Mangroves marching northward: the impacts of rising seas and
temperatures on ecosystems at Kennedy Space Center
Samantha K. Chapman (PI), Wayne Walker (Co-PI), J. Adam Langley (Co-PI), Ilka
C. Feller (Co-PI)
PROJECT SUMMARY
Lying at the interface of land, atmosphere, and ocean, coastal ecosystems, like
those at the Kennedy Space Center (KSC), are particularly sensitive to global
changes, especially sea-level rise and altered temperatures. The low-lying terrestrial
ecosystems at KSC represent a shifting ecotone between mangrove and salt marsh
ecosystems and may serve as a harbinger of climate change impacts on coastal
ecosystems. Marshes and mangroves both provide important ecosystem services
such as protection from storms and carbon sequestration. Perhaps most
importantly, marsh and mangrove plants build soil vertically by a variety of
mechanisms, allowing the land to adapt to sea-level rise where static land would
submerge. However, there are limits to how much sea-level rise these ecosystems
can tolerate, and the limits likely differ between marshes and mangroves. These
differences are important because mangroves are currently invading salt marshes,
potentially altering the provision of these critical services. Our central objectives
are to (1) determine whether marshes or mangroves will dominate in a warmer
future with higher seas, and (2) predict what altered plant composition will
mean for the functioning of ecosystems surrounding the unique and
important facilities at KSC.
We propose to examine how plant community shifts, sea-level rise, and increasing
temperature alter ecosystem carbon storage and soil elevation gain in the marshes
and mangroves surrounding KSC. We will establish a sea-level manipulation of
mesocosms to investigate whether marshes or mangroves will dominate under
predicted future sea levels. We will simulate future warmer temperatures using
automatically retractable canopies that will trap heat during nighttime hours. By
comparing plant species shifts in warmed and control plots, we will determine how
the ecosystems surrounding KSC will look in the future. Using remote sensing
analyses, we will couple shifting plant communities to changes in ecosystem carbon
storage. Finally, we will combine data from the sea level and warming experiments
in a process model that will predict the critical rate of sea-level rise that these
ecosystems can tolerate and how that may change with warming.
This project will elucidate the mechanisms that underlie critical ecosystem functions
and make tangible predictions for how marshes and mangroves will respond to
ongoing climatic warming and sea-level rise. According to a draft of their new
strategic plan, NASA’s Science Mission Directorate will pursue the outcome of
“advancing earth system science to meet the challenges of climate and
environmental change.” Here, we propose to contribute to this mission by
examining how increased temperature and sea levels will alter important coastal
vegetation communities that store carbon, build soil, and protect the unique and
important facilities at KSC.