Size and shape analysis of mineral resources in arroyo willow and their relation to sawfly densities

Abstract

The association between host-plant mineral nutrients and insect herbivory is complex, idiosyncratic, and dynamic. Because of this we employed an unusual statistical method to evaluate the relationship between tenthredinid sawfly herbivory and concentrations of foliar nutrients in arroyo willow, Salix lasiolepis. We discovered that among 20 willow clones and between two years arroyo willow varied in the size (absolute concentrations) and shape (relative concentrations) of five mineral nutrients (Ca, Mg, N, P, and K). Similarly, the densities of five sawfly species varied in size and Shape among clones and between years. In 1984, relative densities, or shape, of the sawfly community was associated with relative concentrations, or shape, of foliar nutrients in 20 willow clones. In contrast, in 1985 absolute densities, or size, was associated with absolute concentrations, or size, of foliar nutrients. This shift from a shape to a size association between herbivory and foliar mineral nutrients may reflect the large difference in winter precipitation and sawfly densities between years: precipitation and sawfly densities were much greater in 1985 than in 1984.

Mixture models of soybean growth and herbivore performance in response to nitrogen–sulphur–phosphorous nutrient interactions

“…When sought specifically, such nonlinear relationships have also been noted by others (e.g. Boecklen et al . 1991; Clancy & King 1993).…”

“…Virtually all studies investigating plant–mineral–herbivore relationships have varied only a single mineral and have not been designed to detect the interactive effects of nutrient proportions (see reviews of Fuchs & Grossmann 1972; Dale 1988; Waring & Cobb 1992). While the need to consider plant mineral ratios has been recognised, few studies have attempted to map empirically herbivore responses to varying nutrient proportions (Mattson & Scriber 1987; McNaughton 1990; Boecklen et al . 1991; Clancy et al .…”

No simple sum: seasonal variation in tannin phenotypes and leaf-miners in hybrid oaks

“…We used size and shape analysis (Mossiman 1970, Boecklen et al 1991 to compare oak hybrids on the basis of absolute and relative concentrations of ellagitannins and total proanthocyanidins. First, we compared taxa with respect to log e +1-transformed concentrations (size).…”

Long-Term Effects of Defoliation on Red Pine Suitability to Insects Feeding on Diverse Plant Tissues

“…Foliar allelochemicals did not reduce Neodiprion larval development or cocoon mass in this or related studies (Larsson et al 1986, Bjorkman and Gref 1993). Likewise, foliar nutrient compositions were generally quite stable, considering the wide range of treatments, although minor changes are known to sometimes have strong impacts on insect nutritional ecology (Clancy et al 1988, Boecklen et al 1991).…”