DigitalUM :: Browsing by Subject "Desertificación"

Browsing by Subject "Desertificación"

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Open Access
A procedure to derive intra- and inter-annual changes on vegetation from NDVI time series. A case study in Spain.
(2020-04-03) Gilabert, M.A.; Martínez, B.; Meliá, J.; Departament de Física de la Terra i Termodinàmica, Universitat de València.
The NDVI time series are characterized by patterns like seasonality, trends and localized abrupt changes or discontinuities resulting from disturbance events. Therefore, they allow us to characterize vegetation dynamics on the basis of different temporal scales. In particular, the subtle, long-term changes convey relevant information on land degradation. The objective of this work is to study the spatial patterns of vegetation activity over Spain and its temporal variability throughout the period 1989-2002. A multi-resolution analysis (MRA) based on the wavelet transform has been implemented on NDVI time series from the MEDOKADS database. The MRA decomposes the original signal as a sum of series associated with different temporal scales. Specifically, the intra-annual series is processed to define several key features in relation with the vegetation phenology. In contrast, the interannual component of the signal is used to detect trends by means of a Mann-Kendall test and map the magnitude of the land-cover change. Finally, a comprehensive identification of the areas presenting a negative value of the magnitude of change is carried out to select those linked to land degradation processes. Results show a major presence of these areas the Southeast of Spain.
Open Access
Abandonment terraced hillside and answer of the fire system: some results from Mediterranean old fields
(2020-04-03) Llovet López, J.; Ruiz Valera, M.; Josa March, R.; Vallejo Calzada, V.R.; Fundación CEAM, Departament d’Ecologia (CEAM); Departament d’Enginyeria Agroalimentària i Biotecnologia
The abandonment of agricultural lands promotes temporal changes both in soil characteristics (i.e., increasing organic matter and other quality indicators) and in plant community (i.e., changing its composition and structure, and increasing the fuel load). As a consequence, we can expect differences in the resilience to fire as succession progresses. The aim of this work is to analyse the capacity of an ecosystem to return to pre-fire conditions as a function of the stage of abandonment of old agricultural lands. The study was carried out in the north of Alicante province (E Spain). In long-term abandoned lands, post-fire rainfall modulated plant response, which in turn determined soil crusting, runoff and erosion dynamics. In recently-abandoned lands, the plant community seemed less dependent on rain to recover. Results show a large increase in soil surface crusting in the short term after the fire and it remained high at medium term in long-abandoned lands colonised by pine forest. Fire scarcely modified runoff and erosion in recently-abandoned lands whereas in forest lands the post-fire values increased by some orders of magnitude and remained highly dependent on rain characteristics in the short and medium term after the fire. The results obtained show evidences of increased vulnerability to fire in long-abandoned lands colonised by pine forests
Open Access
Acciones de lucha contra la desertificación en ambientes semiáridos en el noroeste de Tamaulipas, México
(Murcia, Universidad de Murcia, Servicio de Publicaciones, 2009) Andrade Limas, Elizabeth del C.; Espinosa Ramírez, Martin; Romero Díaz, María Asunción
Open Access
African and local wind-blown dust contributions at three rural sites in SE Spain: the aerosol size distribution
(2020-04-03) Orza, J.A.G.; Cabello, M.; Lidón, V.; Martínez, J.; SCOLAb, Física Aplicada, Universidad Miguel Hernández; Aeolian Erosion Research Group, Universidad Miguel Hernández
The entrainment of particulate material into the atmosphere by wind action on surface soils both disturbed and natural, as well as directly due to human activities like agricultural practices, mineral industry operations, construction works and traffic, is a significant contribution to the aerosol load in Mediterranean semi-arid areas. A further crustal contribution in the region comes from the frequent arrival of African mineral dust plumes. We summarize some of the results obtained after 4-6 -month campaigns at three rural sites in SE Spain where the aerosol number size distribution (31 size bins between 0.25 and 32 μm) was continuously measured. The influence of both local wind speed and the arrival of air masses loaded with African dust on the airborne particulate distribution is assessed. Similarities and differences between the three locations give information that allows a better understanding of the influence of both local wind speed and African dust outbreaks (ADO), while highlight what is mostly related to local features.
Open Access
Agua y agricultura en sistemas áridos: un modelo dinámico del regadío de Mazarrón y Águilas
(2020-04-03) Martínez Fernández, j.; Esteve Selma, Miguel A.; Departamento de Ecología e Hidrología. Universidad de Murcia; Departamento de Ecología e Hidrología. Universidad de Murcia
The intensive use of groundwater resources in the new irrigated lands of Mazarron-Aguilas has led to the over-exploitation of the local aquifers and thus, to seawater intrusion, water salinization and falling off water tables, all of them key processes of desertification. The simulation results show that the unrealistic perceptions about the relationships between irrigated land and water resources constitutes a key factor to explain the highly unsustainable dynamics of irrigated lands in Mazarrón and Aguilas and the whole SE Spain. The increase in water resources does not eliminate the problem because the feedback loops and endogenous factors of the system lead to a further increase in irrigated land and continuation of the water deficit, which shows a highly counter-intuitive behaviour.
Open Access
An evaluation of the MEDALUS ESA index (environmental sensitivity to land degradation), from regional to plot scale
(2020-04-03) Lavado Contador, J. F; Schnabel, S; Gómez Gutiérrez, A.; Grupo de Investigación GeoAmbiental, Universidad de Extremadura
An assessment of the sensitivity to land degradation have been carried out for the region of Extremadura, SW Spain, by means of the modelling approach developed in the European Commission funded MEDALUS project (Mediterranean Desertification and Land Use) which identifies such areas on the basis of an index (ESA index) that incorporates data on environmental quality (climate, vegetation, soil) as well as on anthropogenic factors (management). Two maps of environmental sensitivity to degradation with different legend resolution (4 and 8 classes of sensitivity) have been made. The results of the model were validated at different spatial scales, i.e.; regional and farm scales. True field data on degradation-related variables at the different spatial scales have been used in order to undertake the validation procedures. Selected farms covering different physiographical and socioeconomic characteristics were used to gather data at farm scale. Data gathered from the National Inventory of Soil Erosion was also used to validate the model at the regional scale.
Open Access
Análisis espacio-temporal de los cambios de usos del suelo en la Cuenca del Río Segura
(2020-04-03) Alonso Sarriá, Francisco; Gomariz Castillo, Francisco; Cánovas García, F.; Moreno Brotóns, J.; Instituto del Agua y Medio Ambiente, Universidad de Murcia, Campus de Espinardo
Land use change is a dynamic process that affects heavily to different environmental processes. In this work, a GIS application is designed to analyse land use changes from landsat imagery since 1976 to 2007, a period with important socioeconomic and land use changes in River Segura Basin. This work describes the methodology used to obtain a yearly series of land cover maps of the Demarcación Hidrográfica del Segura (River Segura basin in South East Spain). In order to analyze this great amount of information for a large (more than 18,000 km2) and heterogeneous area, a unified methodology has been developed. It has been used a supervised classification improved by a previous not supervised classification using both spectral (4 or 6 landsat solar spectrum bands depending on the sensor available, MSS or TM, ETM) and two textural variables. The last ones were obtained estimating the semivariogram frunction from the albedo and NDVI layers. Having used two images from different seasons, the total number of variables included in the classification is 12 or 16 depending on the year. Preliminary results show a reduction of the surfaces with traditional dry crop uses and the important increase of irrigation lands during the first half of the 1980s decade. The increase in bare soil areas also reflects the abandonment of traditional crops. Finally, it has been observed an increase in urban areas attributable to demographic trends.
Open Access
Analysing the factors affecting gully development and their relationships with land-use changes in the east Alentejo (Portugal)
(2020-04-03) Roxo, M. J.; Calvo-Cases, A.; Departamento de Geografia e Planeamento Regional, Universidade Nova de Lisboa; Departament de Geografia, Universitat de Valencia
The land abandonment and land-use changes as a consequence of the implementation of the European Union Common Agricultural Policy (C.A.P.), in the SE of Portugal, have been generating, differences in the equilibrium of the geomorphic processes. The head waters catchments of some of the Guadiana River tributaries show in the study area several degrees of gully initiation and development both on the hillsides and valley bottom infill. This gully generation process is closely related with the changes in the soil and cover properties occurring when agricultural practises have been replaced by intensive grazing areas or by abandoned land. High resolution panchromatic and Landsat images, dating from the last 40 years have been analysed in combination with field observations and the analysis of the data from soil erosion plots series in the Estação Experimental de Vale Formoso, in order to establish and parameterise the sequence of changes in soil surface properties and vegetation cover and distribution. The results show the connection between the different degrees of gully development and their morphological characteristics with the land cover properties at different times and after different sequences of land-use changes
Open Access
Aplicación de técnicas hiperespectrales de imagen al estudio de la degradación de suelos en ambientes áridos (Los Monegros, España)
(2020-04-03) Gumuzzio Such, A.; Palacios Orueta, A.; Schmid, T.; Dominguez, J.A.; Gumuzzio, J.; E.T.S.I Montes de Madrid. Departamento de Silvopascicultura, Ciudad Universitaria; CIEMAT, Departamento de Medioambiente, Avda. Complutense; Centro de Estudios Hidrográficos CEDEX; Departamento de Geología y Geoquímica. Universidad Autónoma de Madrid
The aim of this work is to identify characteristics associated to soils affected by degradation within an arid area of Spain using optical hyperspectral airborne data. The methodological approach was developed to determine the spatial distribution of selected soils affected by degradation processes. A satisfactory spatial distribution is obtained where the corresponding soil characteristics are closely related to degradation processes.
Open Access
Aportaciones de la palinología en la reconstrucción del impacto ganadero, en los alrededores de Rascafría (Madrid), durante el Holoceno reciente
(2020-04-03) Gómez González, C.; Ruiz Zapata, M.B.; López-Saez, J.A.; Gil Garcia, M.J.; Departamento de Geología, Universidad de Alcalá,; Laboratorio de Arqueobotánica, Departamento de Historia CSIC
We present the results obtained from the palaeoecological studies about human impact on the vegetal landscape of a peatbog located in Rascafría (Lozoya Valley, Madrid, Central Spain). Palynomorph analysis allows to identify the kind and intensity of human activity and its relation to the trophic changes in the peatbog during the late Holocene (2455±35 BP). Pollen record reveals an anthropic Mediterranean landscape mainly composed by pastures used for grazing. Non Pollen Palynomorphs (NPP) and pH and conductivity sediment have revealed as useful tools for detection of trophic conditions and land use changes.
Open Access
Aportaciones de la teledetección y los SIG para la mejora de los modelos de evaluación de las pérdidas de suelo en Andalucía
(2020-04-03) Moreira Madueño, J.M.; Rodríguez Surián, M.; Ojeda Zújar, J.; Dirección General de Desarrollo Sostenible e Información Ambiental. Consejería de Medio Ambiente.; Departamento de Geografía Física y Análisis Geográfico Regional, Universidad de Sevilla,
The Regional Ministry of the Environment, through the Environmental Information Network (REDIAM), monitors the annual rate of land loss in Andalusia. This phenomenon, which is characterised by a high level of spatial and temporal variance, is particularly influenced by the amount and intensity of rainfall and land uses. The use of high and low resolution satellite images and regional ortophotographs has enabled continuous updating of information on plant cover and land uses, whilst the daily climate information from a network of automated weather and rainfall stations are used to generate monthly rain erosivity maps. This information on land loss is a useful tool for direct analysis or modelling, and provides the basis for identifying and implementing preventive and corrective actions enshrined in the various strategic plans developed by this agency.
Open Access
Cambio temporal en la Huella Ecológica de la Región de Murcia y su uso como indicador de desertificación
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 2004) Hernández Laguna, Enrique; López Bermúdez, Francisco
Open Access
Dynamics of carbon in degraded semiarid soils : effects of organic amendments and associated soil microbial communities= Dinámica del carbono en suelos degradados de zonas semiáridas: implicación de enmiendas orgánicas y comunidades microbianas asociadas
(2015-10-05) Torres Bocero, Irene Florentina; García Izquierdo, Carlos Javier; Bastida López, Felipe; Facultad de Biología
El suelo desempeña funciones de gran importancia para el sustento de la vida en este planeta pero la desertificación producida en el mismo, en las zonas áridas o semiáridas, repercute notoriamente en una abundante pérdida de materia orgánica, y por tanto de carbono orgánico, la cual afecta negativamente a la calidad y la sostenibilidad del suelo. La recuperación del carbono orgánico del suelo hacia unos valores umbrales suficientes para poder gestionar sus funciones básicas es de vital importancia. Por este motivo, la presente Tesis Doctoral tiene como Objetivo entender el ciclo del carbono en suelos semiáridos y el desarrollo de estrategias para la restauración de estos suelos. Para ello nos hemos centrado particularmente en la capacidad que presenta este tipo de suelo para responder a fuentes de carbono exógenas derivadas de residuos vegetales, el papel que desempeña la comunidad microbiana en la degradación de estas fuentes de carbono, y su relación con los ciclos biogeoquímicos de los elementos importantes (C, N y P), con particular incidencia en el del carbono. Se maneja como Hipótesis general de trabajo de esta Tesis Doctoral el hecho de que las comunidades microbianas de suelos áridos y semiáridos tienen una limitada capacidad para el procesamiento de sustratos carbonados, a consecuencia del escaso contenido en materia orgánica que presentan habitualmente estos suelos. Con el objetivo de obtener una información completa sobre la dinámica del carbono orgánico y las enmiendas orgánicas de origen vegetal en relación con las poblaciones microbianas asociadas a su procesamiento, se abordan experimentos en condiciones controladas de laboratorio y campo. La primera parte de la Tesis (Capítulos 1, 2 y 3) se realizó en condiciones controladas de laboratorio, mediante la utilización de tres moléculas de origen vegetal de distinta complejidad: glucosa, celulosa y lignina; dichas moléculas son parte fundamental de los propios restos vegetales que entran al suelo de forma natural. Estas moléculas se utilizaron en su forma enriquecida en 13C (isótopo estable del carbono) con el objetivo de trazar a alta resolución la dinámica de estas materias orgánicas y las poblaciones microbianas implicadas en su procesamiento. En estos experimentos se aplicaron, entre otras, técnicas basadas en el análisis de la composición isotópica del CO2, fracciones hidrosolubles de C, y de sustancias húmicas, así como la composición isotópica de ácidos grasos (PLFA-SIP). Mediante este conjunto de técnicas se pudo trazar exhaustivamente el ciclo del C, evaluando su persistencia, mineralización y las poblaciones microbianas asociadas con la dinámica de estas moléculas. La segunda parte de la Tesis (Capítulos 4 y 5) se realizó a nivel de campo, lo cual representa un escenario real para el estudio de la restauración de suelos. En el Capítulo 4, se evaluó el efecto a largo plazo de enmiendas orgánicas de origen vegetal (residuos de poda fresco y compostado) y de su dosis (150 y 300 t ha-1) en las propiedades químicas, bioquímicas y microbiológicas de un suelo semiárido. Para ello se emplearon diferentes técnicas para medir los cambios en la actividad microbiana después de la adición de la materia orgánica, así como el análisis de ácidos grasos fosfolípidos y el perfil fisiológico de las comunidades microbianas para estudiar los cambios en la biomasa y estructura de la comunidad. En el Capítulo 5, se estudió el efecto que ejerce la adición enmiendas orgánicas a largo plazo en las enzimas involucradas en el ciclo del carbono bajo condiciones semiáridas, además de su influencia en la biomasa y la estructura de la comunidad microbiana. Además, se pretendió completar el conocimiento del ciclo del carbono en este tipo de suelos mediante el estudio de la diversidad de isoenzimas que presentan la celulasa y β-glucosidasa empleando la zimografía. Los cambios provocados en el tamaño de la biomasa microbiana y la estructura de la comunidad microbiana por la adición de las enmiendas fueron estudiados mediante el análisis de los ácidos grasos fosfolípidos. Haciendo una visión global de esta Tesis Doctoral, podemos concluir que los suelos semiáridos, a pesar de su avanzado estado de degradación y no recibir abundantes entradas de C orgánico, presentan una alta disponibilidad biótica para gestionar materia orgánica de origen vegetal de distinto nivel de complejidad y estabilidad. Se ha observado que sólo una pequeña fracción de la comunidad microbiana es capaz de degradar las formas más complejas de carbono, pero esta fracción microbiana es fundamental para el inicio del ciclo del carbono en suelos semiáridos y, por tanto, para la sostenibilidad de estas áreas. Además, las entradas de materia orgánica al suelo mejoran la calidad de los suelos semiáridos a largo plazo, aumentando el contenido en carbono orgánico en los mismos, favoreciendo el crecimiento de la biomasa microbiana y variando la estructura funcional de la comunidad microbiana, como una adaptación ecológica a la presencia de nuevos metabolitos en el suelo derivados de dichas materias orgánicas. Por otro lado, la adición de moléculas compuestas únicamente por carbono, no sólo ejerce un efecto sobre el ciclo del carbono si no que también influye sobre otros ciclos biogeoquímicos como el del nitrógeno o el fósforo como hemos podido ver por los cambios producidos en la actividad enzimática relacionada con estos elementos. Este hecho implica que estos ciclos no pueden considerarse independientes si no que actúan de forma conjunta para condicionar la calidad y sostenibilidad de un suelo. Soil plays a highly important role in sustaining life on earth but soil desertification, in arid and semiarid areas, negatively impacts on a significant loss of organic matter, and therefore of organic carbon, which negatively affects the quality and sustainability of the soil. In such degraded soils, it is of vital importance to restore levels of soil organic carbon to sufficient thresholds to maintain its basic functions. For this reason, the aim of this Doctoral Dissertation is to understand the carbon cycling of semiarid soils and the development of strategies for soil restoration. To reach this goal we have focused on the following topics in particular: the ability of this type of soil to respond to exogenous sources of carbon derived from plants; the role of the microbial community in the degradation of these carbon sources; and the link between these carbon sources and the biogeochemical cycling of the important elements (C, N and P), with a particular focus on carbon. The general working Hypothesis of this Doctoral Thesis is that the microbial communities in arid and semiarid soils have a limited capacity for processing carbonaceous substrates as a result of the low content of organic matter usually found in these soils. In order to obtain complete information concerning the dynamics of organic carbon and plant-derived organic amendments with respect to the microbial populations associated with processing of this organic matter, we conducted experiments in both controlled laboratory and field conditions. The first part of the thesis (Chapters 1, 2 and 3) was carried out in controlled laboratory conditions using three molecules of varying complexity: glucose, cellulose and lignin. These molecules are an essential part of the natural plant inputs to soil. We used glucose, cellulose and lignin molecules enriched with 13C (a stable isotope of carbon) in order to track the dynamics of these organic materials and the microbial populations involved in their processing in high resolution. In these experiments we applied, among other techniques, those based on the analysis of the isotopic composition of CO2, water-soluble fractions of C and of humic substances and the isotopic composition of fatty acids (PLFA-SIP). These techniques made it possible to thoroughly track the C cycle, evaluating the persistence and mineralisation of C in addition to the microbial populations associated with the dynamics of the added molecules. The second part of the thesis (Chapters 4 and 5) was carried out in the field, which represents a real setting for the study of soil restoration. In Chapter 4, we evaluated the long-term effects of plant-derived organic amendments (fresh and composted pruning waste) and of the applied dose (150 and 300 t ha-1) on the chemical, biochemical and microbiological properties of a semiarid soil. Different techniques were used to measure the changes in microbial activity after the addition of organic matter. Furthermore, phospholipid fatty acid analysis and the microbial community-level physiological profile were used to study changes in the biomass and the structure of the microbial community Finally, in the Chapter 5, we studied the long-term effect of organic amendments on the enzymes involved in the carbon cycle in semiarid conditions. In this chapter, we also evaluated the influence of organic amendments on microbial biomass and community structure. Furthermore, we aimed to complete our knowledge of the carbon cycle in semiarid soils by studying the diversity of isoenzymes exhibiting cellulase and β-glucosidase activity by zymography. Changes caused by the amendments in the biomass and the structure of the microbial community were studied by phospholipid fatty acid analysis . Taking a global picture of this Doctoral Thesis, we have reached the conclusion that semiarid soils, despite their advanced state of degradation and the fact they have not received much organic C input, nevertheless have a high level of biotic availability for handling plant-derived organic matter of different levels of complexity and stability. We observed that only a small fraction of the microbial community is able to degrade the more complex forms of carbon, but this microbial fraction is crucial for starting the carbon cycle in semiarid soils and therefore for the sustainability of semiarid areas. Moreover, adding organic matter to the soil improves the quality of semiarid soils in the long term. Indeed, organic amendments increase the content of organic carbon in such soils at long-term, favour the growth of the microbial biomass and change the functional structure of the microbial community as an ecological adaptation to the presence of new soil metabolites derived from the organic matter added. Furthermore, the addition of molecules composed solely of carbon not only has an effect on the carbon cycle but also influences other biogeochemical cycles such as the nitrogen and phosphorus cycles, which we were able to observe through changes in the enzyme activity related to these elements. This implies that these cycles cannot be considered as independent from one another but that they in fact act together to determine the quality and sustainability of a soil.
Open Access
Erosión y desertificación: implicaciones ambientales y estrategias de investigación
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 1998) López Bermúdez, Francisco; Romero Díaz, María Asunción
Open Access
Estimación de volúmenes de suelo perdido por procesos de erosión por piping. Sureste de España.
(2020-03-30) Romero Díaz, María Asunción; Plaza Martínez, J.F; Sánchez Soriano, A.; Belmonte Serrato, F.; Ruiz Sinoga, J.D; Departamento de Geografía, Universidad de Murcia, Campus de La Merced; Departamento de Geografía, Universidad de Málaga, Campus de Teatinos
Piping processes have been widely studied in many countries and regions, but especially in arid environments, on marl soils, reach a great development. We studied eight areas affected by piping, located in the Basin of Mula (Murcia), on terraced farmlands and abandoned about 40 years ago. Have been evaluated sediments mobilized by this process and erosion rates. The erosion rate per plot is 287 t/ha/year, undoubtedly, a very high value of soil losses. For this it is necessary soil conservation practices when these fields are abandoned.
Open Access
Estudio comparativo de un indicador de desertificación para zonas agrícolas semi-áridas, Cuenca de Guadalentín, Sureste de España
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 2000) Hernández Laguna, Enrique; López Bermúdez, Francisco; Romero Díaz, María Asunción; Belmonte Serrato, Francisco
Open Access
Evaluación y seguimiento multitemporal de la desertificación en Andalucía
(2020-03-30) Rodríguez Surián, M.; Moreira Madueño, J.M; Quijada Muñoz, J.; Corzo Toscano, M.; Gíl Giménez, Y.; Dirección General de Planificación e Información Ambiental. Consejería de Medio Ambiente.; Desarrollo de la Red de Información Ambiental de Andalucía.
Desertification, as a process of degradation caused by the confluence of certain arid or semiarid climatic conditions together with aggressive and barely sustainable human activities in the natural and productive environment, and also bearing in mind the current context of climate change, is an environmental phenomenon whose monitoring would seem to be advisable, both with regard to its evolution in recent years and in relation to the changes that the new climatic scenarios may determine, in order to prepare mitigation or enhancement strategies, and also to raise greater awareness of the approaching problems. The availability of historical information in a Geographic Information System referring to land uses and land cover and to climatic data, together with other environmental information (relief, soils, geology, environment management.....), as well as decade-by-decade climatic information on possible future change scenarios until 2100 in the Andalusian Environmental Information Network (REDIAM), has permitted, within the framework the European projects DesertNet I and DesertNet II, the development of models for diagnosing the areas affected by historical desertification processes and the areas of present and future incidence, while at the same time a common methodology is applied to the European context for the delimitation of degradation-sensitive areas. These models have been applied to the entire territory of Andalusia, providing a view of the temporal and spatial incidence of this phenomenon.
Open Access
Indicadores edáficos, vegetales y microbianos (ciliados colpódidos) de procesos de desertificación
(Murcia: Universidad de Murcia, Servicio de Publicaciones, 2002) Costa, Margarita; Gutiérrez, Juan Carlos; Hernando-Costa, Juan; Hernando, Isabel; Martín, Ana; Moreno, Margarita; Sin departamento asociado; Facultad de Biología
La degradación del suelo puede desembocar en procesos de deserti ficación, y ello hace necesario el desarrollo de técnicas de detección precoz de estos problemas. Sobre esta base se han estudiado las características y grado de evolución del suelo en 13 parcelas de la Comunidad de Madrid, en relación con las comunidades vegetales que soportan, el grado de evolución serial de las mismas y las espe cies colpódidas presentes. Cabría esperar que los peores suelos por taran la vegetación más degradada a la vez que una mayor riqueza de ciliados colpódidos, así como que alguna especie vegetal y/o ciliada fueran buenas indicadoras de distintos niveles de deterioro edáfico. Los resultados obtenidos son concluyentes con respecto al aspecto de cada suelo así como de la flora y vegetación que soporta, pero no lo son en cuanto a la presencia específica o diferencial de colpódidos en los más degradados.
Open Access
Las sequías y su impacto en el riesgo de desertificación de la cuenca del Segura : apuntes para la gestión y sustentabilidad del agua
(Murcia : Editora Regional de Murcia, 1997) López Bermúdez, Francisco; Sánchez Fuster, María del Carmen; Editora Regional de Murcia
Como en otras tierras mediterráneas semiáridas con déficit hídrico crónico, los traumatismos inducidos por las sequías muestran múltiples caras: pérdidas de cosechas, reducción de la superficie cultivada, problemas de abastecimiento, debilitamiento de las masas vegetales, incendios, deterioro de suelo y aguas, conflictos sociales, incremento del riesgo de desertificación, etc. Adaptarse a estas situaciones meteorológicas, desarrollar métodos y técnicas de uso y gestión de los recursos naturales al riesgo de las sequías, educar para la sequía y la aridez, se convierten en una necesidad. El riesgo podría ser minimizado con unas políticas ambiental y económica que adaptasen sus intervenciones en la aceptación y previsión de estas realidades climáticas y ambientales.
Open Access
El uso de parámetros edáficos como indicadores de riesgo de erosión. Rambla de Las Moreras, Murcia, SE de España
(2020-03-30) Romero Díaz, María Asunción; Quiñonero Rubio, J.M; Ortiz Silla, R.; Sánchez Navarro, Antonio; Fernández-Delgado Juárez, M.; Gil Vazquez, J.M.; Departamento de Geografía, Universidad de Murcia, Campus de La Merced; Centro de Edafología y Biología Aplicada del Segura (CEBAS), CSIC; Departamento de Química Agrícola, Geología y Edafología, Universidad de Murcia
Uno de los factores que más interviene en la erosión del suelo es su erodibilidad, es decir, la vulnerabilidad que el suelo tenga a la erosión. En este trabajo se estudian varios parámetros (textura, estructura, materia orgánica, profundidad, pedregosidad y cobertura vegetal) en la cuenca de la Rambla de Las Moreras (Murcia) con el objetivo de determinar si algunos de ellos pudieran servir de indicadores de riesgo de erosión. Los resultados muestran como la materia orgánica y la estabilidad de agregados pueden ser buenos indicadores de ello.

Browsing by Subject "Desertificación"

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