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--></style><title>pdf: Forest Service update on drought and forests
of the U</title></head><body>
<div><font face="Verdana Bold">Echohydrological implications of
drought for forests in the United States</font></div>
<div><font face="Verdana">Vose, James M.; Miniat, Chelcy Ford; Luce,
Charles H.; Asbjornsen, Heidi; Caldwell, Peter V.; Campbell, John L.;
Grant, Gordon E.; Isaak, Daniel J.; Loheide, Steven P.; Sun, Ge.
2016.</font></div>
<div><font face="Verdana Bold"><br>
Date:</font><font face="Verdana"> 2016</font><font face="Arial"><br>
</font><font face="Verdana Bold">Source:</font><font face="Verdana">
Forest Ecology and Management (IN PRESS)</font><font face="Arial"><br>
</font><font face="Verdana Bold">Station ID:</font><font
face="Verdana"> JRNL-SRS-2016</font><font face="Arial"><br>
</font><font face="Verdana"><br>
PDF</font><font face="Arial"><br>
</font><font
face="Verdana"><u
>http://www.srs.fs.usda.gov/pubs/ja/2016/ja_2016_vose_001.pdf</u></font
><br>
<font face="Arial"></font></div>
<div><font face="Verdana Bold">Abstract:</font><font face="Verdana">
The relationships among drought, surface water flow, and groundwater
recharge are not straightforward for most forest ecosystems due to the
strong role that vegetation plays in the forest water balance.
Hydrologic responses to drought can be either mitigated or exacerbated
by forest vegetation depending upon vegetation water use and how
forest population dynamics respond to drought. Understanding how
drought impacts ecosystems requires understanding how drought impacts
ecohydrological processes. Because different species and functional
groups vary in their ecophysiological traits that influence water use
patterns, changes in species assemblages can alter hydrological
processes from the stand to the watershed scales. Recent warming
trends and more prolonged and frequent droughts have accelerated the
spread and intensity of insect attacks in the western US that kill
nearly all of the canopy trees within forest stands, changing the
energy balance of the land surface and affecting many hydrologic
processes. In contrast, some eastern forest tree species and size
classes can tolerate drought better than others, suggesting the
potential for drought-mediated shifts in both species composition and
structure. Predicting how these changes will impact hydrologic
processes at larger spatial and temporal scales presents a
considerable challenge. The biogeochemical consequences of drought,
such as changes in stream chemistry, are closely linked to vegetation
dynamics and hydrologic responses. As with other natural disturbances,
droughts are difficult to prepare for because they are unpredictable.
However, there are management options that may be implemented to
minimize the impacts of drought on water quantity and quality.
Examples include reducing leaf area by thinning and regenerating cut
forests with species that consume less water, although a high level of
uncertainty in both drought projections and anticipated responses
suggests the need for monitoring and adaptive management.</font></div>
<div><font
face="Verdana Bold"
> <span
></span> Citation:</font><font face="Verdana">
Vose, James M.; Miniat, Chelcy Ford; Luce, Charles H.; Asbjornsen,
Heidi; Caldwell, Peter V.; Campbell, John L.; Grant, Gordon E.; Isaak,
Daniel J.; Loheide, Steven P.; Sun, Ge. 2016. Echohydrological
implications of drought for forests in the United States.</font></div>
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<div><font size="-1"
color="#000000">================================== Net Primary
Production ==============================<br>
<br>
"Only about a tenth of 1 percent of the energy received from the
sun by the earth is fixed by photosynthesis ...."</font></div>
<div><font size="-1" color="#000000"><br></font></div>
<div><font size="-1" color="#000000">"Worldwide it is about the
equivalent to the annual production of between 150 and 200 billion
tons of dry organic matter and includes both food for man and the
energy that runs the life support systems of the biosphere ... "<br>
<br>
"It is solar energy that moves the rabbit, the deer, the whale,
the boy on the bicycle outside my window, my pencil as I write these
words Expanding human activities are requiring a larger fraction of
the total and are paradoxically making large segments of it less
useful in support of man."<br>
<br>
Woodwell, George.<br>
"The Energy Cycle of the Biosphere."<br>
<i>Scientific American</i>. September, 1970</font></div>
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