Life goes on…. just about. Antarctic hair grass (Deschampsia antarctica)
Although it was mid-winter when I left home earlier this month (and now the garden is reportedly snow covered) there were already signs of spring as the snow drops and daffodils were poking through the soil.
Here in Antarcticait is mid-summer, yet, despite that, most of the ground on the islands all around us is still snow covered. In fact, there has been a particularly heavy snow fall this year, with much more extensive snow cover than this time last year (and reportedly several years prior to that). Many of the limited snow and ice free areas on land are covered by penguin colonies where hundreds / thousands of birds gather to build their stoney nests, lay their eggs and rear their chicks in the hopes that the relative safety of numbers will reduce the risk of chick predation.
So, this does not leave a whole lot of space for plant life, which to be successful requires pockets of land that are usually snow/ice free in the summer, and also areas which are not regularly disturbed by penguins, seals or other animals as the plants grow slowly, over many years.
However, on an afternoon trip to Cuverville Island yesterday when the BAS team was asked to join the inspection team there was plenty of exciting botanical life to be enjoyed (and a few thousand penguins too!!). As soon as we stepped off the small boats and on to land there was the overwhelming smell of penguin, but amongst the rocky snow free outcrops we immediately spotted a haven of green: around 2m x 2m of moss (Sanionia uncinata – a moss which tends to form low growing carpets in fairly wet areas). In addition, although there was none on the bare rocky areas around, growing through the moss was the Antarctic hair grass (Deschampsia antarctica), which, to be honest, looks like a standard UK grass, but as one of only TWO native flowering plants in Antarctica it is always a good spot.
This grass-through-moss scenario highlights one of the many (in my mind at least!) interesting properties of moss: not having roots and usually getting the required moisture and nutrients needed to grow from rain, snow and occasional animal droppings, moss can establish in protected crannies in rocks without any soil. However, the Antarctic hair grass, like any grass at home, does have roots, which need to be kept moist and aerated, usually in some form of soil. So, it is likely that after several years of moss growth on bare rock, organic matter (dead and broken down moss) accumulated, into which the grass could establish and grow. As the grass grows taller and faster than the moss it may well now out compete the moss and take over the cranny in the rocks completely – so it would be interesting to see the progression in a few years time.
When I was able to drag myself away from this initial plant-based excitement, we walked further around the rocky coast of the island, and it was evident that there were fairly extensive areas of moss growing 100-150m up on the steep cliff faces, giving them a green covering, perhaps 10 to 15 cm in depth – again in areas that were not accessible to, or disturbed by, penguins. It is an interesting question to ponder about what exactly are the critical factors for the establishment of the moss, and also how much moss there might be growing in the areas still covered by snow (and thus invisible to us). Amazingly, when there is only a thin covering of snow, enough sunlight can penetrate through and provide sufficient energy for some species of moss to photosynthesise (fix energy and grow), thus extending their growing season slightly beyond the short snow-free Antarctic summer.
Around the penguin colonies themselves there were some bright orange and black lichens growing on the rocks, possibly in response to the nutrient input from the penguin poo. Lichens are fascinating, complex organisms each comprised from a combination of plant + fungi +/- algae! Amongst the rocks we also saw the two largest (I think) native terrestrial animals of Antarctica – not seals or penguins as you might think, but wingless midges and springtails – both of which are under 5 mm in length!
To complete our afternoon on the island Ash Fusiarski (our field assistant or “the chosen one” according to Matt’s Mum!! ) did what he does best and led us all on a steep, snowy (safe!) walk up to the 241 m summit of Cuverville Island, which was warming work, occasionally punctuated by the booming noise characteristic of an ice fall in the vicinity, but well rewarded with spectacular views of the surrounding islands and mountains. It also enabled us to collect a pristine snow sample for isotopic analysis, and, not to be outdone, there was more botanical life at the top. On a small area of snow-free rocky ground both mosses and lichens had established: demonstrating their amazing capacity to grow in what seems to humans very harsh conditions: cold, windy and exposed with very little liquid water or nutrient input.
We then happily glissaded down the hill (slid down the snow on our bottoms) and headed back to ship after a brilliant afternoon – thanks to FCO team and all of the ship’s company for making it happen and enabling me to remind myself how fascinating Antarctic plant life really is.