EPOW - Ecology Picture of the Week

Tough Spot for Climate Change Study

Gates of the Arctic National Park and Preserve, Alaska, USA

Explanation:  Last week we explored a tundra location in the high arctic of Svalbard, Norway.  This week's arctic expedition takes us into the most remote and seldom-visited national park in the U.S.: Gates of the Arctic National Park and Preserve of arctic Alaska..  

In late June of 2017, a colleague and I hired a bush pilot to fly us from the tiny northern Alaskan settlement of Bettles into the eastern Brooks Range and into Gates of the Arctic.  Gates of the Arctic occurs at about 68 degrees north latitude, just above and within the 66.5 degrees north latitude of the Arctic Circle.  There are no roads here.  Or trails.  The only way in would be a massive trek or ... bush flights.  

Our aim was to scout out the heart of the park -- a steeply-walled and narrow river valley -- as a possible location for conducting a multi-year study on how climate change is influencing vegetation and wildlife of the region.  It is known that climate change impacts in the arctic are occurring at about twice the rate as in more temperate latitudes further south, so a study here could provide an "early warning signal" of impending changes for the rest of us. 

But why this narrow valley?

Look at the mountainside here:  the vegetation stretches upslope in very well-defined patterns.  Each vegetation zone contains a unique set of plants and animals.

It is our hypothesis (also see the references listed in Information, further below) that some of the earliest indications of climate change effects on vegetation occur along vegetation ecotones, or the narrow places where different vegetation conditions meet.  Ecotones would be ideal places to establish long-term study plots to monitor changes in plant species, and to monitor the types and changes of wildlife using that vegetation.  

As shown in the photo immediately above, the lowest vegetation zone consists of riparian shrubs and hardwoods along the river's edge.  

Next comes black spruce forest that extends upslope to where it transitions into arctic shrub environments:

Next higher, the arctic shrub zone transitions into the alpine tundra zone:

... and eventually even the alpine tundra zone peters out to bare rocky crags on top.  

Over time, under regional warming trends from climate change, each of these zones would shift upslope, eclipsing one another.  And the associated wildlife of the region -- shrews, voles, moose, and much more -- would follow suit.  We could monitor their populations with a matrix of trail cameras that would shoot video and still photos triggered by movement.  

All good.

BUT ... after we scouted the location as an ideal and potential study site, we decided not to start the study there.  The reasons:  

... access is only by bush plane, very limited by local weather conditions, river levels, and season.  The plane would need to take multiple trips to bring in all camping and study gear along with a small research team, who would stay on site likely for at least a few weeks to set up all monitoring equipment, take vegetation measurements, and get the study established.  

... THEN, the only way out, with all samples taken, as the weather and river level would change, would be via river raft.  We're not aware of anyone having rafted out of the park from here, or if it is even feasible.

... AND there is the concern of encountering brown bears that enjoy meals taken from field camps, so we would always need to remain wary and alert, and pack bear spray if not also a sidearm ... AND moose would likely wander through the riverside camp, and they can be incredibly unpredictable and territorial.

... AND FINALLY, the study would entail scaling these immensely steep and unstable cliff faces, multiple times, to even get to the vegetation zones and their ecotones in the first place:

    
So, in the end, we opted to not establish a ground-based study in this most wonderful, wild, and spectacular location.

Instead, studies of the region can rely on remote sensing imagery that I had established under another study by using low-level flights over the region, coupled with satellite imagery taken over time.

Such are the conditions of conducting field climate-change research here in the arctic!
 
 

Information:
     Arekhi, M., A. Yesil, U. Y. Ozkan, and F. Balik Sanli. 2018. Detecting treeline dynamics in response to climate warming using forest stand maps and Landsat data in a temperate forest. Forest Ecosystems 5(1):art. no. 23.
     Biuw, M., J. U. Jepsen, J. Cohen, S. H. Ahonen, M. Tejesvi, S. Aikio, P. R. Wäli, O. P. L. Vindstad, A. Markkola, P. Niemelä, and R. A. Ims. 2014. Long-term impacts of contrasting management of large ungulates in the arctic tundra-forest ecotone: ecosystem structure and climate feedback. Ecosystems 17(5):890-905.
     Camarero, J. J., J. C. Linares, A. I. García-Cervigón, E. Batllori, I. Martínez, and E. Gutiérrez. 2017. Back to the future: the responses of alpine treelines to climate warming are constrained by the current ecotone structure. Ecosystems 20(4):683-700.
     Smith, A. J., and E. M. Goetz. 2021. Climate change drives increased directional movement of landscape ecotones. Landscape Ecology 36:3105-3116.
     Xu, D., D. An, and J. Zhu. 2022. Dynamics of the alpine treeline ecotone under global warming: a review. Journal of Resources and Ecology 13(3):476-482.

Acknowledgment:
     My thanks to research wildlife biologist colleague Damon Lesmeister -- my supervisor at the time -- for helping establish this 2017 scouting expedition and partnering with me on this field visit and evaluation.