This blog post distills long-term research on prairie biodiversity and its role in weather extremes.
Analyzing nearly 40 years of data from three natural grasslands in Minnesota, Michigan, and Kansas, researchers show that biodiversity can give prairies a built-in shield against extreme climate, but the protection depends on the type of stress.
Drawing on the U.S. Long-Term Ecological Research Network, the study identifies 28 once-a-decade extremes, including major droughts such as 1988 and 2012 and extreme wet events like 2019.
Overall, more diverse plant communities tend to resist productivity losses during extremes better than less diverse ones, with nuance for different disturbance regimes.
Biodiversity and drought resilience in prairies
Across the long record, drought years highlighted the protective role of biodiversity.
More diverse plots tended to maintain higher biomass when water was scarce, illustrating the compensatory dynamics that occur when some species struggle but others thrive under drought conditions.
This pattern aligns with the idea that a diverse community can substitute different functional roles as conditions change.
Recovery after droughts was not only a function of richness but also of evenness—the relative abundances of species.
Plots where species were more evenly distributed recovered more quickly and completely than those dominated by a few abundant species.
Both having many species and not letting a single species overwhelm the community can accelerate rebound after drought stress.
Key mechanisms: richness and evenness
Species richness helps sustain ecosystem function during drought by providing a pool of species with varying tolerances to water stress, enabling continuity of biomass even when some players falter.
Evenness, meanwhile, influences how rapidly a community regains productivity after stress, underscoring that not all diverse communities recover equally well if one species dominates the others.
Different stressors require different diversity attributes
When the climate brings heavy rainfall and flooding, the protective power of biodiversity shifts.
In these wet extremes, species richness proved to be a poorer predictor of stability.
Instead, plots dominated by a few strong species fared best, suggesting that in some disturbances, resilience hinges on the performance of robust dominants rather than on broad species variety.
Implications for prairie management
To strengthen prairie defenses under a more variable climate, conservation must target the specific kinds of diversity that matter for the disturbance at hand.
Practical takeaways include:
- Maintain high species richness to bolster drought resilience
- Promote and monitor evenness to support faster post-drought recovery
- Acknowledge that floods may favor certain robust species; management can support these communities where flooding is common
- Mitigate human pressures such as fertilizer runoff and nitrogen pollution that erode resilience
- Avoid relying on a single biodiversity metric; use a suite of indicators to guide conservation decisions
Broader implications: biodiversity loss and policy
The study highlights a troubling feedback cycle: biodiversity loss reduces ecosystem resilience, making prairies more vulnerable to extremes. This dynamic is amplified by human activities that alter nutrient cycles and degrade habitat structure.
Conservation strategies should be nuanced and disturbance-specific rather than focused on a single metric like richness alone. For policymakers and land managers, the message is clear: protecting prairie biodiversity requires a multifaceted approach that preserves a spectrum of community attributes—richness, evenness, and the presence of robust functional groups—tailored to anticipated stressors.
By aligning conservation actions with the type of disturbance most likely to occur, prairies can better withstand an era of escalating climate extremes. Safeguarding both the breadth (richness) and balance (evenness) of prairie plant communities is essential, but the exact attributes to prioritize depend on the expected disturbance.
Here is the source article for this story: Prairie plants reveal a hidden defense against climate extremes