<!doctype html public "-//W3C//DTD W3 HTML//EN">
<html><head><style type="text/css"><!--
blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 }
--></style><title>Forest conservation/sustainability in time of
die-offs</title></head><body>
<div><font face="Geneva" size="-1">"Defining sustainability is like
trying to define justice or democracy. There are many definitions and
some consensus, but agreement over the specifics is
elusive."</font></div>
<div><font face="Geneva" size="-1"><br>
Donald Floyd, author of<i> Forest Sustainability: The History, the
Challenge, the Promise.</i> © 2002 Forest History Society__80 pp.;
21 photos;_11 maps and figures. __Issues Series booklets are<b>
$9.95</b> (plus $4.00 shipping).<i> Discounts are available if
ordering 10 or more copies</i>.<br>
<u><i>http://foresthistory.org/Publications/Issues/floyd.html</i></u></font
><br>
</div>
<div><font face="Geneva"
size="-1"
>====================================================================<span
></span>=====</font></div>
<div><font face="Geneva" size="-1">On underestimation of global
vulnerability to tree mortality and forest die-off from hotter drought
in the Anthropocene.<br>
Allen, C. D., D. D. Breshears, and N. G. McDowell. 2015.<br>
<i>Ecosphere</i> 6(8):129.<br>
http://dx.doi.org/10.1890/ ES15-00203.1</font><br>
</div>
<div><font face="Geneva" size="-1">Abstract.<b> [Bold added]</b>
Patterns, mechanisms, projections, and consequences of tree mortality
and associated broad- scale forest die-off due to drought accompanied
by warmer temperatures-''hotter drought'', an emerging characteristic
of the Anthropocene-are the focus of rapidly expanding literature.
Despite recent observational, experimental, and modeling studies
suggesting increased vulnerability of trees to hotter drought and
associated pests and pathogens,<b> substantial debate remains among
research, management and policy-making communities regarding future
tree mortality risks</b>. We summarize key mortality- relevant
findings, differentiating between those implying lesser versus greater
levels of vulnerability.<b> Evidence suggesting lesser vulnerability
includes f</b>orest benefits of elevated [CO2] and increased water-use
efficiency; observed and modeled increases in forest growth and canopy
greening; widespread increases in woody-plant biomass, density, and
extent; compensatory physiological, morphological, and genetic
mechanisms; dampening ecological feedbacks; and potential mitigation
by forest management.<b> In contrast,</b> recent studies document more
rapid mortality under hotter drought due to negative tree
physiological responses and accelerated biotic attacks. Additional
evidence suggesting greater vulnerability includes rising background
mortality rates; projected increases in drought frequency, intensity,
and duration; limitations of vegetation models such as inadequately
represented mortality processes; warming feedbacks from die-off; and
wildfire synergies.<b> Grouping these findings we identify ten
contrasting perspectives that shape the vulnerability debate but have
not been discussed collectively. We also present a set of global
vulnerability drivers that are known with high confidence:</b> (1)
droughts eventually occur everywhere; (2) warming produces hotter
droughts; (3) atmospheric moisture demand increases nonlinearly with
temperature during drought; (4) mortality can occur faster in hotter
drought, consistent with fundamental physiology; (5) shorter droughts
occur more frequently than longer droughts and can become lethal under
warming, increasing the frequency of lethal drought nonlinearly; and
(6) mortality happens rapidly relative to growth intervals needed for
forest recovery. These high-confidence drivers, in concert with
research supporting greater vulnerability perspectives, support an
overall viewpoint of greater forest vulnerability globally<b>. We
surmise that mortality vulnerability is being discounted in part due
to difficulties in predicting threshold responses to extreme climate
events. Given the profound ecological and societal implications of
underestimating global vulnerability to hotter drought, we highlight
urgent challenges for research, management, and policy-making
communities.<br>
<br>
</b>=========================================================<br>
"We also infer stress incurred by shifting climate should create an
opening for the establishment of forest types not currently seen in
the conterminous United States."<br>
<br>
Jean Liιnard, John Harrison, Nikolay Strigul. US forest response to
projected climate-related stress: a tolerance perspective.<i> Global
Change Biology </i> August 2016</font></div>
<div><font face="Geneva"
size="-1"><u>http://onlinelibrary.wiley.com/doi/10.1111/gcb.13291/full<br
>
<br>
</u>=======================================================<br>
'"Drought and heat-induced tree mortality is accelerating in many
forest biomes as a consequence of a warming climate, resulting in a
threat to global forests unlike any in recorded history (1-12)."<br>
<br>
" . we conclude with high certainty that
today's forests are going to be subject to continued increases in
mortality rates that will result in substantial reorganization of
their structure and carbon storage."<br>
<br>
Nathan G. McDowell and Craig D. Allen. Darcy's law predicts widespread
forest mortality under climate warming.<br>
<i>Nature Climate Change.</i> Published online 18 MAY 2015<br>
DOI: 10.1038/NCLIMATE2641<br>
<br>
==========================================<br>
"If the vapour-pressure deficit continues increasing as projected
by climate models, the mean forest drought-stress by the 2050s will
exceed that of the most severe droughts in the past 1,000 years.
Collectively, the results foreshadow twenty-first-century changes in
forest structures and compositions, with transition of forests in the
southwestern United States, and perhaps water-limited forests
globally, towards distributions unfamiliar to modern
civilization."<br>
<br>
A. Park Williams, Craig D. Allen, Alison K. Macalady et al.
Temperature as a potent driver of regional forest drought stress and
tree mortality.<i> Nature Climate Change</i> PUBLISHED ONLINE: 30
SEPTEMBER 2012 | DOI: 10.1038/NCLIMATE1693<br>
<br>
=================================================<br>
"From field measurements, aerial photos, and Ikonos satellite
images, we detected significant 1954-2002 tree density declines in the
western Sahel of 18 ` 14% (P 14 0.014, n 14 204) and 17 ` 13% (P
14 0.0009, n 14 187). From field observations, we detected a
significant 1960-2000 species richness decline of 21 ` 11% (P 14
0.0028, n 14 14) across the Sahel and a southward shift of the
Sahel, Sudan, and Guinea zones. Multivariate analyses of climate,
soil, and population showed that temperature most significantly (P <
0.001) explained tree cover changes. Multivariate and bivariate tests
and field observations indicated the dominance of temperature and
precipitation, supporting attribution of tree cover changes to climate
variability. Climate change forcing of Sahel climate variability,
particularly the significant (P < 0.05) 1901-2002 temperature
increases and precipitation decreases in the research areas, connects
Sahel tree cover changes to global climate change. This suggests roles
for global action and local adaptation to address ecological change in
the Sahel."<br>
<br>
P. Gonzalez, C.J. Tucker, H. Sy.Tree density and species decline
in the African Sahel attributable to climate.<i> Journal of Arid
Environments</i> 78 (2012) 55e64 17 November 2011</font></div>
<div><font face="Geneva"
size="-1">doi:10.1016/j.jaridenv.2011.11.001</font></div>
<div><font face="Geneva" size="-1"><br></font></div>
<div><font face="Geneva"
size="-1">========================================================</font
></div>
<div><font face="Lucida Grande" size="-1"
color="#000000">"</font><font face="Lucida Grande" size="-1"
color="#141413">We find that hydraulic damage persisted and increased
in dying trees over multiple years and exhibited few signs of repair
. Contrary to the expectation that surviving trees have
weathered severe drought, the hydraulic deterioration demonstrated
here reveals that surviving regions of these forests are actually more
vulnerable to future droughts due to accumulated xylem
damage."</font><br>
</div>
<div><font face="Lucida Grande" size="-1" color="#141413">WILLIAM R.
L. ANDEREGG et al. Drought's legacy: multiyear hydraulic deterioration
underlies widespread aspen forest die-off and portends increased
future risk.<i> Global Change Biology</i> (2013) 19,
1188-1196,</font></div>
<div><font face="Lucida Grande" size="-1" color="#141413">doi:
10.1111/gcb.12100</font></div>
<div><font face="Geneva" size="-1"><br>
================================================<br>
"Climate-driven forest die-off from drought and heat stress has
occurred around the world, is expected to increase with climate change
and probably has distinct consequences from those of other forest
disturbances."<br>
<br>
William R. L. Anderegg et al. Consequences of widespread tree
mortality triggered by drought and temperature stress.<i> Nature
Climate Change.</i> PUBLISHED ONLINE: 9 SEPTEMBER 2012 |</font></div>
<div><font face="Geneva" size="-1">DOI: 10.1038/NCLIMATE1635<br>
<br>
============================================<br>
"Notably, the recent drought was warmer than the previous
sub-continental drought of the 1950s."</font><br>
<font face="Geneva" size="-1"></font></div>
<div><font face="Geneva" size="-1">" nearly complete tree
mortality across many size and age classes was observed in response to
the recent drought."<br>
<br>
David D. Breshears et al. Regional vegetation die-off in response to
global-change-type drought. Proceedings National Academy of Sciences
October 18, 2005 _ vol. 102 _ no. 42
www.pnas.org_cgi_doi_10.1073_pnas.0505734102<br>
© 2005 by The National Academy of Sciences of the USA<br>
<br>
===================================================</font></div>
<div><font face="Geneva" size="-1">"This review
deals exclusively with observed responses of wild biological species
and systems . "</font></div>
<div><font face="Geneva" size="-1"><br></font></div>
<div><font face="Geneva" size="-1">"Climate change is not a new
topic in biology. The study of biological impacts of climate change
has a rich history in the scientific literature, since long before
there were political ramifications. ..... Observations of range shifts
in parallel with climate change ... date back to the
mid-1700s."</font><br>
</div>
<div><font face="Geneva" size="-1">"A surprising result is the
high proportion of species responding to recent, relatively mild
climate change (global average warming of 0.6 C)." The proportion
of wild species impacted by climate change was estimated at 41% of all
species (655 of 1598)."</font><br>
</div>
<div><font face="Geneva" size="-1">Parmesan, Camille. "Ecological
and Evolutionary Responses to Recent Climate Change."<i> Annual
Review of Ecology, Evolution, and Systematics</i>. 2006.
37: 637-69<br>
<br>
</font></div>
<div><br></div>
<x-sigsep><pre>--
</pre></x-sigsep>
<div><font face="Geneva" size="-1"
color="#000000">=====================================<br>
"The individual scientist can survive for a long time by lying low
in the valley of specialized intellectual interest ... We in science
must get up and face the wind, confront the future." <br>
<br>
William Bevan, "The Sound of the Wind That's Blowing."<br>
<i>American Psychologist.</i> July 1976<br>
<br>
</font><font face="Geneva" size="-2"
color="#000000">=================================================<br>
</font><font face="Geneva" size="-1" color="#000000">" ... all of
us, including scientists, will have to give serious thought to the
notion that economic growth and true sustainable long-term wealth may
now be antithetical."<br>
<br>
Kurt Cobb, "Should Scientists Embrace Economic Growth?"
Scitizen, 16 Oct, 2007<br>
</font><font face="Geneva" size="-4"
color="#FFFF00"><u
>http://www.scitizen.com/stories/Future-Energies/2007/10/Should-Scien<span
></span>tists-Embrace-Economic-Growth/<br>
<br>
</u></font><font face="Geneva" size="-1"
color="#000000">=================================<br>
"Because the decimating factor of economic growth eliminates welfare
factors for virtually all imperiled species via the principle of
competitive exclusion, economic growth may be classified as the
limiting factor for wildlife conservation. The wildlife profession has
been virtually silent about this limiting factor, suggesting that the
profession has been laboring in futility. . The Wildlife Society
should lead the natural resources professions in developing a position
on economic growth."<br>
<br>
Brian Czech. Economic growth as the limiting factor for wildlife
conservation.<i> Wildlife Society Bulletin</i> 2000, 28(1):4-15<br>
<br>
</font><font face="Geneva" size="-2"
color="#000000">==================================================<br>
"The Ecological Society of America (ESA) is a professional
organization with about 10,000 members .... As one might expect,
it can be difficult to produce position statements and other documents
that represent a consensus among all members of such a diverse
society. A case in point is ESA's recent position statement on
economic growth (www.esa.org/pao/ecogrowth_statement.php), which has
already elicited a broad spectrum of passionate responses from
members."<br>
<br>
Alison Power "Ecology and economic growth: the challenge of building
consensus."<i> Frontiers in Ecology and the Environment</i>: (2009)
Vol. 7, No. 6, pp. 287-287.<br>
</font><font face="Geneva" size="-1"
color="#000000"
>------------------------------------------------------------<br>
" energy consumption in 1960 was about half what it is now
[1970]. Surely we had a civilized country then [1960], with roads,
electricity, entertainment, and so on. . Have we, by doubling our
energy consumption, doubled our happiness?"<br>
<br>
Kimon Valaskakis, Peter S. Sindell, J. Graham Smith, and Iris
Fitzpatrick-Martin.<i> The Conserver Society.</i> 1970. Harper &
Row.<br>
</font><font face="Lucida Grande" size="-1" color="#000000"><br>
</font><font face="Geneva" size="-1" color="#000000"><br>
</font><font face="Geneva" color="#000000"><br>
</font><font face="Lucida Grande" size="-1"
color="#000000"></font></div>
</body>
</html>