Anna Florianová (@IBOTCZ; @popecolIBOT), Institute of Botany of the Czech Academy of Sciences, describes her article: Climate-driven shifts in plant-soil feedback of a perennial grass species
As the climate changes, scientists are becoming increasingly interested in how these shifts impact plant growth. Climate change does not only have direct effects on plants, but may also affect plants indirectly, by modifying their interactions with other organisms. One such interaction with possible strong effects on plant performance is plant-soil feedback (PSF), the relationship between plants and the microbiota in the soil they grow in. While both plant and soil microbiota have previously been shown to be affected by climate, the mutual relationships between plants and soil microbiota in response to climate remain to be explored. Our recent study focusing on Festuca rubra, a common perennial grass species, sheds light on the effects of climate on this dynamic interaction.
The model species: Festuca rubra (red fescue). Photo by Z. Münzbergová.
The Experiment: Testing Plant-Soil-Climate Interactions
To understand the Plant-Soil-Climate interaction, we grew Festuca rubra in different conditions in a controlled experiment. We collected plants and soil from two sites with distinct climates—one warmer and one colder—and let the plants grow either in soil with their local soil biota, or with soil biota from the other site. Then, we simulated climate change by growing these plants under both cold and warmer conditions to see how the climate affected the interactions between plants and soil organisms. The goal? To figure out how the climate affects PSF, and to predict how these interactions could shift as global temperatures rise.
Key Findings: Climate Change Breaks the Balance
One of the most striking findings was that soil microbes seem to be highly specialized to their local climate. When soil biota from a colder region were grown under cold conditions, they were particularly effective at suppressing plant growth—likely because local pathogens (harmful microbes that can cause plant diseases) are well adapted to those specific conditions. The same was true for soil from warmer climates. Essentially, the soil microbes “know” their home environment and are best equipped to affect plant growth in those conditions. However, when the climate changed—such as when plants were grown under warmer conditions—the microbes seemed less able to harm the plants.
The adaptation of soil biota to their home climate was even more pronounced when the plants also originated from the same climate. When the plants were grown with local soil biota in their local climate, they experienced negative PSF, meaning that the local microbes actually hindered their growth over time. However, when the same plants were grown in a different climate or with soil microbes from a different climate, the negative effect disappeared. This has important implications for ecosystems. It suggests that plants have a kind of “home-field disadvantage” when it comes to soil microbes that have evolved alongside them. However, if climate change disrupts these well-established relationships—by, for example, making a cold region warmer—plants could escape this negative feedback loop. While that might sound like good news for the plants at first glance, the disruption of these delicate balances could actually lead to major instability in plant communities. If plants are no longer held back by their usual microbial enemies, they might grow unchecked, outcompeting other plant species and leading to unpredictable shifts in the ecosystem.
Moving Forward
Our study highlights that plant-soil interactions are finely tuned to their local environments. When climate changes, these relationships can get thrown out of balance. This could result in plant species getting more or less abundant in ways we don’t fully understand yet, potentially altering entire ecosystems. These findings emphasize the need for more research to understand how different species might respond to changing climates. Every plant-soil interaction is unique and predicting how they will change requires unravelling the complex web of relationships between plants, soil microbes, and the climate. By understanding how these feedback loops work, we can better predict which plant communities will thrive and which might be at risk, helping us to safeguard biodiversity in a changing world.
