Saltcedar Research Programs
A recent comprehensive study of saltcedar distribution in northern Montana suggested that in certain cases, garden plants may have played a role in starting local invasions, because garden plants were found to be older than the invasions, and no other seed sources were nearby. A specific example cited was the Musselshell River, infested with an estimated 24,500 saltcedars ranging from seedlings to approximately 25 years old. Dispersal mechanisms other than localized spread of seed from ornamentals were also suggested for other areas in the study, including long distance seed movement by wind, water, earth-moving equipment, and towed boats. Earlier research, which included a very limited number of garden saltcedars from other areas in the western U.S., indicated that the garden and invasive saltcedar plants were most often different chloroplast genotypes, though the garden genotype did show up rarely within an invasion. We will use chloroplast and nuclear DNA sequence markers to compare genetic identity of garden and invasive saltcedars of the Northern Plains, and thus determine the influence that garden plants have on starting or contributing to nearby invasions.
Contributing Scientist: John Gaskin (Botanist)
A variety of hypotheses have been developed to account for the extremely variable results obtained thus far with D. elongata. Ongoing studies at NPARL include common garden experiments to determine how different saltcedar genotypes affect beetle fitness components, predator exclusion and inclusion experiments to determine how predation affects beetle establishment and population growth rates, DNA studies of the D. elongata complex to better understand species and subspecies boundaries, and field plot studies to determine how water stress in saltcedar affects beetle oviposition and feeding preferences, larval growth rates, and plant response to defoliation.
Contributing Scientist: David Kazmer (Entomologist)