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I’m thrilled to share a new paper on rock glaciers, related landforms, and mountain biodiversity. It began as a post-session chat at the 2019 @BenthosNews meeting and through a team effort, has made its way into one of my favorite journals, @GlobalChangeBio.
A thread... 1/n
A thread... 1/n
Rock glaciers are globally common yet largely overlooked beyond the geomorphological literature (though this is changing!). Basically, they are akin to normal glaciers except with debris on/in them. Thus, lots of subterranean ice but less obvious visually due to cover. 2/n
Though it does obscure them, debris cover serves an important purpose. It insulates rock glaciers/etc. from sun/warm conditions! Thus, they should exist on the landscape longer than “surface” glaciers. See nice work by Anderson/ @sarahecrump et al.: 3/n https://www.sciencedirect.com/science/article/abs/pii/S0169555X1830117X
They are also incredibly common! Indeed, Johnson et al. identified 10,343 (!!) potential rock glaciers in the contiguous United States alone (and concentrated in just 5 states): 4/n
https://essd.copernicus.org/preprints/essd-2020-158/
https://essd.copernicus.org/preprints/essd-2020-158/
They also provide key habitat for terrestrial biodiversity in mountain ecosystems like the American Pika. (Shout out to @marshalhedin for letting us use this great photo in the paper!)
5/n
5/n
And their outflow streams support imperiled aquatic diversity... 6/n https://scholarsarchive.byu.edu/wnan/vol80/iss3/11/
So, that’s all exciting. But it gets better.. it’s not just rock glaciers (b) that provide key habitat to cold-adapted species! Other “cold rocky landforms” are also key, mainly (a) debris-covered glaciers, (c) moraines, (d) taluses, and (e) protalus ramparts. See below.
7/n
7/n
So, we appear to have (1) common but ecologically overlooked features that will (2) persist longer than rapidly receding glaciers *AND* (3) they support cold-adapted (and likely imperiled!) biodiversity in terrestrial and aquatic habitats. Neat, huh? What's next?
8/n
8/n
In the short-term, we think there is huge opportunity to integrate rock glaciers and related landforms into climate refugia/management research. We lay out some practical ideas for a range of species:
9/n
9/n
In the long-term? We need: (1) to continue documenting these features and the bio. they support. (2) Long-term monitoring to link how features are changing to biotic communities. That’s a major goal of the Teton Alpine Stream project (led by me, @streambug, and L. Tronstad). 10/n
This all makes me think about studies like the one below where we showed that high-elevation aquatic insect biodiversity has surprisingly persisted despite deglaciation in @GlacierNPS. Are rock glaciers and related landforms the key? 11/n https://www.pnas.org/content/117/22/12208.short
And finally, while the published version is behind a paywall, this is why we love pre-prints! A very similar version is also on EcoEvoRxiv: https://ecoevorxiv.org/84ydq/
I also see that I never actually linked the paper on the @GlobalChangeBio website. Oops! Here it is: https://onlinelibrary.wiley.com/doi/10.1111/gcb.15510
