Wetlands

To better understand how to establishCarex species from seed in created and restored wetlands, a series of experimental studies was conducted onCarex seed and seedlings. These studies included (1) the effect of seed age (1 to 18 months after collection) on viability and germination, (2) storage conditions (+4,-4 or +4/-4°C; wet or dry) on seed germination, (3) soil moisture on seed germination, and (4), soil amendments (fertilizer, topsoil, and compost) on seedling recruitment and growth. Seeds ofCarex species of several provenances would not germinate to any appreciable extent once they were more than six months old. ForCarex aquatilis, germination could be increased by storing its seed at either 4°C or—4°C. ForCarex lacustris andCarex stricta, seed germination decreased significantly, by about 50 to 100% in all 8 storage treatments. Germination ofCarex stipata seed was highest in 1 cm of standing water, and its seed did not germinate in the driest soil moisture treatment.Carex stricta seed germination was not affected very much by soil moistures. NoCarex spp. were recruited from seed in any of the field soil-amendment treatment plots. In both the greenhouse and field, the addition of compost, topsoil, and fertilizer increased the growth ofCarex stricta. In a greenhouse study, above ground, below ground, and total dry mass increased linearly with the percent compost added. Our results suggest that the probability of establishingCarex spp. from seed in created and restored wetlands in the Upper Midwest would be maximized by using fresh seed, preferably seed produced earlier in the same growing season; by keeping soil moisture levels as high as possible; and by raising the soil’s organic matter content, if need by, through the use of suitable soil amendments to levels found in natural sedge meadows.

The wetlands of the Ganges delta have rendered complimentary habitats to a diverse range of water birds. But human intervention accompanied with some natural factors has deteriorated the quality of these habitats. Present study aims to assess the status of avifaunal habitability of 21 floodplain wetlands, interspersed over the lower part of the Ganges delta by using Avifaunal Habitability Index (AHI). Seven widely used Ecological Indicators namely Avifauna Density, Total numbers of Avifauna, Simpson Index of Species Dominance, Shannon-Weiner Diversity Index, Species Richness, Simpsons Reciprocal Index, and Shannon Evenness Index have been used to compute AHI. The result unveils that wetlands like Purbasthali (11.58), Chariganga (5.51), Char Chakundi–I (4.81) have granted higher avifaunal habitability while wetlands like Sudhakarpur (-4.23), Akandanga (-3.5), and Raibali (-3.29) have revealed perceptible degenerated situation. Spatial variation of the habitability status is examined by Wetland Threat Index (WTI) and size of the wetlands. One way ANOVA-Tukey’s post hoc test exhibits that wetlands with less threat (WTI > 0.08) extends healthier habitats (p < 0.001; F = 5.79) and vice-versa. Subsequently, the study also reveals that larger wetlands (> 101 ha) have recorded greater AHI score than the small wetlands ((< 40 ha) at < 0.001 significance level (F = 13.40)). Therefore, this paper not only categorizes some floodplain wetlands based on AHI but also addresses spatial pattern and determinants of such habitability status over the Ganges delta. This study may attract the researchers and policy makers to assess the health of wetlands by using simple composite index in local to global level.

Most fish and shrimps have valuable ecological and commercial benefits. The difficulties of the collection of distribution records and volatile nature these marine organisms have limited their monitoring and conserving. MaxEnt modeling technique is ideal option for modeling distribution and habitat preference of different marine organisms. In this study, the present distribution of commercial fish and shrimps including orange-spotted grouper John’s snapper, tigertooth croaker, banana and Jinga shrimps was predicted using MaxEnt and a set of environmental layers. Distribution modeling findings showed that this technique reflects well the actual distribution of species. Environmental predictors including iron, calcite, temperature, primary productivity and depth were the most important environmental factors determining the distribution of species. Finding of habitat preferences indicated that the recent habitats of the species have suitable environmental conditions for the species. The Persian Gulf, the Sea of Oman, the North Arabian Sea and Australia coasts of the South Pacific were predicted as the most suitable habitats for species. The finding of this study provided basic data to identify distribution areas and habitat preferences of commercial fish and shrimps for their recent management plans and conservation development.

One hundred sixty-seven Prairie Pothole lakes, ponds and wetlands (largely lakes) previously analyzed chemically during the late 1960’s and early to mid-1970’s were resampled and reanalyzed in 2011–2012. The two sampling periods differed climatically. The earlier sampling took place during normal to slightly dry conditions, whereas the latter occurred during and immediately following exceptionally wet conditions. As reported previously in Mushet et al. (2015), the dominant effect was expansion of the area of these lakes and dilution of their major ions. However, within that context, there were significant differences in the evolutionary pathways of major ions. To establish these pathways, we employed the inverse modeling computer code NetpathXL. This code takes the initial and final lake composition and, using mass balance constrained by the composition of diluting waters, and input and output of phases, calculates plausible geochemical evolution pathways. Despite the fact that in most cases major ions decreased, a subset of the lakes had an increase in SO4 2−. This distinction is significant because SO4 2− is the dominant anion in a majority of Prairie Pothole Region wetlands and lakes. For lakes with decreasing SO4 2−, the proportion of original lake water required for mass balance was subordinate to rainwater and/or overland flow. In contrast, lakes with increasing SO4 2− between the two sampling episodes tended to be dominated by original lake water. This suite of lakes tended to be smaller and have lower initial SO4 2− concentrations such that inputs of sulfur from dissolution of the minerals gypsum or pyrite had a significant impact on the final sulfur concentration given the lower dilution factors. Thus, our study provides context for how Prairie Pothole Region water bodies evolve geochemically as climate changes. Because wetland geochemistry in turn controls the ecology of these water bodies, this research contributes to the prediction of the impact of climate change on this important complex of ecosystems.

The nation’s first deep-draft tanker facility, LOOP INC. (Louisiana Offshore Oil Port), is now in operation off the Louisiana coast in the Gulf of Mexico. The environmental management of this large coastal project has been effective and is a result of cooperative interaction between the state of Louisiana and private industry. LOOP construction activities have inevitably damaged the Louisiana coastal environment. However, the environmental damage has been minimized by strong environmental safeguards built into the enabling legislation and concurred with by LOOP. Environmental input has influenced siting of the LOOP facilities, construction techniques, and operation procedures and has influenced the resolution of many of the environmental concerns that have arisen over the course of the project.

Phragmites australis (cây sậy thông thường) là một loại cỏ lâu năm phân bố rộng rãi trong các môi trường ngập nước, với các phân loài bản địa và du nhập khó phân biệt ở Bắc Mỹ. Chúng tôi đã xác định sự phong phú tương đối của các phân loài và phân bố của các haplotype DNA plastid ở British Columbia, Canada, tại giới hạn phân bố về phía tây bắc của cây sậy thông thường ở Bắc Mỹ. Trong số 203 mẫu được xác định phân loài sử dụng các dấu hiệu phân tử, chúng tôi chỉ nhận diện được 9 cây là phân loài du nhập ssp. australis; tất cả các mẫu còn lại đều là phân loài bản địa ssp. americanus. Hai phân loài này chỉ cùng tồn tại ở một địa điểm. Chúng tôi đã xác định được bốn haplotype bản địa (một haplotype phân bố rộng ở British Columbia và ba haplotype khác có phân bố địa phương hơn) và hai haplotype du nhập. Sử dụng các cây có haplotype đã biết, chúng tôi đã đánh giá tính hữu ích của các đặc điểm hình thái khác nhau và các kết hợp đặc điểm để phân biệt các phân loài bản địa và phân loài du nhập trong khu vực địa lý này. Không có đặc điểm hình thái đơn lẻ nào là đặc trưng, nhưng phân tích thành phần chính và các chỉ số nhận diện dựa trên các kết hợp của các đặc điểm đã phân tách nhất quán các phân loài bản địa và du nhập trong mẫu của chúng tôi. Các kết hợp hai hoặc ba đặc điểm về chiều dài lá lách, chiều dài bẹ và màu sắc anthocyanin của thân cây cho kết quả tách biệt tốt nhất. Những chỉ số này có thể giảm nhu cầu xác nhận các phân loài du nhập sử dụng các công cụ phân tử, tạo thuận lợi cho các nỗ lực giám sát và kiểm soát loại cây xâm lấn này.

A horizontal subsurface flow constructed wetland (HSSF-CW) was constructed to improve the water quality of an artificial lake in Beijing wildlife rescue and rehabilitation center, Beijing, China. Multiple Regression Analysis (MRA) and Artificial Neural Networks (ANNs) including Multilayer Perceptron (MLP) and Radial Basis Function (RBF) were used to model the treatment performance of total phosphorus (TP). In order to increase the model efficiency, input parameters were selected as influent TP concentration, hydraulic retention time, wastewater temperature, month of the year, porosity, area, precipitation and evapotranspiration based on the methods of principal component analysis (PCA) and redundancy analysis (RDA). Genetic algorithm and cross-validation were utilized to find the optimal network architecture and parameters for ANNs. The overall performance of the models was validated using different datasets from the case study spanning 3 years. The results implied that modeling using adequate but crucial parameters can provide an efficient and robust tool for predicting performance. By comparing the three models in terms of model fitness when applied to the prediction, ANNs seemed to be more efficient than MRA in modeling of the areal TP removal and RBF (R2: 0.829, p = 0.000) produced the most accuracy and efficiency indicating strong potential for modeling the TP treatment processes in HSSF-CW systems.

Plant litter produced in the interior of dense emergent stands may directly or indirectly influence invertebrate communities. Low litter may provide structure and refuge to invertebrates while high litter may displace vegetation and decrease oxygen concentration. Within an emergent stand, an edge-to-interior transect study and an interior litter treatment study were performed to investigate the impact of increasing litter densities on the invertebrate community. The interior had more litter, lemnid biomass, and hypoxia than the edge but did not differ in total invertebrate abundance. Low and moderate litter plots in the interior treatment study experienced higher lemnid biomass and greater total invertebrate abundance than the high litter plots, but the high litter plots were characterized by higher invertebrate diversity. There was a significant negative relationship between litter and invertebrate abundance in July and August. Invertebrate patterns were driven primarily by amphipod abundance and may be related to the use of lemnids as habitat. Hypoxic-tolerant and semi-aquatic taxa were associated with high litter, while several algal-feeding taxa were associated with the edge. High litter can reduce abundant invertebrates that support higher trophic levels and shift invertebrate communities. These findings underscore the importance of understanding long-term litter accumulation dynamics in wetland systems.

The benthic invertebrates of three adjacent wetlands in northeastern Ohio, USA were sampled with a benthic corer during May–August 2001. The three wetlands consisted of a deep created wetland that overflowed into a shallow created wetland and a pre-existing natural wetland. The created wetlands were four years old and seeded with cattails. Forty-two invertebrate taxa were collected from all wetlands combined, and 11 taxa were abundant (represented >1% of total). Taxa richness, evenness, and community similarity were comparable among the three wetlands. Seed shrimp (Ostracoda), midges (Diptera: Chironomidae), copepods (Copepoda), fingernail clams (Bivalvia: Sphaeriidae), and water fleas (Cladocera) were the five most abundant taxa (38%, 13%, 11%, 9%, and 8%, respectively). Clams were significantly more abundant in the natural wetland, whereas no significant difference in density of other invertebrates was detected among wetlands. Laboratory inundations of soil taken from the rapidly drying basins of the natural and shallow created wetlands produced 10 taxa that survived the dry periods with desiccation-resistant stages and were dominated by microcrustaceans, Aedes mosquitoes (Diptera: Culicidae), clams, and annelid worms. Our data indicate that the created wetlands developed benthic invertebrate communities that were similar to the adjacent natural wetlands in a short period of time (four years), but clams were slow to colonize the human-made habitats.