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Clonal Foraging In Perennial Wheatgrasses: A Strategy For Exploiting Patchy Soil Nutrients, L. D. Humphrey, D. A. Pyke
Clonal Foraging In Perennial Wheatgrasses: A Strategy For Exploiting Patchy Soil Nutrients, L. D. Humphrey, D. A. Pyke
Aspen Bibliography
1 Foraging by means of plasticity in placement of tillers in response to low- and high- nutrient patches was examined in the rhizomatous wheatgrass Elymus lanceolatus ssp. lanceolatus. Its ability to exploit soil nutrient patches was compared to that of the closely related but caespitose E. lanceolatus ssp. wawawaiensis. 2 Clones of 14 genets of each taxon were planted in boxes consisting of two 30 x 30 cm cells: the 'origin cell' where clones were planted, and the adjacent 'destination cell', with each cell containing soil with either low or high levels of nutrients. 3 The rhizomatous taxon, which can …
Characteristics Of Successful Competitors: An Evaluation Of Potential Growth Rate In Two Cold Desert Tussock Grasses, Eissenstat D. M., Caldwell M. M.
Characteristics Of Successful Competitors: An Evaluation Of Potential Growth Rate In Two Cold Desert Tussock Grasses, Eissenstat D. M., Caldwell M. M.
Aspen Bibliography
Within the first few weeks after seedling emergence, Agropyron desertorum, a more competitive tussock grass, had a much higher mean relative growth rate (RGR) than Agropyron spicatum, a very similar, but less competitive species. However, beyond the early seedling stage, the two grasses had a remarkably similar whole-plant RGR in hydroponic culture and aboveground RGR in glasshouse soil, if root temperatures were above approximately 12° C. At soil temperatures between 5 and 12° C, A. desertorum exhibited a 66% greater aboveground RGR than A. spicatum (P < 0.05). Both species responded similarly to warming soil temperatures. In the field, however, tiller growth rates were generally similar. Neither species showed marked tiller elongation until a couple of weeks after snowmelt, by which time soil temperatures, at least to a depth of 10 cm, were above 12° C for a significant portion of the day. Above-ground biomass accumulation over a three-year period indicated that both grasses had similar potential growth rates whereas Artemisia tridentata ssp. vaseyana, a common neighbor planted in the same plots, had a much greater potential growth rate. The greater competitive ability of adult A. desertorum, as compared to A. spicatum, cannot be attributed to appreciable differences in potential growth rates.