At the Trail Smelter, contaminated seepage water is collected and a portion is diverted for treatment to a large pilot-scale wetland system. The design, construction (in stages from 1997 to 2002) and long term sampling (1998-2007) of the wetland system treating high concentrations of zinc, arsenic and cadmium is presented. The final system configuration has been operating year-round since 2002 treating approximately 15,000 L/d. The system is comprised of two vertical upflow anaerobic (compost) bioreactors followed by three horizontal subsurface flow vegetated wetland cells, a slow sand filter and a final holding cell. Operational sampling was done for water quality (metals and various anions), bacterial communities (MPN, PFLA and DGGE) and vegetation (metals content). After several years of operation one of the anaerobic cells was taken apart and rebuilt in 2002. Extensive solid substrate sampling during deconstruction was analyzed for mineralization (SEM/EDS), metals and carbon content (Rock-Eval pyrolysis) to estimate the potential cell life. The system treats seepage with zinc up to 3800 mg/L (average ~ 260 mg/L), arsenic to 3600 mg/L (average ~ 150 mg/L) and Cd to 83 mg/L (average ~ 4.7 mg/L) which are reduced to <0.5 mg/L (<0.02 mg/L for Cd). Vegetation sampling showed variable uptake into exposed plants at much higher levels than control plants. Plant toxicity was experienced in the system. Evapotranspiration and rhizofiltration are the preferred use of plants as opposed to metal hyper-accumulating plants. Bacterial sampling indicated the presence of sulphate reducing bacteria and a diverse anaerobic microbial community throughout the system despite the high metals entering the system. The predicted life of the anaerobic cell by Rock Eval 6 was 18 years with a range from 17 to 21 years, while based on biomass calculations could range from 14 to 34 years. Where wetlands systems can be successfully used, their cost and environmental and social sustainability is very favourable when compared to chemical treatment systems (e.g. lime-dosing systems). Based on author‟s experience at the Trail and other sites, the design issues faced by full scale wetland systems are presented and recommendations made to ensure a successful system. / Graduate

South Milton Ley is a small coastal wetland in Southern England. A sand-bar forms periodically at its seaward end and separates fresh water from the sea. The common reed Phragmites australis dominates the wetland and when a sand bar is present a shallow freshwater lake forms. Monthly water budgets were prepared for the years 1994, 1995 and 1996 and intermittent flooding of the Ley was also monitored. This information was used to calculate a range of residence times (between one hour and eleven days) and the characteristics of various flow regimes when the sandbar, which dams the Ley, is open or closed. Reed growth and the lake's ecology are potentially influenced by effluent from a sewage treatment works (STW) that discharges into the wetland. Water chemistry and hydrology of the wetland have been studied alongside experiments to investigate any effects of nutrient enrichment from the STW on reed growth. Inflowing and outflowing waters were analysed in order to determine concentrations of total oxidised nitrogen (TON), total dissolved nitrogen (TDN), soluble reactive phosphorus (SRP), total dissolved phosphorus (TDP) and potassium (K). Over the study period the annual load of SRP to the Ley increased from 3.65 gmˉ² aˉ¹ in 1992 to 8.1 gmˉ² aˉ¹ in 1996. TON load rose from 69.35 g mˉ² aˉ¹ in 1992 to 104.8 g mˉ² aˉ¹ in 1996. K fell from 97.3 g mˉ² aˉ¹ in 1994 to 96.4 g mˉ² aˉ¹ in 1996. The STW uses a Reedbed Treatment System (RBTS) to 'polish' its final effluent. The efficiency o f the RBTS was studied and during 1996 the efficiency rate for T ON was 20.9% and for SRP was 9.3%. Measurements of height, diameter, numbers of internodes, density and biomass of reeds collected from South Milton Ley were undertaken during August 1994 and 1995. Results of analyses for 1994 indicate that reeds were thinner and possessed fewer seedheads than those of 1995 but that density was greater. Reed fieldwork during 1994 found that height, diameter, numbers of internodes, biomass and number of seedheads were greater below the STW than above. During 1995 only seedhead production was greater below the outlet. The wettest area of the Ley contained reeds with greatest height and diameter. The driest area produced a higher density of reed growth. Laboratory experiments suggested that low N:K ratios and high P:K produced taller plants. Data from reed fieldwork together with results from hydrology and water chemistry studies were used in a statistical analysis in order to determine which, if any of these factors caused changes in reed growth. A conclusive link between water chemistry, hydrology and plant variables was not found. Correlation analysis for 1994 indicated that high concentrations of SRP and TON could produce thin reeds with low biomass. Analysis for 1995 suggested that elevated K values could produce a high density of short reeds. Water depth was found to have a significant effect (P < 0.001) on diameter. The key factors for reed decline (high water levels from spring to winter which can inhibit reed regeneration and increase residence times, increasing nutrient loads and changes in the ratio of N:P:K which could alter reed growth) are all present. At its present loading the Ley is nutrient rich and does not appear to be buffering wetland waters. After data analysis and fieldwork was completed a bloom of Oscillatoria sp.occurred at the seaward end of the Ley during August 1999. This, the first know occurrence of a bloom may be an indication that changes in the ecosystem of South Milton Ley are occurring. For the future, a programme of nutrient reduction, hydrological management and growing knowledge of wetland processes may prevent adverse changes.

Goss Moor NNR is a unique, rare and nationally-important wetland habitat in Mid- Cornwall. The majority of the habitats were created as a result of a long history of tin-stream mining, which ceased in the early 1900s. Phytosociological surveys of poor-fen and willow carr communities provide the first formal descriptions of the vegetation at this site. The poor-fen survey revealed twelve poor-fen vegetation types, which were distributed along a primary environmental gradient of organic matter depth, surface water height and bare substrate. Separation of the poor-fen communities by a moisture gradient was considered as spatial evidence for hydroseral succession, which begins with the colonisation of open-water pools created by tin excavations. The Salix cinerea ssp. oleifolia willow carr was divided by eight understorey communities, according to age, defined by reference to five sets of aerial photographs of Goss Moor taken over the last six decades. The average number of poor-fen species per unit area in the understorey generally decreased with age. This relationship was related to the increase in canopy cover and, therefore, shade. Willow was found to invade areas with the greatest amounts of accumulated organic material and a low water table. In the oldest and driest willow, oak saplings were found, indicating the beginning of secondary woodland. An architectural analysis of willow showed that useful age descriptors were the height of the first fork, the number of live secondary shoots, tree height and dbh, all of which generally increased with age. Spatial successional patterns were characterised using the lattice-wombling technique in three large rectangles or 'tranomes'. Plant communities were associated with either abrupt or diffuse boundary types. Abrupt boundaries or ecotones were found between heath communities and densely vegetated tall-herb fen and species-poor willow carr wetland vegetation. Diffuse or ecocline transitions occurred between communities with subtle differences in their composition. Spatial relationships between swamp and poor-fen communities were taken as evidence for space-for- time successions, these patterns varied according to location and microtopography. Investigations into the water regime showed water depth was governed by substrate heterogeneity. Homogeneous microtopography was associated with deep inundations and greatest amplitude in water depth, and most closely resembled rainfall fluctuations. The most complex microtopography resulted from the most intense tin-streaming activity. Therefore the anthropogenic history of Goss Moor plays an important role in governing the contemporary water regime and vegetation distribution. Of the wetland communities, rush pasture was the driest and poor-fen the wettest. The communities of open habitats were wetter than the willow communities. The youngest willow community was drier in the summer than the other five vegetation types studied, which was indicative of the conditions necessary for willow scrub colonisation to take place. The N:P ratio revealed that nitrogen was the limiting nutrient in all of the wetland vegetation types suggesting an early stage of successional development. High water levels were thought to be responsible for the prevalence of N-limitation on Goss Moor, creating deoxygenated substrates and leading to the demise of nitrifying bacteria and thus a reduction in the rate of soil N mineralisation. Plant strategies were used to classify the species from a number of wetland communities ranging from open-water pools to willow carr, in order to apply them to Grime's triangular model. The ten communities were ordered into a logical successional sequence. However, the model needs to be modified to account for succession in the aquatic environment. Based on the findings of this thesis, a number of suggestions were made for the effective management of the wetland habitats on Goss Moor. These include: evaluation of willow scrub before removal so those areas of vegetation subsequently opened-up can be monitored; and the creation of new ponds to encourage the growth of certain poor-fen communities, which are species-rich, but only account for a small area of the whole resource.

To aid in reclamation planning for the Genesee Coal Mine in Alberta, I qualified the pre-mined state of wetlands and measured land use and land cover (LULC) change between 1982 and 2007. A generalized linear model (GLM) was developed to explain the presence of wetlands on the pre-mined landscape. Environmental variables used to model the distribution of the wetlands included categorical LULC variables (agricultural land, vegetation, roads, structures, rivers, streams and tributaries), and elevation or elevation-derived terrain variables (slope, terrain ruggedness index, compound topographic index, sinks). Results from the model suggest that pre-mined wetland presence is best explained by agricultural land use, distance to tributaries, terrain ruggedness, distance to rivers, and the interaction between agriculture and roads. Landscape metrics were used to measure changes in landscape fragmentation and wetland structure. Differences in metric values suggest that the landscape has more surface water, less forested or vegetated land cover, and greater fragmentation. / Conservation Biology

Research Doctorate - Doctor of Philosophy (PhD) / The Hunter Estuary Wetlands (NSW, Australia) are important locally, nationally and internationally. They contain significant breeding and nursery grounds for commercial fisheries and are essential shorebird foraging and roost sites. Originally a mosaic of fresh- and salt-marsh, these wetlands have become degraded due to the erection of flood mitigation structures. Reintroduction of a more natural tidal regime is proposed, which is expected to decrease freshwater macrophytes and increase saltmarsh distribution. An a priori approach was undertaken to assess the relative salinity tolerance of three macrophytes, prior to restoration commencing. Study species included a glycophyte, Phragmites australis (Cav) Trin. ex Steudel, and two closely related estuarine saltmarsh species, the invasive exotic Juncus acutus L. and native Juncus kraussii Hochst.. Short- and long-term effects of salinity at key life stages were assessed for each species. For P. australis, the reliability of physiological and morphological responses to salinity stress was assessed under both laboratory and field conditions as potential indicators for future monitoring of initial restoration progress. Competitive/facilitative interactions between the two Juncus species under various salinity regimes were also examined. Results showed salinity affected viability of P. australis but not Juncus species seeds. Irrespective of species, cooler temperatures enhanced germination capabilities under saline conditions. Juncus species displayed superior germination capabilities ≤ 10 ppt salinity; however, unexpectedly, above 10 ppt germination of P. australis was higher. All three species are highly salt tolerant, although salt adaptation mechanisms were found to differ among species. P. australis excluded sodium (Na+) where possible, only accumulating Na+ to toxic levels beyond particular salinity concentrations (~ 20 ppt) and temporal duration (four months). Juncus spp. accumulated Na+ in both root and shoot tissue without noticeable damage. Overtime, J. acutus regulated Na+ uptake at exposure concentrations above 5 ppt salinity, while J. kraussii did not commence regulation until concentrations exceed 10 ppt. A 50% reduction in photosynthesis, biomass, height and density of P. australis was apparent at 20 ppt salinity and mortality at 30 ppt. In P. australis, although height and density were indicative of salinity stress under laboratory conditions, only density showed potential as an indicator of reduced vigour under field scenarios, providing a valuable potential tool to track initial expected restoration trajectories. Although affected, neither Juncus species experienced a 50% reduction in measured endpoints at 40 ppt salinity. However, biomass allocation was asymmetrical. Under stressful conditions, J. acutus maintained shoot increase at the expense of root development. Conversely, as salinity rose J. kraussii preserved root development rather than shoot growth. J. acutus was facilitated by the presence of J. kraussii under freshwater conditions, but suffered a competitive response at 10 ppt salinity. Juncus kraussii was detrimentally affected by being grown with J. acutus at 5 ppt, but unaffected under non-saline and 10 ppt salinity conditions. All three species possess overlapping salinity tolerances. Creating conditions that favour a particular species is perhaps not realistic, given the limited resources of many restoration initiatives. Flooding duration, depth and waterlogging may modify these results. However, the most plausible scenario is that P. australis will continue to dominate marshes after tidal reinstatement. With time, where soil salinity rises above 30 ppt, distribution of Juncus species will increase. The relative salinity tolerances of J. acutus and J. kraussii are analogous. Under mild salinity regimes J. acutus is likely to out-compete J. kraussii. Juncus kraussii is expected to be restricted to areas of high salinity stress.

Research Doctorate - Doctor of Philosophy (PhD) / The Hunter Estuary Wetlands (NSW, Australia) are important locally, nationally and internationally. They contain significant breeding and nursery grounds for commercial fisheries and are essential shorebird foraging and roost sites. Originally a mosaic of fresh- and salt-marsh, these wetlands have become degraded due to the erection of flood mitigation structures. Reintroduction of a more natural tidal regime is proposed, which is expected to decrease freshwater macrophytes and increase saltmarsh distribution. An a priori approach was undertaken to assess the relative salinity tolerance of three macrophytes, prior to restoration commencing. Study species included a glycophyte, Phragmites australis (Cav) Trin. ex Steudel, and two closely related estuarine saltmarsh species, the invasive exotic Juncus acutus L. and native Juncus kraussii Hochst.. Short- and long-term effects of salinity at key life stages were assessed for each species. For P. australis, the reliability of physiological and morphological responses to salinity stress was assessed under both laboratory and field conditions as potential indicators for future monitoring of initial restoration progress. Competitive/facilitative interactions between the two Juncus species under various salinity regimes were also examined. Results showed salinity affected viability of P. australis but not Juncus species seeds. Irrespective of species, cooler temperatures enhanced germination capabilities under saline conditions. Juncus species displayed superior germination capabilities ≤ 10 ppt salinity; however, unexpectedly, above 10 ppt germination of P. australis was higher. All three species are highly salt tolerant, although salt adaptation mechanisms were found to differ among species. P. australis excluded sodium (Na+) where possible, only accumulating Na+ to toxic levels beyond particular salinity concentrations (~ 20 ppt) and temporal duration (four months). Juncus spp. accumulated Na+ in both root and shoot tissue without noticeable damage. Overtime, J. acutus regulated Na+ uptake at exposure concentrations above 5 ppt salinity, while J. kraussii did not commence regulation until concentrations exceed 10 ppt. A 50% reduction in photosynthesis, biomass, height and density of P. australis was apparent at 20 ppt salinity and mortality at 30 ppt. In P. australis, although height and density were indicative of salinity stress under laboratory conditions, only density showed potential as an indicator of reduced vigour under field scenarios, providing a valuable potential tool to track initial expected restoration trajectories. Although affected, neither Juncus species experienced a 50% reduction in measured endpoints at 40 ppt salinity. However, biomass allocation was asymmetrical. Under stressful conditions, J. acutus maintained shoot increase at the expense of root development. Conversely, as salinity rose J. kraussii preserved root development rather than shoot growth. J. acutus was facilitated by the presence of J. kraussii under freshwater conditions, but suffered a competitive response at 10 ppt salinity. Juncus kraussii was detrimentally affected by being grown with J. acutus at 5 ppt, but unaffected under non-saline and 10 ppt salinity conditions. All three species possess overlapping salinity tolerances. Creating conditions that favour a particular species is perhaps not realistic, given the limited resources of many restoration initiatives. Flooding duration, depth and waterlogging may modify these results. However, the most plausible scenario is that P. australis will continue to dominate marshes after tidal reinstatement. With time, where soil salinity rises above 30 ppt, distribution of Juncus species will increase. The relative salinity tolerances of J. acutus and J. kraussii are analogous. Under mild salinity regimes J. acutus is likely to out-compete J. kraussii. Juncus kraussii is expected to be restricted to areas of high salinity stress.

Thesis (M. S. - Soil, Water and Environmental Science)--University of Arizona, 2001. / Includes bibliographical references (leaves 48-50).

Thesis (M.S. - Soil, Water and Environmental Science)--University of Arizona. / Includes bibliographical references (leaves 67-70).

Thesis (M.S. - Soil, Water, and Environmental Science)--University of Arizona. / Includes bibliographical references (leaves 119-122).

Thesis (M. Env. St.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1993. / Includes bibliographical references (leaves [34-40]).