Marsh Ecology Research Program (MERP): Turnover plot data (1980-1989)

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 set includes turnover plot data, collected as part of the vegetation section of MERP.
Determination of aquatic macrophyte annual net primary production is vital to the understanding of the dynamics of freshwater marshes. Macrophyte biomass, both live and dead, is a major storage compartment for carbon, nitrogen and phosphorus in a marsh and a major potential energy and nutrient source for the faunal component of the marsh ecosystem. Macrophyte communities are also essential structural components of the habitat of both invertebrates and vertebrates. The major objective of the long-term monitoring of aquatic macrophytes was to determine the impact of the wet-dry cycle on macrophyte above and belowground net annual production. Standard harvest techniques were used because they were the most direct, simple and reliable techniques available for estimating net annual primary production of macrophytes per unit area (van der Valk, 1989). Sampling for aboveground macrophyte production occurred once in late July or early August during the sampling season, as this is the period where standing emergents reach their maximum standing crop. The appearance of fully-grown Typha sp. was generally used to gauge if macrophytes had reached their maximum standing crop. Both clip plot (MAGs; contained in a separate data package on the KNB) and turn-over plot (TOPs) methods were used to estimate aboveground production (van der Valk, 1989). As a single harvesting method would underestimate net primary productivity, turnover plots were used to correct the data.

For further information on the Marsh Ecology Research Program (MERP), please visit: http://www.ducks.ca/conserve/research/projects/merp/index.html

References
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.
van der Valk, A. 1989. Macrophyte production. In Marsh Ecology Research Program: Long-term Monitoring Procedures Manual. (Eds.) E.J. Murkin and H.R. Murkin, pp. 23-29. Manitoba, Canada: Delta Waterfowl Research Station.

Resulting Publications
van der Valk, A.G., and C.H. Welling. 1988. The development of zonation in freshwater wetlands: an experimental approach. In Diversity and Pattern in Plant Communities. (Eds.) H.J. During, M.J.A. Werger, and H.J. Willems, pp.l45-158. The Hague, Netherlands: SPB Publishers.
van der Valk, A.G., C.H. Welling, and RL. Pederson. 1989. Vegetation change in a freshwater wetland: a test of a priori predictions. In Freshwater Wetlands and Wildlife. (Eds.) RR. Sharitz and J.W. Gibbons, pp.207-217. USDOE Symposium Series 61, Oak Ridge: USDOE Office of Scientific and Technical Information.
van der Valk, A.G. 1994. Effects of prolonged flooding on the distribution and biomass of emergent species along a freshwater wetland coenocline. Vegetatio 110: 185-196.
van der Valk, AG., L. Squires, and C.H. Welling. 1994. Identifying the impacts of an increase in water level on wetland vegetation undergoing succession. Ecological Applications 4:525-534.
van der Valk, A.G. 2000. Vegetation dynamics and models. 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. 37-54. Iowa: Iowa State University Press.
Welling, C.H., R.L. Pederson, and AG. van der Valk. 1988a. Recruitment from the seed bank and the development of zonation of emergent vegetation during drawdown in a prairie marsh. Journal of Ecology 76:483-496.
Welling, C.H., R.L. Pederson, and AG. van der Valk. 1988b. Temporal patterns in recruitment from the seed bank during drawdowns in a prairie wetland. Journal of Applied Ecology 25:999-1007.

Supporting literature on MERP vegetation data
Cornwell, J.C., C. Neill, and J.C. Stevenson. 1995. Biogeochemical origin of Δ34S isotopic signatures in a prairie marsh. Canadian Journal of Fisheries and Aquatic Sciences 52: 1816-1820.
de Swart, E.O.A.M., A.G. van der Valk, KJ. Koehler, and A. Barendregt. 1994. Experimental evaluation of realized niche models for predicting responses of plant species to a change in environmental conditions. Journal of Vegetation Science 5:541-552.
Galinato, M.J., and A.G. van der Valk. 1986. Seed germination traits of annuals and emergents during drawdown in the Delta Marsh, Manitoba, Canada. Aquatic Botany 26:89-102.
McKee, K.L., I.A Mendelssohn, and D.M. Burdick. 1989. Effect of long-term flooding on root metabolic response in five freshwater marsh plant species: Canadian Journal of Botany 67:3446-3452.
Merendino, M.T., L.M. Smith, H.R. Murkin, and RL. Pederson. 1990. The response of prairie wetland vegetation to seasonality of drawdown. Wildlife Society Bulletin 18: 245-251.
Merendino, M.T., and L.M. Smith. 1991. Influence of drawdown date and subsequent reflood depth on wetland vegetation establishment. Wildlife Society Bulletin 19: 143-150.
Neckles, H.A., J.A. Nelson, and R.L. Pederson. 1985. Management of whitetop (Scolochloa festucacea) marshes for livestock forage and wildlife. Delta Waterfowl and Wetlands Research Station Technical Bulletin 1.
Neckles, H.A., and R.L. Wetzel. 1989. Effects of forage harvest in seasonally flooded prairie marshes: simulation model experiments. In Freshwater Wetlands and Wildlife. (Eds.) RR. Sharitz and J.W. Gibbons, pp.127-143. USDOE Symposium Series 61, Oak Ridge: USDOE Office of Scientific and Technical Information.
Neill. C. 1990. Effects of nutrients and water levels on emergent macrophyte biomass in a prairie marsh. Canadian Journal of Botany 68:1007-1014.
Neill, C 1990. Nutrient limitation of hardstem bulrush (Scirpus acutus Muhl.) in a Manitoba Interlake Region Marsh. Wetlands 10: 69-76.
Neill, C. 1990. Effects of nutrients and water levels on species composition in prairie whitetop (Scolochloa festucacea) marshes. Canadian Journal of Botany 68: 1015-1020.
Neill, C. 1992. Comparison of soil coring and ingrowth methods for measuring below ground production. Ecology 73:1918-1922.
Neill, C. 1992. Life history and population dynamics of whitetop (Scolochloa festucacea) shoots under different levels of flooding and nitrogen supply. Aquatic Botany 42: 241-252.
Neill, C. 1993. Growth and resource allocation of whitetop (Scolochloa festucacea) along a water depth gradient. Aquatic Botany 46:235-246.
Neill, C. 1993. Seasonal flooding, soil salinity and primary production in northern prairie marshes. Oecologia (Berl.) 95:499-505.
Neill, C. 1995. Seasonal flooding, nitrogen mineralization and nitrogen utilization in a prairie marsh. Biogeochemistry 30:171-189.
Neill, C., and J.C. Cornwell. 1992. Stable carbon, nitrogen, and sulfur isotopes in a prairie marsh food web. Wetlands 12:217-224.
Pederson, R.L. 1981. Seed bank characteristics of the Delta Marsh: applications for wetland management. In Selected Proceedings of the Midwest Conference on Wetland Values and Management. (Ed.) B. Richardson, pp.61-69. St. Paul: Minnesota Water Planning Board.
Pederson, R.L., and A.G. van der Valk. 1984. Vegetation change and seed banks in marshes: ecological and management implications. Transactions of the North American Wildlife and Natural Resources Conference 49:271-280.
Pederson, RL., and L.M. Smith. 1988. Implications of wetland seed bank research: a review of Great Basin and prairie marsh studies. In Interdisciplinary Approaches to Freshwater Wetlands Research. (Ed.) D.A. Wilcox, pp.81-95. East Lansing: Michigan State University Press.
Seabloom, E.W., K.A. Moloney, and A.G. van der Valk. Constraints on the establishment of plants along a fluctuating water-depth gradient. Ecology 82: 2216-2232.
Squires, L., and A.G. van der Valk. 1992. Water depth tolerances of the dominant emergent macrophytes of the Delta Marsh, Manitoba. Canadian Journal of Botany 70: 1860-1867.
van der Valk, A.G. 1981. Succession in wetlands: a Gleasonian approach. Ecology 62:688-696.
van der Valk, A.G. 1982. Succession in temperate North American wetlands. In Wetlands: Ecology and Management. (Eds.) B. Gopal, RE. Turner, R.G. Wetzel, and D.E Whigham, pp.169-179. Jaipur, India: National Institute of Ecology.
van der Valk, A.G.1986. The impact of litter and annual plants on recruitment of species from the seed bank of a lacustrine marsh. Aquatic Botany 24:13-26.
van der Valk, A.G. 1992. Establishment, colonization, and persistence. In Plant Succession: Theory and Prediction. (Eds.) D.C. Glenn-Lewin, R.K. Peet, and T.T. Veben, pp.60-102. New York: Chapman & Hall.
van der Valk, A.G. 1992. Response by wetland vegetation to a change in water level. Wetland Management and Restoration. Swedish Environmental Protection Agency Report 3492. (Eds.) C.M. Finlayson and T. Larsson, pp.7-16. Solna, Sweden: Swedish Environmental Protection Agency.
van der Valk, A.G., and L. Squires. 1992. Indicators of flooding derived from aerial photography in northern prairie wetlands. In Ecological Indicators: Volume 1. (Eds.) D.H. McKenzie, D.E. Hyatt, and V.J. McDonald, pp.593-602. London, UK: Elsevier.
van der Valk, A.G., and R.L. Pederson. 1989. Seed banks and the management and restoration of natural vegetation. In The Ecology of Seed Banks. (Eds.) M.A. Leck, VT. Parker, and RL. Simpson, pp.329-346. New York: Academic Press.
van der Valk, A.G., R.L. Pederson, and C.B. Davis. 1992. Restoration and creation of freshwater wetlands using seed banks. Wetlands Ecology and Management 1:191-197.
van der Valk, A.G., L. Squires, and C.H. Welling. 1994. Identifying the impacts of an increase in water level on wetland vegetation undergoing succession. Ecological Applications 4:525-534.