Invasive Species, Caribou Habitat Surveys, SOS!

August and the last week or so in July have been just as adventure filled as my first 4 months with the BLM in Fairbanks, Alaska. Invasive species were getting awfully close to seed by the time we made it out to pull along the Steese and Taylor Highways in the Eastern Interior; and though we only saw a dozen or so Caribou, we had to fly out in a helicopter to access areas in their range not disturbed by humans; thankfully the only SOS signals needed on any trip were related to Seeds Of Success. Barring a very windy night up in the White Mountains that caused one tent collapse, and a near sleepless night for everyone up there, that is.

White sweetclover infestation at disturbed site along the Taylor Highway.
Seeds of Success site for collecting Kinnikinnik.

Even the most conspicuous and damaging invasive plants in Eastern Interior Alaska are somewhat limited in their impact to date. I say this with caution, however. In most of the lower 48 states and much of the colonized world, invasive species are only given serious attention once their eradication is nigh impossible. In other words, it’s almost too late. This isn’t to say invasive treatments aren’t worthwhile in those places, just that they cost billions to manage because of the damage done to crops and native habitats – in the US $120 billion a year to be exact (Pimental et al., 2005). In Alaska, at least from what I’ve seen, invasive plant populations are limited to roadsides and cities – of which there are relatively few. What I do see because of this, is a great opportunity to make an impact on removing these species before they become a more serious problem; and even more time, resources, and money have to be thrown at tackling it. Without intervention, it won’t take much for seed to be carried away down streams and rivers, and plants like Melilotus alba (white sweetclover) and Vicia cracca (bird vetch) to begin overcrowding riverbanks as they do on the highways we targeted.

Getting to that, our ‘weed’ pulling began on the Steese Highway at various BLM managed waysides such as those at the Upper and Lower Birch Creek. We stopped at each wayside along the way to monitor, but there were only a few that had infestations of the most damaging species. Interestingly enough, the furthest wayside from Fairbanks had the worst white sweetclover infestation of any! They must have hitched a ride from an unknowing driver, or perhaps in gravel used for the lot. These guys produce an average of 9,710 seeds (Klemow and Raynal, 1981; Klemow, 1982), though some estimates suggest as high as 350,000 per plant. The most concerning factor is that each of those seeds can remain viable for up to 81 years (Crocker, 1945). The picture below is one of the bigger white sweetclover I pulled. They grow in thick patches, sprouting early to overshadow their competitors and developing tap roots that quickly drain moisture from the soil.

Uprooted White Sweetclover.

The following week we drove up the Taylor Highway toward Chicken, stopping along the way to pull more white sweetclover on BLM land between mile-markers 4 and 6. I was lucky enough to have a previous CLM intern’s notes to go off when planning our invasive trips this summer – it was a huge help! After pulling those weeds we drove further up the Taylor to the Department of Transportation (DOT) South Fork Station. This sits at the South Fork of the Fortymile River – the same section of river I floated on earlier this summer – but just across the road. Between the road and the fence, and following the road up to the wayside, is BLM managed land. But on the other side of the fence is state managed land – the DOT Station. In what turned out to be a dichotomy here and perhaps representative of more issues than I should dive into, I found an interesting lesson in land management.

The fence between State and Federally managed land.

From the same notes I mentioned before, the previous intern and now retired biologist had discussed their frustrations at pulling bird vetch on the BLM side of the fence whenever they could because on the DOT side the same invasive species persisted. Talk about futile efforts. I can’t imagine spending a day removing an invasive plant from one side of a fence only for the same vine-like shrub to wrap its tendrils around the wire and have its seed blown onto where you just pulled a few weeks later. When I read this, I remembered a meeting I’d attended earlier in the summer about invasive species management on the Dalton Highway (this road runs through a different field office than the one I’m assigned to but I thought it would be worthwhile to go). At that meeting was someone from the DOT – perfect, I just needed to get hold of them and of course they’d help us eradicate bird vetch from both sides of the fence! Right?

Well, kind of. After exchanging a few emails, I was told that while they couldn’t support the invasive pull with staff or resources, they would allow us to come and pull weeds on their side of the fence. It just had to be approved by a few higher ups, and they needed to know what day we’d be there to do the work. While this wasn’t exactly what I was hoping for, I thought great, at least we can get the work done and maybe next year we’ll get a bit of help! Inter-agency collaboration between the state and federal government is a work in progress, but I’m hopeful.

When we arrived to pull, the staff was happy to let us in and get to work. Bird vetch is a tricky plant to remove as it reproduces both through seed and through rhizomes. This means you need to remove as much (ideally all, though not usually possible) of the root system. Yanking the plant out the ground is thereby ineffective because it simply snaps at the base. A more effective, albeit more time consuming, approach is to slowly pull from as close to the ground as you can and work the root system out of the ground. Naturally this became a competition to see who could remove the longest root!

Craig Townsend, BLM Wildlife Biologist, holding an uprooted Bird Vetch clump.

Following several other weed pulls, I was off to help out a different BLM biologist conducting caribou habitat surveys in the Fortymile and the White Mountains. In partnerships with PhD students and the NASA Arctic-Boreal Vulnerability Experiment (ABoVE), the project has several goals oriented around improving our understanding of caribou impacts on native arctic alpine vegetation, and mapping biomass of plant functional groups with drone assistance. Because of the limited road systems in Alaska, and perhaps one of the most fun things I’ve been lucky enough to do this summer, reaching remote locations for studies such as this one requires travelling via helicopter!

Just about to take off from our Fortymile Caribou Herd site!

Once we arrived at our randomly selected site, it was straight to work setting up the plot. I say that but often the plots were already set up upon my arrival – I had to fly alone because of something to do with weight limits in these little helicopters! My helicopter diet started a little too late apparently. You can see below some of the beautiful views we got to work above:

Rachel Pernick, Drone/Biological Technician, and Jim Herriges, BLM Wildlife Biologist, estimating species cover in the White Mountains.

Caribou tend to eat a considerable amount of lichen among certain shrubs, graminoids, and occasionally mushrooms. As such, lichen identification was a huge part of this project – something I have had relatively limited experience in. Jim, Katie, and Rachel were super helpful in getting me up to speed nonetheless, and after a few days of staring into quarter meter plots identifying, estimating cover, and then trimming biomass of all vegetation, I had them just about down.

Myself in the foreground estimating species cover and Rachel in the background setting up the drone path. It was chilly!

After a site was completed, which took most of a day, the helicopter would fly us to our next site where we’d set up camp, make some dinner, and chill out before starting a new plot nearby the next day. Weather dictated a lot of what we could get done with the need for a drone flyover prior to trimming any biomass. In the mountains that we surveyed, where weather is about as unpredictable as can be, this meant for a couple of days spent waiting in the tent for openings in clouds or fog. The drone can’t capture usable imagery without clear line of sight to the ground.

Jim trying to keep his hands warm while working with the dreaded metal clipboard. Visibility was limited, and the fog disappeared as quickly as it moved in.

A couple of days in the tent out of seven waiting for clear skies weren’t the only times weather worked against us either. On our second night in the White Mountains we knew there was a chance of strong winds and rain, which is why we camped down off one of the ridges in what looked like a well shielded valley. Unfortunately these winds were stronger than expected. That, or our campsite was more exposed than we had anticipated. The work tent I lent to Rachel only lasted about half the night before the guyline snapped under the force of the wind (likely the guyline that a squirrel had partially chewed into earlier this summer!). Shortly after, one of the tent poles snapped as well, ripping a hole in the tent and collapsing it all at once. She managed to grab her belongings, find her way ou tof the fallen tent, and run down into the gear tent– a fortress of a dome tent which went relatively unphased by the gales.

Meanwhile, I was wrapped up in my sleeping bag hoping my tent would make it through the night. The wind didn’t blow constantly, nor did it always blow in the same direction. There were moments where only the pitter-patter of rain could be heard. Then a sudden crash blew into one side, followed by a smashing of wind into the other. I probably slept a total of 2 hours that night. Periods of sleep would be interrupted by the tent pole above my head collapsing down onto me under the force of the wind – not exactly conducive to quality REM. Thankfully my tent made it through the night and so did Jim’s, none of our gear got terribly wet either. All in all it was a wild night that we laughed about in the morning over coffee in the dome! The next day wind and rain continued, though at a much gentler pace. We moved our tents down even lower into the valley below another plateau. Thankfully this was one of the days spent in the tent waiting for clear weather, and occasionally napping as we recovered from the prior near sleepless night!

Original camp set up – dome tent central
Post-storm set up – remaining tents concealed

Compared to the invasive species work and caribou habitat surveys, collecting seeds for the national Seeds of Success program went off without a hitch! One of the targeted species was Arctostaphylos uva-ursi, otherwise called Kinnikinnik, or Bearberry. There’s a huge population of this low growing shrub near the small town of Tanacross, Alaska, so that’s where we drove to gather seed. The goal of 20,000 seeds per species sounds quite daunting at first, but considering there are multiple seeds per berry makes the task more manageable. I’m sure many other CLM-ers have been out collecting too, and hopefully in good conditions! We had a beautiful sunny day to pick berries and collect a couple of herbarium samples, and quite enjoyed the relaxing pace of doing so. The only thing that could have made the day any better would have been if the berries were more edible – Kinnikinnik have the texture of lint if you bite into one! A native group called Gwich’in would eat the berries mashed up and mixed with dried fish or roe in a sort of pemmican, while the Dena’ina would mix them with oil or lard. They preserve quite well and maintain their nutritional value this way. Apparently the berries were also important as a food for survival when Alaska first became colonized, though I’m thankful not to have had to depend on them for sustenance. Trying one was more than enough!


Crocker, W. 1945. Longevity of seeds. Journal of the New York Botanical Garden. 46:48.

Klemow, K. 1982. Demography and seed biology of monocarpic herbs colonizing an abandoned limestone quarry. Syracuse, NY: State University of New York, College of Environmental Science and Forestry. 228p. Dissertation.

Klemow, K.; Raynal, D.1981. Population ecology of Melilotus alba in a limestone quarry. Journal of Ecology. 69: 33-44.

Pimentel, D.; Zuniga, R.; Morrison, D. 2005. Update on the environmental and economic costs associated with alien-invasive species in the United States.
Ecological Economics. 52:3, 273-288, ISSN 0921-8009.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.