Determinants of above-ground carbon stocks and productivity in secondary forests along a 3000-m elevation gradient in the Ecuadorian Andes

Background: Secondary montane forests, covering 30% of forested lands in the Andes, play a crucial role in mitigating the impact of carbon release. However, the mechanisms responsible for carbon sequestration in the above-ground biomass of these forests are not well quantified. Aims: Understanding the determinants of above-ground carbon (AGC) dynamics in secondary forests along a 3000-m elevational gradient in the Andes to assess their mitigation potential. Methods: We assessed how abiotic and biotic conditions and past human disturbances were related to forest structure and composition, AGC stocks and productivity within sixteen 0.36-ha plots established in secondary forest stands of 30–35 years of age. Results: Structural equation models revealed that changes in temperature conditions along the elevation gradient shaped leaf functional composition, which in turn controlled AGC dynamics. Productivity and temperature decreased with increasing elevation and decreased tree community leaf area. Disturbance legacy (Tree mortality) increased with competitive thinning and low soil fertility. Conclusions: We show that temperature drives AGC dynamics by changing the functional trait composition. This highlights the importance of preserving these forests along elevation gradients and implies potentially strong future changes due to global warming.</p

4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

A Stretchable Strain Sensor System for Wireless Measurement of Musculoskeletal Soft Tissue Strains

Measurement of in vivo strain patterns of musculoskeletal soft tissues (MSTs) during functional activities reveals their biomechanical function, supports the identification and understanding of pathologies, and quantifies tissue adaptation during healing. These scientific and clinical insights have motivated the development and application of various strain sensors to quantify MST strains in either intraoperative or dynamic in vivo conditions. In this study, a strain sensor system is developed based on stretchable electronics and radio frequency identification technologies. In this system, a flexible inductor-capacitor-resistor sensor is fabricated such that it can be wirelessly excited by a custom-designed readout box through electronic resonance. The resonant frequency of the sensor changes when the capacitor is stretched, which is then also recorded by the readout box at a sampling rate of 1024 Hz. Suturing the stretchable capacitor onto the MST allows it to be stretched in line with musculoskeletal deformations, hence providing an indirect method to assess strain patterns in vivo. Application of the system ex vivo indicates that the signal remains linear between 0 and 25% strain and is electronically stable in a simulated in vivo environment for one week and over 100 000 cycles of fatigue loadings. The strain sensor exhibits excellent resolution (0.1% strain, approximate to 9 mu m) during wireless strain measurement. Finally, sensor implantation and strain measurement onto the medial gastrocnemius tendon of a sheep indicate that the sensor is able to record repetitive strain patterns in vivo during dynamic movements. This study indicates the potential scientific and clinical applicability in vivo.ISSN:2365-709XISSN:2365-709