Sandsage prairie: floristics, structure, and dynamics of a Great Plains plant community

Sandsage prairie is a shrub-steppe ecological association unique to the Great Plains of North America in which sand sagebrush, Artemisia filifolia, is the dominant and diagnostic element. This paper presents the first comprehensive account of the floristics, community structure, and vegetation dynamics of sandsage prairie throughout its distribution. Sandsage prairie occurs in discontinuous tracts throughout western parts of the central and southern Great Plains in association with dune fields and other areas of sand habitat. The most conspicuous element of the vegetation is shrub-steppe dominated by Artemisia filifolia with a moderate to dense herbaceous layer dominated by perennial grasses. The relative density of Artemisia filifolia canopy cover in the landscape can range from 10% to 50% and is influenced by topographic gradient, climatic variability, fire history, grazing history, and past range management practices. Occurring in mosaic with the shrub-steppe component of sandsage prairie are intergrading but distinct assemblages of herbaceous species tied to varying degrees of disturbance and stabilization within the dune field. A total of 119 plant taxa in 33 families are characteristic of sandsage prairie in the Great Plains, with Poaceae, Asteraceae, Fabaceae, Euphorbiaceae, and Onagraceae the largest families (in descending order). There is a pronounced northsouth gradient to the associated flora, with 34 species (29% of the total) being restricted to or most prevalent in either northern or southern stands of sandsage prairie. Sandsage prairie occurs in highly dynamic habitat subject to a host of natural disturbance factors and as a consequence exhibits a high level of heterogeneity in community structure with frequent shifts in species composition and dominance.

The Sex Pheromone of the Sand Sagebrush Carpenterworm, Holcocerus artemisiae (Lepidoptera, Cossidae)

(Z)-5-dodecen-1-ol (Z5 - 12:OH), (Z)-5-dodecenyl acetate (Z5 - 12:Ac), and (Z)-5-tetradecenyl acetate (Z5 - 14:Ac) were found in the extracts of the female sex pheromone gland of the carpenterworm moth Holcocerus artemisiae Chou et Hua, a pest of Artemisia filifolia. The average amounts of Z5 - 12:OH, Z5 - 12:Ac, and Z5 - 14:Ac in a single sex pheromone gland of a calling moth were (7.14 ± 0.73) ng, (54.20 ± 0.34) ng, and (38.70 ± 0.46) ng, respectively. Electroantennography (EAG) of these compounds and their analogues demonstrated that Z5 - 12:Ac excitated the largest male EAG response, followed by Z5 - 14:Ac. Traps baited with rubber septa impregnated with Z5 - 12:Ac (500 μg/septum) and Z5 - 14:Ac (300 μg/septum) were more effective than traps with other baits or virgin females. Addition of Z5 - 12:OH to rubber septa did not enhance the trap catches, but (E,Z)-3,5-dodecadienyl acetate (E3,Z5 - 12:Ac) enhanced the trap catch.

Sand Sagebrush (Artemisia filifolia) and Brittle Pricklypear (Opuntia fragilis) Control

Experiments were conducted at Bridgeport, NE, during 1983 through 1987 to select alternatives for silvex and 2,4,5-T for sand sagebrush and brittle pricklypear control. Of the six herbicides examined, the butoxyethyl ester of 2,4-D at 2.2 kg ae/ha was equivalent to the propylene glycol butyl ether ester of silvex or 2,4,5-T for sand sagebrush control. The potassium salt of picloram at 0.3 kg ae/ha was equal to silvex for brittle pricklypear control.