& Global warming
09, 2006 20:45 PST
Probably appropriate of nothing, I thought back ten years to a
in the A, B, C islands in SE Alaska...we were looking to
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
(because of the difficulty of getting cloud free imagery in
general, and particularly in regions with glaciers) we weren't
satisfactory imagery. Several months later, we visited the plot
just then beginning to revegetate with pioneering species, the
having receded hundreds of meters. In less than forty years.
This was about the same time that the spruce bark beetle
exploding on the Kenai Peninsula, as Ed Holsten said, due to
winters, that weren't cold enough to keep the beetle in check.
During the last two months spent in Alaska, it was clear from
sources, that Alaskan researchers view the last 50 years as
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.
Global warming story on public radio
12, 2006 19:00 PST
We are straying from eastern native trees a bit here but there
topo mpas that indicate where glacial ice used to be. I was just
driving back from central Alaska (where I lived from 1977 to
yesterday when I looked up and recalled a glacier in a cirque
there in the early eighties and is now gone.
However, the most dramatic example I have seen personally was a
mile icefield/glacier that covered a 5000 foot peak in the
in the 1950's and by the late 80's was gone -- completely gone.
using Google Earth I just looked at the site and all the ice is
Just one tiny little patch of snow at the summit. I visited the
1989 and it was cryptogamic and moss covered soil.
We also had a bad outbreak of spruce bark beetles round here
and on the Kenai Peninsula. A colleague of mine, Ed Berg,
Kenai National Wildlife Refuge says that one reason the beetles
out of control is that long, hot summers allowed the beetles to
their life cycle in one year rather than two, effectively
intrinsic rate of increase. Additionally, the trees that seemed
most susceptible were hybrids between white spruce and Sitka
Sitka spruce can only grow where the precip is sufficient, and
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
too cold for the beetles to overwinter. And where it's not too
not too wet, that's where the hybrid trees are and the beetles
startling number of trees over a certian size class (like about
The Kenai Peninsula has no permafrost and no domestic grazing
and relatively small areas of human develoment. Yet it has
drying wetlands, rising tree line, shrinking glaciers, and
shrubs, all of which are unprecedented, there, at least, and
last 50 years it is clearly visible..