10 Tamarisk control

Does it make sense to control tamarisk? : 

Does it make sense to control tamarisk? Causes great damage and has few beneficial values Estimated costs of controlling tamarisk: site evaluation, eradication, revegetation and monitoring $3,000/acre Estimated costs of water loss due to tamarisk: Municipal water supplies, irrigation, hydroelectric power, recreation, flood control, wildlife habitat $6,000-9,000/acre Net economic benefits of Tamarisk removal across the West over a 55 year period: Net, so cost of eradication taken into account Net benefit ranges from 3.8 to 11.2 BILLION dollars!!!!! Biocontrol is cheaper than $3,000 acre

How can we control Tamarisk? : 

How can we control Tamarisk? Herbicides can spot use on small stands broadcast spray on larger stands Costly may affect other species not many herbicides that are ok for riparian areas Herbicide resistance

How can we control Tamarisk? : 

How can we control Tamarisk? Mechanical control Cutting down and removing Chainsaw, bulldozer, hydroaxe few complex interactions time/money consuming, Single cutting ineffective Best method is to spray or paint cut stumps with herbicide (cut-stump method) within 1 minute. Follow up important!

Biocontrol of tamarisk : 

Biocontrol of tamarisk What is biocontrol? Introduction of natural enemies of invasive species Specialist herbivores or pathogens (vs. generalists) Must conduct research to investigate the biology and ecology of target plant and control agents “host specificity” testing Why is tamarisk a good candidate for biocontrol? many known natural enemies 300 species in Soviet Union, 220 in Israel and Middle East, etc. not very many related species in area for control No Tamaricaceae native in western hemisphere

Biocontrol of saltcedar : 

Biocontrol of saltcedar Leaf beetle, Diorhabda elongata from central Asia Adults and larvae feed on foliage First released in America in 2001 Mortality of tamarisk takes about 6 years So far about 155,000 acres defoliated from the 2001 release Released in Moab UT, 18 river miles defoliated by 2006 Controlled release in Mesa County in 2005

Slide 6: 

Evidence against using biocontrol Rhinocyllus conicus (seed head weevil) introduced to control Carduus nutans (musk thistle) in Nebraska 1972 1993 on rare natives Cirsium canescens (Platte thistle) and C. undulatum (wavy leaf thistle) also competing with native winged flies (Tephritidae)

Restoration : 

Restoration Native cottonwoods and willows may fail to re-establish without intensive replanting (if spring floods are not restored) Natives may not be able to tolerate salt levels. Lack of mycorrhizae in tamarisk dominated soils, may impede colonization for native.