Location and associated carbon storage of erosional escarpments of seagrass Posidonia mats

Seagrasses of the genus Posidonia can form an irregular seascape due to erosional processes exposing thick walls of organic matter-rich soils. However, little is known about the location and characteristics of these particular formations. Here we provide comprehensive estimates of organic carbon (Corg) storage in Posidonia oceanica and Posidonia australis meadows, while providing insight into their location and mechanisms of formation, and highlighting future research directions. Erosional reef escarpments are restricted to shallow highly productive P. oceanica meadows from the Mediterranean Sea and P. australis meadows from the Indian Ocean, and sustain the existence of Corg-rich deposits in surrounding meadows. The thickness of the mat escarpments can reach up to 3 m and their length can vary from few to hundreds of meters. Mechanisms of formation appear to differ among sites, from naturally-induced escarpments by wave action and/or tidal flow to human-induced escarpments by dredging activities. The inter-twined remains of seagrass shoots within the sediment matrix consolidate the sandy substrate and hold the exposed Posidonia mat escarpments together, maintaining a semi-rigid structure. This phenomenon is unusual but of exceptional importance in marine biogeochemical cycles, revealing the largest Corg sinks among seagrasses worldwide (ranging from 15 to 176 kg Corg m−2 in 2 m-thick mats accumulated at 2–249 g Corg m−2 yr−1 over 300–3000 yr)

El profesor universitario en la sociedad de la información y la comunicación

El desarrollo de las nuevas tecnologías de la información y la comunicación está constituyendo un proceso de gran trascendencia social que ha modifi cado radicalmente el sector de las comunicaciones y la forma de vida de las personas, además de evolucionar con gran rapidez en el contexto universitario. En este artículo tratamos de acercarnos a estas dos realidades analizando las nuevas características y posibilidades que nos ofrecen en la actualidad y su infl uencia tanto en el ámbito social como en el desarrollo de nuevos roles y funciones para el profesorado universitario.The development of the new technologies of the information and the communication is constituting a process of great social transcendence that has modifi ed the sector of the communications and the form of people’s life radically, besides evolving with great speed in the university context. In this article we try to come closer to these two realities analyzing the new characteristics and possibilities that it offer us at the present time and their infl uence as in the social environment as in the development of new lists and functions for the university faculty

Los blogs en la enseñanza universitaria: una experiencia práctica

En este artículo describimos una experiencia virtual universitaria desarrollada con 300 estudiantes que cursaban la asignatura de Nuevas Tecnologías aplicadas a la Educación en las especialidades de Educación Infantil, Primaria y Física. Con ella hemos intentado potenciar la utilización de los bitácoras como un recurso didáctico para la formación del conocimiento compartido y la creación de comunidades virtuales.In this article we describe an experience virtual university student developed with 300 students that studied the subject of New Technologies applied to the Education in the specialties of Infantile, Primary and Physics Education. We have attempted potencies the use of the binnacles like a didactic resource for the formation of the shared knowledge and the creation of virtual communities