Some aspects of the ecology and management of Chenopodium rubrum L. in the Delta Marsh, Manitoba
Rayner, Marilyn Ruth
Chenopodium rubrum is an annual mud flat colonizer, primarily of inland marshes, characteristic of hydrarch successions at Delta. The species most commonly associated with C. rubrum in the three Delta habitats studied (Marsh Shores, Wet Meadows and Ridge Marshes) were Phragmites communis, Lycopus asper, Atriplex patula and Aster brachyactis. Borrow pit colonizers included species indicative of saline conditions. A seasonal aspect was noted in the vegetation of Marsh Shores. Senecio congestus, an early season dominant, was replaced by A. brachyactis, A. patula and C. rubrum in September. S. congestus appears sporadically in habitats similar to those of C. rubrum. Although it is usually a winter annual, two summer annual populations were found growing on Marsh shores at Delta. The species is tolerant and can flower when flooded if floral apices can emerge from the water. C. rubrum seedling survival is a waterlogged site was low and flooded individuals died. The species exhibits phenotypic plasticity in response to environmental conditions. The tallest, most branched plants developed in the absence of competition on mud flats exposed early in the spring that were subsequently well drained. Impoverished borrow pit soils produced prostrate plants with sparsely lobed, fleshy leaves abundant in anthocyanins. Waterlogged soils limited branching and overall growth... Results from these investigations and from the literature are integrated into a final discussion on the ecology and management of C. rubrum.