1. Fires & Wolves: Yellowstone
National Park
The World is Complicated!!
Dr. Mark A. McGinley
Honors College and Department of
Biological Sciences
Texas Tech University
2. Yellowstone National Park
• World's First National Park
• A designated World Heritage Site and designated
Biosphere Reserve
• 3,472 square miles or 8,987 square km
• 2,221,766 acres or 898,317 hectares
• 63 air miles north to south (102 km)
• 54 air miles east to west 87 km)
• 96 % in Wyoming, 3 % in Montana, 1 % in Idaho
www.NPS.gov/yell.planyourvisit/factsheet.htm
4. The Act of Dedication
• AN ACT to set apart a certain tract of land lying near the
headwaters of the Yellowstone River as a public park. Be it enacted
by the Senate and House of Representatives of the United States of
America in Congress assembled, That the tract of land in the
Territories of Montana and Wyoming ... is hereby reserved and
withdrawn from settlement, occupancy, or sale under the laws of
the United States, and dedicated and set apart as a public park or
pleasuring ground for the benefit and enjoyment of the people; and
all persons who shall locate, or settle upon, or occupy the same or
any part thereof, except as hereinafter provided, shall be
considered trespassers and removed there from ...
Approved March 1, 1872.
• Ulysses S. Grant- President of USA
11. Yellowstone Fire- 1998
• Starting as many smaller individual fires, the
flames quickly spread out of control with
increasing winds and drought and combined into
one large fire that burned for several months.
• Only the arrival of cool and moist weather in the
late autumn brought the fires to an end.
• A total of 793,880 acres (3,213 km2), or
36 percent of the park was affected by the
wildfires.
http://en.wikipedia.org/wiki/Yellowstone_fires_of_1988
12. Yellowstone Fire 1988
https://www.youtube.com/watch?v=CAgP9fo3f7s
http://videos.howstuffworks.com/tlc/29316-understanding-fire-at-yellowstone-park-video.htm
15. Fire Recovery
• Twenty Years After the 1988 Yellowstone Fires:
Lessons About Disturbance and Ecosystems
• http://www.nrmsc.usgs.gov/files/norock/prod
ucts/Romme%20et%20al%202011Ecosystems.
pdf
• Yellowstone’s life 25 years after fires. Oct 16,
2013. The Durango Herald
• http://www.durangoherald.com/article/20131
016/NEWS06/131019618
17. Reintroduction of Wolves
• Although wolf packs once
roamed from the Arctic tundra
to Mexico, loss of habitat and
extermination programs led to
their demise throughout most
of the United States by early in
the 1900s.
• In 1973, the US Fish and
Wildlife Service listed the
northern Rocky Mountain wolf
(Canis lupus) as an endangered
species and designated
Greater Yellowstone as one of
three recovery areas.
http://www.nps.gov/yell/naturescience/wolves.htm
18. Reintroduction of Wolves
• From 1995 to 1997, 41
wild wolves from Canada
and northwest Montana
were released in
Yellowstone National Park.
• As expected, wolves from
the growing population
dispersed to establish
territories outside the park
where they are less
protected from human-caused
mortalities
http://www.nps.gov/yell/naturescience/wolves.htm
21. Results of Wolf Reintroduction
• http://sfglobe.com/?id=
14064&src=share_fb_n
ew_14064
22. What Does the Data Say
• The Reintroduction of Gray Wolves to
Yellowstone National Park and Central Idaho
– U.S. Fish and Wildlife Service- 1994
– http://www.fws.gov/mountain-prairie/
species/mammals/wolf/eis_1994.pdf
• Wolf Restoration Continued
– http://www.nps.gov/yell/naturescience/wolfrest.
htm
23. Summary
• The gray wolf, after being extirpated in the 1920s and absent for 70 years,
was reintroduced to Yellowstone National Park in 1995 and 1996.
• Since then a three-tiered trophic cascade has been reestablished involving
wolves, elk (Cervus elaphus), and woody browse species such as aspen
(Populus tremuloides), cottonwoods (Populus spp.), and willows (Salix
spp.).
• Mechanisms likely include actual wolf predation of elk, which reduces
their numbers, and the threat of predation, which alters elk behavior and
feeding habits, resulting in these plant species being released from
intensive browsing pressure.
• Subsequently, their survival and recruitment rates have significantly
increased in some places within Yellowstone's northern range. This effect
is particularly noted among the range's riparian plant communities, with
upland communities only recently beginning to show similar signs of
recovery.
24. Changes in Vegetation
• A 2-3 fold increase in deciduous woody vegetation cover, mostly of
willow, in the Soda Butte Creek area between 1995 and 1999.
• Heights of the tallest willows in the Gallatin River valley increasing
from 75 cm to 200 cm between 1998 and 2002.
• Heights of the tallest willows in the Blacktail Creek area increased
from less than 50 cm to more than 250 cm between 1997 and 2003.
Additionally, canopy cover over streams increased significantly,
from only 5% to a range of 14-73%.
• In the northern range, tall deciduous woody vegetation cover
increased by 170% between 1991 and 2006.
• In the Lamar and Soda Butte Valleys the number of young
cottonwood trees that had been successfully recruited went from 0
to 156 between 2001 and 2010.
25. Changes in Biodiversity
• Trophic cascades also impact the biodiversity of ecosystems, and
when examined from that perspective wolves appear to be having
multiple, positive cascading impacts on the biodiversity of
Yellowstone National Park. These impacts include:
• Scavengers, such as ravens (Corvus corax), bald eagles (Haliaeetus
leucocephalus), and even grizzly bears (Ursus arctos horribilis), are
likely subsidized by the carcasses of wolf kills.
• In the northern range, the relative abundance of six out of seven
native songbirds which utilize willow was found to be greater in
areas of willow recovery as opposed to those where willows
remained suppressed.
• Bison (Bison bison) numbers in the northern range have been
steadily increasing as elk numbers have declined, presumably due
to a decrease in interspecific competition between the two species.[
26. Changes in Biodiversity
• Importantly, the number of beaver (Castor canadensis)
colonies in the Park has increased from one in 1996 to
twelve in 2009. The recovery is likely due to the
increase in willow availability, as they have been
feeding almost exclusively on it.
• As keystone species, the resurgence of beaver is a
critical event for the region. The presence of beavers
has been shown to positively impact streambank
erosion, sediment retention, water tables, nutrient
cycling, and both the diversity and abundance of plant
and animal life among riparian communities.
27. The Debate Continues
The World is Complicated!!
• Legend of the Wolf. 2014. Emma Harris
• http://www.nature.com/polopoly_fs/1.14841!
/menu/main/topColumns/topLeftColumn/pdf
/507158a.pdf
• Rethinking predators: Legend of the wolf
• http://www.nature.com/news/rethinking-predators-
legend-of-the-wolf-1.14841
