Succession gradients

 We've spent the past couple of days working on samples from a new field site. One of our main goals for this project is to measure plant and soil properties along a gradient of ecological succession from a receding glacier. Over the past two years of this project, we have measured transects from two different locations. Yesterday, we collected samples from a third transect.

To get to this new field site, which is a ways across the bay on another peninsula, we ride in boats. The presence of the glacier makes it impossible to walk across land to get to the peninsula, so we have to go by water! It is of course deadly if we fall out of the boat into the freezing Antarctic water, so to be extra safe, we have to wear big puffy suits and a lot of safety gear whenever we ride in boats. These big puffy full-body immersion suits provide both flotation and the ability to keep us alive in 5°C water for 1 hr. With the addition of big boots and water proof gloves, we are ready to go!

We traveled across Fildes Bay to another peninsula where one of the Argentinian bases is located, called Base Carlini. After some warm hospitality from the residents of the station, we hiked up into the moraines to find an early-succession site with only early pioneers of moss coverage. As you can see, it's not highly vegetated. There is moss and lichen on the ground, but it's fairly sparse... and partially covered by snow!

Dr. Angelica and Hannah measuring plant cover with cold hands!

Angelica and Hannah measured the resident plant community coverage while I sampled the moss and soil underneath it to bring back to the lab. It was a very cold day, and much of the moss was actually frozen! 

After spending an hour in our early-succession site, we started walking away from the glacier into a mid-succession site. We make the same measurements there to understand how the plants and soil change as they develop over the years of succession. This is called a "chronosequence": when we use space to represent different amounts of time. In other words, the trajectory of walking from close to the glacier away from it towards the coast is like walking through time from recently-exposed soil into older ecosystems that have been exposed for longer periods of time. Those areas that have been exposed longer have had more time to develop a more complex ecosystem. The moss and plant coverage there is much greater, and you can get large "carpets" of moss that look so lush and inviting!

A springtail's-eye view of a moss carpet.

We were about halfway done with the mid-succession sampling when we were told that the weather was getting worse, so we had to go home before it became unsafe to use the boat. We came back to Base Escudero where we have been processing the samples in the lab. We will hopefully be able to return later this week to finish sampling the mid- and late-succession sites!