Local Wetland Research Articles

Sweeden's Swamp: The Morass of Wetland Regulation

Abstract On December 1, 1988, the Pyramid Development Companies asked the United States Supreme Court to decide a wetlands controversy that began when Pyramid's predecessor in title applied for a permit in February 1979.1 The “Sweedens Swamp” case, as it became known in the media, illustrates some of the strange emanations of our overlapping systems of federal, state, and local wetlands regulation.

Effective of Climate on Development of Two Sphagnum Bogs in South‐Central Wisconsin

Aquatic pollen, charcoal, sediment, and accumulation—rate changes from radiocarbon—dated cores from two sites in south—central Wisconsin were studied to explore the evolution of local wetlands since deglaciation. Sphagnum bog evolution in south—central Wisconsin appears to have been directly related to the regional climatic changes during the past 6000 yr (the middle and the late Holocene). Although the two sites had different origins and different early histories, both were deep lakes until 6300 BP when they became shallow ponds dominated by the aquatic macrophyte Brasenia. These wetland changes were concurrent with a regional upland vegetational change from mesophytic forest to Quercus savanna and were caused by a regional decrease in annual precipitation and by an increase in temperature. At °3000 BP, in response to a cooler, wetter climate, both wetlands became Sphagnum—Ericaceae bogs, and the upland vegetation changed to a closed Quercus forest. The paleoecological evidence suggests that bog development is a function of climate and that many bogs have developed in the northern Midwest during the past 3000 yr as effective moisture has increased.

Environment as Artefact. A palaeoecological contribution to the prehistory of southwestern Victoria

Palynology has traditionally been used to reconstruct vegetation, and thence climatic, change, but attention is increasingly being focussed on its potential to address questions related to human history. It is contended in this thesis that palaeoecology, particularly palynology, provides independent evidence of prehistoric land-use and resource exploitation in southwestern Victoria. The study begins by discussing and establishing a theoretical framework in which both palaeoecological and archaeological data can be integrated in order to address questions of human use of the environment. After a review spanning both disciplines the framework of evolutionary ecology, with its emphasis on the historical nature of change, and the generation of change from both within and without the system under scrutiny, is presented as the most appropriate. The Holocene environmental history of the Discovery Bay area is derived from pollen and stratigraphic analyses of a number of sites, including near-coastal lakes, swamps and peats as well as archaeological deposits. Pollen sites were selected to enable the effects of regional and local change to be separated. The major vegetation changes included a pre-11,000 BP phase dominated by Banksia and Asteraceae (Liguliflorae), which gave way to a composite-dominated herbfield/shrubland some time before about 11,000 BP. Casuarina stricta woodland was locally dominant by about 8000 BP, and from 6000-200 BP was the major vegetation type in the area. Within the last 7000 years, environmental changes at Discovery Bay have been more sensitive to coastal geomorphic processes than to climate. These changes included the establishment of interdune and backdune swamp systems at the time of sea level stabilisation about 7000-6000 BP. The interdune swamps were overridden by coastal erosion some time after about 4000 BP, and are now preserved only as peat outcrops on the present beach. Long Swamp underwent a change from estuarine lake to freshwater swamp about 4000 BP. Relative productivities in local environmental zones are compared over the time period. Swamp resources are interpreted as crucial variables due to their high gross productivities and abundant and accessible sources of the plant food staples Typhu and Triglochin . Productivity in the coastal zone as a whole increased after 4000 BP due to freshwater swamp expansion at Long Swamp, while drier conditions in inland southwestern Victoria meant that overall productivity declined in the inland regions. However, there were local increases in humanly accessible productivity in inland areas where very wet environments dried out to form swamps. A detailed fire history is constructed for each pollen site, enabling the separation of local and regional fire regimes. Fire appears to have been an integral and constant part of the dryland forest ecosystems. There was no visible change in the intensity of regional burning over the past 7000 years, and the separation of anthropogenic and other influences was not considered possible. However, the local wetland fire regime is interpreted as reflecting predominantly anthropogenic influences, since natural burning of Typha swamps would have been rare. Because of this, with the earliest evidence of swamp burning at 6800 BP, it is argued that swamps were utilised and managed as soon as they formed. This finding contributes to the conclusion that deliberate swamp management practices have a longer history in southwestern Victoria than is evident in the archaeological record alone. It is further concluded that the archaeological evidence for the suggested intensification of population in southwestern Victoria during the Holocene may have been given an artificial synchroneity by geomorphological processes affecting the coast. As erosion has removed evidence of foredune occupation dating between 6000 BP and about 3000 BP, most dune middens are necessarily younger than this. I n addition, concentration of occupation around inland swamp resources during the apparently drier period of the late Holocene (about 3000 BP), as well as movement towards the expanding freshwater swamps along the coast, must be accounted for before evidence of overall and sudden increases in population can be considered conclusive. The causes and timing of changing settlement and exploitation patterns in southwestern Victoria will be better understood a the history of swamp exploitation is further explored. Â

A Quantitative Method for Stratigraphic Analysis of Bryophytes in Holocene Peat

(1) A new method of analysing the changes in amounts of bryophytes in autochthonous peats is developed. Bryophyte concentration changes (expressed as number of fragments per 100 ml of peat) and percentages of types are calculated and presented in continuous stratigraphical diagrams. (2) A formula used to calculate Sphagnum concentrations is based on counts of Sphagnum plants, branches, and leaves. This makes it possible to present Sphagnum together with other bryophytes in the same diagrams. (3) As an illustration of the method a 3.8-m deep peat core was analysed from Red Lake Peatland, on the bed of Glacial Lake Agassiz in northern Minnesota. Peat accumulation began at this site about 3500 years ago. (4) Scorpidium scorpioides and Calliergon trifarium are the major peat formers during several recurring episodes of peat accuimulation. Seven other species of the Amblystegiaceae are recorded. One or more of six Sphagnum species dominate other periods of the accumulation. Four additional types belong to the Bryaceae, Meesiaceae, Aulacomniaceae and Polytrichaceae. (5) Five local bryophyte zones are sharply delimited in the late Holocene peat of this Red Lake Peatland site. The four lower zones reflect either changes in the water level in a non-patterned fen system or fluctuations in the size of low hummocks formed by emergent, minerotrophic bryophytes in a patterned fen. The uppermost zone indicates the formation of less minerotrophic vegetation on top of the fen peat and periodic advances of the bog margin over the fen at the coring site. (6) Bryophyte concentration data are useful in interpreting peat ontogeny and the local hydrological environment during peat accumulation. The bryophyte assemblages reflect shifts along a minerotrophic-ombrotrophic gradient of one of the dominant components of the local wetland vegetation.

A paleoecological analysis of Quadra Sand at Point Grey, British Columbia, based on indicator pollen

Pollen and spore percentages and concentrations were determined from six peaty zones about 24500 radiocarbon years old at the Point Grey sea cliffs. All samples are dominated by nonarboreal pollen, especially Cyperaceae of local origin and Gramineae. Analysis of 'indicator pollen' suggests that two floristic elements were present, a local wetland component and a montane to subalpine element. This study supports the geological contention that the Quadra Sand was deposited in a braided river environment under a cooler maeroclimate than exists at present. Pollen concentrations in the samples are within the range of some bog and lake sediments presently accumulating in the Fraser Lowland area of southwestern British Columbia, suggesting that climatic conditions were not of alpine severity around 24 500 BP, although the indicator pollen assemblage suggests a climatic regime similar to present-day midmontane or subalpine conditions.

State and Local Wetlands Regulation: The Problem of Taking without Just Compensation

State and Local Wetlands Regulation: The Problem of Taking without Just Compensation