Soil and water bioengineering: practice and research needs for reconciling natural hazard control and ecological restoration

Soil and water bioengineering is a technology that encourages scientists and practitioners to combine their knowledge and skills in the management of ecosystems with a common goal to maximize benefits to both man and the natural environment. It involves techniques that use plants as living building materials, for: (i) natural hazard control (e.g., soil erosion, torrential floods and landslides) and (ii) ecological restoration or nature-based re-introduction of species on degraded lands, river embankments, and disturbed environments. For a bioengineering project to be successful, engineers are required to highlight all the potential benefits and ecosystem services by documenting the technical, ecological, economic and social values. The novel approaches used by bioengineers raise questions for researchers and necessitate innovation from practitioners to design bioengineering concepts and techniques. Our objective in this paper, therefore, is to highlight the practice and research needs in soil and water bioengineering for reconciling natural hazard control and ecological restoration. Firstly, we review the definition and development of bioengineering technology, while stressing issues concerning the design, implementation, and monitoring of bioengineering actions. Secondly, we highlight the need to reconcile natural hazard control and ecological restoration by posing novel practice and research questions

New tools and routines for ecotechnological slope stability analysis

El uso de material vegetal vivo y materiales biodegradables en las obras de estabilización, control de erosión y, en general, restauración ecológica, incluyen en la fase diseño una serie de particularidades a las que la ingeniería civil tradicional no tiene que enfrentarse. Es precisamente esta característica la que está ralentizando la adopción de las técnicas de bioingeniería en el mundo de la obra civil y la geotecnia. La utilización de un lenguaje común entre el mundo de la restauración ecológica y la ingeniería tradicional permitirá tender puentes entre ambas disciplinas y mejorar tanto su colaboración como sus sinergias. Por otro lado, la anterior situación también limita las posibilidades de estandarización e inclusión en pliegos de condiciones de las técnicas de bioingeniería. El objetivo general principal de este trabajo consiste, pues, en aportar nuevas herramientas de calculo y diseño para apoyar el proceso de especialización del sector de la eco-ingeniería y facilitar la transición de los técnicos de la ingeniería civil y la geotecnia al mundo de las obras de restauración ecológica. Para dar respuesta a esta empresa, este trabajo se ha estructurado en cuatro bloques. Un primer bloque aportando un nuevo método para mejorar la simulación del comportamiento mecánico de un suelo con raíces. Un segundo bloque, aportando nuevas metodologías de diseño que incluyan las particularidades de las obras de eco-ingeniería. Un tercer bloque donde se desarrolla una metodología no invasiva para facilitar la toma de datos necesaria para simular los efectos de la vegetación en los análisis de estabilidad. Finalmente, en el cuarto bloque se analiza la evolución de una obra de eco ingeniería para mostrar la gran importancia que tiene la fase de seguimiento en este tipo de obras. ABSTRACT The use of both living plant material and biodegradable materials in slope stabilization and erosion control works, include several particularities at the design level stage that traditional civil and geotechnical engineering do not need to face. This situation is slowing down the incorporation of eco-engineering techniques in traditional engineering sectors. The use of a common language between ecological restoration and traditional engineering will permit building bridges between them as well as improving their collaboration possibilities and synergies. On the other hand, the preceding situation also limits the necessary standardisation process of the eco-engineering works and their inclusion at the procurement stage. The main aim of this work consists in contributing with new design tools to both support the specialisation process of the eco-engineering sector and offer an easier transition for civil and geotechnical engineers to the ecological restoration world. In order to give a suitable answer to the preceding objectives this work has been organised into four blocks. A first block where a new methodology, allowing for a more realistic rooted soil mechanical behaviour simulation, is offered. A second block introducing new design methodologies including the eco-engineering work particularities. A third block, where a non-invasive field work scheme for determining, in a cost effective way, useful information for incorporating the plant effects into soil stability analyses. Finally, a fourth block where an eco-engineering work evolution is analysed in an attempt to highlight the great importance of the monitoring stage in this type of works

Matching seedling size to planting conditions: interactive response with soil moisture

Seedling size is a very important issue when producing plants for restoration projects. Scientific evidence on the appropriate size for drylands is contradictory. Thus, the aim of this study was to evaluate the effect of seedling size during first establishment by conducting a short term greenhouse experiment with Pinus canariensis containerized seedlings. A selection of large (mean height: 33.7 cm) and small (14.3 cm) one-year-old seedlings were planted in pots under two volumetric water content regimes: dry (7%) and wet (15%). Midday shoot water potential was measured in two periods: 10 (prior to root protrusion) and 30 (once the roots had protruded from the plug) days after planting. The length of protruding roots was measured after 30 days. One month after planting, the large seedlings under the dry regime produced more new roots than the small seedlings, but also showed the highest midday water potential values. Therefore, the greater root growth of the former did not offset the higher transpiration demand when planted in dry soils. These results suggest that under uncertainty about the soil humidity levels of dry areas, using small seedlings can improve their short-term survival after planting

Proyecto Ecomed: formación especializada en bioingeniería del suelo y fluvial en el entorno mediterráneo

Soil and water bioengineering involves the use of living plants or cut plant material, either alone or in combination with inert structures, to control soil erosion and the mass movement. Soil bioengineering is such a method that is being more and more adopted within the Mediterranean ecoregion. Bioengineering works have a clear dynamic and changing nature. At the beginning, the initial necessary rigidity is offered by the inert material utilized in the work, As time progresses, the evolving vegetation takes over the stabilizing roles. These particularities influence the design protocols and routines of this type of works. The difficulties engaged when using soil bioengineering in Mediterranean ecoregion requires a highly specialized knowledge triangle within the sector. The Ecomed Erasmus + project gives answer to this situation by including, as one of its main outputs, the development of a specialized modular training programme in soil and water bioengineering in the Mediterranean ecoregion.La bioingeniería del suelo y fluvial son un conjunto de técnicas basadas en la naturaleza (NBSs) cuyo objetivo es la mejora de la resiliencia de espacios con problemas de estabilidad y/o erosión. Estas técnicas están ganando fuerza dentro de las regiones mediterráneas. Las obras de bioingeniería tienen una naturaleza dinámica. Al principio, la necesaria rigidez inicial se desarrolla a través de los materiales inertes utilizados en la obra. Con el paso del tiempo, la vegetación desarrolla el efecto de refuerzo necesario y sustituye a los anteriores elementos en su función estabilizadora. Esta particularidad afecta a los protocolos y metodologías de cálculo de este tipo de obras. Los trabajos de seguimiento de la evolución de la intervención son esenciales para generar retroalimentaciones que permitan mejorar y calibrar los diseños de este tipo de obras. Las dificultades que afrontan este tipo de trabajos en un clima mediterráneo requieren un triángulo de conocimiento altamente especializado (nuevos procesos, métodos y servicios) dentro del sector. Teniendo en cuenta todo lo anterior, el Proyecto Europeo ECOMED (ERASMUS +) tiene, como uno de sus objetivos principales, generar para 2018 un programa de aprendizaje teórico-práctico específico y esencial para la especialización del sector de la bioingeniería mediterránea