Eventually, flooding waters recede, leaving behind a path of destruction and a fundamentally different habitat for non-human beings including plants and soil dwelling macro and microorganisms. Credit: Shutterstock.

By Esther Ngumbi
URBANA, Illinois, US, Oct 21 2024 – Hurricanes Helene and Milton resulted in record-setting rain, flooding, and flash flooding events across several states, including Florida and North Carolina, leaving devastating impacts on people, communities, and infrastructure that will require many years of rebuilding and recovery.

Rarely making to the headlines are the devastating impacts that hurricanes and record-breaking flooding events have on economically important commodity crops, and horticultural and agricultural plants important for meeting and  nutrition security needs.

Similarly, rarely making the headlines are the  devastating consequences flooding has on soil, soil biology and soil health as well as microscopic and macroscopic soil dwelling organisms.

Rarely making to the headlines are the devastating impacts that hurricanes and record-breaking flooding events have on economically important commodity crops, and horticultural and agricultural plants important for meeting and  nutrition security needs

The lack of coverage about the impacts flooding events have on non-human beings needs to change.

Alarmingly, recent research that has investigated the impacts flooding has on soils and has revealed that flooding negatively affects soil biology, functioning and soil microbial communities that underpin plant health.

This includes earthworms, insect larvae, springtails, and beneficial soil microbe communities that perform fundamental functions, including breaking down plant residues, recycling nutrients, and improving crop growth functions.

Moreover, flooding can further lead to soil contamination by heavy metals including copper, iron, zinc, cadmium which further alters fungal and microbial soil communities.

The rapid decline in soil oxygen levels during flooding causes changes in soil biology and microbial communities that are important for maintaining soil health.

Rapidly declining oxygen levels further lead to dramatic changes of soil’s physical, chemical and biological properties including soil pH and nutrient concentrations.

Additionally, flooding results in increases in concentrations of compounds such as hydrogen sulfide, sulfur, manganese, and iron which are toxic and harmful to native soil microbial communities.

Flooding research conducted in my lab at the University of Illinois Urbana Champaign on corn and tomato, as well as  research conducted by other scholars, has shown that flooding is detrimental, and can cause up to 100 percent crop and yield losses.

Our research at the University of Illinois at Urbana Champaign is not just about understanding the impacts of flooding. It’s about finding solutions.

Specifically,  in my lab we investigate the molecular, physiological, metabolic, biochemical, and developmental changes flooding have on diverse tomato and corn varieties.

We also explore how flooding affects plants’ ability to defend themselves against leaf chewing pest caterpillars. Finally, we are examining the effects of flooding on soil microbial communities.

 Notably and worryingly, our experiments have revealed that flooding negatively impacts the growth and development of both tomato and maize plants.

In corn, we found that different plant varieties respond differently, and that some of the wild varieties that are no longer planted are more resistant to flooding. In tomato, we found differences in gene expression, plant chemistry and growth and development in two heirloom tomato varieties.

Eventually, flooding waters recede, leaving behind a path of destruction and a fundamentally different habitat for non-human beings including plants and soil dwelling macro and microorganisms. So far, we know very little about how non-human beings recover.

 It is time to appreciate and talk more about the impacts flooding has on non-human beings. It’s time to extend flooding research to answer the many unanswered questions.

Once we understand flooding impacts, we can develop strategies to water-proof agricultural crops and accelerate progress in building climate-resilient plants.

 

Esther Ngumbi, PhD is Assistant Professor, Department of Entomology, African American Studies Department, University of Illinois at Urbana-Champaign