Terrestrial–marine connectivity: patterns of terrestrial soil carbon deposition in coastal sediments determined by analysis of glomalin related soil protein

Glomalin, an arbuscular mycorrhizal protein component of soil, can be used as an indicator of terrigenous-derived carbon. We measured glomalin in sediments using the terrestrial end-member as a reference in four coastal settings: (1) intertidal seagrass meadows distributed over a rainfall gradient, (2) sediments inshore and offshore from the mouth of a river, (3) coastal coral reefs at various distances from the shore, and (4) intertidal wetlands with varying levels of groundwater influence. Across the rainfall gradient, glomalin in seagrass meadow sediments increased at sites with high mean annual rainfall during the wet season (r(2) = 0.27; F-1,F-29 = 5.75; p = 0.029). Glomalin decreased in inshore river sediments (terrestrial) to offshore (marine) sediments (r(2) = 0.81; F-1,F-17 = 71.7;

Sea level and turbidity controls on mangrove soil surface elevation change

Increases in sea level are a threat to seaward fringing mangrove forests if levels of inundation exceed the physiological tolerance of the trees; however, tidal wetlands can keep pace with sea level rise if soil surface elevations can increase at the same pace as sea level rise. Sediment accretion on the soil surface and belowground production of roots are proposed to increase with increasing sea level, enabling intertidal habitats to maintain their position relative to mean sea level, but there are few tests of these predictions in mangrove forests. Here we used variation in sea level and the availability of sediments caused by seasonal and inter-annual variation in the intensity of La Nina-El Nino to assess the effects of increasing sea level on surface elevation gains and contributing processes (accretion on the surface, subsidence and root growth) in mangrove forests. We found that soil surface elevation increased with mean sea level (which varied over 250 mm during the study) and with turbidity at sites where fine sediment in the water column is abundant. In contrast, where sediments were sandy, rates of surface elevation gain were high, but not significantly related to variation in turbidity, and were likely to be influenced by other factors that deliver sand to the mangrove forest. Root growth was not linked to soil surface elevation gains, although it was associated with reduced shallow subsidence, and therefore may contribute to the capacity of mangroves to keep pace with sea level rise. Our results indicate both surface (sedimentation) and subsurface (root growth) processes can influence mangrove capacity to keep pace with sea level rise within the same geographic location, and that current models of tidal marsh responses to sea level rise capture the major feature of the response of mangroves where fine, but not coarse, sediments are abundant

2017 Scientific Consensus Statement: land use impacts on the Great Barrier Reef water quality and ecosystem condition, Chapter 3: the risk from anthropogenic pollutants to Great Barrier Reef coastal and marine ecosystems

In this chapter, we applied an ecological risk assessment approach to assess the likelihood of exposure and potential risks from land-based pollutants to Great Barrier Reef coastal (floodplain wetlands and floodplains) and marine (coral reefs and seagrass meadows) ecosystems. Ecological risk is defined as the product of the likelihood of an effect occurring and the consequences if that effect was to occur

Drivers of global mangrove loss and gain in social-ecological systems

Mangrove forests store high amounts of carbon, protect communities from storms, and support fisheries. Mangroves exist in complex social-ecological systems, hence identifying socioeconomic conditions associated with decreasing losses and increasing gains remains challenging albeit important. The impact of national governance and conservation policies on mangrove conservation at the landscape-scale has not been assessed to date, nor have the interactions with local economic pressures and biophysical drivers. Here, we assess the relationship between socioeconomic and biophysical variables and mangrove change across coastal geomorphic units worldwide from 1996 to 2016. Globally, we find that drivers of loss can also be drivers of gain, and that drivers have changed over 20 years. The association with economic growth appears to have reversed, shifting from negatively impacting mangroves in the first decade to enabling mangrove expansion in the second decade. Importantly, we find that community forestry is promoting mangrove expansion, whereas conversion to agriculture and aquaculture, often occurring in protected areas, results in high loss. Sustainable development, community forestry, and co-management of protected areas are promising strategies to reverse mangrove losses, increasing the capacity of mangroves to support human-livelihoods and combat climate change

Carbon Stocks of Tropical Coastal Wetlands within the Karstic Landscape of the Mexican Caribbean

Coastal wetlands can have exceptionally large carbon (C) stocks and their protection and restoration would constitute an effective mitigation strategy to climate change. Inclusion of coastal ecosystems in mitigation strategies requires quantification of carbon stocks in order to calculate emissions or sequestration through time. In this study, we quantified the ecosystem C stocks of coastal wetlands of the Sian Ka'an Biosphere Reserve (SKBR) in the Yucatan Peninsula, Mexico. We stratified the SKBR into different vegetation types (tall, medium and dwarf mangroves, and marshes), and examined relationships of environmental variables with C stocks. At nine sites within SKBR, we quantified ecosystem C stocks through measurement of above and belowground biomass, downed wood, and soil C. Additionally, we measured nitrogen (N) and phosphorus (P) from the soil and interstitial salinity. Tall mangroves had the highest C stocks (987 ± 338 Mg ha⁻¹) followed by medium mangroves (623 ± 41 Mg ha⁻¹), dwarf mangroves (381 ± 52 Mg ha⁻¹) and marshes (177 ±73 Mg ha⁻¹). At all sites, soil C comprised the majority of the ecosystem C stocks (78-99%). Highest C stocks were measured in soils that were relatively low in salinity, high in P and low in N: P, suggesting that P limits C sequestration and accumulation potential. In this karstic area, coastal wetlands, especially mangroves, are important C stocks. At the landscape scale, the coastal wetlands of Sian Ka'an covering approximate to ≈172,176 ha may store 43.2 to 58.0 million Mg of C.Keywords: Ignition, Sea level, Mangrove forests, Enrichment, Organic matter, Florida, Biomass, Sediments, Nutrient dynamics, Brazilian AmazonKeywords: Ignition, Sea level, Mangrove forests, Enrichment, Organic matter, Florida, Biomass, Sediments, Nutrient dynamics, Brazilian Amazo

2017 Scientific Consensus Statement: land use impacts on the Great Barrier Reef water quality and ecosystem condition. Chapter 4: management options and their effectiveness

This chapter seeks to answer the following questions: 1. What are the values of the Great Barrier Reef? 2. How effective are better agricultural practices in improving water quality? 3. How can we improve the uptake of better agricultural practices? 4. What water quality improvement can non-agricultural land uses contribute? 5. How can Great Barrier Reef water quality improvement programs be improved? Each section summarises the currently available peer reviewed literature and comments on implications for management and research gaps. This chapter has a wider scope than previous Scientific Consensus Statements, including, for the first time, the social and governance dimensions of management and the management of non-agricultural land uses. These new sections are constrained by a lack of Great Barrier Reef–specific data and information. The relevance of information from other locations must be carefully considered. In comparison, the agricultural practice change and economics sections provide an update on material compiled as part of the 2013 Scientific Consensus Statement. This report has been confined to peer reviewed literature, which is generally published in books and journals or major reports. There is additional evidence in grey literature, such as project and program reports, that has not been included here. Each section of this chapter has been compiled by a writing team and then revised following a series of review processes

Global typologies of coastal wetland status to inform conservation and management

Global-scale conservation initiatives and policy instruments rely on ecosystem indicators to track progress towards targets and objectives. A deeper understanding of indicator interrelationships would benefit these efforts and help characterize ecosystem status. We study interrelationships among 34 indicators for mangroves, saltmarsh, and seagrass ecosystems, and develop data-driven, spatially explicit typologies of coastal wetland status at a global scale. After accounting for environmental covariates and gap-filling missing data, we obtained two levels of clustering at 5 and 18 typologies, providing outputs at different scales for different end users. We generated 2,845 cells (1° (lat) × 1° (long)) globally, of which 29.7% were characterized by high land- and marine-based impacts and a high proportion of threatened species, 13.5% by high climate-based impacts, and 9.6% were refuges with lower impacts, high fish density and a low proportion of threatened species. We identify instances where specific actions could have positive outcomes for coastal wetlands across regions facing similar issues. For example, land- and marine-based threats to coastal wetlands were associated with ecological structure and function indicators, suggesting that reducing these threats may reduce habitat degradation and threats to species persistence. However, several interdimensional relationships might be affected by temporal or spatial mismatches in data. Weak relationships mean that global biodiversity maps that categorize areas by single indicators (such as threats or trends in habitat size) may not be representative of changes in other indicators (e.g., ecosystem function). By simplifying the complex global mosaic of coastal wetland status and identifying regions with similar issues that could benefit from knowledge exchange across national boundaries, we help set the scene for globally and regionally coordinated conservation

Evaluación de los parámetros antropométricos en una muestra nacional de adultos mayores mexicanos

The purpose of this study was to describe anthropometric parameters in a population of Mexican older adults (OA). 516 OA (277 women, 239 men) aged ≥ 65 years were interviewed. Anthropometry and a sociodemographic data questionnaire were performed. Means and standard deviations, prevalence (%) and confidence intervals are reported in the results. SPSS v20.0 was used in the statistical analysis. The combined prevalence of overweight and obesity in our population was 77%. The mean WHR values obtained were (0.97 in men and 0.89 in women). Finally, the percentage of fat in men was 30.6% and in women it was 39.8%. The results of this investigation showed significant differences between men and women in most of the anthropometric measures and nutrition indicators. The prevalence of overweight and obesity reported in the Mexican elderly population was higher than that reported in other studies, which shows an important public health problem in Mexican older adults. More studies are needed at the national level on nutritional parameters in the elderly in order to detect cardiovascular risk factors in a timely manner.El propósito de este estudio fue describir los parámetros antropométricos en una población de adultos mayores (AM) mexicanos. Se entrevistó a 516 AM (277 mujeres, 239 hombres) con ≥ 65 años de edad. Se realizó antropometría, y un cuestionario de datos sociodemográficos. En los resultados se reportan medias y desviaciones estándar, prevalencias (%) e intervalos de confianza. En el análisis estadístico se utilizó el SPSS v20.0. La prevalencia conjunta de sobrepeso y obesidad en nuestra población fue de 77%. Los valores medios de Indice Cintura-Cadera obtenidos fueron (0.97 hombres y 0.89 en mujeres). Por último, el porcentaje de grasa en hombres fue 30.6 % y en mujeres fue 39.8 %. Los resultados de esta investigación arrojaron diferencias significativas entre hombres y mujeres en la mayoría de las medidas antropométricas e indicadores de nutrición. La prevalencia de sobrepeso y obesidad reportada en la población mexicana de edad avanzada fue más alta que lo reportado en otros estudios, lo que muestra un importante problema de salud pública en los en adultos mayores mexicanos. Se requieren más estudios a nivel nacional sobre los parámetros nutricionales en AM con el fin de detectar de forma oportuna factores de riesgo cardiovascular.Actividad Física y Deport