Page 4 - October 2015 Green Builder Magazine
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EDITOR’S NOTE By Matt Power, Editor-in-Chief
The Inside Scoop
2
Future Forests Face Double Jeopardy
Demand for lumber is down, but pests and diseases are bringing new
threats to forests, thanks to climate change.
T REES ARE ONE of the best lays out the problem:
building materials in the “Together, these global change drivers
history of shelter. Wood
structures, kept dry, can are likely to increase the opportunities for
last hundreds of years. the establishment, spread and impact of
new pests and pathogens,” they note.
When most builders Not to say good minds aren’t struggling
or architects talk about alternatives to to contain the tree diseases and pests.
wood—ICFs, SIPs, rammed earth, straw As the researchers highlight, “The
bale and so on—they’re not voting “anti- application of landscape ecology tools
wood.” They’re simply choosing a system and perspectives to forest pathology is
with special qualities right for their improving our understanding of regional
www.greenbuildermedia.com 10.2015 climate or customer. outbreaks of exotic tree fungal pathogens.”
Wood’s place in the building hierarchy should be secure. But many of these threats are simply moving too fast to
It still dominates the homebuilding landscape in the U.S., reverse. The USDA reports that “mountain pine beetles are
although lumber production is down from to about a quarter killing pine and spruce trees throughout the Rocky Mountains
of where it was in 2005, thanks to the slower economy. and western U.S. at an unprecedented rate.” We’ve all heard of
Yet behind the scenes, in the realm of biologists, something ash borers and wood borers, as well. And there are many more.
sinister is afoot. Forests worldwide are under siege—not by Along with invasive insects is the growing incidence of so-
human beings directly, but indirectly, as a result of the way we called exotic disease and fungal attacks on various tree species,
move goods and plants around and the way we’re changing due in large part to poorly controlled commerce in certain
the climate. species. Holdenrieder notes that “The number of newly
A report published last year, for example, titled Forest reported tree pathogens over the last decades is a sobering
Health in a46 Changing World, by Ottmar Holdenrieder e4t. al., reminder of the tree health problems to come. Indeed,
Localities with increased forest mortality related to climatic stress from drought and high temperatures Drought-induced mortality of Pinus Climate-induced mortality of Pinus the likely causes of new exotic tree diseases
Severe mortality of overstorey aspen (Populus sylvestris, Andalucia, Spain (April 2006) sylvestris, Valais, Switzerland (1999) (increased trade, higher temperatures, shifts in
tremuloides) following the 2001–2002 drought host distribution) are supposed to intensify in the
in the parkland zone of Saskatchewan, Canada Pinus yunnanensis stand, Yunnan
(August 2004) Province, China, showing mortality
induced by a drought that resulted in
outbreaks of Tomicus yunnanensis
and Tomicus minor shoot beetles
from 2003 to 200 (July 200)
R.NAVARRO A. RIGLING Z. ZHANG near future.”
M. MICHAELIAN Right now, with lumber demand relatively low,
Drought-induced death of Acacia the wood product industry can easily keep pace
aneura, eastern Australia (200)
with demand. But increasingly, we’re realizing that
R. FENSHAM forest ecosystems are fragile and complex. Forest
C.D. ALLEN C.D. ALLEN pathologists are trying to contain the disease
Mortality after warm drought in the early 2000s, Jemez Mountains, New Mexico, transfer, but nurseries are largely free to import
United States: left, Pinus ponderosa mortality (July 2006); right, mass mortality of and export without much fear of inspection. Land
Pinus edulis and scattered Juniperus monosperma survivors (May 2004)
A dust storm blows developers and woodlot owners also can help by
through a stand of keeping forest land ecologically diverse.
Acacia albida in the There’s no dire shortage of wood for
Senegalese Sahel
where dieback was
documented in the last
half of the twentieth
century (1993)
CREDIT: FAO P. GONZALEZ
T. KITZBERGER H. CHENCHOUNI & M. BENSACI A. BRIKI FAO/FO-6298/G. ALLARD
Mortality of Nothofagus dombeyi in mixed Cedrus atlantica mortality triggered by drought, Belezma National Park, construction on the horizon, but now is the time
N. dombeyi–Austrocedrus chilensis stand, Algeria, with surviving understorey including Quercus ilex (200) to be proactive, and make sure wood remains as a
induced by a warm drought in 199–1999,
northern Patagonia, Argentina (September Dieback and decline of Juniperus
2004) procera, Saudi Arabia (March 2006)
Note: Only localities from the Table are shown; many additional localities are mapped in Allen et al., 2009. healthy “alternative” for builders and remodelers
of the future. —MP
Falling Down. Outbreaks of pests and disease worldwide are damaging
important forests. To see this image full size, click here: http://bit.ly/1LzwFal
Unasylva 231/232, Vol. 60, 2009 Unasylva 231/232, Vol. 60, 2009
