DOI: 10.5063/aa/duc_merp.81.7
title: Marsh Ecology Research Program (MERP): Decomposition of mud-flat species litter bag study data (1983-1985)

description: The Marsh Ecology Research Program (MERP) was a long-term interdisciplinary study on the ecology of prairie wetlands. A scientific team from a variety of disciplines (hydrology, plant ecology, invertebrate ecology, vertebrate ecology, nutrient dynamics, marsh management) was assembled to design and oversee a long-term experiment on the effects of water-level manipulation on northern prairie wetlands. Ten years of fieldwork (1980 -1989), combining a routine long-term monitoring program and a series of short-term studies, generated a wealth of new and diverse information on the ecology and function of prairie wetlands (Murkin, Batt, Caldwell, Kadlec and van der Valk, 2000). This data package includes the litter bag study conducted on the decomposition of mud-flat species, as part of the decomposition section of MERP. The high primary productivity in wetlands ensures that plant litter production and decomposition are important factors in wetland nutrient budgets. There are 3 components of the litter pool in prairie wetlands: standing litter, fallen litter, and dissolved organic compounds that leach from both standing and fallen litter (Davis and van der Valk, 1978). Material enters the standing litter compartment with the death of the leaf or shoots. In prairie marshes, litter is transferred from the standing litter compartment to fallen litter primarily through fragmentation by wind, snow, and ice action. In areas of high muskrat activity, feeding and house building can result in living plant tissues directly entering the fallen litter stage. Once within the fallen litter compartment, decomposition rates increase due to the growth of bacteria, fungi, and other consumers on the litter particles. (Murkin, van der Valk and Nelson, 1989). The MERP decomposition studies are a series of short-term studies examining the decomposition rates of both above- and belowground components of the dominant emergent species and the transfer of litter from the standing to the fallen litter compartment within the experimental cells (Murkin, van der Valk and Nelson, 1989). Three types of decomposition studies were conducted: litterbag studies, dead standing litter (clip plot) studies and matching stems (permanent clips) studies. The objective of this short-term decomposition study was to examine the rate of loss of dry mass, nitrogen and phosphorus from the shoot and root litter of the three dominant mudflat annuals (Aster brachyactis, Atriplex patula and Chenopodium rubrum) in MERP cells when they were still drawn down (1983-1984) and in 1985 when they were reflooded. These three species collectively accounted for up to 90% of the standing crop in the experimental marshes when they were drawn down in 1983 and 1984 (Wrubleski, Murkin, van der Valk and Davis, 1997; Nelson and Davis, 1986). For further information on the Marsh Ecology Research Program (MERP), please visit: http://www.ducks.ca/conserve/research/projects/merp/index.html References: Davis, C.B. and van der Valk. 1978. The decomposition of standing and fallen litter of Typha glauca and Scirpus fluviatilis. Can. J. Bot. 56: 662-675. Murkin, H.R., B.D.J. Batt, P.J. Caldwell, J.A. Kadlec and A.G. van der Valk. 2000a. Introduction to the Marsh Ecology Research Program. In Prairie Wetland Ecology: The Contribution of the Marsh Ecology Research Program. (Eds) H.R. Murkin, A.G. van der Valk and W.R. Clark. pp. 3-15. Ames: Iowa State University Press. Nelson, J.W. and C.B. Davis. 1986. Decomposition. In: Marsh Ecology Research Program: Long-term Monitoring Procedures Manual. (Eds.) H.R. Murkin and E.J. Murkin, pp. 57-65. Manitoba, Canada: Delta Waterfowl Research Station. Wrubleski, D.A., H.R. Murkin, A.G. van der Valk and C.B. Davis. 1997. Decomposition of litter of three mudflat annual species in a northern prairie marsh during drawdown. Plant Ecology 129: 141-148. Resulting Publications on MERP Decomposition studies: Murkin, H.R., A.G. van der Valk and C.B. Davis. 1989. Decomposition of four dominant macrophytes in the Delta Marsh, Manitoba. Wildl. Soc. Bull. 17: 215-221. van der Valk, A.G., J.M. Rhymer, H.R. Murkin. 1991. Flooding and the decomposition of litter of four emergent plant species in a prairie wetland. Wetlands 11 (1): 1-16. Wrubleski, D.A., H.R. Murkin, A.G. van der Valk and C.B. Davis. 1997. Decomposition of litter of three mudflat annual species in a northern prairie marsh during drawdown. Plant Ecology 129: 141-148. Wrubleski, D.A., H.R. Murkin, A.G. van der Valk and J.W. Nelson. Decomposition of Plant Litter in a Newly Flooded Northern Prairie Marsh. Unpublished manuscript. Wrubleski, D.A., H.R. Murkin, A.G. van der Valk and J.W. Nelson. 1997. Decomposition of emergent macrophyte roots and rhizomes in a northern prairie marsh. Aquatic Botany 58: 121-134. Additional MERP Publications on Decomposition Studies Neckles, H.A. and C. Neill. 1994. Hydrologic control of litter decomposition in seasonally flooded prairie marshes. Hydrobiologia 286: 155-165. Nelson, J.W., J.A. Kadlec and H.R. Murkin. 1990. Seasonal comparisons of weight loss for two types of Typha glauca Godr. leaf litter. Aquatic Botany 37: 299-314. Nelson, J.W., J.A. Kadlec and H.R. Murkin. 1990. Responses by macroinvertebrates to cattail litter quality and timing of litter submergence in a northern prairie marsh. wetlands 10: 47-60.