Technical advances and new approaches. Developments in paleaoenvironmental studies. Part III

Paleoenvironmental studies of natural archives like sediment and peat provide a unique glimpse of how environments have changed long before comprehensive monitoring data were collected. A major focus in paleoenvironmental studies has been to use the fossilized remains of algae and other aquatic and terrestrial bioindicators to track ecosystem responses to changing environmental conditions. Here I will elaborate on a series of emerging techniques that are proving themselves useful to further resolve the environmental impacts of major environmental perturbations. I will highlight examples of how new indicators in lake sediments and other archives are used to show how ecosystems were altered by climate shifts, migrating tree lines, and human occupation in some remote Arctic environments. These biomarkers include sediment ancient DNA that can track bioenrichment from a range of aquatic and terrestrial sources including humans. New untargeted biomarker discovery methods  can be used to identify novel biomarkers for paleoenvironmental studies and I will apply these methods to identify new markers that can help track the migration of tree line to examine the effects of long-term changes to the landscape.  These long-term perspectives are needed in environmental studies, especially to resolve questions related to ecosystem stability, natural variability, and natural vs anthropogenic drivers of ecosystem change.