ESCI/ESTU 301: Explorations in Environmental Studies
Prairie Restoration
Case #1: Prairie Restoration on the San Juan Islands: TNC & Yellow Island, The
Friday Harbor Lab, Private Lands and San Juan Island National Historic Park
The San Juan Islands have some of the best remaining examples of prairie plant
communities in the Puget Lowlands. During our upcoming field trip, we will visit sites
on private land, land owned by The Nature Conservancy (TNC), the Friday Harbor Lab
and public land that is managed by the National Parks Service. These sites provide an
interesting mix of issues.
The current setting:
Yellow Island: The current plant community on Yellow Island is described in the
assigned readings by Agee and Dunwiddie 1984 and Dunwiddie 2002. Briefly,
the island is a mixture of open grassland and conifer forest. The island was
nearly treeless at the beginning of the 20th century. However, over the past few
decades, more and more trees have become established in the formerly nonforested portions of the island.
Friday Harbor Lab: The upland portion of the FHL is covered by second and thirdgrowth forest. Most of the trees are Douglas fir (Pseudotsuga menziesii).
Most forest contains 50-100 year old trees, but there are a few 250-400 year
old trees scattered throughout the stand. The growth form of these old trees is
quite different in that they have dead branches extending along the full length
of the trunk; almost all the way to the ground. Foresters refer to these trees as
“wolf trees.” This growth form typically occurs on trees that develop as an
isolated tree rather than in a continuous forest. Trees that develop in a
continuous forest typically “self-prune” in that they drop their lower limbs.
Self-pruning occurs because the respiratory costs of supporting these limbs
exceeds the gains from photosynthesis in the low light levels of the lower part
of the closed forest canopy. The younger trees in the stand show evidence of
self-pruning.
The structure of this stand suggests that, prior to European settlement, this site
contained only a few widely scattered Douglas firs. Presumably, the area
between these trees was covered by prairie vegetation. Other historical
evidence (including some old maps that we will view during our trip) supports
this view. The site includes several shell middens that provide evidence of
extensive use of the site by native Americans.
Private Land: Cady Mountain: This site is covered by Gary oak (Quercus
garryana), Douglas fir and Grand fir (Abies grandis). Most of the older
conifers (up to 1 meter in diameter) are found in the wetter ravines. The oaks
are found on the dryer portions of the site and prairie vegetation, including
Camas (Camassia quamash) is found growing in the more open areas and
under the oaks. Younger conifers (10-30 years old) are scattered throughout
the site and are quite dense in many places. Many of the oaks are in the
process of being overtopped by the conifers. Many of the oaks are dead and
dieing. Historically, most of this site was probably contained widely scattered
oaks and prairie vegetation growing in between.
SJINHP; British Camp: This site is an oak woodland site that is quite similar to
Cady Mountain. The site includes some areas that are much more open than
the Cady Mt. site.
Management Context:
Yellow Island and The Nature Conservancy: TNC acquired Yellow Island
specifically because of the “dramatic display of spring wildflowers” that is
found on the non-forested portion of the island. TNC is a private, non-profit
conservation organization. Their mission is to “save the last great places on
earth.” See their How we work webpage for more information about their
approach. TNC has been around for over 50 years and their management
philosophy has evolved considerably over this time. TNC prides itself on
taking a science-based approach to conservation. The evolution of TNC’s
management philosophy closely tracks the evolution to the field of
conservation biology. TNC acquired Yellow Island in 1979. At that time, they
tended to have a rather hands-off approach to managing natural areas. Their
primary focus was on acquiring ecologically significant sites and protecting
those sites from development. Once protected from outside threats, the
prevailing view was that natural processes would be sufficient to maintain the
site. The Agee and Dunwiddie paper from 1984 signals a shift in scientific
thinking. This paper documents the expansion of woody vegetation on the site.
The paper attributes this expansion to recent increases in summer precipitation.
They also felt that changes in the fire regime might also be an issue. Since the
1984 paper was written, there has been an emerging recognition that burning of
the site by Native Americans may have had a major role in keeping the site
open. The implication of the 1984 paper and the probable role of Native
American burning is that without active management, the “dramatic display of
spring wildflowers” is at risk. Without active management, dense forest would
probably expand to cover the entire island. What should TNC do?
Friday Harbor Lab: FHL is owned and operated by the University of Washington.
(Click here for information about the lab) This is a world-renowned marine
research lab. The lab also happens to include some forestland. As far as I can
tell, the forest mostly provides a nice place for students and researcher to take
walks. Restoration of this site to a prairie would involve the removal of a
substantial amount of forest. Initially, this would look like a large clearcut.
FHL is located at the entrance to Friday Harbor. The economy of Friday
Harbor is critically dependant upon tourism. Should prairie restoration be a
priority for FHL? You might choose to restrict restoration to a portion of the
site. It might be helpful to consider
Private Land: Cady Mountain: The site that we will visit includes a complex of
about 120 acres that is owned by about 9 different families. The background
and priorities of these individuals is diverse. A federal grant from the Natural
Resources Conservation Service is available (Click here for information). This
program can fund up to 75% of the costs of habitat restoration projects.
Individual landowners are required to contribute 25% of the costs out of their
own pockets. The program can pay for the cost of labor involved in removing
conifers that encroach on the oak woodlands and for the purchase of seedlings
and other material. The grant will not pay for any costs associated with
prescribed burning. The big concern here is the liability associated with these
burns. Should the NRCS fund this project? If the federal government feels
that oak woodland restoration is really important, why not pay 100% of the
cost? Why should the individual landowner contribute their time and money to
this effort? On the other hand, given that these sites are not open to the public,
should we spend federal dollars (your tax money) doing work on private lands?
What are the fire liability issues? One of the landowners is a retired US Forest
Service employee with considerable experience in silviculture and prescribed
fire.
SJINHP; British Camp: The ecological issues here are essentially the same as at
Cady Mt.. Since the federal government manages this site, the bureaucratic
issues are quite a bit different. Park scientists first proposed doing a prescribed
burn at this site in 1997. The planning for this fire was substantial. Young
Hill Rx Fire Plan Unit One.doc (Note: this is a 62 page document! DO NOT
print this out! Skim the document to get a feel for what is involved. The
document includes some color air photos that provide a good feel for the site.)
After preparing the fire plan, they held many public meetings seeking input.
This took years….and years. In 2000, there was an incident with a prescribed
fire on lands managed by the National Park Service in New Mexico:
http://www.cnn.com/2000/US/06/07/control.fires.02/
http://www.disasterrelief.org/Disasters/010509losalamosyear/
This resulted in a moratorium on prescribed fires on NPS lands nationwide.
What should we do at British Camp? Should we burn?
Obstacles to restoration:
European Hares: Way back in the late 1800s someone started raising European hares
on San Juan Island for food. They got loose and there is now a breeding
population of hares everywhere on the island. They do not occur on Yellow
Island. On San Juan Island, the hare population has gone through huge
population fluctuations. The population crashed about a decade ago. No one
knows exactly why but it may have been due to some sort of virus. The
population is now recovering but is still low compared to historic levels. Hares
do extremely well in open prairie vegetation and not as well in dense secondgrowth forest. They can have a huge impact on prairie restoration efforts.
Invasive plants: Scotch Broom is the Great Satan of invasive plant species. Recent
clearcuts seem to be particularly vulnerable to invasion by Scotch Broom.
Many other species of invasive species are present as well.
Smoke: Restoration and maintenance of prairies and oak woodlands requires the use
of fire. The smoke associated with these fires can have consequences for air
quality.
DW; 4/15/04