‘Microbes are so resilient, they can help us adapt to climate change’

Steven D. Allison

teaches microbial and ecosystem ecology at the

University of California, Irvine

. He tells

Times Evoke

about how microbes can benefit us in a warming world:
I’m interested in studying how microorganisms like bacteria and fungi are responding to climate change as well as how they could help us address the climate problem through the important functions they provide. Microbes are everywhere in our environment, and vital for our planetary cycles as they provide the opposite function to plants — the latter take carbon dioxide out of the atmosphere during photosynthesis while taking up nutrients from the soil and storing these in their biomass. When plants, animals or plankton perish, microbes recycle all these nutrient and carbon forms, making them available for new life to grow. Microbes also do carbon sequestration — perished microbes stick in the soil, adding reformulated compounds to

earth

. This strengthens soil health.

STAYING ALIVE: Studies of climate change impacts on soil microbes were conducted recently at the Loma Ridge Global Change Experiment in Irvine,

California

, where plastic covers reduced rainfall in order to reach experimental drought plots by nearly 50%. Interestingly, the microbial communities managed to survive the climate shock. Photo Courtesy: S. Allison



Importantly, crops need microbes to grow — with climate change, there are worries about heatwaves and droughts causing immense stress to plants. They will need all the help they can get to maintain our food supply. Now, certain microbes live in very close association with plant roots — they help roots acquire nutrients which actually make plants grow better and improve crop yields. So, as the climate changes, we need to discover the most effective microbes that help plants in stressful conditions and the most practical ways to add these to certain soils, like degraded ones, to boost crop growth.



Microbe resilience is fascinating. These are incredibly complex organisms and almost four billion years of evolutionary history have shaped the microbes present in the planet today. Microbes also evolve very quickly in response to changes in climate — they can alter their genetic material almost in real time. Different species can take on new roles too — hopefully, that will offer us some buffering against climate shocks. If a certain microbe helps plants grow, but perishes in a heatwave, another heat-adapted type could take over and provide a similar benefit. That replacement and buffering capacity is evident across the hugely diverse microbiomes we see around the world.

SCIENCE IN PROGRESS: Researchers developed enclosures of white nylon to house microbial communities — these have microscopic pores that allow water and nutrients but not microbes to pass through them, testing the impacts on the movements of carbon and nutrients at the soil surface. Photo Courtesy: Lucy Lu via S. Alliso
We recently conducted a study on this — we took microbes living on the top of the mountains in southern California and another type living in the hot deserts. We switched them, putting the mountain microbes in the desert and vice versa. We’re talking of a five to ten-degree change in temperature but I was shocked to see the microbe sets did just fine — they could cope with that massive temperature shift and continue their functions, breaking down and recycling perished material.




There is huge metabolic and genetic potential in microbes that adapts fast to climate change. Other research also shows microbes have very interesting ways to cope with the environment. Within just a few generations, we can see major genetic changes which help them adapt. Microbes have many ‘life history strategies’ or diverse ways to deal with stress, acquire resources, obtain chemical compounds, compete and interact with each other. Their complex networks of interactions determine Earth’s geochemical cycles — they are incredibly resilient and yet, quite unappreciated. Alongside, the microbiome itself is a very complex adaptive system — natural selection and evolution have formed systems there which have properties that might resemble intelligence.

I would not posit this as being intelligence of the level of higher animals like humans — but there is a potential of adaptation that resembles certain properties of higher intelligence. And this discovery makes studying microbes even more exciting.