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Adaptation of coastal marsh species to global climate change.
Blum, Michael*,1, 2, McLachlan, Jason2, Saunders, Colin2, 1 Molecular Ecology Research Branch, Cincinnati, OH2 Duke University, Durham, NC
ABSTRACT- Recent work has shown that plants exhibit heritable responses to changes in atmospheric CO2. Given that atmospheric CO2 has steadily increased since the industrial revolution, it is possible that plants are under selection for tolerance to high CO2 concentrations. Like migration, adaptation may buffer populations and limit the threat of extinction due to climate change. We have begun studies on two eastern North American coastal marsh plant species (Scirpus olneyi, Spartina patens ) to determine whether these coastal plants may evolve in response to increased CO2 concentrations. Studies involving both species are now underway to determine the genetic component of phenotypic responses to changes in atmospheric CO2. Common garden experiments determining responses to CO2, salinity and temperature changes, alongside comparison of genotype frequencies across time will likely indicate whether specific genotypes are favored under conditions of increased CO2. Complementary work is being done to assess the genetic variability of extant populations at microsatellite loci, alongside research that involves the recovery and analysis of DNA from macrofossils deposited in coastal sediments since the industrial revolution. Our preliminary studies show that DNA can be recovered from 100-200 year old S. olneyi seeds, and greenhouse studies have shown that these seeds are viable after such long periods of dormancy. Data on adaptive potential stand to improve current physiology-based models and may provide more accurate predictions of how coastal species respond to global climate change.
Key words: coastal marsh, adaptation , climate change