New publication: Ongoing species migration due to historical (and current) climate change

Determining the rate of species spread at leading range edges (and contraction at trailing edges) is critically important to projections of species survival under climate change - conservation and management are all contingent on those estimates.  Some species are projected to move rapidly, but we're lacking a lot of contemporary studies of ongoing migration of dominant forest species.  There are lots of paleo records of historical movement, but less so of contemporary migration, because in many cases it's been accomplished.  Few cases of current movement - not from anthropogenic warming, but warming after the last major glaciation (circa 15,000 years ago) - are documented.  Lodgepole pine is one, and it's very interesting - another is Alaska yellow-cedar.  

The Alaska system can tell us quite a bit about how potentially dominant, canopy species move through intact forests - not an easy task.  It's one thing to move into recently deglaciated landscapes, or during periods of disturbance (like lodgepole).  What about intact and healthy, functioning ecosystems?  Are they more or less difficult to migrate through?  It's not an easy task.  Intact ecosystems are tight places, and most resources are spoken for.  It's also challenging to study.

First, John had to determine if yellow-cedar was indeed migrating, as hypothesized.  It appears that Alaska yellow-cedar is moving north, and has been, since the last Ice Age.  A recent paper by John Krapek, who did this work while a Masters student in the lab, now outlines that leading range edge and documents the extent to which the species has yet to move - in essence, the rate at which cedar is lagging behind climate.  Yellow-cedar appears to pulse forward, rather than smoothly tracking climate, with the pulse being dependent on snowy conditions - specifically the Little Ice Age a few centuries ago.  This is not good news, as those conditions are becoming more and more rare.

Through multiple lines of investigation, John was able to trace the establishment of leading populations of yellow-cedar (small groups ahead of the main range of the species) and model the overall available niche, as well as look forward to see if the landscape will remain hospitable.  It's a great read.

Krapek J, Hennon PE, D'Amore DV, Buma B.  Despite available habitat at range edge, yellow-cedar migration is punctuated with a past pulse tied to colder conditions. Diversity and Distributions.  In press.

The northerly edge of Alaska yellow-cedar is comprised of small populations north of the main range boundary.  These stands (from 1-50+ trees) are small, isolated, and represent migration due to climate warming - and can tell us quite a bit about the rate of migration and how species move through intact ecosystems.  This figure shows estimates for when those stands established (minimums).  The leading edge appears to be comprised of populations which got their start near the tail end of the Little Ice Age.  

The northerly edge of Alaska yellow-cedar is comprised of small populations north of the main range boundary.  These stands (from 1-50+ trees) are small, isolated, and represent migration due to climate warming - and can tell us quite a bit about the rate of migration and how species move through intact ecosystems.  This figure shows estimates for when those stands established (minimums).  The leading edge appears to be comprised of populations which got their start near the tail end of the Little Ice Age.