Effects of defoliation and competition on total non-structural carbohydrates of spotted knapweed
Issue Date
1994-11-01Keywords
Pseudoroegneria spicatacarbohydrates
Centaurea maculosa
introduced species
plant competition
grazing
Metadata
Show full item recordCitation
Lacey, J. R., Olson-Rutz, K. M., Haferkamp, M. R., & Kennett, G. A. (1994). Effects of defoliation and competition on total nonstructural carbohydrates of spotted knapweed. Journal of Range Management, 47(6), 481-484.Publisher
Society for Range ManagementJournal
Journal of Range ManagementDOI
10.2307/4003001Additional Links
https://rangelands.org/Abstract
Spotted knapweed (Centaurea maculosa Lam.) is replacing native bunchgrasses and interfering with resource management objectives on many ranges in the northern Intermountain Region. Herbicides, biological control agents, and fire have not successfully contained spotted knapweed. Since knapweed is grazed in some situations, effects of defoliation and competition on total nonstructural carbohydrates (TNC) of spotted knapweed plants were determined in this study. Transplanted knapweed plants were grown for 6 months in a greenhouse under 3 levels of competition with bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] Love) and 3 levels of defoliation. Total nonstructural carbohydrates (pool and concentration) were determined at the end of the experiment. Concentration and pools of carbohydrates generally varied among stems, roots, crowns, and with monthly defoliations. Importance of stems for carbohydrate storage was more evident in analyses of pools rather than concentrations. Monthly defoliations decreased carbohydrate concentrations by about 50%, and pools by about 80% respectively within stems, roots, and crowns. While competition from bluebunch wheatgrass influenced total nonstructural carbohydrates concentrations, it did not influence pools. Although frequent defoliations of spotted knapweed reduced carbohydrates, other factors probably limit the feasibility of using grazing animals to control spotted knapweed on native bunchgrass ranges in western North America.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/4003001