Relationship of tarbush leaf surface terpene profile with livestock herbivory

TitleRelationship of tarbush leaf surface terpene profile with livestock herbivory
Publication TypeJournal Article
Year of Publication1998
AuthorsEstell RE, Fredrickson E.L., Anderson D.M., Havstad K, Remmenga M.D.
JournalJournal of Chemical Ecology
Date PublishedJanuary 1, 1998
Accession NumberJRN00262
Keywordsdiet selection, Epicuticular wax, Flourensia cernua, leaf surface chemistry, monoterpenes, sesquiterpenes

Tarbush (Flourensia cernua DC.) is a Chihuahuan Desert shrub with a resinous leaf surface containing terpenes that may affect livestock herbivory. Cattle, sheep, and goats were densely stocked in paddocks containing tarbush in two consecutive years for six to nine days and defoliation of 160 plants was recorded daily. Plants were categorized as exhibiting high or low defoliation. Leaves were collected from these plants the third year for chemical analysis. A selection procedure was used to generate two variable sets closely related to defoliation category. One set contained 14 variables (dry matter, ash, -pinene, sabinene, 3-carene, p-cymene, limonene, camphor, bomeol, cis-jasmone, â -caryophyllene, alpha-humulene, ledene, and flourensadiol) and the other set contained 14 unidentified compounds. When subjected to multivariate analysis, each group distinguished between the two defoliation categories (P <0.001 and P <0.0019 for known and unknown variable sets, respectively). These data support the hypothesis that leaf surface chemistry of individual tarbush plants is related to extent of defoliation by livestock.