Rapid Losses of Surface Elevation following Tree Girdling and Cutting in Tropical Mangroves.

Discussion Conclusions Materials and Methods Acknowledgments Author Contributions References Reader Comments (0) Figures Abstract The importance of mangrove forests in carbon sequestration and coastal protection has been widely acknowledged. Large-scale damage of these forests, caused by hurricanes or clear felling, can enhance vulnerability to erosion, subsidence and rapid carbon losses. However, it is unclear how small-scale logging might impact on mangrove functions and services. We experimentally investigated the impact of small-scale tree removal on surface elevation and carbon dynamics in a mangrove forest at Gazi bay, Kenya. The trees in five plots of a Rhizophora mucronata (Lam.) forest were first girdled and then cut. Another set of five plots at the same site served as controls. Treatment induced significant, rapid subsidence (−32.1±8.4 mm yr−1 compared with surface elevation changes of +4.2±1.4 mm yr−1 in controls). Subsidence in treated plots was likely due to collapse and decomposition of dying roots and sediment compaction as evidenced from increased sediment bulk density. Sediment effluxes of CO2 and CH4 increased significantly, especially their heterotrophic component, suggesting enhanced organic matter decomposition. Estimates of total excess fluxes from treated compared with control plots were 25.3±7.4 tCO2 ha−1 yr−1 (using surface carbon efflux) and 35.6±76.9 tCO2 ha−1 yr−1 (using surface elevation losses and sediment properties). Whilst such losses might not be permanent (provided cut areas recover), observed rapid subsidence and enhanced decomposition of soil sediment organic matter caused by small-scale harvesting offers important lessons for mangrove management. In particular mangrove managers need to carefully consider the trade-offs between extracting mangrove wood and losing other mangrove services, particularly shoreline stabilization, coastal protection and carbon storage.

Traversing digital learning landscapes: an Institutional and faculty case study.

Within the UK, there is a growing awareness to better understand what online educational technologies can offer in relation to learning and teaching, and how social technologies are changing communication and collaboration out with formal education. The concept of the ‘digital university’ is being widely debated within the UK Higher education sector (McCluskey and Winter, 2012), becoming embedded in educational policy, and beginning to be explored within many institutions. This session will report on one such institutional initiative, undertaken at Edinburgh Napier University in Scotland. A Digital Futures Working Group was established to: benchmark best practice in key areas including digitally enhanced education and digital literacies development; identify areas for short term action; and to produce a robust ‘digital agenda’ to inform the future direction of the university. Pivotal to this was the recognition to evolve staff digital pedagogical practices and to harness emerging digital opportunities, meet learner expectations, and meet wider expectations for contemporary able citizens. This session will be delivered in two parts. Firstly we will provide an insight into the focus of the project and the rich picture methodology used to consult with staff and students. Secondly we will specify the outcomes produced, and provide a case study of how the Faculty of Health, Life and Social Sciences engaged with the process and the progression of their digitally enabled educational practices.