Alaska & Global warming   Don Bertolette
  Mar 09, 2006 20:45 PST 

Probably appropriate of nothing, I thought back ten years to a summer spent
in the A, B, C islands in SE Alaska...we were looking to establish inventory
plots every 4.4 kilometers, and one particular one fell, in the context of a
topographic map base (dated in the early 1960s, like many AK topos are), on
a glacier. We then tried to view this location with satellite imagery, but
(because of the difficulty of getting cloud free imagery in Alaska in
general, and particularly in regions with glaciers) we weren't able get
satisfactory imagery. Several months later, we visited the plot location,
just then beginning to revegetate with pioneering species, the glacier
having receded hundreds of meters. In less than forty years.
This was about the same time that the spruce bark beetle population was
exploding on the Kenai Peninsula, as Ed Holsten said, due to unusually warm
winters, that weren't cold enough to keep the beetle in check.
During the last two months spent in Alaska, it was clear from multiple
sources, that Alaskan researchers view the last 50 years as significantly
out of hrov, nrov, and many other rov...


There are some out of the ordinary warming events as well. For instance,
peat cores in AK that show a history of 10,000 years have no woody
material until the last 50 or so years. In other words this is a major
warming event for teh last 10,00 years.

And remember peat preserves very, very well.

Roman Dial
RE: Global warming story on public radio   Roman Dial
  Mar 12, 2006 19:00 PST 


We are straying from eastern native trees a bit here but there are many
topo mpas that indicate where glacial ice used to be. I was just
driving back from central Alaska (where I lived from 1977 to 1988)
yesterday when I looked up and recalled a glacier in a cirque that was
there in the early eighties and is now gone.

However, the most dramatic example I have seen personally was a 3 square
mile icefield/glacier that covered a 5000 foot peak in the Alaska Range
in the 1950's and by the late 80's was gone -- completely gone. Indeed
using Google Earth I just looked at the site and all the ice is gone.
Just one tiny little patch of snow at the summit. I visited the site in
1989 and it was cryptogamic and moss covered soil.

We also had a bad outbreak of spruce bark beetles round here (Anchorage)
and on the Kenai Peninsula. A colleague of mine, Ed Berg, ecologist with
Kenai National Wildlife Refuge says that one reason the beetles got so
out of control is that long, hot summers allowed the beetles to finish
their life cycle in one year rather than two, effectively doubling their
intrinsic rate of increase. Additionally, the trees that seemed to be
most susceptible were hybrids between white spruce and Sitka spruce.
Sitka spruce can only grow where the precip is sufficient, and maybe
they are able to "weep" the penetrating female beetles out as they try
to get in and lay eggs. Perhaps the white spruce grow where it is simply
too cold for the beetles to overwinter. And where it's not too cold and
not too wet, that's where the hybrid trees are and the beetles hit a
startling number of trees over a certian size class (like about 10
inches DBH).

The Kenai Peninsula has no permafrost and no domestic grazing animals
and relatively small areas of human develoment. Yet it has substantially
drying wetlands, rising tree line, shrinking glaciers, and expanding
shrubs, all of which are unprecedented, there, at least, and over the
last 50 years it is clearly visible..