Understanding the interplay between ecological and evolutionary processes within entire ecosystems has emerged as an important research area called “eco-evo dynamics”. Before joining UTM, I showed that genetic variation within plant populations has cascading ecological effects on large and diverse arthropod and plant communities. In collaboration with Ayco Tack and Tomas Roslin (Helsinki), we recently showed that the methods most researchers use to study the ecological effects of genetic variation are flawed because they lead to a bias in favour of finding stronger effects of genetic variation than actually exist in nature (see Tack, Johnson and Roslin 2012 Oikos). We also suggest methodological remedies to the problem.
Current Ph.D. student Connor Fitzpatrick is now examining how genetic variation and evolution in plants shapes soil ecosystems, including the flux of nutrients, the abundance of soil arthropods and the composition of soil microbes. Connor recently found that genetic variation in plant traits ofO. biennis has a dramatic effect on the decomposition of leaf tissue and the activity of soil microbes. In some cases, these effects of genetic variation on the soil ecosystem interact with the effects of insect herbivores to influence nutrient turnover and the early performance of seedlings in the next generation.
Our current experiments extend on this work by examining how evolutionary change in O. biennis populations affect soil ecosystems. This work will involve sequencing the soil microbiome using PCR enrichment and next-generation Illumina sequencing, plus a suite of assays of soil chemistry and microbial function.