Predicting Global Patterns in Mangrove Forest Biomass

Understanding spatial variation in carbon storage in natural habitats is critical for climate change mitigation efforts such as REDD. Terrestrial forests are being mapped with increasing accuracy, but the distribution of ``blue carbon'' in marine ecosystems remains poorly understood. We reviewed the literature to obtain field data on carbon storage and fluxes in mangroves world-wide. Using this material we developed a climate-based model for potential mangrove above-ground biomass (AGB) with almost four times the explanatory power of the only previous published model. From this model, we present the first ever global map of potential mangrove AGB and estimate a total global mangrove AGB of 2.83 Pg, with an average of 184.8 t ha−1. Data on other carbon stocks and fluxes confirm the importance of mangroves in carbon accounting. The map highlights the high variability in mangrove AGB and indicates areas that should be prioritised for mangrove conservation and restoration

Desenvolvimento de um roteiro conceitual para a gestão da biodiversidade e dos serviços ecossistêmicos no Caribe mexicano

Coral reefs and mangroves support rich biodiversity and provide ecosystem services that range from food, recreational benefits and coastal protection services, among others. They are one of the most threatened ecosystems by urbanization processes. In this context, we developed a conceptual framework for the management of biodiversity and ecosystem services for these coastal environments. We based our workflow on two sections: “Information base” and “Governance” and use the Puerto Morelos Coastal region as a case study for coastal protection. Puerto Morelos is between two of the most touristic destinations of Mexico (Playa del Carmen and Cancun) that has experienced an increase of population in the past four decades resulting in an intensification of multiple threats to its ecosystems. We characterized the two ecosystems with a “Management Units” strategy. An expert-based ecosystem services matrix was also described in order to connect mangroves and coral reef ecosystems with the multiple beneficiaries. Then an ecosystem model (conceptual model and Global Biodiversity model) was developed. The conceptual model was useful in understanding the interplay processes between systems regarding the ecosystem service of “Coastal Protection”. The Global Biodiversity model evidenced the human-induced shifts in the biodiversity for mangrove and coral reefs ecosystems. Also, a projection for 2035 of “best” and “worst” scenarios was applied using GLOBIO3. A DPSIR conceptual framework was used to analyze environmental problems regarding ecosystem services maintenance. Finally, we evaluated a set of policies associated with these ecosystems that favor coastal protection integrity. This framework facilitates the identification of the most relevant processes and controls about the provision of coastal protection service. It can also be useful to better target management actions and as a tool to identify future management needs to tackle the challenges preventing more effective conservation of coastal environments.Recifes de coral e manguezais possuem rica biodiversidade e fornecem serviços ecossistêmicos, tais como, alimento, recreação, proteção costeira, entre outros. Esses ecossistemas encontram-se entre os mais ameaçados pelos processos de urbanização. Nesse contexto, desenvolvemos um roteiro conceitual para a gestão da biodiversidade e dos serviços ecossistêmicos desses ambientes costeiros. Organizamos nossa sequência de passos de trabalho em duas seções: “Base de informações” e “Governança” e usamos a região costeira da cidade de Puerto Morelos (México) como um estudo de caso para analisar o serviço de proteção de costa. Puerto Morelos encontra-se entre dois dos destinos mais turísticos do México (Playa del Carmen e Cancún), e portanto sua população vem aumentando nas últimas quatro décadas, resultando na intensificação de múltiplas ameaças para os ecossistemas. Primeiramente, caracterizamos os dois ecossistemas identificando-os como “Unidades de Gestão”, detalhando seus principais componentes e processos. Através de uma “Matriz de serviços ecossistêmicos”, construída com base na opinião de especialistas, foram sistematizados os principais serviços ecossistêmicos prestados pelos manguezais e recifes de corais aos múltiplos beneficiários. Em seguida, foi desenvolvida uma modelagem do sistema (e ecossistemas) através de sua representação na forma de um modelo conceitual e um modelo numérico de Biodiversidade Global. O modelo conceitual facilitou a compreensão dos processos de interação entre sistemas em relação ao serviço “Proteção Costeira”. O modelo numérico evidenciou as mudanças induzidas pelo homem na biodiversidade dos ecossistemas de manguezal e recifes de coral. Além disso, uma projeção dos cenários “melhor” e “pior” foi desenvolvida para 2035 usando GLOBIO3. A Estrutura conceitual DPSIR foi aplicada para analisar problemas ambientais relacionados à manutenção dos serviços ecossistêmicos. Finalmente, avaliamos um conjunto de políticas públicas associadas a esses ecossistemas e que favorecem a integridade da proteção costeira. Portanto, o roteiro facilitou a identificação dos principais processos e controles para a provisão de um serviço ecossistêmico. Além disso, pode ser útil para direcionar melhor as ações de gerenciamento, bem como, uma ferramenta para identificar necessidades futuras de planejamento e gestão para enfrentar desafios que permitam uma conservação mais eficaz dos ambientes costeiros.Fil: Sánchez Quinto, Andrés. Universidad Nacional Autónoma de México; MéxicoFil: Costa, Julliet Correa da. Universidade Federal de Santa Catarina; BrasilFil: Zamboni, Nadia Selene. Universidade Federal do Rio Grande do Norte; BrasilFil: Sanches, Fábio H. C.. Universidade Federal de Sao Paulo; BrasilFil: Principe, Silas C.. Universidade de Sao Paulo; BrasilFil: Viotto, Evangelina del Valle. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Casagranda, Maria Elvira. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Lima, Francisco A. da Veiga. Universidade Federal de Santa Catarina; BrasilFil: Possamai, Bianca. Universidade Federal Do Rio Grande.; BrasilFil: Faroni Perez, Larisse. Universidade Federal de Juiz de Fora; Brasi

The influence of stand age on benthic decomposition and recycling of organic matter in managed mangrove forests of Malaysia

Decomposition of sediment organic matter was examined in relation to forest age in 2-, 15- and 60-year old, managed Rhizophora apiculata (Blume) stands in the Matang Mangrove Forest Reserve of peninsular Malaysia. Rates of O2 consumption (range: 11.5–21.4 mmol m−2 d−1) and CO2 production (range: 8.9–20.9 mmol m−2 d−1) were equivalent among the forests indicating that early diagenesis is not linked to stand age and age-related differences in rates of forest production. There were, however, site differences in the dominance of specific diagenetic pathways. Rates of sulfate reduction (to 40 cm depth) averaged 8.9±3.1 mmol S m−2 d−1 and 7.2±0.3 mmol S m−2 d−1 in the 15- and 60-year old forests, respectively, accounting for most (75–125%) of the total mineralization. In contrast, sulfate reduction (3.0±0.5 mmol S m−2 d−1) constituted a considerably smaller proportion (42%) of total organic matter oxidation at the 2-year old forest. Rates of solute efflux across the sediment-water interface and vertical profiles of dissolved Mn and NO2−+NO3− suggest that manganese reduction and denitrification–nitrification, coupled with aerobic respiration, account for most oxidation of organic matter at the 2-year old forest. The loss of particulate organic matter and the increased importance of aerobic and suboxic processes in the 2 year-old forest suggest some impact from disturbance of tree removal. A shift to proportionally less sulfate reduction in sediments of regenerating forests may result in greater availability of dissolved nutrients and some trace metals, and serve to reduce exposure of R. apiculata seedlings to anoxic, toxic solutes (e.g., sulfides). This diagenetic shift may facilitate rapid seedling growth and regeneration of forests

The influence of fish cage aquaculture on pelagic carbon flow and water chemistry in tidally dominated mangrove estuaries of peninsular Malaysia

The impact of floating net cages culturing the seabass, Lates calcarifer, on planktonic processes and water chemistry in two heavily used mangrove estuaries in Malaysia was examined. Concentrations of dissolved inorganic and particulate nutrients were usually greater in cage vs. adjacent (≈100 m) non-cage waters, although most variability in water-column chemistry related to water depth and tides. There were few consistent differences in plankton abundance, production or respiration between cage and non-cage sites. Rates of primary production were low compared with rates of pelagic mineralization reflecting high suspended loads coupled with large inputs of organic matter from mangrove forests, fishing villages, fish cages, pig farms and other industries within the catchment. Our preliminary sampling did not reveal any large-scale eutrophication due to the cages. A crude estimate of the contribution of fish cage inputs to the estuaries shows that fish cages contribute only ≈2% of C but greater percentages of N (32–36%) and P (83–99%) to these waters relative to phytoplankton and mangrove inputs. Isolating and detecting impacts of cage culture in such heavily used waterways—a situation typical of most mangrove estuaries in Southeast Asia—are constrained by a background of large, highly variable fluxes of organic material derived from extensive mangrove forests and other human activities