Los paisajes de la montaña mediterranea malagueña

El Cambio Global se refiere a todas aquellas transformaciones de gran escala que repercuten sobre el funcionamiento del sistema planetario, ya sea afectando los componentes biofísicos (agua, aire, suelos, biodiversidad), alterando el comportamiento de las comunidades y ecosistemas y/o generando efectos en los sistemas socioeconómicos, en un continuo proceso de retroalimentación, y cuya principal manifestación se evidencia en paisaje. Uno de los métodos más usados para su estudio se basa en el concepto de geosistema (método GTP), de Bertrand, vinculado directamente con el de sistema eco-geomorfológico, de Lavee, incluyendo los procesos que en el mismo concurren, como consecuencia de las relaciones que se establecen entre sus elementos (clima, relieve, suelo, vegetación, y agua), tanto a escala espacial como temporal, a lo que hemos de añadir la acción antrópica. En el sur de España, en general, y en la montaña mediterránea malagueña, en particular, ha sido definido un umbral climático con incidencia dual en el paisaje. Este trabajo propone una aproximación metodológica integrada compuesta por el análisis de la dinámica climática, los cambios espacio-temporales en ambos ámbitos, uno subhúmedo y otro semiárido, y los procesos eco-geomorfológicos y ambientales asociados a dichos cambios, en el contexto del Cambio Global, así como su repercusión mediática, con el fin de establecer los posibles escenarios futuros y desarrollar políticas territoriales de mitigación, mediante la consolidación de una economía circular.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Impact of HydroPolymers on the soil biological components in mediterranean drylands

Soil degradation affects more than 52 million ha of land in counties of the European Union. This problem is particularly serious in Mediterranean areas, where the effects of anthropogenic activities (tillage on slopes, deforestation, and pasture production) add to problems caused by prolonged periods of drought and intense and irregular rainfall. Soil microbiota can be used as an indicator of the soil healthy in degraded areas. This is because soil microbiota participates in the cycle elements and in the organic matter decomposition. All this helps to the young plants establishment and in long term protect the soils against the erosion. During dry periods in the Mediterranean areas, the lack of water entering the soil matrix leads to a loss of soil microbiological activity and it turns into a lower soil production capabilities. Under these conditions, the aim of this study was to evaluate the positive effect on soil biological components produced by an hydro absorbent polymer (Terracottem). The aim of the experiment was to evaluate the impact assessment of an hydropolymer (Terracottem) on the soil biological components. An experimental flowerpot layout was established in June 2015 and 12 variants with different amount of Terracottem were applied as follow: i) 3.0 kg.m3 ; ii) 1.5 kg.m3 and; iii) 0 kg.m3. In all the variants were tested the further additives: a) 1% of glucose, b) 50 kg N.ha-1 of Mineral nitrogen, c) 1% of Glucose + 50 kg N.ha-1 of Mineral nitrogen d) control (no additive). According to natural conditions, humidity have been kept at 15% in all the variants. During four weeks, mineral nitrogen leaching and soil respiration have been measured in each flowerplot. Respiration has been quantified four times every time while moistening containers and alkaline soda lime has been used as a sorbent. The amount of CO 2 increase has been measured with the sorbent. Leaching of mineral nitrogen has been quantified by ion exchange resins (IER). IER pouches have been placed on the bottom of each container, and after completion of the experiment mineral nitrogen leaching has been evaluated by distillation and titration method. Results from respiration have shown statistically significant differences between the variants. According to control, soil with polymers have shown significant difference when comparing respiration with independence of the additive used. CO 2 production in the first week has exceeded the sum of the outputs of the following weeks. Mineral nitrogen leaching measurement has shown statistically significant differences. The lowest leaching has been occurred in control variant, while the highest in variant containing only the addition of mineral nitrogen. Research results may conclude that the biological part of the test soil is not limited by a lack of components, the only thing that suppresses its activity is the lack of moisture. After moistening it leads to a rapid growth of soil activity, without causing the nutrients loss. Besides, Terracottem has affected soil activity neither positively nor negatively, but it considers being a suitable tool for reducing the drought impact in arid and semi-arid areas.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Organic amendments as restoration techniques in degraded arid and semiarid systems: A review

There is an increasing concern at the global scale about interrelated environmental problems such as soil degradation, desertification, erosion, and climate change impacts (Hueso-Gonzalez et al., 2014). Indiscriminate use of agro-chemicals, excessive and deep tillage, excessive irrigation, among many others factors, have largely contributed to soil degradation, particularly in arid and semi-arid areas (Lal, 2008). Soil is an essential nonrenewable resource with extremely slow formation and regeneration potential (Muñoz-Rojas et al., 2016a and c, Martínez-Murillo et al., 2016). The decline in organic matter content of many soils is becoming a major cause of soil degradation, particularly in dryland regions (Muñoz-Rojas et al., 2016b) where low soil fertility cannot maintain sustainable production in many cases (Hueso-González et al., 2015). The use of soil organic amendments is a common practice in agricultural management and land restoration that can help to improve physical and chemical soil properties, soil structure, temperature and humidity conditions, as well as nutrient contents which are essential for plant growth (Guerrero et al., 2001). Under degraded conditions, several studies have shown their benefits for improving soil physical, chemical and biological properties (Jordan et al., 2010 and 2011). However, there are many research gaps in the knowledge of the effects of climatic conditions on their application, as well as the adequate types of amendment and doses and decomposition rates, (Hueso-Gonzalez,2016). All these factors are crucial for the success in their application. Here, we review long-term experiments worldwide studying the benefits associated with the application of organic materials, particularly, in restoration of arid and semiarid ecosystems together with the possible threats and risks that can result from their use. We will specifically adress: (1) type of amended and benefits arising from their use, (2) application methods and more common doses and, (3) risk derivates for their application.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Assessment of the vegetation cover in a burned area 22-years ago using remote sensing techniques and GIS analysis (Sierra de las Nieves, South of Spain).

The study aim was to characterize the vegetation cover in a burned area 22-years ago considering the previous situation to wildfire in 1991 and the current one in 2013. The objectives were to: (i) compare the current and previous vegetation cover to widlfire; (ii) evaluate whether the current vegetation has recovered the previous cover to wildfire; and (iii) determine the spatial variability of vegetation recovery after 22-years since the wildfire. The study area is located in Sierra de las Nieves, South of Spain. It corresponds to an area affected by a wildfire in August 8th, 1991. The burned area was equal to 8156 ha. The burn severity was spatially very high. The main geographic features of the burned area are: mountainous topography (altitudes ranging from 250 m to 1500 m; slope gradient >25Remote sensing techniques and GIS analysis has been applied to achieve the objectives. Landsat 5 and Landsat 8 images were used: July 13th, 1991 and July 1st, 2013, for the previous wildfire situation and 22-years after, respectively. The 1990 CORINE land cover was also considered to map 1991 land uses prior the wildfire. Likewise, the Andalucía Regional Government wildfire historic records were used to select the burned area and its geographical limit. 1991 and 2013 land cover map were obtained by means of object-oriented classifications. Also, NDVI and PVI1 vegetation indexes were calculated and mapped for both years. Finally, some images transformations and kernel density images were applied to determine the most recovered areas and to map the spatial concentration of bare soil and pine cover areas in 1991 and 2013, respectively. According to the results, the combination of remote sensing and GIS analysis let map the most recovered areas affected by the wildfire in 1991. The vegetation indexes indicated that the vegetation cover in 2013 was still lower than that mapped just before the 1991 widlfire in most of the burned area after 22-years. This result was also confirmed by other techniques applied. Finally, the kernel density surface let identify and locate the most recovered areas of pine cover as well as those areas that still remain totally or partially uncovered (bare soil.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Enzymatic activities in a semiarid soil amended with different soil treatment: Soil quality improvement

The use of soil quality indicators may be an effective approach to assess the positive effect of the organic amendment as good restoration methods. Relying on the natural fertility of the soil, the most commonly chemical and physical parameters used to evaluate soil quality are depend to the soil biological parameters. The measurement of soil basal respiration and the mineralization of organic matter are commonly accepted as a key indicator for measuring changes to soil quality. Thus, the simultaneous measurement of various enzymes seems to be useful to evaluate soil biochemical activity and related processes. In this line, Dehydrogenase activity is widely used in evaluating the metabolic activity of soil microorganisms and to evaluate the effects caused by the addition of organic amendments. Variations in phosphatase activity, apart from indicating changes in the quantity and quality of soil phosphorated substrates, are also good indicators of soil biological status. This study assesses the effect of five soil amendments as restoration techniques for semiarid Mediterrenean ecosystems. The goal is to interpret the status of biological and chemical parameters in each treatment as soil quality indicators in degraded forests. The main objectives were to: i) analyze the effect of various organic amendments on the enzimatic activity of soil; ii) analyze the effect of the amendments on soil respiration; iii) assess the effect of these parameters on the soil chemical properties which are indicative of soil healthy; and iv) evaluated form the land management point of view which amendment could result a effective method to restore Mediterranean degraded areas. An experimental paired-plot layout was established in southern of Spain (homogeneous slope gradient: 7.5%; aspect: N170[U+F0B0]). Five amendments were applied in an experimental set of plots: straw mulching; mulch with chipped branches of Aleppo Pine (Pinus halepensis Mill.); TerraCotten hydroabsobent polymers; sewage sludge; sheep manure and; control (without amendment). Five years after the amendment addition, soil from the 12 plots was sampled. Three samples were collected from each plot (36 soil samples in total) from the soil surface, e.g. 0-10 cm, in which most soil transformations occur. Soil indicators analyzed were: i) EC; ii) pH; iii) soil organic C (SOC); iv)total Nitrogen (N); v) Carbon of microbial biomass; vi) Dehydrogenase activity; Phosphatase activity and; vii) basal respiration. According to our results, the straw mulch, pinus mulch and sewage sludge treatments helped to maintain the SOC and N at high levels, five years after the amendment addition and comparing to the control. A similar trend has been registered for the dehydrogenase activity, phosphatase activity and basal respiration. Conversely, regarding to control, when the soils were amended with polymers or manure, no significant differences in soil chemical and biological properties were found. In conclusion, from a land management standpoint, the use of pinus mulch, straw mulch and sewage sludge have been proved as a significant method to increase soil quality on Mediterranean semiarid degraded forests.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Moderate effectiveness of multiple-use protected areas as a policy tool for land conservation in Atlantic Spain in the past 30 years

Protected areas (PAs) are the main global policy instrument to avert the current biodiversity crisis by conserving important species and habitats on site. Yet important pressures around PAs and in PAs, notably land use-land cover (LULC) changes, jeopardise the conservation role of these tools. In Spain, as well as in most developed countries, land development is the main pressure on its rich biodiversity. Here, we used a semi-experimental Before-After-Control-Impact (BACI) research design with covariates to ascertain whether three categories of multiple-use PAs including Nature Parks, Sites of Community Importance (SCIs) and Special Protection Areas (SPAs) have been effective to prevent land development in Atlantic Spain between 1987 and 2017 using CORINE Land Cover (CLC) data. We split our census sample of PAs according to two geographic zones: coastal zone and inland zone, and four administrative sub-zones (regions with distinctive governance systems): Galicia, Asturias, Cantabria and the Basque Country. We created and tested the validity of three types of controls specific to each PA category: standard 5-km buffer controls, bio-physically adjusted standard controls, and bio-physically adjusted random controls across zones. Multiple-use PAs reduced, though not completely avoided, land development in all zones and sub-zones compared with controls. An effectiveness gradient among PA categories was apparent: NPs ≥ SCIs > SPAs. Coastal areas, both protected and unprotected, experienced greater land development rates than inland areas, with coastal SPAs showing poor effectiveness results. The Basque Country was the best-performing region regarding PA effectiveness, with the remaining regions showing similar PA performance results regardless of the prevailing political party in power for most of the study period. Random controls had the greatest bio-physical similarity to their cases and produced larger control areas than standard buffer controls

Impact of prescribed fire in soil properties after 5-years: experimental study.

Wildfires are a serious problem in areas with a Mediterranean climate owing to the hot summers and drought conditions providing perfect conditions for wildfire, especially when there are large amounts of fuel accumulation and continuity between forested areas. In the Mediterranean, high severity fires that spread rapidly are common and difficult to be extinguished. Thus, the identification of tools to reduce fire spread and minimize their incidence and effects is crucial. Preventive forestry is a good tool for achieving forest structures with lower amounts of fuel and a greater resistance to fire. Prescribed fire is the planned use of fire under predetermined weather, fuel and topographic parameters to achieve clearly defined objectives as controlling fire regimes by managing fuel, counteracting the disappearance of biomass-consuming land management practices and reducing the overall fire risk. Normally, prescribed fires are low intensity fires and, if managed adequately, do not cause any damage to trees, especially in Mediterranean ecosystems where trees are resilient to fire. Besides, prescribed fires usually have different impacts on soils, water resources, biodiversity, the risk-reduction of wildfires and carbon storage. Prescribed fires usually are of low/moderate severity. Because of this, the effects of prescribed fires on soils properties may vary from one site to another. The objectives of our study are to: i) determine the impact of the prescribed fire just after and ii) 5-years later with respect to natural conditions. To do this, in 2011, a prescribed fire was conducted in one experimental area of Mediterranean rangeland. After the fire, soil samples (0-5 cm of depth) were taken in burned and unburned plots in order to analyse: pH, electrical conductivity (EC), soil organic carbon, cationic exchangeable capacity (CEC), aggregate stability (AS), and hydrophobicity. The results indicated that: i) prescribed fire only had significantly effects in CEC just after the fire; 5-years after, there were no significant differences between the unburned and burned plots, but two soil properties significantly changed when burned soil samples from 2016 and 2011 were compared: EC and AS in the fraction of 0.053-0.125 mm. In general, the soil properties were not substantially modified by the prescribed fire, supporting the idea it is a very useful tool with very low impact for managing Mediterranean rangelands in order to reduce fuel accumulation and fire risk.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Optimización de la estrategia de muestreo en campos abandonados mediante funciones variogramas.

Los campos abandonados en la montaña mediterránea suelen verse afectados por la degradación del suelo y la erosión hídrica. Su sistema ecogeomorfológico es de gran variabilidad espacio-temporal y su resiliencia depende del clima y de la degradación edáfica en el momento del abandono. Esta degradación depende de factores locales por lo que la variabilidad espacial del proceso es muy elevada. Las funciones variogramas permiten conocer dicha variabilidad y la correlación espacial entre las variables y mejorar la estrategia de muestreo según dichos factores locales.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Asociación de Geógrafos Españoles. Universitat Illes Balear

Effects of fire and time in soil properties and geomorphological processes from peridotites relieves (South of Spain)

The province of Málaga is characterised by a great variety in geological and geomorphological processes affecting the Cordillera Bética relieves. One of the most impressive element is that of the peridotite relieves from which the most important one is Sierra Bermeja, though other peridotite rock outcrops can be found in other areas of the province. All together, the peridotite relieves constitute one of the largest ultramafic rock outcrop worldwide (>300 Km2). The peridotite is an igneous, hard and very dense rock composed by olivine and pyroxene. During the weathering the olivine is easily altered converting the peridotite into a clear blueish rock called serpentine accompanied by clay, and Fe and Mg oxide and hydroxide giving the typical red colour on surface. The soil developed over these relieves is called serpentine soil and characterised by exceptional limitations in nutrients (N, P, K, Ca, Mg) and high proportion of heavy metals (Cr, Ni, Co, Cu) influencing dramatically the type of vegetation covering the peridotite relieves. Historically, the peridotite relieves have been extremely deforested for grazing and wooded industry. Nowadays, all of them are covered by natural vegetation but in very different evolution stages: from very dense coniferous forest to shrubland covering soils scarcely. Apart from the deforestation, this is consequence of wildfires: in fact, the most extensive wildfires in the province of Málaga have mainly occurred over peridotite relieves. Because of this, their eco-geomorphological features in vegetation, soils and geomorphic processes, can be different from one site to another. The aim of this study is a preliminary characterization of the eco-geomorphological conditions from peridotites relieves affected by fire and, namely, evaluating the impact of fire and time in some soil properties and geomorphic features. To do this, several sites from peridotites relieves affected by fire since 1991 until 2017 were selected. In all of them, a field survey was conducted and consisted in the inventory of geomorphic processes associated to water erosion as well as the soil sampling at 0.5 cm of depth. In laboratory, the following soil properties were analysed: gravels, texture, organic matter content, pH, electrical conductivity, cationic exchangeable capacity, hydrophobicity, and aggregate stability. The results show the impact of fire and the eco-geomorphological evolution of the peridotites sites affected by wildfires in time. Nevertheless, more research are needed in order to achieve a better comprehension of the eco-geomorphology in this type of relieves impacted by wildfires considering the fire severity.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Available water modifications by topsoil treatments under mediterranean semiarid conditions: afforestation plan

During dry periods in the Mediterranean area, the lack of water entering the soil matrix reduces organic contribu- tions to the soil. These processes lead to reduced soil fertility and soil vegetation recovery which creates a positive feedback process that can lead to desertification. Restoration of native vegetation is the most effective way to regenerate soil health, and control runoff and sediment yield. In Mediterranean areas, after a forestry proposal, it is highly common to register a significant number of losses for the saplings that have been introduced due to the lack of rainfall. When no vegetation is established, organic amendments can be used to rapidly protect the soil surface against the erosive forces of rain and runoff. In this study we investigated the hydrological effects of five soil treatments in relation to the temporal vari- ability of the available water for plants. Five amendments were applied in an experimental set of plots: straw mulching; mulch with chipped branches of Aleppo Pine (Pinus halepensis L.); TerraCotten hydroabsobent polymers; sewage sludge; sheep manure and control. Plots were afforested following the same spatial pattern, and amendments were mixed with the soil at the rate 10 Mg ha-1. In control plots, during June, July, August and September, soils were registered below the wilting point, and therefore, in the area of water unusable by plants. These months were coinciding with the summer mediter- ranean drought. This fact justifies the high mortality found on plants after the seeding plan. Similarly, soils have never exceeded the field capacity value measured for control plots. Conversely, in the straw and pinus mulch, soils were above the wilting point during a longer time than in control plots. Thus, the soil moisture only has stayed below the 4.2 pF suction in July, July and August. Regarding the amount of water available was also higher, especially in the months of December, January and February. However, the field capacity value measured has not showed any differences regarding the control. For these treatments, the survival sapling rates measured were the highest. Sludge, manure and polymers showed a moisture retention capacity slightly more limited than straw and pinus mulch. Likewise, it has been found that the area of usable water by plants was also lower, especially during the months of January and February. This situation is especially sharpened in plots amended with manure. In this treatment, the upper part of the soil profile was below the wilting point for six months a year (from April to August). For this treatment, the survival sapling rates measured were the lowest. In conclusion, from a land management standpoint, the pinus and straw mulch treatments have been shown as effective methods reducing water stress for plants. In this research, mulching has been proved as a significant method to reduce the mortality sapling rates during the mediterranean summer drought.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech