Zonation, Competitive Displacement and Standing Crop of Northwest Iowa Fen Communities

Well developed Iowa fens contain three distinct vegetation zones (border zone, sedge mat zone and discharge zone). On the average, the above ground standing crop of these zones is 425, 197 and 528 g/m2 respectively. Species growing on these fens show three basic distributional patterns: (1) they grow in the border and discharge zones; (2) they grow primarily in the sedge mat zone or (3) they grow in all three zones. Individual plants of species growing in the border and/or discharge zone are on the average 1.6 to 2.7 times taller and weigh 1.8 to 5.4 times more than when they grow on the sedge mat zone. Species with primarily bimodal or ubiquitous distributions show the greatest decline in height and weight when found in the discharge zone. The three Iowa fen zones are a result of differences in environmental conditions, plus competitive displacement of the dominant sedge mat species from the border and discharge zones

The History of Plant Ecology in Iowa as Reflected in the Proceedings of the Iowa Academy of Science

All plant ecology papers published in the Proceedings from 1887 to 1973 were identified. On the average only 1.4 papers were published per year. An examination of the number of papers published in successive five-year intervals indicates that there were three distinct periods in the history of plant ecology in Iowa with three individuals dominating each period: 1887-1931 - L. H. Pammel, B. Shimek, and Ada Hayden; 1932-1951 - H. S. Conard, J. M. Aikman, and Ada Hayden; 1952-1971 - J. M. Aikman, R. F. Thorne, and R. Q. Landers. There have been very few active plant ecologists in Iowa, and more than 50 percent of all the papers published in the Proceedings were authored or co-authored by only 10 people. All the papers identified are also classified according to subject matter

Floristic Composition and Structure of Fen Communities in Northwest Iowa

Iowa fens have three distinct, concentric vegetation zones: a border zone, a sedge mat zone, and a discharge zone where ground water supplying the fens comes to the surface. Calamagrostis inexpansa Gray, Viola nephrophylla Greene, Scirpus americanus Pers. and Carex spp. are the dominants in the border zone. The composition of this zone is quite variable both within and between fens. The sedge mat is composed primarily of Rhynchospora capillacea Torr. Other species normally found in this zone are Lobelia kalmii L., Muhlenbergia racemosa (Michx.) BSP, Parnassia glauca Raf., Triglochin maritima L. and Scirpus americanus. Although all of the species in this zone are also found in the other zones, this zone is readily distinguishable because of the low stature of the vegetation. The discharge zone is dominated usually by Carex spp. or Calamagrostis inexpansa, except at one fen where Phragmites communis Trin. and Helianthus grosseserratus Martens are the dominants. The sedge mat zone on the average has fewer species per quadrat (5.8 versus 6.0 and 8.6), lower Shannon-Weaver index (0.8 versus 1.15 and 1.40) and higher Simpson\u27s index (0.58 versus 0.42 and 0.32) than the discharge and border zones, respectively

A Checklist of the Aquatic and Wetland Vascular Plants of Iowa: I. Ferns, Fern Allies, and Dicotyledons

This paper is an annotated checklist of the aquatic and wetland ferns, fern allies, and dicotyledons of Iowa and is based primarily on published floristic surveys. For each species, information about its habitat, distribution, synonomy, and frequency of occurrence is provided, plus a distribution map. A total of 9 ferns, 6 fern allies, and 262 dicotyledons are considered aquatic or wetland species in Iowa

Treatment of waste from a confined hog feeding unit by using artificial marshes

A 1-year study has been completed to evaluate use nf artificial marshes as a teatment system for waste from confined hog feeding operatiuns, A 3 x 2 factor ial experimental design was employed to evaluate the performance of marshes planted with one of three emergent species (Sparganium eurycarpum Phragniites austi:alis, glauca)and receiving three different loadings of hog waste. Each treatment was replicated twice, For each marsh, a complete hydrological and nutrient (N, P) budget was deter­ mined. Data on COD and solids were also collected. The growth of the plants, particularly rates of vegetative reproduction, were also monitored regularly throughout the growing season to examine the effect of sludge accumulation on plant vigor. Because the odor associated with present animal waste handling systems has been a major problem, the most important feature of artificial marshes treating hog waste is that they seem not to have developed any odors during their first year of operation . Emergent plants have a system of inter­nal air spaces that allows oxygen from the leaves to diffuse into the rhizomes and roots, Enough oxygen seems to be diffusing out of the roots and into the accumulating sludge to prevent it from becoming completely anaerobic. During the summer of 1977, the marshes produced a superior effluent to that of an anaerobic lagoon. Up to 70% of the TVS and 50% nf the COD waa re­ moved by the marshes, largely through meuhanical filtration. Approximately 17% of the N and P was removed, mostly by uptake into the plants. Design criteria for these marshes and suggested modifications are pre­sented

The language of intervention: A review of concepts and terminology in wetland ecosystem repair

As programmes and projects aimed at addressing wetland degradation gain momentum in South Africa, it is critical that related ideas are communicated among and between researchers, practitioners, management agencies, land-owners and the general public in a common language. This paper explores the meaning of ‘restoration’ and ‘rehabilitation’; terms that we suggest are key to understanding and advancing South Africa’s efforts to address wetland degradation. In its essence, the paper is a critical review of wetland ecosystem repair concepts and terminology from local and international literature. The major products of the paper are proposed definitions of the terms ‘restoration’ and ‘rehabilitation’ in a South African wetland science and management context. Although the terms are often used interchangeably, we argue that their absolute distinction will allow scientists and practitioners to better understand what it is that ecosystem repair interventions aim to achieve. We suggest that the terms be distinguished on the basis of what could be considered their respective ecological starting points, where ‘restoration’ applies to part of a system or a system in its entirety that has been completely and permanently, but not irreparably altered, and essentially removed from the landscape, and ‘rehabilitation’ applies to part of a system or a system in its entirety that has not been removed from the landscape through complete and permanent alteration, but is in a degraded state. Thus, ‘wetland restoration’ is defined as the process of reinstating natural ecological driving forces within part or the whole of a completely and permanently altered wetland to recover former or desired ecosystem structure, function, biotic composition and ecosystem services, while ‘wetland rehabilitation’ is defined as the process of reinstating natural ecological driving forces within part or the whole of a degraded wetland to recover former or desired ecosystem structure, function, biotic composition and ecosystem services