Wetland Ecosystems

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Dissolved organic carbon characteristics in surface ponds from contrasting wetland ecosystems: a case study in the Sanjiang Plain, Northeast China

Dissolved organic carbon characteristics in surface ponds from contrasting wetland ecosystems: a case study in the Sanjiang Plain, Northeast China

Wetland conversion activities in the Sanjiang Plain were extensive in the past 50 yr (Song et al., 2008). The conversion of natural ecosystems to artificial wetlands (i.e., rice paddy land) in this region has been accompanied by wetland degra- dation caused by the decrease of standing water depth and the input of nutrients during agricultural activities (Song et al., 2011) as well as the changing climate (Qian and Ruby Leung, 2007). Our previous study found that the DOC con- centration from the surface pond decreased from the natural phialiform wetlands to rice paddy lands (Wang et al., 2010), while there was no significant difference between the ripar- ian wetland and degraded wetland (Song et al., 2011). How- ever, these preliminary findings are insufficient, thus, here a continuous two-year DOC monitoring was installed to ex- amine whether the observed variations in DOC concentra- tions were maintained. Furthermore, we aimed to compare the DOC concentrations between (1) the natural riparian wet- land and rice paddy land, (2) the DOC differences between phialiform wetlands and degraded wetlands, and lastly, (3) to compare DOC concentrations from rice paddy land and those from degraded wetland to clarify which exerts more in- fluence on DOC dynamics. Especially, we want to figure out the DOC spectral characteristics among these different sites. Here absorbance at 400 nm was used, and also at 465 nm and 665 nm (Thurman, 1985) to represent the DOC color charac- teristics (Thurman, 1985; Wallage et al., 2006). A wide va- riety of studies have predicted DOC concentrations based on water color measurements (Moore and Jackson, 1989; Tao, 1998; Worrall et al., 2002, 2003; Worrall and Burt, 2005). This study aimed to better understand the aquatic DOC dy- namics from different wetland ecosystems in the context of land use change and climate change.

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Fire and Water: New Perspectives on Fire’s Role in Shaping Wetland Ecosystems

Fire and Water: New Perspectives on Fire’s Role in Shaping Wetland Ecosystems

This special issue of Fire Ecology is dedicated to furthering scientific understanding of the role fire plays in the development and functioning of wetland ecosystems. While not initially intuitive, the concept of fire exerting significant influence on how wetland envi- ronments function has only recently become a prominent topic of discussion among re- searchers, although it has been recognized by the management community for some time. This new interest in determining how large scale disturbances modulate ecological pro- cesses in wetlands led to a series of invited talks at a Fire in Wetlands session during the 9 th International Association for Ecology (INTECOL) meeting in Orlando, Florida, USA,

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Peatland and wetland ecosystems in Peruvian Amazonia : indigenous classifications and perspectives

Peatland and wetland ecosystems in Peruvian Amazonia : indigenous classifications and perspectives

Through millennia of experience and interaction with certain environments, many indigenous peoples have developed sophisticated and culturally specific environmental knowledge systems (Berkes et al. 1998, Davidson-Hunt and Berkes 2003, Folke 2004, Sileshi et al. 2009). These knowledge systems express themselves not just in the information that indigenous people hold, for example, about traditional medicinal plants, game species, or climate patterns, but also in their daily practices and in their wider beliefs and worldviews, often termed cosmovision, cosmology, or “kosmos” (Toledo 1992, Toledo and Barrera- Bassols 2009). One important element of indigenous environmental knowledge systems is the classification of habitats, ecosystems, or landscapes (Berkes et al. 1998, Omotayo and Musa 1999, Shepard et al. 2001, Davidson-Hunt and Berkes 2003, Duvall 2008, Levinson 2008, Johnson and Davidson-Hunt 2011, Molnár 2013, Wartmann and Purves 2018). Such classification systems rely on various indicators to delimit boundaries between spatial units. These may be related to the vegetation, e.g., the presence of certain salient plant species, or abiotic factors such as soil types, hydrology, or topography of an area. Studies of indigenous classification systems have been conducted in many different contexts around the globe, e.g., to identify rain forest habitats with the Matsigenka of the Peruvian Amazon (Shepard et al. 2001), habitat types recognized by traditional herders in the Hungarian Hortobágy salt steppe (Molnár 2013), physical geographic concepts of Maninka farmers in Mali (Duvall 2008), or the landscape and seascape terminology of the inhabitants of Rossel Island, Papua New Guinea (Levinson 2008).

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Viral and metabolic controls on high rates of microbial sulfur and carbon cycling in wetland ecosystems

Viral and metabolic controls on high rates of microbial sulfur and carbon cycling in wetland ecosystems

Our results indicate that phylogenetically diverse sulfate-reducing bacteria (SRB) and methanogens are the keys to driving rapid carbon and sulfur transformations in PPR wetland sediments. Candidate SRB identified in this study spanned ten phyla, with some affiliating to taxa only recently described as potential sulfate reducers (Acidobacteria, Armatimonadetes, Planctomycetes, Can- didatus Schekmanbacteria, and Gemmatimonadetes) or that had not been previously described as such (Amini- cenantes). Candidate methanogens are affiliated to five orders, with particularly abundant sequences related to the genera Methanosaeta, Methanoregula, and Methano- follis. Recovered SRB MAGs encoded versatile metabolic potential, likely reflecting adaptations to dynamic geo- chemical conditions in the shallow wetland sediments. Based on the metabolic potential encoded in draft ge- nomes, marker gene analyses, and available candidate substrates, a variety of electron donors (i.e., methyl- amines, methanol, ethanol, 2-propanol, acetate, formate, hydrogen/CO 2 ) could fuel sulfate reduction and meth-

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Dwindling Wetland Ecosystems: A Survey of Impacts of Anthropogenic Activity on Marura Wetland, Kenya

Dwindling Wetland Ecosystems: A Survey of Impacts of Anthropogenic Activity on Marura Wetland, Kenya

The phosphate values did not show much fluctuation during the study and ranged from 1.31±0.06 mg/L (dry season) (Ref: Table 1) to 1.86±0.10 mg/L (wet season) (Ref: Table 1). Findings from this study revealed that phosphates of the dry season had a mean value of 1.31±0.06 mg/L and the wet season had a mean value of 1.86±0.10 mg/L (Table 3). The values of phosphate were higher in the wet season as compared to the dry season and were above the recommended standards by the KNWQS of <0.05 (mg/L) (Table 13). This is an indication of probable source of pollution that is releasing phosphates into the River. Numerous studies have demonstrated an association between watershed land use and phosphate loading to surface waters. These findings are in agreement with those of Omernik, Luz E and Allan [25,26,27] describing the relationships between land use and water quality are surprisingly variable at the scale of entire watersheds [25,26,27]. Presence of phosphates in water indicates the possibility of algal blooms which can cause death of aquatic animals. Algae provide essential ecosystem services and, as such, are the key element of the aquatic food web [28]. The result revealed that there was significant variation in phosphates, and can be attributed to excessive nutrients input into wetlands can cause perturbation of the ecosystem. Further, the results reveal that there is pollution from other sources upstream as higher values of phosphates were revealed in the control over the wet season. Phosphate is considered to be the primary driver of eutrophication of aquatic ecosystems, where increased nutrients loads lead to increased primary productivity. These eutrophic states indicate nutrient enrichment as result of human activities such as runoff from agricultural lands and the discharge of municipal and industrial wastes into Marura Wetland.

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Role of intertidal wetlands for tidal and storm tide attenuation along a confined estuary: a model study

Role of intertidal wetlands for tidal and storm tide attenuation along a confined estuary: a model study

et al., 2015). Unfortunately these wetland ecosystems are and have been under a lot of pressure due to urban, agricultural and industrial expansion. An estimated 25 % of the world’s intertidal estuarine habitat has been lost due to land reclama- tion (French, 1997). Over the last 3 decades globally, 50 % of salt marsh and 35 % of mangrove ecosystems have been lost or have degraded due to human activity (Alongi, 2002; Millenium Ecosystem Assessment, 2005). With the loss of these wetland ecosystems, their protective function is also lost, making low-lying coasts, deltas and estuaries more vul- nerable to flood risks. Although traditional hard engineer- ing solutions, like dikes and storm surge barriers, are widely perceived as the ultimate solution to combat flood risks, the combination with ecosystem-based flood defense – i.e. the conservation and restoration of tidal wetlands for flood at- tenuation – is likely to be more sustainable and cost-effective in the long term for many critical deltas and estuaries world- wide (Temmerman et al., 2013). Wetland ecosystems can ef- fectively keep up with sea level rise by natural sediment ac- cretion (Kirwan and Temmerman, 2009; Kirwan et al., 2010), which makes them in the long term more sustainable than static engineering structures. Apart from storm surge atten- uation, wetlands also effectively attenuate wind waves and associated shoreline erosion, even during extreme wave con- ditions (Möller et al., 2014). They further deliver additional ecosystem services like carbon sequestration, water qual- ity regulation, nutrient cycling, biological production, and many others (Barbier et al., 2011). Only a limited number of

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A proposed functional classification of european wetlands: Development and testing

A proposed functional classification of european wetlands: Development and testing

Across Europe there has been a pattern of wetland loss and degradation as development and agriculture have intensified and as a result few, if any, entirely natural wetlands remain. The following examples of wetland loss and degradation are taken from a comprehensive description of wetland loss within Europe by Hollis and Jones (1991). In France freshwater meadows, bogs and woods once covered l.Smillon hectares but due to flow alteration of major river systems, through dam construction, these wetlands are currently being lost at a rate of 10,000 hectares per year. The Wadden Sea wetland area stretches from Den Helder in the Netherlands to Esbjerg in Denmark but since 1963 350km^ of the total wetland area have been embanked altering the natural hydrological regime and therefore the wetland ecosystems. In the Netherlands alone 55 percent of the nation’s wetland areas have been lost since 1950 with a further 29km^ drained between 1979 and 1983. Over a similar period peatland areas within Belgium have been heavily drained reducing the total wetland area from 35,000 hectares to 3,500 hectares. In Italy, during Roman times it is estimated that wetland areas covered 7.4 million hectares but by 1865 only 764,000 hectares remained whilst by 1972 this had diminished to only 192,000 hectares. In Britain wetland areas have been drastically reduced; for instance; 60 percent of the remaining, and already massively reduced, area of lowland raised bogs were lost or significantly damaged between 1948 and 1978 by afforestation, peat digging, reclamation or repeated burning. Lake margins and marshland wetland areas of Greece have been reduced to 40 percent of the original area due to land drainage for agriculture (Skinner and Zalewski, 1995). The degree of wetland loss and alteration, illustrated by these examples, extends to every country in Europe.

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Land Cover Change Analysis with Special Reference to Forests and Paddy Wetlands of Neyyar and Karamana River Basins, Kerala, SW India Using GIS and Remote Sensing

Land Cover Change Analysis with Special Reference to Forests and Paddy Wetlands of Neyyar and Karamana River Basins, Kerala, SW India Using GIS and Remote Sensing

Forests and Wetlands referred to the respective ‘lungs’ and ‘kidneys’ of the landscapes, but are continuously exploited unscientifically in search of profits and means of subsistence. These ecosystems play a central role in functioning of the biosphere, provide various environmental services by regulating climate, hydrological and biogeochemical cycles and directly and indirectly contribute to socio-economic development. By acting as a sink for greenhouse gases, forests and wetlands help to mitigate the effects of climate change. However, through agriculture, urban and suburban development, much of the forest and wetland resources have been lost and with them many of the important functions that they provide also adversely affected. In Kerala State, the forest and wetland ecosystems have assaulted various adverse changes with growing demands, creating crisis in the environment. Studies done by Menon and Bawa (1998), Jha et al (2000) revealed that substantial conversions of forests take place in Kerala in the past were done for agricultural expansion, plantation development and for various other developmental activities.

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Successional changes in plant composition over 15 years in a created wetland in South Korea

Successional changes in plant composition over 15 years in a created wetland in South Korea

The first vegetation survey was conducted in October 1999, at 1 year after construction. We re-surveyed the vegetation in the created wetland 15 years later in May 2013. Species were monitored while walking through the research sites, and a list of plant species was recorded. Some species that were difficult to identify were col- lected and confirmed in the laboratory. The identifica- tion, naming, and classification of plant species were performed with reference to the Coloured Flora of Korea (Lee 2003), the Korean Plant Names Index (www.na- ture.go.kr), and the New Illustrations and Photographs of Naturalized Plants of Korea (Park 2009). Plants were categorized as obligate upland (OBU), facultative upland (FACU), facultative (FAC), facultative wetland (FACW), or obligate wetland (OBW) species following the field guide entitled “Categorizing Vascular Plant Species Oc- curring in Wetland Ecosystems of the Korean Peninsula” (Choung et al. 2012; Choung et al. 2015).

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WATER PROPERTIES AND ZOOPLANKTON DIVERSITY OF AGHALOKPE WETLAND IN DELTA STATE, NIGERIA

WATER PROPERTIES AND ZOOPLANKTON DIVERSITY OF AGHALOKPE WETLAND IN DELTA STATE, NIGERIA

Characterizing the basic components of our wetlands is the first step to successfully utilizing these important resources and no such data on this wetland are available. On this background, weekly examination of water properties and zooplankton diversity of Adagbarasa wetland from April to May 2015 was carried out. Water quality results, in the present study indicate that Aghalopke wetland showed favourable conditions for aquatic lives but for low oxygen levels (0.05- 3.5 mg/L). Linear correlation and cluster analyses results revealed catenation of most of the water properties which demonstrated the connectivity of the wetland. Air and water temperature, dissolved oxygen, acidity, alkalinity, carbon dioxide, conductivity were identified as chief drivers of the study area’s water properties. Upon careful observation (zooplankton assemblage), four (4) taxonomic groups were found; Copepoda, Rotifera, Cladocera and Protozoa. The numerical stock taking found copepods more in biomass (120/ml) than species (only 2 records) while rotifers had 16 species being dominant, sub dominant in biomass (103/ml). Rotifers, copepods and protozoa had positive negative associations with some water variables. The zooplankton diversity indices (0.44 to 1.76) revealed a deteriorated environment.

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NHANRS Scientific Wetland Buffer REPORT

NHANRS Scientific Wetland Buffer REPORT

Task C. A review of the NH Method database and its possible use to identify HVWs was performed. The purpose of the NH Method is to provide “a valuable educational tool for increasing understanding about the functions and values of wetlands.” After review of the data, the Work Group agreed that the NH Method is an excellent tool to assist Town officials “to make decisions to tailor wetland protection for those values it views as most important. For example, a town may wish to protect wetlands with high scores for flood storage, or large wetland complexes that provide important wildlife habitat.” However, all were reminded on the NH Method limitations. As stated in the NH Method manual, “the NH Method is not a substitute for more detailed site-specific studies. Where these studies are required, e.g. a detailed wildlife study or water quality assessment or wetland boundary delineation, other site specific methods should be used.” One goal of the Work Group was to minimize cost for the landowner or applicant to identify whether the trigger for a buffer exists on their property. On that basis, a motion was made and unanimous vote passed to not use NH Method values for determining wetland buffers, but rather to seek a simplified approach for identifying wetlands where buffers could be warranted. Task D. Other wetland assessment methodologies were reviewed and discussed for identifying HVWs. These included the US Army Corps of Engineers (Army Corps) Highway Methodology 6 , EPA’s review of 16 Rapid Assessment Methods (RAMs) 7 , Rhode Island RAM 8 , Washington State Wetland Function Assessment Methods (WFAM) 9 , Hydrogeomorphic Approach for Assessing Wetland Functions (HGM Approach) 10 , and the pending Army Corps/EPA New England Wetland Functional Assessment method 11 . Erica Sachs (EPA) made a presentation to the Work Group on the latter; however, it has not been finalized and it is unknown when all reviews will be completed for its release. None of the existing methods appeared suitable to the Work Group for generalized use.

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Entrepreneurial ecosystems in Poland: Panacea, paper tiger or Pandora’s box

Entrepreneurial ecosystems in Poland: Panacea, paper tiger or Pandora’s box

This section demonstrates that, while there have been examples of successes in the development of entrepreneurial activity in Polish regions, success at building entrepreneurial ecosystems has been qualified. These examples show how difficult it can be to build broad networks and foster meaningful engagement within systems. In particular, they show that one- dimensional policies—those focused only on certain elements of the ecosystem such as attracting firms or building links between actors—often fail to consider highly contextual and informal barriers. In the cases discussed here these included weak sectoral development, low incentives for local engagement, and a lack of trust at both firm and individual levels. From a policy perspective, these failures may not seem particularly grave. After all, policies often underperform due to unforeseen factors. However, an incomplete application of an ecosystems approach can also have important negative consequences across the economic spectrum. For this reason, we liken entrepreneurial ecosystems to Pandora’s box – they are attractive but can provoke a range of unintended consequences.

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Changes in the Water, Soil, and Vegetation of a Wetland after a Decade of Receiving a Sewage Effluent

Changes in the Water, Soil, and Vegetation of a Wetland after a Decade of Receiving a Sewage Effluent

hydrological or the chemical environment, or some combination of both. Evidence from the literature would suggest that water level is likely to be a major factor causing vegetation shifts in the short term. In addition to the obvious killing of vegetation (such as manuka) adapted to a drier environment, the continuous flooding brought about by the effluent discharge will eliminate the wetting and drying cycles that occur in unamended wetlands due to peaks in winter runoff, and summer evapotranspiration respectively. Thus species which require a period of drawdown in which to germinate would be eliminated (Whigham, 1985). This may account in some measure for the absence, e.g., of the fern Blechnum minus from the sewage wetland. However, it seems more likely that it is simply the depth of water that has caused the near elimination of these species and also Baumea rubiginosa and Coprosma tenuicaulis. For example it would appear that E. sphacelata is the only rooted macrophyte able to survive in deep (0.4-0.6 m) waters at the head of the wetland (site 1), and even this plant was absent when the water depth exceeded 0.6 m. Conversely, transport within the effluent stream may be responsible for the introduction of other species such as Ranunculus amphitrichus and Polygonum punctatum which were found only in the sewage wetland. It may be noted that each of these latter species (and also Polygonum salicifolium and Lotus pedunculatus which only occurred in trace proportions in the reference wetland) grow elsewhere only on sites of moderate to high trophic status, whereas species such as the fern Gleichenia dicarpa grow naturally on sites of very low trophic status.

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Fish utilisation of wetland nurseries with complex hydrological connectivity

Fish utilisation of wetland nurseries with complex hydrological connectivity

The physical and faunal characteristics of coastal wetlands are driven by dynamics of hydrological connectivity to adjacent habitats. Wetlands on estuary floodplains are particularly dynamic, driven by a complex interplay of tidal marine connections and seasonal freshwater flooding, often with unknown consequences for fish using these habitats. To understand the patterns and subsequent processes driving fish assemblage structure in such wetlands, we examined the nature and diversity of temporal utilisation patterns at a species or genus level over three annual cycles in a tropical Australian estuarine wetland system. Four general patterns of utilisation were apparent based on CPUE and size-structure dynamics: (i) classic nursery utlisation (use by recently settled recruits for their first year) (ii) interrupted peristence (iii) delayed recruitment (iv) facultative wetland residence. Despite the small self-recruiting ‘facultative wetland resident’ group, wetland occupancy seems largely driven by connectivity to the subtidal estuary channel. Variable connection regimes (i.e. frequency and timing of connections) within and between different wetland units (e.g. individual pools, lagoons, swamps) will therefore interact with the diversity of species recruitment schedules to generate variable wetland assemblages in time and space. In addition, the assemblage structure is heavily modified by freshwater flow, through simultaneously curtailing persistence of the ’interrupted persistence’ group, establishing connectivity for freshwater spawned members of both the ‘facultative wetland resident’ and ‘delayed recruitment group’, and apparently mediating use of intermediate nursery habitats for marine-spawned members of the ‘delayed recruitment’ group. The diversity of utilisation pattern and the complexity of associated drivers means assemblage compositions, and therefore ecosystem functioning, is likely to vary among years depending on variations in hydrological connectivity. Consequently, there is a need to incorporate this diversity into understandings of habitat function, conservation and management.

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Spatio-Temporal Changes in Land Use Patterns Influencing the Size of Namulomge Wetland, Wakiso District, Central Uganda

Spatio-Temporal Changes in Land Use Patterns Influencing the Size of Namulomge Wetland, Wakiso District, Central Uganda

As indicated in Table 4.1, 36% of farmers were in the age bracket between 20 and 30, 36% again in the age bracket of 30 and 40 and 28% in the age bracket of 40 and 50. The ages of most farmers were between 20 and 40 years. This age range can be considered as “young and middle age generation” which is strong and energetic and is actively involved in agricultural practices, with a longer planning horizon, more adopters (Nabahungu and Visser, 2011) and therefore greater ability to improve wetland agriculture and improve their livelihood. The age of the farmer is significant showing that those who are young are likely to appreciate the present status values and functions of wetlands as may be interested in utilising wetland resources. However, these findings are contrary to what Mwakubo and Obare (2009) found out. The reason is that older people lack incentives to invest in wetland conservation practices because they have less energy to utilise wetland resources. Age connotes experience and perhaps an accumulation of wealth and thus older people may not overuse wetlands resources (Mwakubo and Obare, 2009). Because of this, we expect a much more sustainable use of Namulonge wetland system which does not appear to be the case.

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Mathematical modelling of biological wastewater treatment of oxidation pond and constructed wetland systems

Mathematical modelling of biological wastewater treatment of oxidation pond and constructed wetland systems

Constructed wetland system can be considered as a secondary or tertiary treatment facility for treating wastewater originated from the residential, municipal and industrial areas [4]. Besides playing an important role in wastewater treatment process to remove contaminants including organic matter and inorganic matter (based on COD removal and BOD removal), it is also helpful in maintaining the landscape that preserve the natural habitats of flora and fauna [5–7]. Wetlands treatment is defined as a treatment system using the aquatic root system of cattails, reeds, and similar plants to treat wastewater applied to either above or below the soil surface [8–10].

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Patterns in Wetland Microbial Community Composition and Functional Gene Repertoire Associated with Methane Emissions

Patterns in Wetland Microbial Community Composition and Functional Gene Repertoire Associated with Methane Emissions

IMPORTANCE Wetlands are the largest nonanthropogenic source of atmospheric methane but also a key global carbon reservoir. Characterizing belowground microbial communities that mediate carbon cycling in wetlands is critical to accurately predicting their responses to changes in land management and climate. Here, we studied a restored wetland and revealed substantial spatial heterogeneity in biogeochemistry, methane production, and microbial communities, largely associated with the wetland hydrau- lic design. We observed patterns in microbial community composition and functions correlated with biogeochemistry and methane production, including diverse microorganisms involved in methane production and consumption. We found that methanogenesis gene abundance is inversely correlated with genes from pathways exploiting other electron acceptors, yet the ubiquitous presence of genes from all these pathways suggests that diverse electron acceptors contribute to the energetic balance of the ecosystem. These investigations represent an important step toward effective management of wetlands to reduce methane flux to the atmosphere and enhance belowground carbon storage.

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Predicting Ecosystem Response to Perturbation from Thermodynamic Criteria

Predicting Ecosystem Response to Perturbation from Thermodynamic Criteria

Most ecosystems are under considerable stress, having been perturbed by human intrusions including, popula- tion reduction, the introduction of foreign species, habitat fragmentation, contamination, and general global warm- ing. Fortunately, ecosystems can often recover from per- turbations and can even evolve and adapt to new bound- ary conditions [1]. However, successful recovery de- pends on the inherent stability of the system, which is a complex function of the individual interactions among all the participating species and among species and their environment. Given that typical ecosystems contain over 3000 species [2], understanding the nature of this stabil- ity, and thus predicting ecosystem response to perturba- tion, is far from trivial, but indispensable for developing a quantitative approach to conservation.

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Measuring and Evaluating Restoration of Hydrology in Coastal Plain Forested Wetlands of North Carolina.

Measuring and Evaluating Restoration of Hydrology in Coastal Plain Forested Wetlands of North Carolina.

In order to identify useful models, I use nonriverine wet hardwood forests as a test case. I selected this community type because it is one of the most commonly restored wetland communities in North Carolina (e.g., see EEP 2006, 2008) and it occurs across a hydrologic/edaphic gradient with two similar community types, mesic mixed hardwood forests and nonriverine swamp forests (Schafale 1999; Schafale 2012). In order for a model to be helpful to wetland restoration practitioners, it would have to be able to simulate the appropriate hydrologic regime of the community being restored and not of a different community. In previous studies, my colleagues and I found that these three communities have distinct water table level patterns (a common proxy for hydrologic regime) which are correlated with the unique composition of each community (Johnson et al. 2012, 2013). These water table level patterns were quantified using measures from the Indicators of Hydrologic Alteration (IHA) method (Richter et al. 1996). The Indicators of Hydrologic Alteration method summarizes daily hydrographs (a graph of water level over time) using thirty-three ecologically relevant measures of water level behavior (Richter et al. 1996). Such relationships could be used to judge whether models are correctly simulating the water table level patterns of nonriverine wet hardwood forests and not the other two similar communities.

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Wetland restoration and nitrate reduction: the example of the peri urban wetland of Vitoria Gasteiz (Basque Country, North Spain)

Wetland restoration and nitrate reduction: the example of the peri urban wetland of Vitoria Gasteiz (Basque Country, North Spain)

A principal components analysis was performed on the analytical data from surface as well as groundwaters (366 analyses in all) taken between January 2001 and February 2002. The factorial plane I-II (Fig. 9) reflects the most important information, with factor I (45.8 % of the variance) characterised by bicarbonates, sulphates, calcium and magnesium, and factor II (22.3 %) characterised by nitrates. The waters with a higher nitrate content correspond to those samples taken from the Ilarratza spring and from well SC21, both representative of the groundwaters of the quaternary aquifer in cultivated areas (Table 2); in particular, well SC21 represents the groundwaters that enter the Zurbano wetland. In the wetland area, there are nitrate losses, as illustrated in plane I-II: waters in piezometer P-5, drainage ditches Z- 3 and Z-4, and at the outlet of the wetland (Z-8) are clearly

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