at the vernacular level. Also, there is a need for colleges in India to offer undergraduate courses in ecology. 

Any advice for young ecologists? 

We have some really great ecologists in the country today and more institutes offering courses in ecology. But many tend to work in evolution, behavioural and population-level ecology; few study larger-scale systems like climate modelling, energy and water cycles. Ecologists need to address these questions since they are critical in today’s world. My further advice – read, read, read! Also, spend more time in the field. Only when you spend time in the field can you reach a greater depth of understanding of ecological processes. 

How can we interest the future generation to take up stewardship of our Earth?

Immersion is key here since we learn through experiential and immersive learning. It is also critical that schools introduce nature and Earth education early, not just as classroom learning, but through, say, citizen science activities. Having undergraduate programs that bring technological, ecological and social aspects together is important. We have excellent young minds. We just need to engage them to work on planetary problems.

What are your observations on the trajectory of ecological research in India?

It has been very positive since India has a lot more early-career ecologists of excellent cadre. But we need more. In terms of ecological research, we as a country seem to have lagged behind others in setting up long-term research monitoring programs. The Ministry of Environment and Forests has approved long term ecological observatories and that is a good sign, as it is better to start late than never.