Marsh

Worldwide, governments, the private sector, and non-government organizations face the challenge of balancing wetland conservation with promotion of wise use of resources and appropriate associated economic development. Similar challenges exist in Alberta. Over the span of a few decades the province has evolved from no wetland policy to a leader on no-net-loss policy and practice. However, as a revised policy is poised to be announced, Alberta may now become a province with potentially diminished wetland protection if replacement of lost wetlands is not considered. As growth continues in the province, Albertans are becoming increasingly concerned about environmental issues, as are those elsewhere in the world. At this juncture, Alberta has the unique opportunity to continue the leadership charge on wetland policy and practice, and can set the precedent for effective and balanced wetland conservation and management in Canada, and elsewhere.

Wetlands are Alberta’s keystone ecosystem and resource. Keystone ecosystems are those that are particularly important from the perspective of ecology or management, and whose influence and significance is greater than their geographic presence. In Alberta, wetlands are found in all biomes and are inextricably linked to the province’s aquatic and terrestrial ecosystems. Alberta’s wetlands provide a wide range of functions and values. This keystone ecosystem will become progressively more important with increased development and climate change. The state of Alberta’s wetlands is a bellwether for the condition of the province’s aquatic resources and, ultimately, the quality of life for Albertans.

In Alberta there are two primary wetland types in two geographic regions that require two different management strategies. Most of the province’s wetlands are peatlands (bogs, fens, conifer swamps) in the Peatland Zone. This region coincides with, but is larger than, the green area (78% vs. 61%). Here wetland loss is generally unknown but likely relatively smaller compared to the south. Current and planned developments, however, will likely lead to significant wetland losses here. The remaining wetlands in Alberta are mineral soil wetlands (marshes, shallow water wetlands, and shrub swamps) found primarily in the province’s Mineral Soil Wetland Zone. The zone is similar to, but smaller than, the white area (22% vs. 39%). Here wetland loss approaches 65% and it is critical to preserve what remains, restore what has been impacted, and construct new wetlands to add value.

The Peatland and Mineral Soil Wetland regions differ significantly by wetland type, area, land ownership, population, land use pressure, and authority to set regulations. Herein lays the opportunity for Alberta to lead the development of two novel policies and practices that will address the different requirements of both zones. Examples of wetland policy and practice exist in other provinces and countries that can be used as models. In Alberta, policy for wetlands in the Mineral Soil Wetland Zone, where the highest loss has occurred, would benefit from a no-net-loss and a mitigation sequence of 1) avoid impacts, 2) mitigate or minimize impacts, and 3) compensate for irreducible impacts. The established 3:1 compensation ratio with a sliding scale for distance from original wetland is a useful replacement for lost wetland function and value until a standardized wetland evaluation system can be developed for this zone. Application of the mitigation sequence concept in Alberta has recently been identified as disfavouring avoidance of wetlands with resulting wetland loss. However, with some adjustment, no-net-loss and wetland compensation can remain proven concepts that enhance wetland conservation in Alberta.

Mineral Soil Wetland Zone policy is the low-hanging fruit in Alberta. Policy development in the Peatland Zone is more challenging and will require extensive consultation, resources, funding, and research. Here, time is of the essence. Nothing less should be acceptable given that the province’s most ambitious development plans are in the region with the most wetlands. In the interim, priority should be given to conserving wetlands in the region until the creative solutions can be explored and a Peatland Zone policy developed.

Both wetland policies would be enhanced with support from the following programs and products: a validation program for qualified wetland workers and agencies; a provincial wetland inventory; a made-in-Alberta wetland classification, and; individual evaluation systems for the Peatland and Mineral Soil Wetland Zones using holistic broad-based indicators including hydrological, biological, social, rarity, and other aspects. Care must be taken when determining function and placing values on wetlands. Wetland rarity is independent of function and value as much as function is independent of value. Rarity or importance must not be used at the cost of the lost function and value in ‘common’ wetland types that are deemed nonessential. There is an important temporal aspect of value. Value judgements made on wetlands today may not reflect future values, the same way that past value judgements have not served us in the present. Wetlands must remain a legacy.

The province, industry, and academic institutions can support a research centre of excellence for applied wetland science in western Canada. Scientists have been conducting wetland research in Alberta for over 30 years. The research continues to grow and there is excellent expertise and top-rate research facilities. Through consolidation of expertise and resources, Alberta can become an international exporter of wetland knowledge, technology, and innovation. Current climate change models are forecasting an overall movement of development northwards into peatland-rich areas of Canada and Alberta is uniquely placed to develop progressive techniques for wetland construction, restoration, and mitigation.

Wetlands in Alberta are at a crossroads. They are the province’s keystone resource. The challenge is to balance conservation of our wetland legacy with wise use of resources and appropriate economic development. Alberta now has the opportunity to be among those jurisdictions that play a key leadership role in the development of novel and effective wetland policy, practice, research, and technology.

In the tropics, seasonally flooded forests (SFF) harbor fewer tree species than terra firme (i.e. non-flooded) forests. The low species diversity of tropical flooded forests has been ascribed to the paucity of species with adaptations to tolerate flooding. To test the hypothesis that flooding is the only factor restricting most species from SFF, we compared plant morphological and physiological responses to flooding in 2-month old seedlings of 6 species common to SFF and 12 species common to terra firme forests. Although flooding impaired growth, total biomass, maximum root length and stomatal conductance in most species, responses varied greatly and were species-specific. For example, after 90 days, flooding reduced leaf area growth by 10–50% in all species, except in Tabebuia, a common species from non-flooded habitats. Similarly, flooding had a 5–45% negative effect on total biomass for all species, except in 1 SFF and 1 terra firme species both of which had more biomass under flooding. A principal component analysis, using the above responses to flooding, provided no evidence that SFF and terra firme species differed in their responses to flooding. Flooding also caused reductions in root growth for most species. Rooting depth and root: shoot ratios were significantly less affected by flooding in SFF than in terra firme species. Although flood tolerance is critical for survival in flooded habitats, we hypothesize that responses to post-flooding events such as drought might be equally important in seasonal habitats. Therefore, we suggest that the ability to grow roots under anoxia might be critical in predicting success in inundated habitats that also experience a strong dry season.

Diatom analyses of sediment cores extracted from three lakes in coastal southeastern South Australia reveal that, for most of the mid-late Holocene, they were shallow, brackish to saline systems with limited flow of water from continental sources. The construction of a substantial network of drains in the early years of settlement, to maximise transportation and agricultural production through wet winters, lead to abrupt freshening of the lakes. Interestingly, despite substantial nutrient loads to Lake Bonney SE (there are two Lakes Bonney and Frome in South Australia, which is why the lakes in the southeast of the state are differentiated with ‘SE’) associated with the commissioning and expansion of pulp and paper mills, a wastewater treatment plant discharge and agricultural runoff, there is only moderate evidence of nutrient enrichment in the lake, possibly because the post-impact assemblages are dominated by taxa with broad ecological preferences. Despite being preserved within a conservation park, eutrophication associated with agriculture is evident in the diatom assemblages of Lake Frome SE, which has a catchment more than twice that of Lake Bonney SE. Mullins Swamp, on the other hand, supports few indicators of eutrophic conditions. The freshening of these lakes is against the tide of salinisation from rising saline groundwaters in most wetlands across southeastern Australia.

Artificial wetlands have become highly important habitat for a variety of bird species particularly waterbirds due to loss and degradation of natural wetlands. Avian community structures in two artificial wetland habitats i.e., man-made marsh and lake were investigated to identify the suitability of the habitats for avian species, habitat preference and food resources. Distance sampling point count method detected 35272 bird individuals of 98 species from July to November 2010. Ninty four bird species were recorded from man-made marsh and thirty one species from the lake area. Acridotheres tristis (6.34% of all detections) was the most dominant bird species of man-made marsh and Passer montanus (0.41%) was the most dominant bird species of lake habitat. On the contrarily, Microhierax fringillarius and Turdoides earlei (each 0.01%) were the rarest species of man-made marsh and Dinopium javanense (0.02%) was the rarest species of the lake habitat. The bird relative abundance of man-ma...

The Florida Everglades is a mosaic of short and long-hydroperiod marshes that differ in the depth, duration, and timing of inundation. Algae are important primary producers in widespread Everglades’ periphyton mats, but relationships of algal production and community structure to hydrologic variability are poorly understood. We quantified differences in algal biomass and community structure between periphyton mats in 5 short and 6 long-hydroperiod marshes in Everglades National Park (ENP) in October 2000. We related differences to water depth and total phosphorus (TP) concentration in the water, periphyton and soils. Long and short-hydroperiod marshes differed in water depth (73 cm vs. 13 cm), periphyton TP concentrations (172μg g−1 vs. 107 μg g−1, respectively) and soil TP (284 μg g−1 vs. 145 μg g−1). Periphyton was abundant in both marshes, with short-hydroperiod sites having greater biomass than long-hydroperiod sites (2936 vs. 575 grams ash-free dry mass m−2). A total of 156 algal taxa were identified and separated into diatom (68 species from 21 genera) and “soft algae” (88 non-diatom species from 47 genera) categories for further analyses. Although diatom total abundance was greater in long-hydroperiod mats, diatom species richness was significantly greater in short- hydroperiod periphyton mats (62 vs. 47 diatom taxa). Soft algal species richness was greater in long-hydroperiod sites (81 vs. 67 soft algae taxa). Relative abundances of individual taxa were significantly different among the two site types, with soft algal distributions being driven by water depth, and diatom distributions by water depth and TP concentration in the water and periphyton. Periphyton communities differ between short and long-hydroperiod marshes, but because they share many taxa, alterations in hydroperiod could rapidly promote the alternate community.

Sediment and American oyster (Crassostrea virginica) collected from nine selected marsh/estuarine ecosystems in Savannah, Georgia were analyzed for elements such as Al, As, B, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Si, and Zn. Sediments were extracted by ammonium acetate (NH4OAc), Mehlich-3 (M-3), and water procedures, whereas an acid digestion procedure was adopted for oyster tissue. Concentrations of elements were higher in M-3 extractions followed by NH4OAc and water extraction procedures. Calcium and Mg was greater in sediments by any of the extractions, whereas other elements differed depending upon the extraction procedures. There were no significant spatial variations (p 4OAc/water extraction procedure and Fe and Al by water extraction procedure. Contamination of Al, B, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Si, and Zn in oyster tissue ranged from 399 to 1460, 231 to 254, p

Different strains of cyanobacteria were isolated from salt-marsh of Venice Lagoon. One of them was used in the laboratory to colonize artificial substrates to induce a better colonization of eroded sediments. Different materials for cyanobacteria colonization were used from silica, zeolite to sediments. Different tests were made to improve cyanobacteria survival and exo-polysaccharide production under diverse conditions to consolidate sediments.

Suspended sediments in tidal creeks and sediments deposited on the adjacent marsh surface, collected concurrently at Mud Bank (MB) and Sixty Bass (SB) in North Inlet, SC from March, 1991 until February, 1992 were compared. For 8 consecutive days of each lunar month (waxing moon neap tide until full moon spring tide), sediment traps collected daily and water pumped from the adjacent creek at 3.1 hour intervals (mid-flood, high tide, and mid-ebb) were analyzed for inorganic and organic sediment, as well as carbon and nitrogen content. Salinity, sea level, Pee Dee River discharge, rainfall, temperature, wind, and inundation time were examined as forcing functions. SB creek connects to the oceanic inlet, but MB is located near the tidal node where brackish and high salinity waters meet in a sharp halocline. Although the duration of inundation is approximately twice as long as SB (12.5 hr/d:7.4 hr/d) because of a 27 cm elevation difference. MB averaged more deposition (5.3 mg/d/cm 2 : 4....

Salt marshes are among the most abundant, fertile, and accessible coastal habitats on earth, and they provide more ecosystem services to coastal populations than any other environment. Since the Middle Ages, humans have manipulated salt marshes at a grand scale, altering species composition, distribution, and ecosystem function. Here, we review historic and contemporary human activities in marsh ecosystems—exploitation of plant products; conversion to farmland, salt works, and urban land; introduction of non-native species; alteration of coastal hydrology; and metal and nutrient pollution. Unexpectedly, diverse types of impacts can have a similar consequence, turning salt marsh food webs upside down, dramatically increasing top down control. Of the various impacts, invasive species, runaway consumer effects, and sea level rise represent the greatest threats to salt marsh ecosystems. We conclude that the best way to protect salt marshes and the services they provide is through the in...

Le gisement Néolithique moyen de Lillemer s' étend sur 30 hectares. Découvertes fortuites, prospections diverses et sondages ont permis de rassembler une collection lithique de plusieurs milliers d'objets et une trentaine de formes céramiques attribuées à cette ...