Decomposition of three mudflat annual species in a northern prairie marsh during drawdown / Dale A. Wrubleski, Henry R. Murkin, Arnold G. van der Valk, and Craig B. Davis.

Includes bibliographical references (pages 146-148).

The loss of dry mass, nitrogen and phosphorus from shoot and root litter of mudflat annuals was examined in a
series of experimental marshes in the Delta Marsh, Manitoba, Canada. Litter bags containing shoot material of
three mudflat annuals (Aster laurentianus Fern., Atriplexpatula L., and Chenopodium rubrum L.) were placed on
the sediment surface of the marshes under drawdown conditions. In addition, litter bags containing root material of
these three species were shallowly buried. Approximately 70% and 50% of both shoot and root litter, respectively,
was still present after one year in the field. During the second year when the marshes were flooded, shoot and root
litter lost an additional 20% and 0% of their mass, respectively. Except for Chenopodium roots, which accumulated
nitrogen and phosphorus during both years, shoot and root litter lost from 0 to 50% of their nitrogen and phosphorus
early in the first year, with levels generally remaining constant through the remainder of the study period. Our results
indicate that mudflat annual litter decomposed slowly and would provide abundant habitat for aquatic invertebrates
when these marshes were reflooded. However, most nutrient loss took place in the first year when the litter was
unflooded, with little loss occurring in the second year when flooded.