Natural water resources often contain fluorides and chlorides due to wastewater discharge; however, excessive exposure to fluorides can pose health risks to humans. Elevated chloride levels can negatively affect aquatic fauna and disrupt the reproductive rates of plants. This study assessed constructed wetlands (CWs) featuring monocultures (including Canna hybrid, Alpinia purpurata, and Hedychium coronarium) and polycultures (combinations of species from the monoculture systems) of ornamental plants (OPs) to evaluate their efficiency in removing fluorides and chlorides. The results revealed that the ornamental plants flourished in the CW conditions without sustaining any physical damage. C. hybrid demonstrated the longest roots and the highest volume, as well as greater height compared to other species. However, this did not affect the ion removal efficiency. In polyculture systems, 42.2 ± 8.8% of fluoride was removed, a result that was not significantly different (p > 0.05) from the removal rates observed in monocultures of C. hybrid (42.5 ± 7.5%), H. coronarium (36.8 ± 7.0%), or A. purpurata (30.7 ± 7.9%). For chloride, a similar pattern emerged, with 32.4 ± 4.8% removed in constructed wetlands (CWs) using a polyculture of ornamental plants, a figure that was also not significantly different (p > 0.05) from the removal percentages in monocultures of C. hybrid (29.1 ± 5.3%), H. coronarium (28.1 ± 5.0%), or A. purpurata (32.0 ± 5.7%). Our results indicate that CWs with polyculture species contribute to pollutant removal at levels comparable to those found in monoculture systems. However, polyculture systems offer enhanced aesthetic appeal and biodiversity, incorporating various ornamental flowering plants. The use of this eco-technology for removing fluoride and chloride pollutants helps prevent river contamination and associated health issues.

Stored carbon varies among wetlands, yet they rank among the highest carbon accumulating ecosystems. Leaf litter production and aboveground carbon storage are frequently used as proxies for estimating primary productivity, which can be affected by flooding, salinity and other environmental factors. The objective of this study was to quantify leaf litter production and soil carbon density in two coastal tropical wetland types, namely mangrove swamps and forested freshwater wetlands. Water and soil physicochemical properties, together with leaf litter production, were measured bimonthly between 2007 and 2009 in wetlands of both types, located on the coast of the Gulf of Mexico. The soils ranged from entirely mineral to entirely organic in the top metre. Mangrove sites had relatively uniform hydroperiods and moderately reductive soils, whereas forested freshwater wetlands had reducing conditions. Electrical conductivity was lower and pH less acidic in forested freshwater wetland soils. Litterfall was around 1000 g m-2 yr-1 and annual production did not differ significantly between wetlands, despite the presence of acidic soils with prolonged flooding and high salinity in the mangrove swamps. Also, there were no consistent differences in soil carbon density between the two wetland types. Some forested freshwater wetlands had low litter production and high soil carbon density, whereas some mangrove swamps had high litter production and low soil carbon density. We present information regarding aboveground biomass turnover and belowground carbon storage in coastal tropical forested wetlands which is greatly needed to support us in understanding, valuing and conserving these neglected ecosystems.

Changes in the sequence of an organism's genome, i.e., mutations, are the raw material of evolution. The frequency and location of mutations can be constrained by specific molecular mechanisms, such as diversity-generating retroelements (DGRs). DGRs have been characterized from cultivated bacteria and bacteriophages, and perform error-prone reverse transcription leading to mutations being introduced in specific target genes. DGR loci were also identified in several metagenomes, but the ecological roles and evolutionary drivers of these DGRs remain poorly understood. Here, we analyze a dataset of >30,000 DGRs from public metagenomes, establish six major lineages of DGRs including three primarily encoded by phages and seemingly used to diversify host attachment proteins, and demonstrate that DGRs are broadly active and responsible for >10% of all amino acid changes in some organisms. Overall, these results highlight the constraints under which DGRs evolve, and elucidate several distinct roles these elements play in natural communities.

Mangroves play an essential role in the global carbon cycle. However, they are highly vulnerable to degradation with little-known effects on greenhouse gas (GHG) emissions. This study compared seasonal soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes from a black mangrove (Avicennia germinans) forest in the Tampamachoco coastal lagoon, Veracruz, Mexico, in areas subjected to different degrees of environmental degradation (full canopy, transitional and dead mangrove), caused by hydrological perturbation. Furthermore, we aimed at determining the environmental factors driving seasonal fluxes. There was a combined effect of seasonality and degradation on CH4 fluxes, highest during the rainy season in the dead mangrove (0.93 ± 0.18 mg CH4 m-2 h-1). CO2 fluxes were highest during the dry season (220 ± 23 mg CO2 m-2 h-1), with no significant differences among degradation levels. N2O fluxes did not vary among seasons or degradation levels (− 3.8 to 2.9 mg N2O m-2 h-1). The overall CO2-eq emission rate was 15.3 ± 2.7 Mg CO2-eq ha-1 year-1, with CO2 as the main gas contributing to total emissions. The main factors controlling CH4 fluxes were seasonal porewater salinity and the availability of NO2–, NO3–, and SO4–2 in the soil, favored by high water level and temperature in the absence of pneumatophores. The main determining factors controlling CO2 fluxes were water level, porewater redox potential, and soil Cl– and SO4–2 concentration. Finally, N2O fluxes were related to NO2–, NO3–, and SO4–2 soil concentrations. This study contributes to improving the knowledge of soil GHG fluxes dynamics in mangroves and the effect of degradation of these ecosystems on the coastal biogeochemical cycles, which may bring important insights for assessing accurate ways to mitigate climate change protecting and restoring these ecosystems.

Coastal zones are characterized by the interactions between continents and oceans and, therefore, between fresh and salt surface and groundwater. The wetlands of coastal zones represent transitional ecosystems that are affected by these conditions, although little is known about the hydrogeochemistry of wetlands, especially coastal wetlands. In the present study, the hydrogeochemical characterization of coastal freshwater herbaceous wetlands in the Ciénaga del Fuerte Protected Natural Area in Veracruz, Mexico, in the American tropics was carried out per plant community. Four herbaceous wetlands (alligator flag, saw grass, cattail, and floodplain pasture) were monitored to understand the origin of the water feeding these ecosystems, the hydrogeochemical composition of groundwater, and the relationship between the groundwater and ecology of these ecosystems during dry and rainy seasons. The results indicate that Ciénaga del Fuerte is located in a regional discharge area and receives local recharge, so it is fed by both regional and local flows. The chemical composition varied temporally and spatially, creating unique conditions that determined the habitat occupied by the hydrophytic vegetation. The spatiotemporal behaviour of groundwater is one factor that, along with the hydroperiod, determines wetland dynamics and affects wetland biota (ecohydrogeochemistry). Generalist plant communities established in zones of local recharge, whereas other more specialized and/or plastic communities inhabited zones receiving regional flows with greater ion concentrations. This information forms the basis for establishing an appropriate scale (municipal, state, or larger regions) for the sustainable management of goods and services provided by the wetlands.

Wetlands play an important role as carbon stores; however, these ecosystems also contribute to the emission of greenhouse gases (GHG). In this study, we compared the carbon balance (CB) in coastal freshwater marshes and swamps. We use three different methods, which are described in the literature. The first is based upon the CB basis (Carbon-emission subtracted to Carbon-sequestration), without considering the global warming potential (GWP) of GHG. The second method is a CB considering the GWP, and the third method estimated the wetland function as carbon sink or source, by using a dynamic model with different horizon times (20, 100 and 500 years). With the first method, the studied wetland soils functioned as carbon sinks. Using the second method, the carbon in the form of GHG was up to 5 times more than sequestered carbon, however, the methodology does not consider the dynamics of gases in the atmosphere. By using a dynamic model that integrates productivity, plant respiration, the half-life of the gases and soil carbon emitted as methane, it was found that these ecosystems are net sinks carbon at horizon times of 500 years. This outlines a need to conserve and restore wetlands, and demonstrates the wetlands role as carbon sinks without concerning that they are sources of GHGs.

Introduction: The characteristics of coastal wetlands are the result of hydrogeo-morphological interactions between the continent and the ocean, which cause an environmental gradient, hat results in different vegetation types such as mangroves, freshwater marshes, swamp forests and palm swamps. Objective: To characterize the hydroperiod and physicochemical variables of water and soil and their effect on the distribution of vegetation in the Sistema de Humedales El Castano. Methods: A total of 11 permanent sampling units (UM) were established by defined strata: five in the mangrove, two in swamp forest, two in freshwater marshes and two in the flooded pasture. From May 2016 to October 2017 the vegetation was characterized and the water levels and physicochemical parameters (superficial, interstitial and groundwater) were sampled monthly for: salinity, and pH; and the soil for: bulk density, humidity percentage, and redox potential. Results: Mangroves are the closest to the sea, have the lowest diversity (H: 1.66) and species richness (14), they are dominated by Laguncularia racemosa and Rhizophora mangle. have the highest values of interstitial and groundwater salinity, (> 10.8 ups), remain flooded for 4 to 12 months per year, and have a redox potential of 14.57 mV. Immediately, inland, there are remnants of the swamp forests (11: 2.18 and 18 species), dominated by Pachira aquatica, with 5 ups interstitial and groundwater salinity, flooded from 0 to 6 months per year, with a redox potential of 119.07 mV. These forests are followed inland by freshwater marshes (H: 1.92 and 16 species), dominated by Typha domingensis with 6.1 ups interstitial and groundwater salinity', flooded for 5 to 8 months per year and a redox potential of 125.9 mV. Finally, furthest inland is the flooded pasture, a modified herbaceous wetland for cattle grazing (11: 3.44 and 50 species) dominated by Paspalum conjugatum, where interstitial and groundwater salinity is less than 0.5 ups, it stays flooded for 5 to 9 months and the redox potential is 151.23 mV. Conclusions: In each type of vegetation, the structure, composition, and diversity are different, with a high turnover of species that indicates a gradient defined by salinity. The vegetation in the SHC follows the patterns of typical organization of the tropical coastal wetlands, mangroves, swamp forests and herbaceous wetlands, in this case the freshwater marshes and flooded pastures. The factor that define the distribution of the vegetation is the salinity and the gradient that is observed are a function of the hydrological dynamics that depends on the mixing of marine and freshwater.

Introduction: The characteristics of coastal wetlands are the result of hydrogeomorphological interactions between the continent and the ocean, which cause an environmental gradient, hat results in different vegetation types such as mangroves, freshwater marshes, swamp forests and palm swamps. Objective: To characterize the hydroperiod and physicochemical variables of water and soil and their effect on the distribution of vegetation in the Sistema de Humedales El Castaño. Methods: A total of 11 permanent sampling units (UM) were established by defined strata: five in the mangrove, two in swamp forest, two in freshwater marshes and two in the flooded pasture. From May 2016 to October 2017 the vegetation was characterized and the water levels and physicochemical parameters (superficial, interstitial and groundwater) were sampled monthly for: salinity, and pH; and the soil for: bulk density, humidity percentage, and redox potential. Results: Mangroves are the closest to the sea, have the lowest diversity (H: 1.66) and species richness (14), they are dominated by Laguncularia racemosa and Rhizophora mangle, have the highest values of interstitial and groundwater salinity, (> 10.8 ups), remain flooded for 4 to 12 months per year, and have a redox potential of 14.57 mV. Immediately, inland, there are remnants of the swamp forests (H: 2.18 and 18 species), dominated by Pachira aquatica, with 5 ups interstitial and groundwater salinity, flooded from 0 to 6 months per year, with a redox potential of 119.07 mV. These forests are followed inland by freshwater marshes (H: 1.92 and 16 species), dominated by Typha domingensis with 6.1 ups interstitial and groundwater salinity, flooded for 5 to 8 months per year and a redox potential of 125.9 mV. Finally, furthest inland is the flooded pasture, a modified herbaceous wetland for cattle grazing (H: 3.44 and 50 species) dominated by Paspalum conjugatum, where interstitial and groundwater salinity is less than 0.5 ups, it stays flooded for 5 to 9 months and the redox potential is 151.23 mV. Conclusions: In each type of vegetation, the structure, composition, and diversity are different, with a high turnover of species that indicates a gradient defined by salinity. The vegetation in the SHC follows the patterns of typical organization of the tropical coastal wetlands, mangroves, swamp forests and herbaceous wetlands, in this case the freshwater marshes and flooded pastures. The factor that define the distribution of the vegetation is the salinity and the gradient that is observed are a function of the hydrological dynamics that depends on the mixing of marine and freshwater.

This study investigated pollutants (fluoride, chloride, nitrate, ammonia, phosphates, sulphate and total and volatile solids) removal efficiency from domestic wastewater and plant growth during 195 days in domiciliary constructed wetland (DCWs) microcosms. DCWs were planted with monoculture of Canna hybrid, Alpinia purpurata and Hedychium coronarium and polyculture of the same ornamental flowering plants (OFP), having river rock as a porous substrate. All OFP survived in the DCWs conditions without physical damage. C. hybrid showed the highest length and volume of roots and the highest height and number of flowers than other species in both, mono and polyculture systems. H. coronarium, did not produce flowers. A. purpurata grew better in monoculture than polyculture. Ammonia nitrogen removal was significantly higher in DCW microcosms with monocultures of C. hybrid than with monocultures of A. purpurata (p=.037), but no significantly different than monocultures of H. coronarium (p=.466), Contrary, removal efficiency of this ion was significantly higher in polyculture than mocultures of A. purpurata (p=.024) and H. coronarium (p=.0.032) but no significantly different than monoculture of C. hybrid.The other parameters were removed similarly in both cultures of plants (20-81%; p >.05). Polycultures of OFP are a good option for wastewater treatment in DCWs.

In this study, we aimed to investigate, through high-resolution metagenomics and metatranscriptomics, the composition and the trajectories of microbial communities originating from a natural sample, fed exclusively with methane, over 14 weeks of laboratory incubation. This study builds on our prior data, suggesting that multiple functional guilds feed on methane, likely through guild-to-guild carbon transfer, and potentially through intraguild and intraspecies interactions. We observed that, under two simulated dioxygen partial pressures-low versus high-community trajectories were different, with considerable variability among the replicates. In all microcosms, four major functional guilds were prominently present, representing Methylococcaceae (the true methanotrophs), Methylophilaceae (the nonmethanotrophic methylotrophs), Burkholderiales, and Bacteroidetes. Additional functional guilds were detected in multiple samples, such as members of Opitutae, as well as the predatory species, suggesting additional complexity for methane-oxidizing communities. Metatranscriptomic analysis suggested simultaneous expression of the two alternative types of methanol dehydrogenases in both Methylococcaceae and Methylophilaceae, while high expression of the oxidative/nitrosative stress response genes suggested competition for dioxygen among the community members. The transcriptomic analysis further suggested that Burkholderiales likely feed on acetate that is produced by Methylococcaceae under hypoxic conditions, while Bacteroidetes likely feed on biopolymers produced by both Methylococcaceae and Methylophilaceae.

The aim of this study was to quantify carbon stocks and the emission of the greenhouse gases (N2O and CH4) in mangrove forests with different vegetation assemblies in coastal lagoons of Veracruz Mexico. The vegetation included: black mangrove BM, dominated by Avicennia germinans, white mangrove WM, dominated by Laguncularia. racemose, red mangrove RM, dominated by Rhizophora mangle and mixed mangrove MM, dominated by the three species. Soil C stocks ranged 187-671 Mg C ha(-1) without significant (p = 0.149) differences among the mangroves with different vegetation. Significantly (p = 0.049) higher tree biomass C stock was observed in RM (127 Mg ha(-1)) than in MM (24.23 Mg ha(-1)). Methane emissions in RM (0.58-6.03 mg m-2 min-1) were significantly higher (p b 0.05) than in MM. (0.0035-0.07 mg m(-2) min(-1)), in WM (-0.0026-0.029 mg m(-2) min(-1)) and in BM (0.0054-0.0097 mg m(-2) min(-1)),during rainy, windy and dry season.RM had the longest period of inundation, the highest soil carbon concentration, and the lowest salinity. CH4 emissions showed a significantly positive correlation with soils carbon concentration, water level and water pH and, negative correlation with water salinity and Cl-1 concentration in soil and water. Emissions of N2O (0.04-3.25 mu g m(-2) min(-1)) were not significantly different among the mangroves with different vegetation, but they showed seasonal variations, with higher emissions during windy and dry seasons. N2O emissions showed significantly positive correlations with soil nitrate concentration and soil temperature. Results of this research are useful for mangrove conservation and restoration strategies to maximize carbon storage and mitigate greenhouse gas emissions. (c) 2020 Elsevier B.V. All rights reserved.

Background: Radial oxygen release by wetland plants is a process that creates aerobic conditions in the sediment that enhance aerobic microbial activity. Such activity has a big impact on wetland environmental services. Little is known about radial oxygen release by native macrophytes of tropical wetlands. Study site: Veracruz, Mexico Research Questions: Which of the most abundant native macrophytes from tropical wetlands have the higher radial oxygen release? What is the effect of hydrological conditions on radial oxygen release of the most abundant native wetlands plants of tropical wetlands? Methods: Root production, root porosity and Oxygen radial release were measured in 7 native macrophytes of tropical wetlands in Veracruz. The macrophytes were grown under three hydrological conditions: capillarity, saturation and flooding. Results: The species that produced more weight and volume of root (Pontederia Sagittata, Sagitaria lancifolia y Thalia geniculata) showed low radial oxygen released base on dry weight. Under flooding conditions, radial oxygen release per plant showed significant differences between the species, being Typha dominguensis the specie with the highest oxygen radial release (148 +/- 46 mu mol O-2 d(-1)) and Leersia ligularis the plant with the lowest radial oxygen release (22 +/- 46 mu mol O-2 d(-1)). Conclusion: Flooding conditions decreased root volume and weight of native macrophytes from Veracruz wetlands, also increased root porosity and in general stimulated higher radial oxygen release per plant, with significant differences among the studied plants, indicating that radial oxygen release depend of plant phenological characteristics and the hydrological conditions.

Antecedentes: La liberación de oxígeno por las plantas de humedales es un proceso fisiológico que oxigena el sedimento favoreciendo la actividad de los microorganismos aeróbicos, dicha actividad impacta los servicios ambientales de los humedales. Poco se sabe sobre la liberación de oxígeno por las plantas nativas de los humedales de México.Preguntas: ¿Cuál de las macrófitas más abundantes de los humedales de Veracruz, presenta la mayor liberación de oxígeno radial? y ¿Las condiciones de inundación tienen algún efecto en la liberación de oxígeno radial de las macrófitas nativas de los humedales costeros?Área de estudio: Veracruz, México.Métodos: Se mido la producción y porosidad de la raíz, y la liberación de oxígeno por el método de citrato de titanio en 7 de las especies nativas de los humedales de Veracruz, crecidas bajo tres condiciones hidrológicas: capilaridad, saturación e inundación.Resultados: Las especies con mayor peso y volumen de raíz ( Pontederia sagittata, Sagitaria lancifolia y Thalia geniculata ) mostraron bajas liberaciones de oxígeno radial en base a peso seco. La liberación de oxígeno por planta bajo condiciones de inundación mostró diferencias significativas entre las especies, Typha domingensis mostró mayor liberación de oxígeno (148 ±46 µmol O2 d-1) y Leersia ligularis la menor (22 ± 46 µmol O2 d-1). Conclusión: La inundación ocasionó una disminución en la producción de biomasa de las raíces de las plantas nativas de los humedales de Veracruz, un aumento en la porosidad y estimuló la libración de oxígeno por planta, encontrándose diferencias significativas entre las plantas estudiadas.

Tropical wetlands are commonly used for cattle ranching and have been modified either by draining them or introducing non-native species that are palatable to cattle. Some of these introduced species have become wetland and dune invaders. In Mexico, the introduction of antelope grass (Echinochloa pyramidalis) and its effects are being documented. This grass species is highly appreciated by cattle ranchers and is invading natural wetlands. It has C4 photosynthesis, high biomass production and high vegetative propagation, is tolerant to grazing and able to grow in both flooded and dry conditions. It is reducing plant biodiversity by increasing its own aerial coverage, changing wetland hydrology, reducing faunal habitat and causing soil physicochemical changes (e.g. vertical accretion). Reducing its dominance and increasing the density of native wetland species is difficult, expensive and time-consuming. We began a restoration project in a coastal wetland in central Veracruz, Gulf of Mexico, which included using shade to control the invader. This strategy reduced E. pyramidalis cover and increased the cover of native species, highlighting the importance of understanding the functional differences between native and invasive species when developing strategies for the control and eradication of problematic species.

In this study, we made a review about carbon stocks and fluxes in Mexican freshwater wetlands. Data for carbon storage in roots, soil and biomass have been reported for marshes, forested wetlands and flooded grasslands in southeast Mexico: Veracruz, Chiapas and Yucatan. The largest carbon stock in freshwater wetlands is in the soil (150 Mg C ha(-1) a 650 Mg C ha(-1)) and the forested wetlands showed the highest values. The carbon stock in the biomass ranges from 10 Mg C ha(-1) to 162 Mg C ha(-1), and forested wetlands showed the highest values. Carbon fluxes measured as litter fall have been reported for forested wetlands in Veracruz (6 Mg C ha(-1) year(-1) a 9 Mg C ha(-1) year-1) only. Methane and carbon dioxide fluxes ranged from 0.01 mg C m(-2) d(-1) to 1244 mg C m(-2) d(-1), and 0.009 g C m(-2) d(-1) to 11 g C m(-2) d(-1) respectively for Veracruz and Tabasco wetlands. Such carbon fluxes increased up to ten times, when wetlands are transformed to grasslands. It is concluded that the number of publications and study sites on carbon dynamics in Mexican freshwater wetlands is still very small. Therefore, it is necessary to increase the research in this area and enact laws that protect these important carbon sinks.

The three elemental components of Constructed Wetlands (CW) are microorganisms, filter media, and vegetation. This chapter analyzes the water problems in the State of Veracruz and present three experiences of treatment performance and one experience of greenhouse gas emissions in CWs with ornamental plants to mitigate water pollution, under tropical and subtropical conditions in the State of Veracruz, Mexico. CWs for one single family residence wastewater treatment, CWs for student dormitories wastewater treatment, and CWs for communities' wastewater treatment. Methane and nitrous oxide emissions were measured in the pilot scale treatment wetland in Pinoltepec, Emiliano Zapata, Veracruz, using the closed chamber method. Water samples were taken from influent and effluent of each cell every other week, from June to October 2013 in Emiliano Zapata, from June to November 2016 in Xalapa, and from October 2015 to February 2016 in Actopan.

Este trabajo hace una revisión bibliográfica sobre los almacenes y flujos de carbono en humedales de agua dulce en México. Se encontraron datos sobre almacenes de carbono en suelo, biomasa aérea y raíces en humedales herbáceos (popales, tulares y carrizales), humedales arbóreos (selvas inundables y palmares) y en humedales transformados en potreros que aún se inundan, para tres estados del sureste mexicano: Veracruz, Yucatán y Chiapas. El mayor almacén de carbono se ha registrado para el suelo de las selvas inundables (150 Mg C ha-1 a 650 Mg C ha-1). Los almacenes de carbono en la biomasa área de las selvas inundables fueron de 10 Mg C ha-1 a 162 Mg C ha-1, siendo también los valores más altos. Con respecto a los flujos de carbono medidos como caída de hojarasca en selvas inundables, solo se encontraron datos para Veracruz (6 Mg C ha-1 año-1 a 9 Mg C ha-1 año-1). Los flujos de metano y bióxido de carbono estuvieron en el intervalo de 0.01 mg C m-2 d-1 a 1244 mg C m-2 d-1 y 0.009 g C m-2 d-1 a 11 g C m-2 d-1 respectivamente, para Veracruz y Tabasco, y dichas emisiones aumentan hasta 10 veces en humedales transformados en potreros. Se concluye que aún son muy pocas las publicaciones y pocos los sitios estudiados sobre la dinámica del carbono en humedales de agua dulce, por lo que hay que incrementar la investigación en esta línea, ya que los humedales son importantes sumideros de carbono y es necesaria una legislación que proteja las reservas de carbono en estos ecosistemas.

Mexico has extensive coastal wetlands (4,243,137 ha), and one of its most important sites is the Alvarado Lagoon System, located in the Papaloapan River Basin on the Gulf of Mexico. The land cover dedicated to livestock and sugarcane has increased: by 25 % in 2005 and 50 % in 2010, with a loss of wetland vegetation and the carbon that it stores. We found that the Net Present Value of mangrove carbon offsets profit is equal to $5822.71, that of broad-leaved marshes is $7958.86, cattail marshes $5250.33, and forested wetlands $8369.41 per hectare, during a 30-year-carbonoffset contract. However, the opportunity cost from conserving wetland instead of growing sugarcane is positive according to REDD+ methodology, e.g., broad-leaved marsh conservation ranged from $6.73 to $20 USD/t CO2e, that of cattail marshes from $12.20 to $32.65 USD/t CO2e, and forested wetlands from $7.15 to $20.60 USD/t CO2e, whereas the opportunity cost between conservation and livestock was negative, it means that conservation is more profitable. The cost-benefit analysis for assessing investment projects from a governmental perspective is useful to determine the viability of conserving coastal wetlands through carbon offset credits. It also shows why in some areas it is not possible to conserve ecosystems due to the opportunity cost of changing from one economic activity (livestock and sugarcane) to carbon offsets for protecting wetlands. Furthermore, it allows for a comparison of carbon markets and assessment in terms of REDD+ and its methods for determining the social cost per ton of carbon avoided.

In the present work, a new equation to predict the maximum inter-story drift demands of mid-rise steel framed buildings is proposed in terms of a new ground motion intensity measures based on the spectral shape. For this aim, the maxim\um inter-story drift of steel frames with 4, 6, 8 and 10 stories subjected to several narrow-band ground motions is estimated as a function of the spectral acceleration at first mode of vibration SaT1, which is commonly used in earthquake engineering and seismology, and with a new parameter related to the structural response known as INp. It is observed that the spectral-shape-based intensity measure INp is the parameter best related with the structural response of the selected steel frames under narrow-band motions. For this reason, an equation to compute the maximum inter-story drift demand of mid-rise steel frames as a function of INp is proposed. The equation is useful for the rapid seismic assessment.