UCI Greenhouse

Picture caption: An assortment of the manzanita cultivars, all native to California.

Undergraduate researcher, Mikayla Kaliski, is studying the difference in the types of volatile organic compounds emitted by a variety of manzanita cultivars. Previous results suggest manzanitas emit a lot of sesquiterpenes – compounds that influence important atmospheric and ecological processes.

Picture caption: Native Artemisia californica seedlings are grown in the UCI greenhouse in soil inoculated with microbial communities with or without previous exposure to drought to assess how plant-microbe feedbacks influence drought response.

Plants and microbes independently alter key soil properties which can affect the performance of both communities, especially under future global change. Our current project aims to understand how these biotic interactions impact the way plants and microbes respond specifically to drought. We paired native Artemisia californica seedlings with soil microbial communities which had experienced 10 years of ambient local precipitation or a 50% reduction in rainfall. We are now measuring how these plant-microbial combinations perform under well-watered or drought conditions.

Picture caption: Propagated Baccharis salicifolia in the UCI greenhouse, in exclusionary cages to prevent and control for inadvertent attack from herbivores and induction of VOCs, prior to and during the experimental period.

As a form of indirect defense against herbivory, plants emit VOCs (volatile organic compounds) that carry specific information about the herbivore species and their abundance. These emissions recruit natural enemies of the herbivore, such as predatory arthropods, parasitoids, and insectivorous birds, which reduce the herbivore load on the plant. Conspecific or heterospecific neighboring plants, “receivers”, can eavesdrop on the VOCs from the “emitter” and use this information to adjust their defenses specific to the emitter’s attacker, a theory called “plant communication”. With our work, we are investigating whether plant communication results in primed indirect defenses in receivers, causing an enhanced “cry for help” via VOCs following attack, and thus increases the recruitment and attraction of the herbivore’s natural enemies. We are testing this with the plant species Baccharis salicifolia and their specialist insect herbivore Uroleucon macolai in the UCI greenhouse, native species found throughout southwestern US and Northern Mexico. By studying the dynamics of plant communication and indirect defense we can further our understanding of plant-herbivore interactions, as well as provide insight in applications for agricultural pest management with the goal of reducing pesticides.

Picture caption: Native seedlings are grown in the greenhouse and used for restoration of park land in Orange County.

One of the goals of the restoration project at “The Bowl” in Crystal Cove State Park is to determine whether traits of native plants influence their establishment and survival in the restoration of a degraded site in Crystal Cove State Park.  CEB students and staff worked with Crystal Cove State Park ecologists to design the experiment.  Native plants were grown in the UCI greenhouse and transplanted into the field at Crystal Cove.  Preliminary results suggest that a diverse mix of native plants with a variety of functional traits resulted in the highest native cover at the site.