The Story of the Caribou and the Lichen

998 Tango Papa!

A giant blender vibrates the entire world. We approach it and let it whisk us into the air across this giant, sloppy tundra. A tundra where, in some places is so flat and so wild, that the rivers bend and loop upon themselves enough that they seem to go nowhere. Former oxbow lakes appear as slightly greener, U-shaped depressions hanging on to the river like forgotten appendages. Occasionally a pingo will appear on the horizon. This is an ice dome up to hundreds of feet tall that has heaved itself out of the tundra throughout the years, and sits on the tundra as a perfect lump of short plants. Just a foot beneath those plants is pure ice. This landscape never turns fully green. The tussocks (Eriophorum vaginatum, or cotton grass) that form it are plants decades old who build upon their former selves. Rising up to two feet above the mucky flats, these tufted tussock plants have dozens of dead leaves from previous years for every live leaf of this year. In places, this single plant can make up an astonishing amount of the total biomass. Therefore, it never gets truly green here in the arctic tundra, because even in the height of the growing season, most of the biomass is still dead. These landscape level features are so easy to see from a helicopter!

Views over the tundra from the chopper. The brown area is all cottongrass tussocks.

A caribou. This was in Denali National Park because there aren’t any where we were in the summer.

We were out there to collect AIM data on caribou and reindeer rangelands. Reindeer are simply domestic caribou. During winter, herds of these animals migrate to the Seward peninsula to forage on lichen atop windblown ridges. You know life is rough when your winter grounds get to -40F (or C, it’s the same at this temperature) and you can only eat nutrient scarce lichen on exposed areas with huge windchill. Yikes. This lichen, being a lacking and slow-growing commodity, can make caribou populations quite volatile. When a lot of lichen is exposed, herd numbers grow, and when it becomes overgrazed, they shrink. The BLM formerly let up to 80,000 reindeer use the Peninsula, which created a profitable reindeer meat industry in the 30’s and 40’s. However, scientists determined that reindeer were negatively impacting wild caribou herds by eating their food. Since this industry was competing with the largest caribou herd in North America, tensions flared. The BLM decided to increase restrictions on reindeer grazing permits. Currently there are very few reindeer in this part of Alaska. It’s sort of hard to imagine the BLM taking this sort of drastic action to stamp out local industry, given their multiple-use ethic. Until, that is, I realized they were dealing with Indians instead of white folks. I am aware I don’t have all of the information, but I just can’t imagine the BLM actively managing for conservation 60+ years ago at the expense of white cattle grazers in the lower 48. It would be great if that was the case, but I realize the BLM has a more missions than just conservation.

Here’s 20 species of lichen I collected on one of our days in the field. I got pretty good at identifying these creepy little creatures.

Anyways, we collected AIM data, along with supplementary data, to monitor caribou rangeland health on the peninsula. Parts of this project are new, whereas some permanent transects date back to 1980. The objective is to determine how the lichen resources are used.

Each year the caribou grow a new set of antlers. In the winter, they typically shed them on ridges where they forage for lichen.

We definitely saw use of lichen by caribou, and in some places they had ‘cratered’ the ground. This is where they eat the lichen all the way down and begin to dig up the ground beneath. And you might be wondering, as I did, how can lichen support big game? Well, this lichen isn’t like lower 48 lichen. This lichen forms mats up to a foot thick and can cover huge areas of ground, so in places there is a lot of it.

A view from the helicopter on our ride back to Nome, the regional metropolitan area of 3500 people.

This project was great. I got to spend quite a bit of time with my supervisor and the lead botanist at the University of Alaska Anchorage, along with lots of other fun folks. I’ve never been so removed from the rest of the world. It’s pretty tranquil out there.

And of course a salmon picture. This was taken just outside the BLM facility in Nome, Alaska. The pink salmon were swimming in huge numbers while I was there.

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