Evaluating seedling emergence and flow conditions promoting establishment.  We investigated saltcedar seed viability and emergence in the MSU Plant Growth Center (PGC) under a range of storage temperatures and times. Results indicated that warmer temperatures reduce saltcedar seed viability, but seeds can remain viable for greater than 6 months at cooler storage temperatures. The research also looked at the age of saltcedar trees (based on analysis of tree rings) on the Bighorn and Yellowstone Rivers and Fort Peck Reservoir in an attempt to correlate establishment year with historical flow events or reservoir levels. Along the rivers, there was no relationship between establishment and flow, indicating that saltcedar establishes equally well under many flow conditions. At Fort Peck Reservoir, establishment was related to declining water level, and a rising water level led to population mortality. The results of this research have been synthesized into a publication and submitted to the journal Invasive Plant Science and Management.

Assessing plant community and soil characteristics after saltcedar invasion and treatment.  In 2009 we conducted an investigation focusing on saltcedar invaded sites along the Yellowstone and Big Horn Rivers and Fort Peck Reservoir. In this research project, we obtained information on soil characteristics (specifically salt accumulation) of saltcedar invaded sites, as well as knowledge of plant community recovery after treatment and removal of saltcedar. This research will assist in future saltcedar treatment projects by helping land managers understand and predict what vegetation will occupy the site subsequent to saltcedar treatment, and by providing soil information which will assist in future selection of species for revegetation. The results of this research are currently being synthesized for publication in a peer-reviewed journal.

Assessment of saltcedar effects on mycorrhizae.  During 2010, greenhouse studies will be conducted to evaluate the effects of saltcedar on mycorrhizae (beneficial plant root-fungi interactions in which fungi obtain carbon from plants and in turn, through their extensive hyphae network, assist plants in obtaining water and nutrients). Saltcedar reportedly degrades the mycorrhizal fungal community in soil, which may make restoration of mycorrhizae-dependent species difficult. Research will be conducted in the PGC using soil collected from saltcedar invaded sites and adjacent un-invaded sites on the Bighorn and Yellowstone Rivers and Fort Peck Reservoir. Plants that are known to readily form mycorrhizae will be grown in the different soils. After approximately 5 weeks of growth, the roots of the plants will be examined to determine if they formed mycorrhizae. Results will allow researchers to determine how saltcedar affects mycorrhizae, and this information will facilitate restoration efforts.

Screening plants for site restoration.  Additional studies will be conducted in the summer of 2010 to determine what vegetation is suitable for restoration of saltcedar degraded sites. Saltcedar impacted soil from field sites will be used as the growth medium, and several grasses and forbs will be screened to determine which perform best. Results will be used to develop recommendations for species to plant for restoration. 

Lehnhoff E, Menalled F and Rew L (2011) Tamarisk (Tamarix spp.) Establishment in its Most Northern Range. Invasive Plant Science and Management. 4:58-65.http://wssajournals.org/doi/abs/10.1614/IPSM-D-10-00036.1

More detailed results will be available in the future.

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