Decomposition of emergent macrophyte roots and rhizomes in a northern prairie marsh / Dale A. Wrubleski, Henry R. Murkin, Arnold G. van der Valk, and Jeffrey W. Nelson.

Includes bibliographical references (pages 132-134).

Dry mass, nitrogen and phosphorus content in belowground litter of four emergent macrophytes
( Typha glauca Godr., Phragmites australis (Car.) Trin., Scolochloa fi~stucacea (Will&)
Link and Scirpus lacustris L.) were followed for 1.2 years in a series of experimental marshes,
Delta Marsh, Manitoba. Litter bags containing roots and rhizome materials of each species were
buried in unflooded soil, or soil flooded at three water depths (1-30, 31 60, > 60 cm). There
were few differences in dry mass loss in unflooded or flooded soils, and depth of flooding also
had little effect on decomposition rates. In the flooded sites, Scolochloa and Phragmites roots lost
more mass (48.9-63.8% and 59.2-85.5%, respectively) after 112 days than 7~vpha and Scirpus
(36.3-43.6 and 37.0-47.2%, respectively). These differences continued through to the end of the
study, except in the shallow sites where Scirpus roots lost more mass and had comparable mass
remaining as Scolochloa and Phragmites. In the unflooded sites, there was little difference
between species. All litters lost nitrogen (22.9-90.0%) and phosphorus (46.3 92.7%) during the
first 112 days, then levels tended to remain constant. Decay rates for our belowground root and
rhizome litters were comparable to published literature values for aboveground shoot litter of the
same species, except for Phragmites roots and rhizomes which decomposed at a faster rate
(-k = 0.0014-0.0032) than shoots (-k = 0.0003-0.0007, [van der Valk, A.G.. Rhymer, J.M..
Murkin, H.R., 1991. Flooding and the decomposition of litter of four emergent plant species in a
prairie wetland. Wetlands 11, 1-16]).