Is resistance futile? Resilience may best help nature prevail

When nature faces intense storms, it may be better to adapt and recover than try to resist.
 
According to a new study comparing the impacts of hurricanes, resilience is a more realistic management strategy for coastal areas. If disturbance events were not increasing in frequency and magnitude, resistance might be the best strategy, said study co-author John Kominoski, an ecologist in the Institute of Environment and lead principal investigator for the Florida Coastal Everglades Long Term Ecological Research program at FIU. That’s because disturbances would be infrequent and the probability of being impacted would be relatively low. But in times of greater storm frequency and intensity from accelerated climate change, there simply might not be enough time for resistance to take hold for some species.
 
“Our understanding of resilience — how can we expect nature to return to prior conditions is changing,” Kominoski said. “The ability to go with the flow confers more resilience but things that are anchored like trees, they are more resistant and can exhibit that resistance at a cost. In a general sense, resilience would allow organisms to adapt to changing conditions and bounce back but some organisms don’t.”
 
That’s why the idea of trying to enhance both resistance and resilience in coastal ecosystems may be an impossible task, according to Christopher Patrick, lead author of the study and researcher at William & Mary’s Virginia Institute of Marine Science.
 
“If it takes 25 years for one tree species to grow large enough to resist the average hurricane, but hurricanes now start impacting an area every 20 years, it’s probably a waste of effort to try to cultivate it,” Patrick said. “The best restoration strategy depends on the frequency and intensity of disturbance events both now and in the future.”
 
All told, the researchers used pre- and post-storm monitoring surveys to analyze patterns of ecosystem resistance and resilience from 26 Northern Hemisphere storms.  These made landfall between 1985 and 2018 in states from Texas to North Carolina, as well as in Puerto Rico and Taiwan. They gauged storm characteristics and impacts via total rainfall, maximum rainfall rate, and wind speed; then grouped their study areas into four ecosystems (freshwater, saltwater, wetland, and terrestrial) and five “response categories,” for a grand total of 4,138 time series datasets. The response categories documented post-storm changes not only in the distribution and abundance of living things — populations of mobile animals such as fishes, sedentary animals such as oysters, and vascular plants such as mangroves — but also in the ecosystem’s biogeochemistry (e.g., salinity, nutrients) and hydrography (e.g., depth and shoreline position).
 
“In the face of a changing climate and shifts in extreme weather events like hurricanes, it’s critical that we make good decisions about how to protect and restore ecosystems,” said Mike Heithaus, executive dean of FIU’s College of Arts, Sciences & Education and a marine scientist who contributed data to the study on predator movements during the storms. “The insights we were able to gain from working across so many locations with so many collaborators and leveraging multiple long-term studies are critical for helping ensure the long-term health of coastal systems.”
 
Kominoski said data from long-term ecological research enables researchers to detect how the impacts of catastrophic events can leave an indelible mark on sensitive ecosystems, such as Florida’s Everglades.
 
The study, published in Science Advances, revealed a repeated pattern of trade-offs between resistance and resilience across ecological categories. The authors note these patterns are likely the outcomes of evolutionary adaptation and conform to ecological-disturbance theories, suggesting consistent rules govern ecosystem susceptibility to tropical cyclones.
 
The research team comprises 23 scientists from 11 states, Puerto Rico, and Taiwan. FIU contributors included Heithaus, Kominoski, FIU Institute of Environment Director Todd Crowl, Assistant Professors Jeremy Kiszka and Rolando Santos, as well as technician Sara Wilson and Assistant Teaching Professor Elizabeth Whitman. FIU alumni Bradley Strickland, now a postdoctoral researcher at Virginia Institute of Marine Science, J. Aaron Hogan, now a postdoctoral researcher at University of Florida, and David Lagomasino, an assistant professor at East Carolina University, were also among the contributors.
 
Their study is linked to a Research Coordination Network formally known as the Hurricane Ecosystem Response Synthesis Network funded by the National Science Foundation to synthesize knowledge concerning ecosystem responses to hurricanes. Joining Kominoski and Patrick as co-authors and members of the network’s leadership team are Bill McDowell, professor at the University of New Hampshire, and Beth Stauffer, associate professor at the University of Louisiana at Lafayette.