Les zones humides naturelles méditerranéennes sont des écosystèmes rares et vulnérables souvent altérés par les pollutions des milieux adjacents. Le développement de zones humides artificielles (ZHA) servant au traitement secondaire des pollutions permettrait de limiter l’impact des activités industrielles sur les milieux naturels. Pour végétaliser ces ZHA et tolérer les contraintes du climat méditerranéen, l’utilisation d’espèces végétales locales éco-adaptées est recommandée. Toutefois ce type de ZHA, utilisant des plantes locales méditerranéennes, a fait l’objet d’un nombre restreint de travaux. Les objectifs de cette thèse sont donc : - de suivre la biocénose implantée et spontanée d’une ZHA pour évaluer la mise en place de ce nouvel écosystème (suivis floristique, faunistique et phytoplanctonique),- d’évaluer ses fonctionnalités et son efficacité épuratoire (suivis physico-chimique et biologique),- de questionner la pérennité de tels systèmes dans une contexte de changements globaux, notamment climatique. Les résultats montrent qu’un nombre restreint d’espèces végétales locales sélectionnées peut permettre la création d’un nouvel écosystème fonctionnel et durable qui soutient l’enjeu de biodiversité, tout en améliorant le traitement des effluents rejetés par le bassin industrialisé. Ces travaux valident l’intérêt des ZHA à hélophytes locales en méditerranée pour traiter les pollutions de bassins versants industrialisés mais un effort de recherche reste à faire pour adapter la conception aux spécificités des sites dans une véritable démarche d’ingénierie écologique. / Natural wetlands in Mediterranean areas are rare and vulnerable ecosystems, frequently impacted by various pollutants from nearby environments. In order to decrease industrial activities lethal effects on natural areas, constructed wetlands (CWs) are an interesting opportunity to remediate their pre-treated wastewaters. Such CWs would take advantage with using local plant species, well adapted to Mediterranean climate’s rigors. Nevertheless, CWs planted with Mediterranean plant species are still scarce and poorly studied. Aims of this thesis are thus:• to follow up on planted and adventive biocœnosis of a CW (flora, fauna and phytoplankton), in order to assess a novel ecosystem settlement,• to get better knowledge on its functions and remediation efficiency (physico-chemical and biological parameters),• to question durability of such techno-ecosystems in a context of global changes (with focus on climate).Main result let us know that it only takes a few local plant species, wisely chosen, to allow the settlement of a sustainable and fully functional ecosystem, supporting biodiversity stakes while increasing the remediation of pre-treated wastewaters collected from industrialized catchment. This work assess CWs planted with local helophytes as a powerful tool to treat industrialized catchment wastewaters in Mediterranean area, but researches are still needed to fit each design with each site characteristics, following a sustainable ecological engineering approach.

This thesis aims to propose a design of a vertical flow constructed wetland for a village up to 500 PE. The project is conducted for the town of Vlachova Lhota (Zlín district), and two alternatives are presented here. The first is based on mechanical pre-treatment and an intermittently loaded vertical flow constructed wetland. This alternative meets the state limits of wastewater discharge, which was demonstrated by a calibrated model of the effectiveness of an intermittently loaded vertical flow constructed wetland. This model was designed by Ing. Mirka Němcová using Hydrus software. The second alternative includes, in addition to the first design, tertiary sewage treatment. Tertiary treatment was proposed as an effective solution to removing all monitored pollutants in wastewater discharge. A combination of technologies of tertiary sewage treatment has not been put into practice, therefore the outcome and the effectiveness of the process can only be estimated. Tertiary sewage treatment would function as the first operational research unit, which could produce further findings in the field of sewage treatment using nature-based methods.

Appreciation of the ecological and economic values associated with healthy salt marshes has led to a recent rise in the number of marshes that are being targeted for restoration by dike removal. The success of restoration is often measured by the return of marsh plants, though this overlooks a key component of salt marshes, that of the invertebrate community within marsh sediments. To evaluate the short-term recovery of these invertebrates, sediment cores were collected across an elevational gradient in a recent dike removal marsh, one and two years post removal, and a nearby reference marsh. Abundance, richness and diversity as well as morphospecies community composition were compared across treatment groups (Reference, Removal) and elevation zone (High Marsh, Low Marsh). Morphospecies richness, abundance and diversity were significantly higher in Low Marsh samples than in High Marsh samples, though no statistically significant differences were found across treatments of the same elevation (e.g., Reference Low Marsh versus Removal Low Marsh). Pair-wise ANOSIM results found significant differences between community compositions across treatments, specifically Reference Low Marsh and Removal Low Marsh. The marsh edge, the lowest point of vascular plant growth before transitioning to tide flats, is considered a high stress environment for emergent vegetation. Plant establishment and survival in this low elevation zone is limited by the tolerance to inundation duration and frequency and anoxic sediments. Bioturbation and burrowing by macroinvertebrates increases the surface area exposed to surface water for gas exchange, increasing the depth of the redox potential discontinuity layer. Crabs that make stable, maintained burrows have been shown to increase oxygen penetration into sediment, improving plant productivity. Such crabs are not found in salt marshes of the Pacific Northwest of North America. However, other burrowing invertebrates may have a positive impact on plant health in these areas by reducing abiotic stress due to anoxic sediments, thereby allowing plants to establish and survive lower in the intertidal zone. To assess this potential relationship, study plots of Distichlis spicata were selected at equivalent elevations at the lowest point of plant establishment at the marsh edge. Focal plant rhizomes were severed from upland ramets and assigned an invertebrate abundance treatment based on a visual burrow count surrounding each plant (9 cm diameter). Focal plants were visited monthly from July to September 2016, plant health variables of chlorophyll content and chlorophyll fluorescence (photosynthetic efficiency), and sediment ORP readings were collected. Plant survivorship was significantly higher in plots with invertebrates, 96% of plants in 'With Invertebrate' plots and 50% of plants in 'No Invertebrates' plots survived the duration of the study. Plant health (chlorophyll content and chlorophyll fluorescence) generally increased with increased invertebrate presence though, not statistically significant. There may be potential for improved plant productivity and resilience to plants at the marsh edge due to invertebrate burrowing activity. This benefit could help mitigate projected losses in plant productivity due to sea level rise, though more research is needed to investigate the mechanism by which these invertebrates confer a health benefit to plants at the marsh edge.

Stormwater runoff from developed land is a source of pollution and excessive flow to waterways. The most commonly employed practices for flow and volume control are stormwater ponds and basins (also referred to as detention and retention ponds). These structures can be effective at controlling peak discharge to water bodies by managing flow timing but are often ineffective at removing nutrients, particularly in dissolved forms. Pond morphology coupled with place-specific characteristics (like soil type and drainage area characteristics) may influence plant community composition in these water bodies. The interaction of physical, chemical, and biological elements in stormwater ponds may affect their water quality performance in more significant ways than previously understood. Floating treatment wetlands (FTW) are floating rafts of vegetation that can be constructed using a variety of materials and are an emerging technology aimed at improving the pollutant removal and temperature control functions of stormwater ponds. Previous studies with field research in subtropical and semiarid climatic regions found incremental nutrient removal improvement correlated with FTW coverage of pond surface area. However, data on their performance in cold climates is lacking from the literature. This dissertation presents data from a three-year study examining the performance of FTW on stormwater pond treatment potential in cold climate conditions and optimal vegetation selection based on biomass production, phosphorus (P) uptake, and root architectural characteristics that enhance entrapment functionality. To put the FTW pond performance data into context, results from a survey of seven permitted stormwater ponds in Chittenden County, Vermont and the ponds' associated variability in influential internal and external dynamics are also discussed. Pond morphology, drainage area land use, soil types, and biological communities are analyzed for correlative relationships to identify design factors that affect pond performance but are not controlled factors in stormwater system permitting.

The feasibility of predicting porewater salinity based on calibrated surface electromagnetic methods is discussed in a coastal wetland on the southern banks of Tampa Bay in West-Central Florida. This study utilizes a new method to float commercial land based electromagnetic (EM) instruments in shallow marine waters of less than 1.5 meters. The floating EM-31 (Geonics, Ltd.) effectively sensed the magnitude and lateral extent of high and low salinity porewaters within mangrove lined ditches and ponds. Resistivity and EM geophysical methods are merged with direct sampling data to calibrate layers in electromagnetic models to infer shallow (<30m) groundwater salinity patterns. Initial marine resistivity surveys are necessary to discriminate between equivalent EM model solutions for seafloor conductivities beneath shallow (0.1-1.5m) marine (~30 ppt) waters. Using formation factors computed from nearby resistivity surveys, porewater conductivity predictions based on surface EM-31 and EM-34 measurements are successful at distinguishing overall porewater salinity trends. At the Tampa Bay study site, the most distinctive terrain conductivity anomalies are associated with mangroves bordering marine waters. Highly elevated porewater conductivities are found within 5m of the mangrove trunks, falling sharply off within 10m, presumably due to saltwater exclusion by mangrove roots. Modeling indicates the shallow water EM-31 measurements probably lack the resolution necessary to image more subtle porewater conductivity variations, such as those expected in association with diffuse submarine groundwater discharge. However, the technique has potential application for locating high contrast zones of freshwater discharge and other salinity anomalies in shallow and nearshore areas not accessible to conventional marine resistivity or land-based arrays, and hence may be useful for interdisciplinary studies of coastal wetland ecosystems.

Title from screen page; viewed 10 Dec. 2004. Includes bibliographical references. Electronic publication; full text available in PDF format; abstract in HTML format. xvi, 314 leaves : ill. ; 30 cm.

This dissertation considers three topics under the themes of wetland restoration, urban sprawl, and recreation demand employing spatial data and analysis. A key question addressed in the first essay is how we can identify priority areas for wetlands restoration along the Louisiana coast under the Coastal Wetlands Planning, Protection, and Restoration Act by estimating amenity values received by nearby residents from hypothetical wetlands restoration projects. The second essay evaluates the effectiveness of alternative land-use policy variables for controlling development in a sprawling metropolitan area during two extreme market conditions. The third essay estimates the effect on consumer welfare from improved satisfaction of recreation information availability.

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This thesis examines the wetland sacrifices that were performed in Northern Europe in the Iron Age. Skedemosse on central Öland is the largest wetland sacrifice in Sweden and was the site of a cult which sacrificed animals and humans. Between the late second century and well into the fifth century the place was also used for large sacrifices of military equipment. New radiocarbon dates has shown that the place functioned as a ritual place from the Pre Roman Iron Age and into the Late Viking Age. Both in the Iron Age and later wetlands seem to have been both venerated and feared and the thesis discusses why this came to be, and how it can be seen in the archaeological material. A smaller part of the sacrificial site of Skedemosse was selected for a closer study and it was possible to establish several depositions which appear to have been treated slightly different from each other. The investigations of the animal sacrifices have focused on the horses as they are the most common animal. The horse was an important mythological animal in the Iron Age and they were equally important in the cult. The horses in Skedemosse were eaten in ritual meals, and it is possible that some of them took part in ritual races along the ridge east of the former lake.  Such races were called skeið and the name Skedemosse may be derived from this word. Skedemosse is also rare because the remains of ca 38 people have been found in it. Some of these people have suffered a violent death. They are compared to other bog bodies from northern Europe and the follow a similar pattern to those; In the Pre Roman Iron Age mainly women and children were sacrificed and after the first century AD mainly men ended up in the lake.

Like life-history theory, wildlife management decisions are typically predicated on trade-offs between benefits associated with investing resources to achieve higher reproductive or survival rates versus costs or risks of achieving those goals. On the Canadian prairies, most waterfowl conservation resources are directed to policies and programs that seek to increase duck nesting success. Limited attention has focused on post-hatching life-cycle stages, yet, despite considerable recent work on duckling survival rates, many uncertainties remain concerning how abiotic and biotic factors affect duckling survival rates. The role of upland habitat characteristics may be important but has received limited attention. I evaluated hypothesized sources of variation in duckling survival for 617 mallard (Anas platyrhynchos) broods on 27 Canadian prairie-parkland sites, with emphasis on assessing effects of managed and remnant natural upland habitats. I contrasted suites of a priori and post hoc exploratory models that incorporated effects of landscape, weather, female and brood-related variables to explain variation in duckling survival rates. Survival was lower for ducklings that used areas with high proportions of semi-permanent wetlands, as well as for broods that travelled farther overland. Exploratory analyses revealed further that survival of ducklings was negatively related to the amount of managed hayland. In contrast, duckling survival was positively associated with the amount managed grassland. There was no evidence of trade-offs between benefits of managing habitat to enhance duck nesting success versus costs in terms of lower subsequent duckling survival.<p> I also addressed unresolved questions about how birds balance costs and benefits of selecting habitats by determining the survival consequences of habitat choices made during brood-rearing. In theory, fitness should be higher in preferred habitats, but this assumption is rarely tested. Fitness consequences (i.e., duckling survival) of habitat selection patterns were determined at landscape and local scales using logistic regression and information-theoretic model selection techniques. Best-approximating landscape-level models indicated that mallard females selected brood-rearing areas with a high proportion of wetland and perennial upland habitats, but duckling survival was not related to habitat selection patterns at this scale. At finer spatial scales, females selected brood-rearing areas with high proportions of wetland habitats, but, contrary to expectation, duckling survival was lower when females raised their broods in these areas. Females avoided areas with abundant perennial cover and wetlands with little vegetative cover and, consistent with prediction, duckling survival was higher when females selected areas with low perennial cover. Thus, females did not consistently select brood-rearing habitats that conferred the highest fitness benefits. Rather, the relationship between habitat selection and duckling survival depended on spatial scale and habitats considered.