Contributed by Sarah Castle
From the tropical Andes of Peru to the icefields of Alaska, glaciers are rapidly melting. As ice melts, we are left with an annually resolved gradient in soil development. Substrates closest to the glacial terminus are the youngest while substrates furthest from the terminus are older. Deglaciated landscapes, with their barren rock and lack of vascular plant cover, often appear to be devoid of life. On the contrary glacial soils, albeit low diversity, are teeming with microscopic organisms that take up residence immediately following the retreat of ice. Looking at how soil biota and the soil environment develop with time in these relatively simple landscapes may help us to unravel the relationships between community structure and ecosystem function that may be otherwise obscured in more complex soil systems.
In my own work as a Ph.D. candidate in the Department of Ecosystem and Conservation Sciences, I am examining microbial communities at glacial sites in both North and South American continents. It appears that young glacial soils host bacterial communities that are very different in terms of structure and function when compared to communities originating from older parts of the landscape. What is more interesting is that bacterial communities from distant locations (Peru, Washington, and Alaska) undergo successional change that results in a microbial community that is same regardless of where you are in the world.
Though glacial retreat is one specialized type of ecosystem disturbance, there are many other natural and human caused disturbances that influence microbial communities and their functions. The study of natural gradients may offer us some insight into how to maintain and restore degraded systems.
More information about Sarah Castle’s research can be found here: www.cfc.umt.edu/biogeochemistry