Skills and Expertise
Research Items (41)
Post-fire hillslope stabilization treatments aim to reduce runoff-erosion risks following forest fires by counteracting the impact of fire on key soil and hillslope properties. Here we evaluate the effectiveness of wood shred mulch, long-leaved pine needle mulch, and polyacrylamide (PAM) in reducing post-fire runoff and erosion in two volcanic soil types of contrasting wettability using rainfall simulations (55 mm h−1 for 30 min) at the microplot (0.25 m2) scale. The cover provided by the wood shreds and pine needles led to a reduction of runoff and erosion in both the wettable—(62% and 92%, respectively, for wood shreds, and 55% and 87%, respectively, for needle mulch) and the extremely water-repellent soils (44% and 61%, respectively, for wood shreds). In contrast to what might be expected, PAM did not reduce runoff or erosion when applied to the extremely water-repellent soils, suggesting that PAM should not be applied in this terrain type. Although more research is needed to determine whether the high effectiveness of pine needle mulch and wood shred mulch fully translates to coarser scales, the results are encouraging in terms of these materials’ ability to provide effective and relatively economic mitigation treatments for fire-induced runoff-erosion risks in volcanic soils.
Nutrient availability can be a limiting factor in the recovery of ecosystems after wildfire. Its evaluation is therefore critical for selecting appropriate restoration strategies in the post-fire period. This study explores, for the first time, the use of thermogravimetry (TG) as a rapid proxy for nutrient availability and soil recovery. Soil samples from five burned and unburned sites in Andisols of Tenerife (Spain) were selected to examine the medium-term impact of fire. Key soil chemical parameters (pH, EC, CEC, main cation and anions in the soil solution, TOC, TN and available P) were determined and TG performed. Burned soils showed significantly higher pH, Ca2+ and Mg2+ and a lower CEC, TOC and TN than the unburned counterparts, and a site-dependent response for soluble SO42- and available P was observed in the medium-term. Time elapsed since fire could have masked additional fire-impacts. TG data allowed reasonable prediction of most soil properties and parameters, with r2 ranging from 0.4 to 0.9. The results demonstrate that soluble nutrients content is directly related to the amount of ash in the soil. The decrease of labile carboxyl-C was associated with an increase of pH and decrease of CEC, whereas the increase of recalcitrant and refractory pools was associated with the amount of TOC and TN. The results suggest that this novel application of an established method can provide, following an initial calibration step, rapid and inexpensive proxies for key parameters necessary for assessing fire-induced ecosystem degradation and designing suitable restoration strategies in the post-fire period.
Andosols are the most characteristic soils of volcanic regions such as the forested, fire-prone, hillslopes of the mountainous Canary Islands (Spain). Due to their volcanic nature, these soils have traditionally been considered highly resistant to water erosion processes in undisturbed conditions, but are also highly susceptible to environmental disturbances. In addition, volcanic terrains often underlie heavily-populated, steep areas where torrential rains are frequent, increasing the threat to the population and infrastructures down-slope. Numerous hydrological and erosional catastrophic events in disturbed Andosols in the Canary Islands and worldwide, leading to major losses to lives and properties, have been historically and recently reported. The impact of environmental alterations such as land use change on hydrological and erosional response of Andosols has been widely studied in the Canary Islands and worldwide. However, the effect on this soil type of wildfires, generally considered one of the main geomorphological agents, and historically connected to the forested fire-prone Andosols of the islands, has had scant attention to date. This review seeks to redress this knowledge gap by: (i) evaluating the factors affecting the susceptibility of Andosols to catastrophic hydrological and erosional events; (ii) summarizing the published studies on the impact of fire and the post-fire response of this soil type and the specific restoration measures developed to date; and (iii) identifying research gaps and suggesting new lines of investigation in order to reduce the hydrological and erosional risks in these particular terrains.
Los Andisoles son los suelos característicos de las regiones volcánicas como las laderas de cotas medias y húmedas de las islas más montañosas del archipiélago canario (Rodríguez Paz et al., 2010; Tejedor et al., 2009). Estos suelos han sido tradicionalmente considerados como altamente resistentes a los procesos de erosión hídrica gracias a su elevada capacidad de infiltración así como una baja susceptibilidad a la erosión en condiciones naturales, que permiten su desarrollo en zonas de elevada pendiente. Sin embargo, la elevada susceptibilidad a las perturbaciones ambientales de los componentes que le aportan esta estabilidad hace que este equilibrio hidrológico y erosivo sea muy frágil ante el impacto de los incendios forestales. Esta inestabilidad de los Andisoles frente a los cambios ambientales, junto con su ubicación en zonas de elevada pendiente cercanas a áreas urbanas con gran densidad de población, hace que estos suelos sean considerados uno de los más susceptibles a los procesos erosivos catastróficos como riadas, deslizamientos de laderas o flujos de barro inducidos por la alteración de sus condiciones naturales. En la historia y presente de las Islas Canarias se encuentran numerosas alusiones históricas y vivencias recientes como riadas, acarreos o flujos de barro directamente relacionados con lluvias intensas o persistentes tras incendios forestales y que en algunos casos han tenido resultados catastróficos. Este estudio pretende revisar las experiencias, estudios e innovaciones técnicas de restauración desarrolladas en esta tipología de suelos tras incendios forestales en las Islas Canarias.
Training in the restoration of degraded land in Spain has traditionally been linked to qualifications related to the environment, such as Forestry Engineering, Agronomy, Mining and science degrees like Biology, Environmental Science and Geology. Each of these degrees focuses on its own particular areas of specialty, such as hydrologic restoration, ecological restoration, restoration of mining areas and so on. In general, training focuses on learning and understanding key aspects related to the definition of degraded land, philosophies of restoration of physical environments and the development of restoration plans. This paper describes the skills covered, according to different programmes and certifications, in the training currently offered in Spain in restoration of degraded land. It also identifies the needs and highlights innovations in training. Finally, the future provision of graduate studies is analysed through a European Master Programme in Climate Change and Restoration of Degraded Land, RECLAND, belonging to the Lifelong Learning Programme of the European Union, which aims to cover the necessary skills to train future technicians in the restoration of degraded areas and improve knowledge of the effects of climate change on these processes.
Social and industrial progress has been historically linked to water resources availability and management. Although water is a renewable resource, water scarcity and water resources degradation are, nowadays, worrying issues in many countries such as Spain. The implementation of the EU Water Framework Directive has not been straightforward in Spain because, while some actions have proved their usefulness, others seem to have been counterproductive. Relevant changes are taking place in Spain to achieve sustainable water resources management, both in quantity and quality. Spanish universities offer a wide range of specialized training at master and degree level related to sustainable and integrated water management from different perspectives: technical, social, environmental and energy-related. This paper presents and summarizes different studies related to water resources in Spain, according to their competencies and professional skills, in order to provide recommendations on the training of future managers in this country. According to the information gathered, a European Master of Water Resources Management is recommended as a way of summarizing and standardizing current knowledge in water disciplines in Spain.
The role of the forests on the hydrology of volcanic island environments is critical, mainly due to both its protection against erosion and its reduction of the runoff and increase of the water infiltration. In the Canary Islands, forest location in the western islands caters to meteorological, ecological and hydrological factors, as the water availability, orography and the presence of trade winds among them. From a forestry perspective, vegetation of volcanic islands acts as a buffering as it boosts precipitation from fog condensation mainly in western islands with higher altitudes. Besides, it is also remarkable the role of the forest on the planning process of island watersheds, including water-related natural hazards management by its study, flood prediction, hillslope stability estimation, etc. due to the torrential rainfall regime. At last, forest also affects the erosion processes and soil conservation as it promotes infiltration and due to the protection of the canopy and the forest floor against the raindrop impact, one of the main issues of oceanic islands which affect directly and indirectly their hydrological cycle. Different study cases related to the role of forest in volcanic islands are reviewed throughout this work.
Climate change has become a hot topic both in the scientific community and the population in general. Despite the climate pattern has been changing continuously during the Earth's history due to changes in the atmosphere, topography, volcanic activity, and other natural factors, this change seems to have been exacerbated recently due to the alteration of the greenhouse gases content in the atmosphere by the humanity. It is easy to understand why the water cycle is one of the most environmental drivers affected by climate change. Global warming, leaded last century by the climate change, has involved alterations in the temperature, precipitation and evaporation patters. From the point of view of the water resources, these changes include an increase in the freshwater losses from terrestrial sources (glaciers, ice and snow, lakes, soil moisture, swamps, groundwater, marches and rivers) by evaporation and sublimation from fresh water deposits and transpiration from the vegetation, but also change in the rainfall quantity and patterns. As a result, climate change has leaded short- and long-term alterations in the frequency of extreme water-related events such as floods of droughts, which directly impact, on the quantity but also water resources quality, especially in islands environments.
- Dec 2014
Soil burn severity indexes have been developed to rapidly assess ecosystem damage from vegetation fires and predict associated risks during the post-fire period. In terms of the hydrological impacts of fire, the lack of measurable relationships between the commonly determined parameters and post-fire hydrological responses has limited their potential to predict and mitigate post-fire hazards. This study examines the link between post-fire organic matter characteristics, and main soil physical and hydrological properties (clay content, bulk density, aggregate stability, water retention, water repellency, rainfall–runoff ratio and sediment concentration in runoff) in order to explore the potential use of organic matter characteristics as a proxy for the fire impact on hydrology-related soil properties. Soil samples from five fire-affected burned and unburned control sites in Andisols areas of Tenerife (Canary Islands, Spain), studied previously for hydrological processes, were selected and thermogravimetric (TG) analysis was carried out to evaluate fire impacts on their organic matter composition. The TG data were used to perform simple linear regressions with soil hydrological properties. The organic matter composition was relatively homogeneous among the unburned sites, despite substantial within and between site variability regarding other soil properties examined which simplified the assessment of soil burn severity. The fire led to a decrease in the relative amount of the labile organic matter pool and an increase in the recalcitrant and/or refractory pool depending on study site. The TG data, using 10 °C temperature range steps, allowed reasonable prediction of most soil properties and parameters, with R2 ranging from 0.4 to 0.9 and with R2 ≥ 0.6 for 6 of the 8 parameters evaluated. The labile pool and the dehydration range positively affected bulk density, aggregate stability, wilting point and water repellency and negatively field capacity and sediment concentration, whereas the refractory pool showed the opposite trend. The recalcitrant pool was unrelated to other soil properties except for clay content and runoff. These results, in conjunction with the simplicity of the TG analysis suggest that, after an initial calibration step to link TG data to site-specific post-fire soil properties, the novel approach introduced in this study could serve as a useful tool for the rapid and cost-effective evaluation of soil burn severity, and anticipated soil hydrological responses after a fire.
Environmental restoration initiates or accelerates the recovery of an ecosystem which has been degraded, damaged or contaminated by human activity or natural agents. Environmental restoration projects may focus on restoring the environment or mitigating the negative environmental impacts of other projects or actions.
Wildfires are increasingly recognized as the primary natural hazard affecting forests and woodlands (Pausas, 2004), and changing the soil properties due to the heat (Aznar et al., 2013). They are also the factor that determines the increase in soil and water losses (Cerdà, 1998a; Shakesby, 2011). Fire contributes to increase the surface runoff due to the water repellency (Mataix-Solera et al., 2004; Cerdà and Doerr, 2008) although a quick recovery is found when vegetation is recovered (Cerdà, 1988b; Guénon et al., 2013). Within the recovery process ash is the key factor once the vegetation is recovered (Bodí et al., 2011; León et al., 2013; Pereira et al., 2013). To reduce the impact of forest fires some strategies were developed (Prats et al., 2013). The fire direct and indirect impacts on ecosystems and the human population, infrastructures, supplies and goods have been increasing over the last decades due to climatic and socio-economic changes and are projected to increase further in the future. In the densely populated volcanic regions that are characterized by steep and fire-prone slopes, Andisols are the main soil type. Their mineralogical properties provide them with specific chemical and physical properties which strength their fertility and resistance to erosion but also differentiate their response to environmental disturbances such as land use change (Jiménez et al., 2006; Neris et al., 2012) but also forest fires and agricultural burning (Neris et al., 2013; Poulenard et al., 2001). Despite their relevance for human development and safety, little specific knowledge exists about them and papers addressing their singularities are limited. This works seeks to compile and review existing scientific works focused on the effects of fire on this particular type of soils, evaluate their response to this disturbance and identify knowledge gaps related to the fire-induced risk in Andisols in order to develop new lines of research
- Sep 2013
Depending on the severity of the fire, forest fires may modify infiltration and soil erosion processes. Rainfall simulations were used to determine the hydrological effects of fire on Andisols in a pine forest burned by a wildfire in 2007. Six burned zones with different fire severities were compared with unburned zones. Infiltration, runoff and soil loss were analysed on slopes of 10% and 30%. Forest floor and soil properties were evaluated. Unburned zones exhibited relatively low infiltration (23 and 16 mm h−1 on 10% and 30% slope angles, respectively) and high average runoff/rainfall ratios (43% and 50% on 10% and 30% slope angles, respectively), which were associated with the extreme water repellency of the forest floor. Nonetheless, this layer seems to provide protection against raindrop impact and soil losses were found to be low (8 and 16 g m−2 h−1 for 10% and 30% slope angles, respectively). Soil cover, soil structure and water repellency were the main properties affected by the fire. The fire reduced forest floor and soil repellency, allowing rapid infiltration. Moreover, a significant decrease was noted in soil aggregate stabilities in the burned zones, which limited the infiltration rates. Consequently, no significant differences in infiltration and runoff were found between the burned and the unburned zones. The decrease in post-fire soil cover and soil stability resulted in order-of-magnitude increases in erosion. Sediment rates were 15 and 31 g m−2 h−1 on the 10% and 30% slope angles, respectively, in zones affected by light fire severity. In the moderate fire severity zones, these values reached 65 and 260 g m−2 h−1 for the 10% and 30% slope angles, respectively. Copyright © 2012 John Wiley & Sons, Ltd.
Given its singular properties and location, forest floor (litter + duff) is a key factor in hydrological processes. Water infiltration research was carried out for the present study in Andisols at ten sites, six of which had coverings of pine forest and four of rainforest. Rainfall simulations were conducted on gentle, moderately-steep and steep slopes (10, 30 and 50%) to determine infiltration, runoff and soil loss as a function of the forest floor characteristics. The duff on the pine forest soils consists of moderately porous, extremely hydrophobic and consistent semi-decomposed organic material, which is rich in fungi hyphae. The duff on the rainforest soils is formed by highly porous, loose, semi-decomposed organic material. The study results highlight the influential role played by the forest floor in infiltration and runoff. Infiltration barely reaches 20 mm h− 1 in pine forest, compared to 50 mm h− 1 in rainforest. As a consequence, the pine forest runoff is twice that recorded in rainforest sites. The wetting front on gentle and moderately-steep slopes evidences the influence of the duff on infiltration. In pine forest, most of the rainwater remains in the duff and infiltration depends little therefore on the underlying mineral soil properties. In rainforest, the wetting front extends below the duff and the well-developed soil structure is a major factor in water infiltration. The differences noted in the two parameters are not found on the steep slopes. No soil loss differences are observed between the two vegetation covers and forest floors despite the greater runoff in pine forest. The results demonstrate the protective effect of the organic covering and how the stability of the Andisols helps combat water erosion processes.
Soil water infiltration is an important process whose behaviour depends on external factors and soil properties that vary depending on the type of soil. The soil parameters affecting the infiltration capacity of six soil orders all formed on volcanic materials (andisols, vertisols, alfisols, aridisols, inceptisols, and entisols) and contribute to the differences between them were studied in this paper. A total of 108 sites were selected on the island of Tenerife (Spain). The main soil properties were analysed and the steady-state infiltration rate measured using a double-ring infiltrometer. The relationship between the soil properties and infiltration was modelled using statistical Principal Components Analysis and regressions. The research concludes that the relation between structural development and texture play a decisive role. The high structural development of non-vitric andisols, due to the high organic matter and short-range-order mineral content, leads to an extremely fast infiltration rate. The structural instability and fine texture of aridisols produce low infiltration. In less developed soils (entisols and vitric andisols) where aggregate formation is minimal or non-existent, the coarse grain size is the relevant factor determining their very fast and extremely fast infiltration. In vertisols and alfisols, which have strong aggregation but low stability, clay type and content play an important role and lead to a moderate and moderately fast steady-state infiltration rate, respectively. In the most typic inceptisols, with moderate structural development and stability, the balance of the properties is largely responsible for the intermediate infiltration rate observed.
Forest fires affect soil physical, chemical and mineralogical properties. However, the magnitude of these changes depends on both fire properties, such as the peak temperature reached and duration or depth achieved; and initial soil properties (soil type) as for example soil moisture, organic matter content or soil structure characteristics. Although many works have studied the effects of fire on the chemical properties of different soil types, its effects on Andisols properties have been omitted until now. Taking into account the high susceptibility to drying processes showed by the properties of Andisols affected by land use changes, it could be expected that the fire effects on their chemical properties may differ from those shown by other types of soil. In this study, the main chemical properties in addition to the specific andic properties of burned pine forest Andisols were compared to their unburned control. The chemical properties of ashes found after fire at the soil surface were also studied. The results show a slightly increase in EC and pH after the fire due mainly to the higher content of cations of the soil solution. Ashes derived from the vegetation and soil organic matter consumption by fire could be the main source of these elements in the soils after a fire, as they showed a high cation content. However, the rise in EC and pH is lower than the reported by most authors for other soil types. This behaviour could be related to the higher organic matter content of this soils, even after fire, and the buffering effect of organic compounds on the soil EC and pH changes after the fire. As other authors have shown, a decrease in both the total and active organic content after the fire was also observed as a result of the fire event. The specific andic properties of Andisols were also affected. The P retention of these soils slightly declines as a consequence of fire, while the content of short-range-order products was also modified, but no statistically significant differences between burned and control soils were found.
The study of climate change and degraded land requires the study of causal relations between human causes and land use changes. Specialized training through European Masters on environmental management and its risks and threats will dynamically link people from different disciplines and from outside academia to improve students’ experience which will enable them to learn to deal with multi disciplinary decision making solution. This will allow for students not to be just inserted into one system or discipline, but simultaneously into a process of learning about the relation between education, political, social, ecological and economic environment. But the most innovative aspect of these teaching strategies and methodologies is the link created between teaching innovation and environmental disciplines. There is not such an offer that combines and links these two major aspects directly related and focuses the educational pro-gram in this combination. From this perspective, which is widely recognized by experts, students will have an innovative and useful learning experience on the is-sue covered by the program.
Numerous Spanish and European syllabus of civil and mining engineering colleges lack contents related to volcanic environments, including oceanic islands such as Canary Islands or Azores. Knowing their particularities and being able to manage them complement the academic training needed to be applied to all types of territory in the current globalized work market. The technical singularities of the hydrology or geotechnics of volcanic environments are complex. Thus, the educational facilities related to them should be as efficient and innovative as possible. It is well known that the knowledge of the singularities of volcanic lands facilitate obtaining a job. Last, but not least, e-learning including virtual laboratories could globalize the training and internationalize the teaching and professional profiles.
In volcanic islands, the rainfall regime and its torrential nature, together with the steep slopes and the soil types present are considered to be some of the main factors affecting forest hydrology and soil conservation. In such environments, rain regime is generally irregular and characterized by short and intense rainfalls, which could cause destructive flows at times, followed by long periods of rain absence. The volcanic nature of these islands have as a direct resultant steep slopes which influences the runoff volume and speed, as well as the amount of topsoil susceptible to be detached and transported downstream. The soil type also affects the susceptibility to erosion processes. Andisols are the most typical soil on volcanic islands. Their particularities derive their mineral constituents, called short-range-order products, which provide these soils with an increased structural stability, which in turn reduces their susceptibility to erosion. However, the land use changes and the environmental factors such as rain regime and steep slopes may be determinant factor in destabilizing these soils and ultimately a cause for soil erosion and runoffs, which become a threat to the population downstream. Green barriers have been traditionally used to prevent or reduce these processes, also to enhance the dew effect and the fog water collection, and as a firebreak which acts as a barrier to slow or stop the progress of a wildfire. Wooded species present and subsequently their performance have a major influence on their effectiveness. The use of this natural erosion and fire control methods on volcanic islands is discussed in this paper.
The rapid economic and social development in recent decades has created new forms of vulnerability to natural hazards and increased existing ones. In recent years, more than half of the world’s population has established residence in cities and urban centres. This process of population concentration, coupled with the increasing number of inhabitants of the planet has led in many parts of the world to an unprecedented urban development. Under these conditions, new population centres are characterised in many parts of the world by a lack of proper planning and therefore the generation of new risks to people. According to the International Strategy for Disaster Reduction (UNISDR), in addition to traditional natural hazards, others have been generated by the increasing number of informal settlements, social inequality, environmental degradation and the process of global climate change. This paper is focus on those problems with the aim to provide a introduction on the Disaster Risk Reduction.
The study of climate change and degraded land requires the study of causal relations between human causes and land use changes. Specialized training through European Masters on environmental management and its risks and threats will dynamically link people from different disciplines and from outside academia to improve students’ experience which will enable them to learn to deal with multi disciplinary decision making solution. This will allow for students not to be just inserted into one system or discipline, but simultaneously into a process of learning about the relation between education, political, social, ecological and economic environment. But the most innovative aspect of these teaching strategies and methodologies is the link created between teaching innovation and environmental disciplines. There is not such an offer that combines and links these two major aspects directly related and focuses the educational program in this combination. From this perspective, which is widely recognized by experts, students will have an innovative and useful learning experience on the issue covered by the program.
Europe is facing an accelerated climate change as a result of global warming and as a result population departure and consequent abandon of rural areas due to the increase floods, forest fire, lack of water, land slide, etc, and there is a need to find ways to support management of such hazards by providing adequate training on environmental security and management. One academic proposal for understanding and training appropriate personnel to mitigate threats to the environment is higher education, so in this way, authors proposed an MSc Program related to environmental security. Another strong point of this program is to prepare students for the regional and global postgraduate job market. This paper is intended to explain and analyze the stages of preparation of documentation and project management, whole preparation of a Master Erasmus Program, including teaching strategies, such as Virtual Learning Platform that contains learning materials in a digital format including text, audio-material, images and video-material, meetings as a tester workshops organized in participating countries, future interaction with the student etc. Finally, the document is intended as an aid to future teachers to detect a lack of training in an area that affects the environment in Europe so they can propose a training program, innovative and high acceptance towards the Graduates of Business and Planning faculties who intend to work in the infrastructure projects, graduates of environmental faculties who intend to specialise in environment disasters management. This work has been funded by the Education, Audiovisual and Culture Executive Agency (EACEA), as an Erasmus Multilateral Project through project number 517629-LLP-1-2011-UK-ERASMUS-EMCR.
Erasmus 2009-2013 is a cooperation and mobility programme in the field of higher education that aims to enhance the quality of European higher education. In 2012 it was proposed a training program (Master Degree) related to Climate Change and the restoration of degraded lands. UPM, the promoter of this project, has identified a clear lack of educational provision regarding Climate Change, Degraded Land and its Restoration, in both educational and non-educational settings. UPM has got an expertise in developing tailored e-learning programmes and their strengths rely on their ability to adapt ICT solutions to the particular needs of the educators by incorporating the latest developments in communication. UPM is a leader in land slide assessment and environmental restoration, as well as in waste management. The study of climate change and degraded land requires innovative techniques in teaching that will be analyzed and discussed in the following document. These techniques should be integrated among the various project partners, which increase the difficulty of applying homogeneous. Another complex issue is the environmental disparity in each area, from a subtropical climate (Canary Islands) and volcanic origin to a continental climate, this makes difficult the realization of general documents that may have application in all the territories and of course that the contents can be useful to all students. This work has been funded by the Education, Audiovisual and Culture Executive Agency (EACEA), as an Erasmus Multilateral Project through project number 526746-LLP-1-2012-1-ES-ERASMUS-EMCR.
Andisols are soils with high structural development and aggregate stability, characteristics that play a major role in their high infiltration rate. They are, however, vulnerable to environmental changes, particularly those associated with land use modifications. The present work aims to ascertain the influence of modifications to land use as well as vegetation cover on the steady-state infiltration rate and associated properties of Andisols on the volcanic island of Tenerife (Canary Islands, Spain). Thirty two sites were selected in three categories of land use/vegetation cover (green forest, pine forest and cropped areas). The infiltration rate was studied using a double ring infiltrometer. Other soil properties which influence infiltration – organic matter content, texture, structure, bulk density, water retention capacity and water repellency – were also studied. Infiltration is extremely rapid under green forest (796 mmh− 1) but falls considerably under pine forest (188 mmh− 1) and in formerly cropped soils (67 mmh− 1). The statistical analysis shows that the main soil properties affected by a change in land use/vegetation and which determine infiltration are soil aggregation, structural stability and, to a lesser extent, organic matter and bulk density. Compared to the green forest sites, a notable reduction in soil aggregation, structural stability and organic matter, and an increase in bulk density, are observed in the formerly cropped soils. Although less pronounced, the same tendency is seen also in the pine forest sites when compared to their green forest counterparts. The results confirm the vulnerability of Andisols' soil properties and infiltration to land use modification, while also highlighting the influence of the type of forest cover present.
Macaronesia consists of a group of several islands , volcanic in origin, scattered in the North-East Atlantic off the coast of Africa, The archipelagos and islands are (from North to the South; Azores, Madeira, Canarias and Cape Verde).The total inhabitants are more than two millions. Three of them belong to countries in the European Union: Azores and Madeira to Portugal and the Canary Islands to Spain and Cape Verde is an independent country. Agriculture and tourism are the mainstay of Macaronesia’s economy and development. Other important fact on this region is the Macaronesian forest that is the subtropical cloud forests endemic to the Atlantic islands. In this document will be studied the fundamental aspects that affected by forest , insular hydrology and rural development, mainly water erosion control, the use of water and forests and finally the precipitation of fog will be discussed.
Macaronesian consists of a group of several islands, volcanic in origin, scattered in the North- East Atlantic off the coast of Africa, The archipelagos and islands are (from North to the South; Azores, Madeira, Canarias and Cape Verde). The total inhabitants are more than two millions. Three of them belong to countries in the European Union: Azores and Madeira to Portugal and the Canary Islands to Spain and Cape Verde is an independent country. Agriculture and tourism are the main stay of Macaronesian’s economy and development. Other important fact on this region is the Macaronesian forest that is the subtropical cloud forests endemic to the Atlantic islands. In these volcanic islands, the rainfall regime and its torrential nature, together with the steep slopes and the soil types present are considered to be some of the main factors affecting forest hydrology and soil conservation. In the case of Canary and in Azores archipelago, another important factor to understand the water resources regulation in the islands is the fog precipitation. In the Canary Islands this effect occurs from the 600 meters, powered by vegetation adapted to this type of precipitation. Finally, in the region of Macaronesian, forests also has a role in the promotion of sustainable tourism, people are looking for experiences related to the environment, so that in addition to traditional forest use, this tourism could develop rural sites associated with forest. In this document, it will be studied the fundamental aspects that affected by forest, insular hydrology and rural development, mainly related with water erosion control, the use of water and forests and finally the precipitation of fog.
Management of soil for water erosion control is based on sensible soil conservation practices. Wildfires alter the water infiltration process in soils, while also modifying the hydrological behaviour of the watersheds in which they occur. Rainfall simulations and rainfall data analysis were used to determine the hydrological and erosive effects of fire in Andisols with pine forest burned by a wildfire in 2007 during the post fire period. On the one hand, no significant differences in infiltration and runoff were found between the burned and unburned zones. The low infiltration values observed in the unburned zones and the disparate impact of the fire on the forest floor and on the soil properties explain this behaviour.Contrary, sediment rates increased considerably in the post fire period. The soil loss values in the burned zones exceed those recorded in the unburned zones by two orders of magnitude. Post-fire soil cover and soil stability ultimately determines soil losses. Methods used to protect soils after wildfires will be discussed.
Las enseñanzas de las titulaciones técnicas tienen un componente complejo y una serie de análisis, procesos, modelos y cálculos de difícil comprensión. En relativamente muchas ocasiones, es muy complejo transmitir competencias y destrezas al alumno sobre esquemas que suceden en la realidad o procesos ingenieriles con una simple foto, esquema en la pizarra o transmisión verbal. Por ello la inclusión de las nuevas tecnologías, sobre todo las multimedia y las digitales, han creado un gran vector de aprendizaje facilitando la labor tanto a docente como alumno. Una de las primeras evoluciones a mediados de los años 90 fue el uso del videocasete y de transparencias como método compatible con el uso de la pizarra clásica. Posteriormente, ya con la integración plena de las nuevas tecnologías en el aula el uso de las presentaciones digitales en pantalla como apoyo de la clase magistral es una estrategia docente de uso masivo, posteriormente estas presentaciones fueron complementándose con fotos, videos y animaciones. Este apoyo no sólo ha servido para el alumnado sino también para el profesor con menos experiencia, que ha podido en cierta manera apoyarse en estas presentaciones para el desarrollo de la asignatura. A partir de este punto, se ha evolucionado hacia los campus virtuales, un almacén de documentación con ciertas funciones interactivas entre el docente y el alumnado. Otro paso más en la evolución tecnológica ha sido la web 1.0 del profesor, cuya evolución natural ha sido el blog docente con sus actualizaciones y dinamismo, lo que hoy se puede entender como una web 2.0. Los siguientes pasos naturales deberían ir en la dirección de una mayor interacción del alumnado con estas herramientas digitales, como los laboratorios virtuales, simuladores y, más concretamente, en las titulaciones técnicas con elementos digitales que puedan desarrollar destrezas y competencias de diseño en ingeniería, sus cálculos y análisis asociados.
Forest fires modify the main properties of affected soils. Soil physical properties of Andisols with pine forest burned were evaluated. Five burned zones were compared to unburned counterparts. Soil texture, structure, bulk density, water retention capacity and water repellency were determined. As most studies report, soils showed an increase in the sand and/or silt content related to a noticeably reduction in clay content in the zones affected by fire. According to these reports, cementation processes involving Al and Si hydroxides as cements during the fire are the main factors controlling this behaviour. Regarding to soil structure, aggregation and aggregate stability decreased considerably in burned zones, as is usually reported. The decrease in soil binding such as organic matter, clay content and short-range order products explains this trend. Nevertheless, bulk density and water retention capacity, some of the main characteristic properties of Andisols, showed contradictory patterns compared to most studies. Water retention capacity at -33 kPa increases considerably after fire, whereas at -1500 kPa no major changes were observed. Preliminary conclusions indicate that the high water retention of ashes included into the soil explains this trend at -33 kPa. On the other side, the decrease in organic matter and clay content offsets the water retention increase at -1500 kPa due the ash incorporation. In opposition to most studies, an important reduction in bulk density was observed in burned soils. Some authors have reported that the desiccation process leads to a loss of aggregation resulting in low-density microaggregates in Andisols of Tenerife. These soils are known locally as "dusty-soils". Finally, a decrease of soil water repellency was also observed in most zones after fire, despite a large number of studies reporting the opposite. The soil organic matter decline might be the key factor of this trend.
We studied the soil temperature regimes of the volcanic island of Tenerife (Canary Islands, Spain), which is situated in the Atlantic Ocean between 27 and 28° N. Th e island is 2034 km2 in size and its highest point is 3718 m above sea level. Direct temperature measurements were taken during a 4-yr period at 103 sites, at a depth of 50 cm, in altitudinal sequences from the north and south slopes of the island. In contrast to continental situations, soil temperature regimes from all latitudes are found within a small area of the island. Seven of the nine regimes considered by Soil Taxonomy have been identifi ed—hyperthermic, thermic, mesic, isohyperthermic, isothermic, isomesic, and cryic—and are widely distributed according to elevation and orientation. In the mid-altitude zone on the north face, which is infl uenced by the trade winds, regimes typical of tropical regions were found, while above 3000-m elevation, a high-latitude regime was also described. Th e wide diversity of soil temperatures in such a small area is explained by the variability of a range of factors, including elevation, the orientation of the mountain systems, and the infl uence of the trade winds. In addition to recording the presence of temperature regimes from diff erent latitudes in a subtropical island, we documented a cryic regime at this latitude for the fi rst time.
- May 2010
Infiltration is a crucial process in the hydrological cycle, since it controls - among other things - the generation of run-off, erosion and aquifer recharge. Undisturbed Andisols are considered resistant to water erosion; a characteristic closely associated with their high porosity that permits a rapid rainfall infiltration and high structural stability. In spite of that, the high content of organic C on this type of soils, and the positive relation between this property and water repellence, could allow the presence of some soil surface characteristics that may change this behaviour. The aim of this work was to study the influence of these hydrophobic layers on water infiltration and soil loss on Andisols of Tenerife. Twelve sites were chosen, all of which are located on the northern side of the island of Tenerife (Canary Islands, Spain), between 825-1400 m.a.s.l. The soils are allophanic Andisols (Typic/Lithic Hapludands and Typic Haplustands) and vitric Andisols (Typic Udivitrands) under pine forest. In each site, soil surface features with potential hydrological implications were described. To determine infiltration, a rainfall simulator with the following characteristics was used: 35 x 25 x 30 cm metal box with nozzles in the bottom, 2.5 cm apart (diameter of drops = 2-3 mm). The 4 box adjustable legs were set at 2 m height. Prior to installing the rainfall simulator, study zones were marked out using 30 cm-tall metal sheets. Each area measured approximately 875 cm2 and measurements were taken for slopes of 10 and 30% when it was possible. At the end of the slope a 25 cm-wide collector was semi-buried to collect runoff and sediment. Rainfall of variable intensity between 50-70 mmh-1 was simulated for periods of 30-45 minutes. Time to runoff (TR), volume to runoff (VR), steady-state infiltration rate (IR), runoff/rainfall ratio (RR), soil loss rate (SED) and sediment concentration (CSED) were measured. For some of the studied soils, the formation of horizons made up with pine needles embedded with fungi mycelia was observed. These layers were highly water-repellent and could be easily detached from the underlying soil. When comparing the soils in which these are present with those devoid of them, the former showed an average decrease of 40% in TR and VR for both slopes. The IR suffered a decrease of nearly 40% and 30%, and the RR an increase of 40% and 20% for slopes of 10 and 30% respectively. Contradictory, soil loss showed a decrease in sites where this layer was present, 20% and 40% in SED, and 15% and 50% in CSED for slopes of 10% and 30% respectively. As a conclusion, despite the reduction in IR and the increase in RR, the presence of this layer in soils seems to provide them with a high resistance to drop impact, and a modification of water dynamics leading to a decrease of soil loss.
The term iso in soil temperature regimes has been used in Soil Taxonomy to distinguish between tropical and temperate zones. It defi nes regimes with temperature differences of less than 6°C between summer (June, July, and August) and winter (December, January, and February). In the northern hemisphere, however, these months are not necessarily the warmest and coldest months. The island of Tenerife, which lies between 28 and 29° N near the Tropic of Cancer, is a transition point between the temperate and tropical regions. The trade winds, affecting mainly the northern side of the island, are the main reason for the presence of a tropical zone featuring iso, isomesic, and isothermic temperature regimes. In this zone, the warmest and coldest months are displaced by 2 to 3 mo compared with the months indicated in Soil Taxonomy. We examined the characteristics of “iso” regimes and a number of other possible methods for determining isotivity: the warmest and coldest months, astronomical summer and winter, and the equinoxes. We concluded that the soil temperature regime of the zone most infl uenced by the trade winds—a zone with rainforest vegetation and where tropical characteristics are most in evidence—would not lose its “iso” character under any of the methods. We suggest using the warmest and coldest months instead of summer and winter for the purposes of defi ning “iso” status. To facilitate estimations, we also suggest that the temperature of the equinox days be used. Changing the limit from 6 to 5°C would not affect the tropical soils of the island of Tenerife.
The volcanic island of Tenerife (Canary Islands) has a wide variety of Andisols which have formed on recent pyroclast materials (Udands, Ustands, Xerands and Vitrands). The Udands are situated on the northern side of the island, at heights where condensation of the trade winds occurs (900-1600m), while the Ustands are also located mostly on this side, albeit at a lower altitudinal strip. Under natural conditions, these soils present favourable physical properties, with high structural stability and resistance to water erosion. The aim of the present work is to study modifications in the Basic Infiltration Rate (BIR) caused by a change in the use of the soils. 26 Udands zones (11 natural and 15 modified) were selected along with 11 Ustands zones (4 natural and 7 modified). The typical vegetation in the natural zones is, in the case of the Udands, ‘fayal-brezal’ (Myrica faya, Erica arborea) or Canarian pine (Pinus canariensis), and pine in the case of the Ustands. The main modifications to use were as follows: deforestation, deforestation and grazing, repopulation of pines, abandoned farmland or farmland currently in use. The infiltration velocity was estimated using the double ring method, with at least three repetitions. The results obtained show that, in the soils with natural vegetation, the BIR is higher in the Udands (very fast) than in the Ustands (fast), averaging 575 mmh-1 compared to 150 mmh-1. In the soils with modified cover the values fall to 96 mmh-1 and 91 mmh-1 respectively. We conclude that modified use leads to a drastic reduction in the BIR of Andisols, causing it to change from very fast-fast to moderately fast, with the consequent increase in runoff and water erosion. Palabras clave: Andisoles, Islas Canarias, Tenerife, infiltración, cambio de uso
- May 2006
Soil erosion and infiltration are influenced by chemical, mineralogical, and physical soil properties. Typically, erosion increases with decreasing infiltration. Undisturbed Andisols are considered to be highly stable and resistant to water erosion. A wide variety of Andisols can be found on the island of Tenerife (Canary Islands). The objective of the present paper was to determine the infiltration rate of five Andisols and assess the influence of deforestation and a change in vegetation on the infiltration rate. Apparent hydraulic conductivity was measured using a double ring infiltrometer in soils from the Vitrixerands, Hapludands, Haplustands and Fulvudands great groups. The Infiltration rates in the natural soils were very high and in all cases were greater than 130 mm hr-1 (5.1 in hr-1). Harvesting the natural vegetation appeared to increase the bulk density, while also reducing organic matter and the apparent saturated hydraulic conductivity values. Under these conditions erosion can be stimulated.
The use of salic pyroclasts as soil mulch is a common management practice in arid conditions in southern and south-eastern parts of the island of Tenerife (Canary Islands, Spain). It forms the basis for a traditional farming technique, which is known locally as ‘jable’. In its various forms the practice, used at heights of 300-1500 metres, covers an area of 3,850 hectares. The present work examines its influence on soil temperature and particularly on the estimation of Classes of Soil Temperature (Soil Survey Staff, 1999). Soil temperature was measured monthly at 50 cm depth in six covered plots and in adjacent uncovered plots, all located at different altitudes: 325-375, 600, 825 and 1275 m. In each season, measurements were also taken at 0, 10, 20, 30, 40 and 50 cm. The thickness of the mulch covering varied between 23 cm and 43 cm. The natural altitudinal soils sequence was as follows: aridisols, vertisols andvertic inceptisols, and inceptisols. The covered soil is currently used to grow grapes and/or potatoes while the natural soil has natural vegetation. The results evidence the buffering effectof the system, which is more marked at the lower heights of the sequence. Whereas the natural soils have a hyperthermic temperature regime (annual soil temperature, mean 22ºC, and a difference between mean summer temperature, mst, and mean winter temperature, mwt, > 6ºC) the soils under the pumice are isohyperthermic (mean 22ºC and mst-mwt < 6ºC). At approximately 600 m, the natural soils are thermic (15mean<22ºC and mst-mwt >6ºC) and the covered soils are isothermic (mst-mwt < 6ºC). This situation is maintained up to 800/900 m, where the buffering effect of the pumice is less pronounced. The temperature profiles are also influenced by the system. In the natural soils, temperature decreases with depth, while in the covered soils this occurs only in summer. The management system helps prevent high temperatures and enables the soil to be used for farming.
In arid and semiarid regions with scarce rainfall and frequent erosion processes a variety of farming practices have been devised to conserve soil and water. One of these consists of the use of organic and inorganic materials as surface mulch. The use of volcanic materials for this purpose is commonplace in arid parts of the Canary Islands (Spain). In the south and south-east of Tenerife extensive surface coverings of salic volcanic materials (outcrops and pyroclasts) from Pliocene-Quaternary eruptions have propitiated the development of a peculiar farming practice known as 'jable'. The technique involves the placing of a layer of salic pyroclasts to facilitate soil and water conservation. Cultivation takes place in the underlying soil. The pyroclast mulch is of variable thickness (20-50 cm) and the degree of mixing with the soil also varies greatly, depending on the age of the system. In some parts, where the pyroclasts have suffered some weathering, cultivation is possible directly on them. Potatoes are the most frequently-grown crop in this dry farming system. The present paper studies the effect of this traditional practice on soil water infiltration capacity. A number of sites, situated at heights between 300 and 1200 m.a.s.l. and with different soils (Aridisol, Vertisol, Inceptisol), were chosen. Each site contained plots covered with a (35-45 cm) layer of salic pyroclasts and other plots which were left uncovered. Infiltration rate was measured using a double ring infiltrometer, with three replications in each case. The results show the importance of this traditional practice in arid and semi-arid regions. Irrespective of the type of underlying soil, the infiltration rate improved considerably (to the extent that the infiltration class was modified by at least one category) and runoff was reduced.
Awards & Achievements (10)
Grant · Jun 2013
Grant to attend the 4th FESP Meeting (Lithuania). FESP2013 Organizing Committee
Award · Feb 2013
Outstanding PhD Award. University of La Laguna
Grant · Jan 2006
Fellowship for short visits of PhD students (Lleida). Gobierno de Canarias
Grant · Oct 2005
Fellowship for short visits of PhD students (Lleida). Gobierno de Canarias
Grant · Mar 2003
Research fellowship for PhD Studies. Gobierno de Canarias (Spain).