A review of methodologies and success indicators for coastal wetland restoration

Coastal wetlands are considered to be amongst the most productive ecosystems and can provide invaluable ecological services. However, coastal wetlands are listed amongst the most threatened ecosystems suffering from anthropogenic activities. The loss or degradation of coastal wetlands has drawn a high level of attention to wetland restoration. Improvement of the structure and function of degraded, damaged and destroyed wetlands may be achieved through ecological restoration. Large numbers of restoration projects have been conducted worldwide based on different restoration goals and different methods. It is undoubtedly important to evaluate whether coastal wetland restoration is successful. However, coastal wetland restoration assessment has become challenging because of current disagreement on definitions and concepts of restoration evaluation. We reviewed the methodology of coastal wetland restoration and criteria for success evaluation, and then summarized the issues for current wetland restoration and success evaluation based on literature review. Moreover, we used an estuarine wetland affected by urbanization as a sample to demonstrate how to establish a success indicator system for guiding wetland restoration and evaluating the success of wetland restoration.     

Capacity of a temperate intertidal seagrass species to tolerate changing environmental conditions: Significance of light and tidal exposure

Seagrass meadows perform several important ecological roles in coastal areas. However, with multiple stressors threatening these aquatic plants, their current rate of decline is likely to increase, so understanding their ability to acclimate to a range of environments may be key to their survival. Light availability is critical for seagrass health, with loss of water clarity likely to cause decline. This study assessed the ability of the temperate intertidal species, Zostera muelleri, to compensate for variations in light in its natural environment. The impacts of light during inundation (high tide) and exposure (low tide) were examined along a vertical gradient from the high to low intertidal at two sites with differing light histories. Photo-acclimation was evaluated through morphological and physiological characteristics over two tidal cycles. Results were consistent with seagrasses having optimized their photosynthetic capacity, with physiological acclimations being site specific. Longer-term morphological changes were also noted, suggesting a dissimilar light history between sites for an extensive period. Interestingly, at the site with the greatest light range, but the lowest light penetration at depth, a significant reduction in photosynthetic activity during air exposure was observed. This suggests that Z. muelleri is capable of tolerating light stress through photo-acclimation, allowing for the more efficient harvesting of light at low levels. Overall, this study demonstrates that Z. muelleri has the ability to adjust both physiologically and morphologically to changing environmental conditions, a key aspect to survival and persistence in temperate intertidal zones.     

Spatial variance and spatial skewness: leading indicators of regime shifts in spatial ecological systems

Ecosystems can undergo large-scale changes in their states, known as catastrophic regime shifts, leading to substantial losses to services they provide to humans. These shifts occur rapidly and are difficult to predict. Several early warning signals of such transitions have recently been developed using simple models. These studies typically ignore spatial interactions, and the signal provided by these indicators may be ambiguous. We employ a simple model of collapse of vegetation in one and two spatial dimensions and show, using analytic and numerical studies, that increases in spatial variance and changes in spatial skewness occur as one approaches the threshold of vegetation collapse. We identify a novel feature, an increasing spatial variance in conjunction with a peaking of spatial skewness, as an unambiguous indicator of an impending regime shift. Once a signal has been detected, we show that a quick management action reducing the grazing activity is needed to prevent the collapse of vegetated state. Our results show that the difficulties in obtaining the accurate estimates of indicators arising due to lack of long temporal data can be alleviated when high-resolution spatially extended data are available. These results are shown to hold true independent of various details of model or different spatial dispersal kernels such as Gaussian or heavily fat tailed. This study suggests that spatial data and monitoring multiple indicators of regime shifts can play a key role in making reliable predictions on ecosystem stability and resilience. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Seagrasses of south–west Australia: A conceptual synthesis of the world's most diverse and extensive seagrass meadows

South–west Australia contains extensive seagrass meadows along 2,500 km of coastline from the shallow subtidal to 50+ m water depths, and in many of the 51 bar-built estuaries along the coast. There are geomorphological differences between the south and west coasts that result in different patterns of swell exposure influencing the processes that structure seagrass habitats. In this paper, ‘sheltered’, ‘exposed’ and ‘estuarine’ seagrass habitat types are defined for south–west Australia to synthesize processes influencing seagrass communities. Sheltered habitats in south–west Australia are characterized by high light, low to moderate water motion and sporadic disturbance from storms, making them ideal habitats for a diversity of seagrass assemblages. Exposed seagrass habitats are characterized by the presence of strong and consistent ocean swells (3–8 m), predominantly from the south or south–west and seagrasses exhibit a suite of adaptive traits to survive the effects of exposure to ocean swell and associated sand movement. These include morphological features such as heavy fiber reinforcement to strengthen the aboveground stems or leaves, deep vertical rhizomes and life history traits such as rapid growth and high seed set. Within estuarine habitats highly dynamic seagrass communities are the result of fluctuating annual cycles in temperature, light and salinity. Compared to global seagrass meadows, coastal south–west Australian seagrass habitats experience high light, low nutrients and high water movement. Despite these differences, similarities with other regions do exist and here we place the habitats of south–west Australia into a global context using comparative data. The wide array of morphology and life history traits displayed among seagrass species of south–west Australia are presented in a conceptual model including habitat type, physical stressors and seagrass responses. The combination of adaptations to the habitats and processes that define them make south–west Australia a region where there is an unusually high number of co-occurring seagrass species, the highest in the world for a temperate environment (19 species), and approaching the species diversity of many tropical environments. Linking aspects of seagrass habitat, physical aspects of the environment and seagrass life history provides a context for applying knowledge gained from seagrasses in south–west Australia to other coastal ecosystems throughout the world.     

Coastal Wetlands Planning, Protection, and Restoration Act: A programmatic application of adaptive management

The Coastal Wetlands Planning, Protection, and Restoration Act (CWPPRA), commonly referred to as ‘The Breaux Act’, has provided some of the resources necessary to begin implementing a comprehensive, large-scale, long-term coastal wetland restoration program for Louisiana USA. Due to the dynamic nature of this ecosystem and the uncertainty associated with large-scale restoration, adaptive management principles were embedded throughout CWPPRA’s organizational structure, planning process, project implementation, and monitoring program to facilitate achieving the mandates associated with the Breaux Act. Feedback loops were established within and between each of the programmatic components to encourage continuous learning, which is central to adaptive management. The knowledge gained has led to institutionalized change in projects as well as the program. This paper describes how the formation of the CWPPRA Task Force and associated committees and groups resulted in an integrated coast-wide process for planning, selection, construction, operation, maintenance, monitoring, and scientific evaluation of 84 restoration projects implemented or scheduled for implementation throughout coastal Louisiana.     

Emergy-based indicators of regional environmental sustainability: A case study in Shanwei,Guangdong, China

Understanding which factors mainly affect the environmental sustainability of a Region is a very crucial concern for many Chinese planners and policy-makers. In this study, the emergy accounting method is applied to the production and consumption activities of the city of Shanwei, a seaside urban area in Guangdong region, China. The emergy method provides a comprehensive assessment of a system, by generating a consistent set of indicators capable to capture the dynamics of the system as a whole and its efficiency in converting resources into an economic product and welfare. At the same time, the approach is capable to provide details about a system's performance over time, its use of renewable versus nonrenewables sources, local versus imported, concentrated versus dispersed and finally labor intensive versus fuel intensive processes. The main local renewable and nonrenewable emergy flows supporting the investigated area were included in the accounting, together with the flows of imported energy, goods, machinery, labor and services. Coal plays a crucial role for electricity generation, industrial uses, but also gasoline and diesel for transport affect the overall sustainability to a non-negligible extent. An Emergy Sustainability Indicator (ESI) of the local economic and social system is calculated and compared with the average value of the Chinese economy, based on the assumption that a process or system is unsustainable if it contributes to lower the overall sustainability of the region or country. This is quantified by the requirement that always must be ESI_local ≧ ESI_country. Results confirm that the most crucial factor for this region sustainability is the use of coal as a non-renewable and imported energy source. The calculated emergy indicators translate into a set-aside buffer land demand capable to mitigate, dilute, and uptake the environmental impact of human-dominated activities. Unfortunately, such buffer land demand is much higher than the land actually available. As a result, both the ESI-based sustainability equation as well as the lack of support land make the city's production and consumption patterns unsustainable and call for different lifestyles and environmental policies.     

Sensitivity and resistance of soil fertility indicators to land-use changes: New concept and examples from conversion of Indonesian rainforest to plantations

Tropical forest conversion to agricultural land leads to a strong decrease of soil organic carbon (SOC) stocks. While the decrease of the soil C sequestration function is easy to measure, the impacts of SOC losses on soil fertility remain unclear. Especially the assessment of the sensitivity of other fertility indicators as related to ecosystem services suffers from a lack of clear methodology. We developed a new approach to assess the sensitivity of soil fertility indicators and tested it on biological and chemical soil properties affected by rainforest conversion to plantations. The approach is based on (non-)linear regressions between SOC losses and fertility indicators normalized to their level in a natural ecosystem. Biotic indicators (basal respiration, microbial biomass, acid phosphatase), labile SOC pools (dissolved organic carbon and light fraction) and nutrients (total N and available P) were measured in Ah horizons from rainforests, jungle rubber, rubber (Hevea brasiliensis) and oil palm (Elaeis guineensis) plantations located on Sumatra. The negative impact of land-use changes on all measured indicators increased in the following sequence: forest < jungle rubber < rubber < oil palm. The basal respiration, microbial biomass and nutrients were resistant to SOC losses, whereas the light fraction was lost stronger than SOC. Microbial C use efficiency was independent on land use. The resistance of C availability for microorganisms to SOC losses suggests that a decrease of SOC quality was partly compensated by litter input and a relative enrichment by nutrients. However, the relationship between the basal respiration and SOC was non-linear; i.e. negative impact on microbial activity strongly increased with SOC losses. Therefore, a small decrease of C content under oil palm compared to rubber plantations yielded a strong drop in microbial activity. Consequently, management practices mitigating SOC losses in oil palm plantations would strongly increase soil fertility and ecosystem stability. We conclude that the new approach enables quantitatively assessing the sensitivity and resistance of diverse soil functions to land-use changes and can thus be used to assess resilience of agroecosystems with various use intensities.     

The use of ground beetles (Coleoptera: Carabidae) and spiders (Araneae) as bioindicators of sustainable forest management: A review

International and Canadian national and provincial level policy have proposed the use of criteria and indicators to examine the sustainability of renewable resource management. Species suitable as ecological indicators are those whose biology are sensitive to disturbance and therefore demonstrate a negative effect of management on the processes or functioning of the ecosystem. Ground dwelling invertebrates such as carabid beetles and spiders have strong potential as ecological indicators as they are readily surveyed in sufficient numbers for meaningful conclusions to be drawn, have a stable taxonomy and, at least in the case of ground beetles, are readily identified. They are good local scale indicators of ecosystem disturbance in forested landscapes at both the short and long time scales, responding to both clearcut logging and fire differently. Ground beetles and spiders in boreal Canada may not be good indicators of disturbance at landscape scales, as little response to the creation of forest edges and habitat fragmentation has so far been observed. We propose that these bioindicators be used as part of local-level validation monitoring to test hypotheses about disturbance impacts. In this way, bioindicators are used in a research setting to evaluate silvicultural practices, providing a rating of their sustainability for a given broad forest type grouping.     

Ethnobiology, socio-economics and management of mangrove forests: A review

There is growing research interest in the ethnobiology, socio-economics and management of mangrove forests. Coastal residents who use mangroves and their resources may have considerable botanical and ecological knowledgeable about these forests. A wide variety of forest products are harvested in mangroves, especially wood for fuel and construction, tannins and medicines. Although there are exceptions, mangrove forest products are typically harvested in a small-scale and selective manner, with harvesting efforts and impacts concentrated in stands that are closer to settlements and easiest to access (by land or by sea). Mangroves support diverse, local fisheries, and also provide critical nursery habitat and marine productivity which support wider commercial fisheries. These forests also provide valuable ecosystem services that benefit coastal communities, including coastal land stabilization and storm protection. The overlapping of marine and terrestrial resources in mangroves creates tenure ambiguities that complicate management and may induce conflict between competing interests. Mangroves have been cut and cleared extensively to make way for brackish water aquaculture and infrastructure development. More attention is now given to managing remaining forests sustainably and to restoring those degraded from past use. Recent advances in remotely sensed, geo-spatial monitoring provide opportunities for researchers and planners to better understand and improve the management of these unique forested wetlands.     

Responses to environmental stressors in an estuarine fish: Interacting stressors and the impacts of local adaptation

Common killifish, Fundulus heteroclitus, are found in marshes and estuaries along the Atlantic coast of North America from Newfoundland to Florida. Although these habitats are highly productive, they are also characterized by variation in a number of abiotic stressors, including temperature, salinity, oxygen, and anthropogenic toxicants, which vary substantially in both space and time. In order to survive in these habitats, killifish must be able to cope with these stressors, both individually and in combination. There is substantial evidence to suggest that populations of F. heteroclitus have undergone local adaptation to multiple abiotic stressors, including temperature, salinity, and toxicants, but most studies have examined the effects of single stressors in isolation. Here I review some of the studies on local adaptation in F. heteroclitus, focusing on the molecular basis of local adaptation to abiotic stressors, and the acute responses to these stressors both singly and in combination. This work demonstrates that there are substantial interactions between the responses to both natural and anthropogenic stressors at the cellular level.     

Adaptive management: a synthesis of current understanding and effective application

Summary Adaptive management (AM) remains a commonly cited, yet frequently misunderstood, management approach. The aim of AM is to improve environmental management through ‘learning by doing’ and understand the impact of incomplete knowledge, but AM more commonly consists of ad hoc changes in managing environmental resources in the absence of adequate planning and monitoring. Here, we trace and review the development of AM, the central roles of consultation, collaboration and of monitoring, and of quantitative models and simulations. We identify a series of formalized, structured steps included in one AM cycle and review how current AM programs build upon such cycles. We conclude that the best AM outcomes require rigorous and formalized approaches to planning, collaboration, modelling and evaluation. Finally, simulating potential outcomes of an AM cycle in the presence of existing uncertainty can help to identify management strategies that are most likely to succeed in relation to clearly articulated goals.     

Digital repository of associations between environmental variables: A new resource to facilitate knowledge synthesis

Responsible care and management of Earth's resources requires scientific support, but the pool of underused research is growing rapidly. Environmental science research studies describe associations between variables (e.g. statistical relationships between stressors and responses). We propose open-access and online sharing of such associations. This concept differs from various efforts around the world to promote sharing of primary research data, but holds similar goals of improved use of existing knowledge. The initiative is made possible by recent developments in information technology and evolving online culture (e.g. crowdsourcing and citizen science). We have begun to connect existing projects that catalog and store associations, thereby moving toward a single virtual repository. Researchers and decision makers may share and re-use associations for myriad purposes, including: increasing efficiency and timeliness of systematic reviews, environmental assessments and meta-analyses, identifying knowledge gaps and research opportunities, providing evolved metrics of research impact, and demonstrating connections between research and environmental improvement.     

Contrasting responses of seagrass transplants (Posidonia australis) to nitrogen, phosphorus and iron addition in an estuary and a coastal embayment

Addition of nutrients to sediments has been proposed as a means of enhancing transplantation success in seagrasses. The effects of nutrient and iron additions to natural sediments on the growth and morphology of Posidonia australis transplants were evaluated in underwater plots in two contrasting environments: a coastal embayment (Princess Royal Harbour) with sandy sediments and little riverine input, and an estuary (Oyster Harbour) with organic-rich sediments and subject to seasonal river flow from a large rural catchment. Sixty six planting units spaced 1 m apart were transplanted in situ in each location. Nitrogen (N) and phosphorus (P) were added in a randomized factorial design using slow release fertilizer granules at the start of the experiment and repeated every 4-5 months for 2 years. In a concurrent experiment, chelated iron Fe EDTA was added to modify the sediment sulphur cycle.In Oyster Harbour, the addition of N significantly increased leaf N concentrations but reduced total biomass and biomass of leaves. Addition of P significantly increased leaf P concentrations and number of living leaves per transplant, leaf area, leaf length, length of longest rhizome axis and total rhizome length. Combined N + P addition resulted in a significant increase in leaf P concentrations and leaf area per plant only. In Princess Royal Harbour, addition of N produced significant increases in leaf variables (total and leaf biomass, number of shoots and living leaves, leaf area, and leaf length) but there were no significant differences observed in below ground plant parts (rhizomes). Addition of P had no significant effects on any growth measurements. Addition of N + P combined increased number of living leaves and leaf area significantly. δ¹⁵N in mature leaf tissue were significantly more negative for N and N + P treatments at both locations.Our results indicated that N limitation was occurring in the coastal embayment, Princess Royal Harbour whereas in the more estuarine Oyster Harbour, P was limiting plant growth. Addition of FeEDTA produced equivocal results at both sites and we suggest these results are confounded by the addition of N and C in the EDTA. We caution the use of nutrient addition to transplants of slow growing seagrasses such as P. australis without a thorough understanding of the nutrient status of the system, estuarine or coastal embayment, in which they are to be transplanted.     

A new class of composite indicators for measuring well-being at the local level: An application to the Equitable and Sustainable Well-being (BES) of the Italian Provinces

The aim of this paper is to propose a class of composite indicators for measuring well-being at the local level, which takes into account the variability between and within the local units.Although we believe that well-being is a multidimensional concept and cannot be reduced to a single measure, we also stress the importance of aggregating the information of several well-being indicators into a reduced number of composite indicators, one for each well-being domain, which play a crucial role in policymaking and benchmarking.As an application, we focus on the Equitable andSustainable Well-being of the Italian Provinces. In particular, based on a dataset containing 41 elementary indicators, we aggregate them by domain, comparing different aggregative approaches and illustrating the difference in the rankings of the Italian Provinces they produce. Finally, as an illustrative example, we focus on a member of the class of composite indicators that accounts both for vertical variability (between the Provinces) and horizontal variability (within the Provinces). The construction of a composite index for each domain allows us to evaluate and compare multidimensional well-being among the Italian Provinces.     

Response of traplining bumble bees to competition experiments: shifts in feeding location and efficiency

Summary In field experiments, we mapped the regular foraging routes (traplines) of marked bumble bees visiting Aralia hispida. When other bees were removed to create localized competitive vacuums, the marked bees shifted their feeding activity toward the removal areas. Bees foraging in these competitive vacuums probed more flowers per inflorescence than control bees. One bee's foraging was studied intensively before and after its local competitors were removed. Compared to four nestmates foraging elsewhere, the focal bee's trip times were shorter (p<0.005) and its food collection rate was marginally higher (P=0.064) during the removal, although all the bees foraged similarly before the removal. These observations indicate that traplining bumble bees opportunistically modify their use of space in response to the activities of other bees in a highly competitive environment.     

The physiological role of the free 20S proteasome in protein degradation: A critical review

Background

It has been almost three decades since the removal of oxidized proteins by the free 20S catalytic unit of the proteasome (20SPT) was proposed. Since then, experimental evidence suggesting a physiological role of proteolysis mediated by the free 20SPT has being gathered.

A global assessment of Echinococcus multilocularis infections in domestic dogs: proposing a framework to overcome past methodological heterogeneity

Echinococcus multilocularis, the aetiological agent of human Alveolar Echinococcosis, is transmitted between small mammals and wild or domestic canids. Dogs infected with E. multilocularis as dead-end hosts. Whereas E. multilocularis infections in wild hosts and humans have been well-studied in recent decades, infections in domestic dogs are sparsely reported. This literature review and meta-analysis highlighted gaps in the available data and provided a re-assessment of the global distribution of domestic dog E. multilocularis infections. We found 46 published articles documenting the prevalence of E. multilocularis in domestic dogs from 21 countries across Europe, Asia and North America. Apparent prevalence estimates ranged from 0.00% (0.00–0.33%) in Germany to 55.50% (26.67–81.12%) in China. Most studies were conducted in areas of high human Alveolar Echinococcosis. By accounting for reassessed diagnostic sensitivity and specificity, we estimated true prevalence in a subset of studies, which varied between 0.00% (0.00–12.42%) and 41.09% (21.12–65.81%), as these true prevalence estimates were seldom reported in the articles themselves. Articles also showed a heavy emphasis on rural dogs, dismissing urban ones, which is concerning due to the role urbanisation plays in the transmission of zoonotic diseases, especially those utilising pets as definitive hosts. Lastly, population studies on canine Alveolar Echinococcosis were absent, highlighting the relative focus on human rather than animal health. We thus developed a framework for investigating domestic dog E. multilocularis infections and performing risk assessment of dog-associated transmission to fill the gaps found in the literature.     

Using recruitment age, territorial fidelity and dispersal as decisive tools in the conservation and management of peregrine falcon ( Falco peregrinus ) populations: the case of a healthy population in Northern Spain

Methods of evaluating population trends have recently received particular attention because of perceived declines in several species during the twentieth century. We have studied demographic traits of the peregrine falcon (Falco peregrinus) population in Bizkaia (Northern Spain) for 11 years. This species suffered a severe decline in the 1950s and 1960s and started to recover in the 1980s and 1990s, although the recovery trends differed between areas. In our study area the peregrine falcon density is one of the highest found in Spain. The frequency of juvenile breeders was 2.0%, the mean age at first breeding being 3.7 calendar years for males and 4.0 cy for females. The territorial fidelity was at least 3.4 years for males and 3.7 years for females. Females dispersed on average 80.5 km and males 51.8 km during their pre-breeding movements, whilst distance between birthplace and breeding territories was on average 108.5 km for females and 64.5 km for males. We studied the relationships between adult turnover, recruitment age, territorial fidelity and dispersal in a healthy population in order to establish population dynamics. A combination of these parameters, not just age at first breeding, could be used as a potential early warning signal indicating future changes, prompting their consequences to be evaluated. This approach could lead to the reclassification of the large-scale health of a population. Its utilization would allow resources to be directed into helping “ailing” subpopulations, detecting causes of decline, and developing adequate recovery strategies.     

A review of microcystin detections in Estuarine and Marine waters: Environmental implications and human health risk

Toxin production by harmful cyanobacteria blooms (CyanoHABs) constitutes a major, worldwide environmental threat to freshwater aquatic resources that is expected to expand in scale and intensity with global climate change. Extensive literature exists on the most frequently encountered cyanotoxin, microcystin, in freshwater environments. Yet, the expansion of microcystin producing CyanoHABs and the transport of contaminated inland waters to estuarine and coastal marine waters has only recently received attention. This paper synthesizes information on the salinity tolerance of microcystin producing cyanobacteria and summarizes available case reports on microcystin presence in estuarine and coastal waters. We highlight a potential food-borne exposure route to humans by reviewing the growing body of evidence that shows microcystins can accumulate in coastal seafood. These cases reinforce the importance of freshwater nutrient reduction and the need for freshwater management efforts to look beyond lacustrine and riverine systems. Events reviewed here likely only represent a small proportion of cases where microcystins affect estuarine and coastal waters. We strongly suggest increased monitoring and research efforts to understand, react to, and prevent ecological and health problems associated with the growing problem of toxic CyanoHABs in coastal environments.