From the Field: Bill Buck in Cape Horn, Day 13
February 2, 2012; Isla Gordon, middle arm of Bahía Tres Brazos, approximately 54º58’S, 69º41’W
You might have noticed that I didn’t write yesterday. About 5 p.m. I came down with a bad headache and went to my bunk. Apparently I missed some bad seas, including 9-10 foot waves in the Beagle Channel as we moved sites. I got up around 8 p.m., decided against dinner, took a couple of aspirin and went back to bed. I didn’t get up until about 8 a.m. I still have a mild headache, but felt that I needed to deal with yesterday’s collections.
So, while the others are out collecting this morning, I got yesterday’s haul onto the dryer and am now catching up on my blog. I had hoped to do this on the deck because it wasn’t raining this morning, and there were even a few patches of sun, but typical of the region, the skies have darkened again, and it is now spitting rain (at least not sleet or snow). I have managed to be able to sit outside, but under cover, which is a real treat because, once again, the scenery is spectacular. My vista is a row of snow-capped peaks, with much of the snow fresh. Usually when it is raining at sea level it is snowing on the mountains and since yesterday was colder than usual, the snow is lower down on the slopes.
And it is yesterday that I want to write about. The engines started about 6 a.m. I had been told the night before that it would be about a two hour ride to our destination, Pía Fiord. This fiord has two arms, and we were scheduled to hit both, the northeast (approximately 54º46’S, 69º35’W) in the morning, and the northwest in the afternoon. The Romanche Glacier has several branches which come down to the sea here, with a small piece of land separating them. We could tell we were getting close when the frequency of small icebergs increased. Our Zodiacs had to move slowly to avoid all the sea ice and we were put ashore on a small spit of land projecting into the harbor.
This is a popular stop, and several years ago I stopped here while on a cruise ship on which I was given a free room and collected samples while the other passengers went ashore. Another perk of that trip, occasionally at about 8 a.m., the crew would chip-off some glacial ice for a pre-breakfast whiskey! Despite its popularity, Pía Fiord is really a beautiful site.
Although I had been here before, my previous collecting mission was a study in quick and dirty plundering; I only had time to pick up the most conspicuous mosses. This time I had as much time as I wanted and therefore was able to more systematically survey the area.
I have never been one of those people who is obsessed with adding one more dot to a map in order to fill in distribution data, and so I have to keep reminding myself that in working on a flora, I need to do just that. But no matter how many ties I remind myself of this, it is still all too easy to pass over yet another common species while on the hunt for the real gems. And boy were there gems at Pía Fiord.
Once again I was able to find one of the rare lantern mosses (Andreaea fuegiana) that we sought so desperately at Caleta Coloane in the first half of the trip. I now know the reason I had overlooked the species on previous trips. It seems to have a very specialized ecology, growing on inclined to vertical rock outcrops with light–but more or less constant–water flowing over it. In this saturated condition, the small cushions, mostly less than 2 inches in diameter, look like many of the common, dark-pigmented liverworts that dominate the habitat.
Apparently experience counts in hunting mosses, just as it does in so many other aspects of life. Blanka and I had been together at Coloane (the weather having driven the others back to the ship) and so both of us now seem to understand the ecology of this rare–or at least seldom collected–moss, and sure enough we both found it yesterday. To collect this moss has become a goal for Juan, and it is like salt rubbed into the wound every time I bring it back and he doesn’t. Like me, he needs to get past the habit of ignoring the liverwort-looking bryophytes.
From my previous trip to Pía Fiord, I recalled that the spit of land where we came ashore becomes an island at high tide. Immediately upon remembering this, I headed back there early to monitor the situation. Certainly the access was less than when we disembarked, but I thought we would be out before it really became a problem. I used this opportunity to collect on the soon-to-be island and found a few nice mosses that I hadn’t seen on the mainland.
During the second half of this trip, we have gained a second, but smaller, Zodiac which has a maximum capacity of four passengers plus a motorist. Our larger Zodiac usually has two crew members (a motorist and someone in the bow) and can hold as many as eight passengers, though fewer in rough seas. As I waited for the appointed pick-up time, the wind picked up, and the seas became white-capped. I then noticed the smaller Zodiac being lifted back onto the ship off in the distance; an ill omen of weather to come.
When noon arrived, the larger Zodiac came to get us, ferrying us back to the ship in two groups, five and four. On the way back a cold wind blew (we were adjacent to glaciers after all) and the waves sprayed us with frigid salt water. Even with wet gloves, my fingers were really cold and I hate to imagine how cold Xiaolan’s and the motorist’s fingers must have been with no protection.
The Zodiac returned for the second group, but unfortunately, once again, some of our group were late. Being the leader, it unfortunately falls on me to say something. I have no children, and I have no interest in being the father-figure disciplinarian., however, Matt and I agreed that something needed to be said; it is both inconsiderate to be late and it can be a safety issue. So, once again I pulled aside the worse offender for a little talk, stating that this would be the last time I would say anything, and that if it happened, then that person would not be invited back on future expeditions. This is by far the worst aspect of the trip for me, but it would be irresponsible of me to shirk it. (Note: thankfully, it never happened again.)
During lunch we moved to the northwest arm of Pía Fiord. Small icebergs dotted the seascape and limited the Zodiac to the east side of the fiord as we approached yet another glacier. Most of our group chose to hit the shore near the glacier, but after my morning responsibilities, I opted for a little solitude and chose a small stream valley quite close to where our ship was anchored. On both sides were patches of moss-covered, but otherwise bare soil, probably a result of a particularly large deluge-like event in the not-too-distant past resulting in large scale erosion.
These early successional habitats are hard to find, because although the climate here is harsh, bare soil is rapidly colonized. What makes this possible is the nitrogen-fixing cyanobacterium, Nostoc. Hornworts have pockets of the cyanobacterium in their thalli; the mosses often have small free-living colonies of Nostoc among their leaves; and the ubiquitous Gunnera magellanica has Nostoc colonies in its rhizomes. All these “leak” nitrogen into the environment and encourage plant growth, much like a high nitrogen commercial fertilizer would. Therefore, habitats with extensive areas of mostly bare soil are infrequent and short-lived.
Nevertheless there is a whole suite of bryophytes that have specialized in this kind of habitat, before the vascular plants arrive and out-compete them. I must have spent almost 45 minutes within ten yards of the shore picking up one small moss after another. The hair-cap mosses (Polytrichaceae) were particularly abundant and diverse. I slowly worked my way upstream and found the mosses changing, presumably due to the increased shade. On one streamside rock, provided with a constant high humidity from the splashing current, I found several mosses, but only one really excited me; it was (again!) one of the rare lantern mosses, Andreaea nitida. As before, it helped tremendously to know the ecology of the species in order to find it. Once again, though, I realized I was overlooking the common mosses, and so as I worked back downstream I tried to pick these up. As I approached the shore for my 4:15 p.m. pick-up time, an earlier Zodiac was passing by, so I waved it down. Back on board the ship I was able to get all my day’s collections numbered. It was shortly after that that my headache struck.
It is now about 10:30 a.m. and I am reluctant to get all suited up in my head-to-toe rubberized gear for what would probably be at most an hour of collecting. So, I will instead enjoy the relative quiet of the ship (except the constant rumble of the generator) until the others return (hopefully on time!).
February 2, 2012; Isla Gordon, western arm of Bahía Tres Brazos, ca. 54º59’S, 69º45’W
After babbling on for so long this morning, I am reluctant to write again, but two things demand attention; the weather and this afternoon’s field site. Today’s weather has been amazing. Although slightly overcast, with an occasional break in the clouds, there has been no real rain. It is warmer than it has been and the air has been calm. It is such a surprisingly nice day, even the crew is commenting on it.
What capped off the day though was my afternoon collecting site. Even from the ship it reminded me of the one truly old-growth forest we found last year. Such forests are exceedingly rare. They require surrounding mountains to shelter them from the wind, and a permanent river which drops its silt and results in deep soils. Only then can trees get really large. Here the largest trees are at least six feet in diameter, and harbor a suite of species that require a long-term, stable habitat with high humidity. Hornworts and liverworts carpet the forest floor and the numerous large fallen logs. Mosses are in a minority, but those that do occur are often small–and in small quantity–and mostly restricted to this special habitat. Small, curious birds who harbor no fear of humans come within inches, chirping away. The whole effect of the forest is that of a kind of wonderland. Although I could go on and on about this very special habitat, no words can accurately capture the mystical nature of such a place.
Tonight we go back to the same anchorage we used last night, alongside a small island near the mouth of Bahía Tres Brazos. Tomorrow we move onto the Garibaldi Fiord, and possibly the last glacier access of our trip. It’s hard to believe we have only about five more days on the ship. How time flies!
Ed. note: NYBG scientist and Mary Flagler Cary Curator of Botany, Bill Buck is currently on expedition to the islands off Cape Horn, the southernmost point in South America, to study mosses and lichens. Follow his journeys on Plant Talk.
Bill Buck’s Previous Reports From the Field: