If you look at a satellite photo of the area around Kangerlussuaq there is a notable crack in the landscape running from east to west. The crack, which we conjecture is an ancient fault or vein of softer rock has been scoured by glaciers deeper than the surrounding material, makes an oddly narrow (200-500m wide) notch across the landscape. The notch traverses across valleys and mountains all the way from the ice to the ocean. Where this notch ascends one particular hillside is a site where we will be doing some of our more intensive study work. The valley it creates gives us a cross section from North facing slope to South facing slope in a very short distance compared to the large glacial valleys elsewhere. Another likely unnamed land feature, the valley has now been dubbed with the latin name of the aquatic plant which grows in the ponds there (Hiparus Vulgaris) as Vulgaris Valley. Within this site, Julia is working to learn more about the history of soil formation since the glaciers retreated several thousand years ago. The soils differ dramatically from the deep organic matter rich loess on the N facing slope, covered in rich sod, to the nearly barren mix of willow, grass tufts, and lichens growing on the cobbley, eroded, glacial till which covers the south facing slopes.
In the morning we discussed the factors which affect soil formation, including climate, organisms, parent material, and relief. Of these, climate appears to be playing a major role in this landscape. The whole area receives only 15.5 cm (about 6”) of rain each year and is super dry. The key difference between the north and south slopes is that the south facing slopes are baked dry by the sun, and have, at some point in the past, had most of the loess deposits eroded away by winds, leaving patches of bare cobbles which have been colonized by little other than lichens. One of Julia’s interests is how the loess removal has impacted the carbon balance on these select areas, and she had set up a bunch of equipment to measure soil respiration rates – or the amount of CO2 given off by the soils. The rain had other ideas, however, and despite Julia’s best efforts to get out here CO2 sampling equipment, it was simply too rainy to risk the expensive electronics.
Another piece of science that we were hoping to do was a lot less impacted by rain. Lauren Culler is working on the aquatic ecosystems in the lakes around Kangerlussuaq, including the two within Vulgaris Valley. Her work centers on understanding how abiotic (nonliving) factors, such as temperature, pH, and nutrient flows both into and out of the lakes, impact the species present and productivity in the ecosystems. There are a wide array of ponds with different abiotic factors in the area which Lauren hopes to measure so that she can make hypotheses about what the ecosystem wide changes will be caused as climate change shifts these abiotic factors in all of the ponds. Understanding the ponds today requires two major data collection efforts. First she needs to measure the abiotic factors in a given pond, then she needs to figure out what organisms are living there, and in what quantity. This will give an idea of which organisms thrive under which conditions. Taking water samples and installing dataloggers allow her to characterize the abiotic factors present in a pond. That’s not the fun part though. The fun part is figuring out what’s living there. Sampling the ecosystems which are currently present in the many different ponds essentially translates to scooping up literally thousands of little creatures from the water. Most of the ponds in the area have no fish, and therefore have incredible macroinvertebrate life. Macroinvertebrates, I learned, is a good, scientific sounding way to say insects, crustaceans, worms, and other little backbone-free creepy crawlies that aren’t necessarily insects. One scoop of the nets in Vulgaris Valley dumped into a white pan for viewing contained thousands and thousands of macroinvertebrates, including beetles (the top predator in the ponds), daphnia (a small crustacean), worms, caddisfly larvae (which build their own homes out of grasses), mosquito pupae, and blackfly larvae. Even the most grossed out members of the group (who swore never to drink from the lake again) were too intrigued by the array of life present to look away.
The ultimate goal of Lauren’s project is to use the current connection between species and the pond characteristics they live in to make predictions about how the pond life will change in the area if the ponds become warmer, dryer, or change in some other way. Essentially she is substituting space for time by driving around from one pond to the next rather than waiting many years to see how a particular pond’s ecosystem changes as it dries up, hoping that she can find ponds in a variety of different stages.
The day closed out back at camp with a visit from the KISS staff, currently between flight programs, being nice enough to bring out some more fuel for our petroleum thirsty cook stoves and socialize a bit. Kathy, who is one of several pioneering women in polar logistics, was kind enough to tell some stories about her years of experience on the job, and provide words of wisdom and mentoring to members of our group as we hiked up a nearby hill to catch the ever-earlier Arctic sunset.