Evolutionary processes influence ecosystem forecasts, study shows

Researchers may have unlocked a new key to predict ecosystem responses to environmental change – trait evolution. A team of researchers, including CCS affiliate Kathe Todd-Brown, Ph.D., studied how the differences in plant traits that are passed down and the way they evolve can forecast the future for coastal wetland ecosystems.

How heritable trait variations in S. americanus can impact marsh accretion and carbon sequestration

The team examined sixteen genotypes of a common marsh sedge to determine how heritable variation and rapid evolution has driven trait change and ecosystem processes, as this range represented two age cohorts – ancestral (1931 to 1973) and descendant (1994 to 2016.) They found notable differences in measured traits such as aboveground and belowground biomass and stem density, height and width.  

The approximately fifty years of trait evolution resulted in plants allocating less biomass belowground and distributing biomass shallower. This has impacted wetlands’ ability to withstand flooding through soil surface accretion and its ability to accumulate carbon. These capabilities were higher in plants from the mid-1900s compared to today’s plants.  

In this study, rapid evolution destabilized this ecosystem by negatively impacting its resilience to sea level rise but may impact other ecosystems in different ways, which highlights the need to account for evolutionary processes to forecast ecosystem dynamics.   

Full paper