78 research outputs found

    Coastal risk mitigation by green infrastructure in Latin America

    Get PDF
    This paper aims to highlight the prevailing experiences of Latin America and to clarify what ‘green infrastructure’ entails in addition to describing seven case studies from a range of coastal ecosystems (wetlands, coastal dunes, beaches and coral reefs) at scales varying from local to regional. The case studies are categorised according to their degree of naturalness (nature-based, engineered ecosystems, soft engineering, ecologically enhanced hard infrastructure and de-engineering). Generally, the implementation of green infrastructure projects aims to increase resilience, enhance the provision of ecosystem services, recover biodiversity, reduce the negative effects of hard infrastructure and implement corrective measures. The greatest benefits of these projects relate to the creation of multi-functional spaces, which often combine the above advantages with improved opportunities for recreation and/or economic activities. It is hoped that this paper will disseminate the experience in green infrastructure among academics and practitioners and stimulate wider adoption of green infrastructure projects and good practices

    Flora en playas y dunas costeras de MĂ©xico

    Get PDF
    Background and Aims: The first updated floristic checklist, supported with herbarium specimens, is presented for beaches and coastal sand dunes of Mexico.Methods: The analysis is based on the revision of 14 national and foreign herbaria. A 2 × 2 km grid was placed over a map of the coastal sand dunes of Mexico to reference the herbarium records, corresponding to the 2180 sites and 12,419 examples of plants documented. Indices of diversity, similarity, taxonomic diversity, and redundancy were calculated.Key results: The flora of the beaches and coastal sand dunes of Mexico consists of 153 families, 897 genera, and 2075 species of vascular plants. These represent 9.5% of the vascular flora of Mexico. The herbaria with high indices of redundancy (IR≄0.7) are the herbarium of the Universidad Nacional AutĂłnoma de MĂ©xico (IR=0.9), the Centro de InvestigaciĂłn CientĂ­fica de YucatĂĄn (CICY, IR=0.8), the Centro de Investigaciones BiolĂłgicas del Noroeste (HCIB), the Instituto de EcologĂ­a, A.C. (XAL) and the Natural Museum in San Diego (SD), each with an IR of 0.7. Five floristic regions are clearly recognized, which correspond to the seas of Mexico. The North Pacific has the highest taxonomic diversity and the South Pacific has the least. The Gulf of California, Gulf of Mexico and the Caribbean Sea have very similar taxonomic diversity. The species with the most recorded occurrences are Trianthema portulacastrum (165), Croton punctatus (107), Echites umbellatus (106) and Ipomoea pes-caprae (90). Considering the ecotonal nature of the ecosystem, most dune plants are shared with neighboring vegetation (forests, scrubs, wetlands, such as marshes or mangrove swamps).Conclusions: This first checklist of the flora of beaches and coastal dunes is the baseline for multiple future studies: floristic, biogeographic, and ecological. Moreover, this list will be important if used in environmental assessments and coastal zone plans.Antecedentes y Objetivos: Se presenta el primer listado florĂ­stico de las playas y dunas costeras de MĂ©xico, actualizado y respaldado por ejemplares de herbario.MĂ©todos: Se revisaron 14 herbarios nacionales y extranjeros. Se sobrepuso una retĂ­cula de 2 × 2 km al mapa de la costa y de las dunas costeras de MĂ©xico para referir todos los registros que corresponden a 2180 sitios con 12,419 ejemplares de plantas. Se calcularon Ă­ndices de diversidad, similitud, diversidad taxonĂłmica y redundancia.Resultados clave: La flora registrada consta de 153 familias, 897 gĂ©neros y 2075 especies de plantas vasculares, las cuales representan 9.5% de la flora vascular de MĂ©xico. Las cinco colecciones con Ă­ndices de redundancia altos IR≄0.7 son los herbarios de la Universidad Nacional AutĂłnoma de MĂ©xico (MEXU, IR=0.9), del Centro de InvestigaciĂłn CientĂ­ficas de YucatĂĄn (CICY, IR=0.8), y los del Centro de Investigaciones BiolĂłgicas del Noroeste (HCIB), el Instituto de EcologĂ­a, A.C. (XAL) y el del Museo de Historia Natural de San Diego (SD), cada uno con un IR de 0.7. Se reconocen cinco regiones florĂ­sticas que corresponden a los mares de MĂ©xico. El PacĂ­fico Norte tiene mayor diversidad taxonĂłmica y el PacĂ­fico Sur menor diversidad taxonĂłmica. El Golfo de California, Golfo de MĂ©xico y Mar Caribe tienen diversidades taxonĂłmicas similares. Las especies con mĂĄs registros son Trianthema portulacastrum (165), Croton punctatus (107), Echites umbelllatus (106) e Ipomoea pes-caprae (90). Por el carĂĄcter de ecotono de las dunas costeras, la mayorĂ­a de las especies se comparten con los tipos de vegetaciĂłn vecinos (selvas, matorrales, y humedales como las marismas y manglares).Conclusiones: Esta primera lista de la flora en playas y dunas de MĂ©xico es la base para mĂșltiples estudios florĂ­sticos regionales y locales, biogeogrĂĄficos, y ecolĂłgicos; ademĂĄs, que serĂĄ importante para su uso en temas de impacto ambiental y manejo costero

    Multi-messenger observations of a binary neutron star merger

    Get PDF
    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Multi-messenger Observations of a Binary Neutron Star Merger

    Get PDF
    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∌ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ÈŻ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∌ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∌10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∌ 9 and ∌ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

    AnĂĄlisis de la flora de dunas costeras del litoral atlĂĄntico de MĂ©xico

    Get PDF
    The object of this paper is to analyze the Mexican coastal flora of the Gulf and Caribbean. Floristic and vegetation analysis of 44 beach sites comprising the Atlantic littoral of Mexico, revision of herbarium specimens (MEXU and XAL) and bibliography was used to obtain information. It was used to build a data base resulting in 655 species and 91 families. Species number per family and per site was obtained. Growth forms, species distribution in microhabitats, presence of species with different distribution or habitat preference (i.e. coastal, belonging to other vegetation types or secondary) are analyzed. Species frequency distribution along the Gulf sites is also discussed. Endemics and new records for Mexico are given. A synthesis of the coastal flora, its composition and problematics are analyzed, within the framework of an ecological point of view.En este trabajo se presenta un anĂĄlisis de la flora vascular de las dunas costeras del litoral mexicano del Golfo de MĂ©xico y del Mar Caribe, obtenido a travĂ©s del muestreo de 44 sitios, de la revisiĂłn de ejemplares de herbario y de la bibliografĂ­a. Con la informaciĂłn se elaborĂł una base de datos que integra 655 especies pertenecientes a 91 familias. Se determinĂł el nĂșmero de especies y gĂ©neros por familia, asĂ­ como la cantidad de especies y de familias presentes en cada sitio de colecta, al igual que las formas de crecimiento. Se enlistan las especies colectadas y su presencia a lo largo de las playas muestreadas del Golfo y Caribe. Se indican los taxa endĂ©micos para MĂ©xico

    AnĂĄlisis de la flora de dunas costeras del Litoral AtlĂĄntico de MĂ©xico

    Get PDF
    En este trabajo se presenta un anĂĄlisis de la flora vascular de las dunas costeras del litoral mexicano del Golfo de MĂ©xico y del Mar Caribe, obtenido a travĂ©s del muestreo de 44 sitios, de la revisiĂłn de ejemplares de herbario y de la bibliografĂ­a. Con la informaciĂłn se elaborĂł una base de datos que integra 655 especies pertenecientes a 91 familias. Se determinĂł el nĂșmero de especies y gĂ©neros por familia, asĂ­ como la cantidad de especies y de familias presentes en cada sitio de colecta, al igual que las formas de crecimiento. Se enlistan las especies colectadas y su presencia a lo largo de las playas muestreadas del Golfo y Caribe. Se indican los taxa endĂ©micos para MĂ©xico
    • 

    corecore