[Awclist] [Fwd: RRFW Riverwire - TAMMIES TARGETED IN DROUGHT MITIGATION EFFORTS]

[Thomas Robey]

-------- Original Message --------
Subject: 	RRFW Riverwire - TAMMIES TARGETED IN DROUGHT MITIGATION EFFORTS
Date: 	Wed, 14 Dec 2005 19:45:59 -0700
From: 	Riverwire <riverwire at rrfw.org>
Reply-To: 	<Riverwire at rrfw.org>
Organization: 	River Runners for Wilderness
To: 	riverwire at rrfw.org



RRFW Riverwire – TAMMIES TARGETED IN DROUGHT MITIGATION EFFORTS

December 14, 2005

Tamarisk, that bane of southwestern rivers, is being targeted by river 
managers, volunteers and a nonprofit group in an effort to recoup the 
loss of precious river flows, particularly in the current drought. The 
tamarisk tree, native to the Middle East, was introduced early last 
century to stabilize bank erosion, but quickly naturalized, crowding out 
native species and sucking as much as 500,000 acre-feet a year of scarce 
desert water by some estimates.

Prior to the construction of Glen Canyon Dam, tamarisk growth was 
limited to higher elevation terraces and tributaries in Grand Canyon 
National Park (GCNP), but stable flow regimes in most years encouraged 
their spread. The high flow of 1983, over 100,000 cfs, killed one third 
of the tamarisks below the 60,000 cfs water mark. In 1996 the 
short-duration “spike flows” of 45,000 cfs and lower failed to remove 
any tamarisks. Flows in 2000, with short, low peaks below 33,000 cfs, 
followed by steady flows, caused an increase in the already widespread 
germination of tamarisks.

Tamarisk control was initiated in Grand Canyon National Park in 1998. To 
date, 134,808 trees have been removed from 4,496 acres in 63 tributaries 
of the river. An average of 12% of the removed trees required follow up 
treatment in order to fully eradicate. Volunteers donated 8,000 
volunteer hours valued at $137,500.

Tamarisk removal is particularly critical in GCNP, as this World 
Heritage Site contains 1737 different plant species and has more floral 
diversity than, and the most plant species of, any national park. 42% of 
Arizona’s native flora is represented in the park.

Colorado’s Horsethief Canyon and Dinosaur National Monument are among 
the sites selected for the release of the tamarisk’s only known 
predator, the salt cedar leaf beetle. The beetle is currently chewing 
away at 3 sites and could be released in Dinosaur National Monument 
soon, after completion of a required Environmental Assessment. There 
will be pre- and post-monitoring at each site for five years with data 
being collected every two weeks. Because the beetle cannot reproduce in 
areas with fewer than 14 ½ hours of sunlight per day, release is 
confined to areas above 38^ degrees north. Once a tree has been 
defoliated by the beetles, the leafless tree is then manually eradicated.

The San Miguel River, a tributary of the Dolores River in the Upper 
Colorado River Basin, remains one of the few naturally functioning 
riparian ecosystems in the Western United States. The Tamarisk 
Eradication Project is preserving and protecting the biological health 
of the riparian areas throughout the San Miguel River Watershed by 
removing non-native invasive trees in order to establish the San Miguel 
as the only naturally functioning—and free of non-native trees—river in 
the Upper Colorado River Basin by 2006.

Nancy Seamons, Environmental Coordinator for River Runners for 
Wilderness, attended the Tamarisk Symposium in Grand Junction, Colorado, 
co-hosted by The Tamarisk Coalition and the Colorado State University 
(CSU) Cooperative Extension biennially. This year’s symposium, held on 
October 12 -14, 2005, was well attended by nearly 250 national and 
international researchers, on-the-ground program managers, environmental 
representatives and federal/state/local agencies. Participants heard 
presentations and discussed topics including current research, control 
projects, restoration, mapping and funding, legislation and planning, 
economics and biological control 
<http://www.tamariskcoalition.org/?q=glossary#term22>.

Throughout the summer of 2005, the Tamarisk Coalition mapped tamarisk 
and Russian olive (another non-native tree wreaking havoc) along the 
riparian corridors of the Arkansas and Colorado Rivers and their 
tributaries. Accessing the rivers by roads and the river channel itself, 
field technicians are “ground truthing,” or verifying the presence and 
characteristics of tamarisk and Russian olive stands in comparison to 
satellite and aerial photos.

The Tamarisk Coalition is a 501(c)3 non-profit whose mission is to 
provide education, technical assistance, and coordinating support for 
the restoration of riparian lands and is working with Congress to 
provide $80 million over five years for tamarisk control and 
revegetation for large scale projects, critical research, long term 
management and funding options. To learn more about tamarisk and 
invasive plants, visit the Tamarisk Coalition web site at 
www.tamariskcoalition.org <http://www.tamariskcoalition.org/>.

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