Why Should We All Care About Frozen Mud?

Post by: Peter Regier

I was recently fortunate enough to get an opportunity through the CUAHSI Pathfinder fellowship to conduct research in Alaska as an extension of my work with the FCE-LTER. The Pathfinder is designed to support new experiences for students working primarily in one field or one location. My project is a cross-LTER collaboration between the FCE site in Florida and the Bonanza Creek (BNZ) LTER site in interior Alaska. I’m using water quality sensors that measure the chemistry of small streams, including the concentrations of dissolved organic carbon (DOC), nitrate, and other water quality parameters. The sensors look like this:

We are using sensors to look at differences in water chemistry in streams spanning a gradient of permafrost coverage. Permafrost is ground that stays frozen year-round, and is a globally important sink of carbon. The permafrost in the region where I’m working is discontinuous, and has “drunken forests” of black spruce that grow at strange angles as the permafrost and seasonally thawed soils underneath goes through melt and refreeze cycles:

In permafrost, water can’t flow through the soil and therefore can’t transport carbon from soils to streams. Also, biological activity is slower so less soil carbon is exported from permafrost to the atmosphere compared with seasonally thawed soils. However, changes in the Arctic climate have spurred increased melting in some permafrost regions, putting the carbon currently stored there at risk of loss to streams, rivers, and ultimately the ocean.

A large shift in the amount of carbon in freshwater systems can have important environmental consequences, including altering water chemistry and optical properties of streams and rivers. Such shifts in water quality can impact the plants and animals adapted to these stream ecosystems. On a larger scale, changes in carbon and nitrogen transported from melting permafrost ultimately influence the biology, chemistry, and ecology of the Arctic Ocean. The goal of the current project is to better understand how permafrost influences the concentration of nutrients like carbon and nitrogen moving through Arctic streams influenced by discontinuous permafrost. To look into this, we have placed sensors in four different streams (black stars on the map below), all located at the Caribou Poker Creek Research Watershed (CPCRW):

We are collecting data on water chemistry every 15 minutes throughout the summer and will be able to compare and contrast how streams located in the same area but underlain by different amounts of permafrost respond to snowmelt, rainfall and other potential drivers of nutrient concentrations and transport. By collecting all this data and analyzing it, we will be able to better explain the role of permafrost in controlling water quality and gain a clearer understanding of how future changes in the global climate may impact Alaska’s freshwater environments.

Our field sites at the CPCRW are in a dramatically different environment than I am used to in Everglades. Instead of boats, we access our study sites with ATVs:

Also unlike the Everglades, you occasionally get snowed on while you work:

Instead of alligators, crocodiles, dolphins and manatees that roam the FCE, CPCRW and the surrounding areas are home to bears, moose, caribou, porcupines, and all sorts of other critters:

The FCE and BNZ are very different locations, but the focus of my research at the CPCRW aligns closely with the questions driving my research with the FCE: what are the links between organic carbon (and now nitrogen for this project) and water and how will a changing climate affect these relationships? This is just one small part of the larger question: what will our planet look like in 20 or 50 or 100 years, and how will that affect the way we live our lives? We are in an era of changes in the natural world, and cities, states and countries are responding to these changes differently. Some are embracing information about climate change and proactively working to ensure quality of life for future generations. Others have decided these changes are either overstated or non-existent, and frequently question the quality of research and blame scientists for misleading the public. Now, more than ever, it is essential that science continues to push forward towards a clearer, comprehensive understanding of how our world works, particularly in the face of shifting global climates and shifting attitudes towards the scientific community.

As I move forward in my career, I am extremely grateful to have opportunities to expand my world-view, expose myself to new tools and techniques to answer the questions I want to ask, and have experiences that increase my sense of wonder at the diversity, complexity and fragility of our planet. My work in Alaska would not be possible without the support and guidance of the following cool peeps and their labs: