Author: postMigrator

Oak Ridge National Laboratory – US Department of Energy
News Release
March 5, 2008

Killer freeze of ’07 illustrates paradoxes of warming climate

OAK RIDGE, Tenn., March 5, 2008 – A destructive
spring freeze that chilled the eastern United
States almost a year ago illustrates the threat a
warming climate poses to plants and crops,
according to a paper just published in the
journal BioScience. The study was led by a team
from the Department of Energy’s Oak Ridge
National Laboratory.

The “Easter freeze” of April 5-9, 2007, blew in
on an ill wind. Plants had been sending out young
and tender sprouts two to three weeks earlier
than normal during an unusually warm March. Plant
ecologists, as well as farmers and gardeners,
took note of the particularly harsh turn of the
weather in early April.

Continue reading

I have the complete article as pdf file. Feel free to ask.
Lance

NATURE
VOL 421
2 JANUARY 2003

A globally coherent fingerprint of climate change
impacts across natural systems
Camille Parmesan* & Gary YoheÝ

* Integrative Biology, Patterson Laboratories
141, University of Texas, Austin, Texas 78712, USA
Ý John E. Andrus Professor of Economics, Wesleyan
University, 238 Public Affairs Center,
Middletown, Connecticut 06459, USA
………………………………………………………………………………………
Abstract:
Causal attribution of recent biological trends to
climate change is complicated because
non-climatic influences dominate local,
short-term biological changes. Any underlying
signal from climate change is likely to be
revealed by analyses that seek systematic trends
across diverse species and geographic regions;
however, debates within the Intergovernmental
Panel on Climate Change (IPCC) reveal several
definitions of a ‘systematic trend’.  Here, we
explore these differences, apply diverse analyses
to more than 1,700 species, and show that recent
biological trends match climate change
predictions. Global meta-analyses documented
significant range shifts averaging 6.1 km per
decade towards the poles (or metres per decade
upward), and significant mean advancement of
spring events by 2.3 days per decade. We define a
diagnostic fingerprint of temporal and spatial
‘sign-switching’ responses uniquely predicted by
twentieth century climate trends. Among
appropriate long-term/large-scale/multi-species
data sets, this diagnostic fingerprint was found
for 279 species. This suite of analyses generates
‘very high confidence’ (as laid down by the IPCC)
that climate change is already affecting living
systems.

———————————————————————————————————————————-

——– Original Message ——–
Subject: [Stumps] PLOS : Fire moving higher
Date: Wed, 5 Mar 2008 08:46:44 -0700
From: Lance Olsen <lancolsn@gmail.com>
To: Climate Change and Biodiversity list <gwspecies@lists.onenw.org>

Over and over again, we see changes at the high latitudes matched by
changes at the high altitudes. For an example from the Northern
Hemisphere, the glacial melting at Greenland is matched by the glacial
melting at Glacier National Park. Likewise, we see concern for the
high latitude polar bear matched by concern for a high altitude
species like the pika.

Well, of course, since high latitude and high altitude share so much,
including temperature levels and species not found at lower
altitude/latitude. And the ptarmigan probably deserves some special
notice, because it is distributed over low elevations at high
latitudes and at high elevations at lower latitudes like Glacier
National Park.

Continue reading

PNAS | March 4, 2008 | vol. 105 | no. 9 | 3410-3415
OPEN ACCESS ARTICLE

BIOLOGICAL SCIENCES / ECOLOGY

Impact of an extreme climatic event on community assembly
Katherine M. Thibault, and James H. Brown

Department of Biology, University of New Mexico,
Albuquerque, NM 87131; and Department of Biology,
Furman University, Greenville, SC 29613

Abstract:
Extreme climatic events are predicted to increase
in frequency and magnitude, but their ecological
impacts are poorly understood. Such events are
large, infrequent, stochastic perturbations that
can change the outcome of entrained ecological
processes. Here we show how an extreme flood
event affected a desert rodent community that has
been monitored for 30 years. The flood (i) caused
catastrophic, species-specific mortality; (ii)
eliminated the incumbency advantage of previously
dominant species; (iii) reset long-term
population and community trends; (iv) interacted
with competitive and metapopulation dynamics; and
(v) resulted in rapid, wholesale reorganization
of the community. This and a previous extreme
rainfall event were punctuational
perturbations-they caused large, rapid
population- and community-level changes that were
superimposed on a background of more gradual
trends driven by climate and vegetation change.
Captured by chance through long-term monitoring,
the impacts of such large, infrequent events
provide unique insights into the processes that
structure ecological communities.

desert rodents | incumbency advantage | punctuational dynamics

Freely available online through the PNAS open access option: Go to
http://www.pnas.org/cgi/content/full/105/9/3410

—————————————————————————————————————————