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Dr. Jaime Martínez-Valderrama
Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef”, Universidad de Alicante

Basic Info


Research Keywords & Expertise

0 System Dynamics Model
0 Rangelands management
0 Desertification
0 Groundwater Investigation
0 Climate change and water resources

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Desertification
Climate change and water resources
System Dynamics Model

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Short Biography

Jaime Martínez-Valderrama is a PhD Engineer in Agriculture Engineering specialized in Desertification and Global Change with 20 years of experience in drylands: Southern Europe, Africa, Asia and South America. Since 2019 he has been working as a postdoctoral researcher at the University of Alicante. He has participated in more than 20 research projects and has several publications in high impact journals. His main experience is related to the use of system dynamics models in the study of groundwater and rangelands.

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Editorial
Published: 10 July 2021 in Scientific Programming
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This special issue delivers a platform in which researchers expose intersections between algorithm design, software platforms, and hardware architectures to deal with emerging challenges in the scientific field of management of water and water-dependent resources. Since the call for papers was announced in June 2019, this special issue has received 10 manuscripts. After a rigorous review process, 6 papers have been finally accepted for publication. Published papers deal with groundwater quality monitoring, coastal groundwater-dependent irrigation agriculture, desertification risk, water recovery from tailings, future scenarios of water resources, and vulnerability of coastal aquifers.

ACS Style

Francisco J. Alcalá; Jaime Martínez-Valderrama; Francisco Gomáriz-Castillo; Carlos G. Hernández; José M. Cecilia. Scientific Programming Tools for Water Management. Scientific Programming 2021, 2021, 1 -3.

AMA Style

Francisco J. Alcalá, Jaime Martínez-Valderrama, Francisco Gomáriz-Castillo, Carlos G. Hernández, José M. Cecilia. Scientific Programming Tools for Water Management. Scientific Programming. 2021; 2021 ():1-3.

Chicago/Turabian Style

Francisco J. Alcalá; Jaime Martínez-Valderrama; Francisco Gomáriz-Castillo; Carlos G. Hernández; José M. Cecilia. 2021. "Scientific Programming Tools for Water Management." Scientific Programming 2021, no. : 1-3.

Journal article
Published: 24 March 2021 in Journal of Arid Environments
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This essay approaches land degradation by targeting its ultimate thermodynamic causes, rather than its immediate environmental consequences. The objective is to make some propositions that could help understand the essence of the process, and contribute to a theoretical framework to be developed. These propositions are: 1. Human populations are an ecosystem component, not an external driver. 2. Coupled Human and Natural Systems (CHANS) tend to increase their overall complexity over time. CHANS complexity cannot feasibly be managed. 3. CHANS are made up of two types of subsystems, a consuming Foreland (FL) consisting of the human population, and a producing Backland (BL) in its environment. 4. The FL maintains its order at the expense of simplifying the BL, which becomes an entropy sink. This is the essence of ecological degradation, which is inherent to CHANS persistence. 5. Land degradation is an ecological state, not a landscape type. Hence it should be assessed within a complete range of states of ecological maturity. 6. Land use creates degradation proportional to the simplification of the ecosystems involved. Such degradation can be defined as a decrease in exergy, and results in loss of management options. Three associated corollaries are: a) A more effective target may be to regulate rather than attempt to eliminate land degradation; b) Monitoring ecological degradation trajectories may be more effective than assessing land degradation states; c) Land degradation can be decreased by maximizing the potential for interconversion between land uses.

ACS Style

Gabriel del Barrio; Maria E. Sanjuán; Jaime Martínez-Valderrama; Alberto Ruiz; Juan Puigdefábregas. Land degradation means a loss of management options. Journal of Arid Environments 2021, 189, 104502 .

AMA Style

Gabriel del Barrio, Maria E. Sanjuán, Jaime Martínez-Valderrama, Alberto Ruiz, Juan Puigdefábregas. Land degradation means a loss of management options. Journal of Arid Environments. 2021; 189 ():104502.

Chicago/Turabian Style

Gabriel del Barrio; Maria E. Sanjuán; Jaime Martínez-Valderrama; Alberto Ruiz; Juan Puigdefábregas. 2021. "Land degradation means a loss of management options." Journal of Arid Environments 189, no. : 104502.

Journal article
Published: 17 February 2021 in Land
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The stabling of livestock farming implies changes in both local ecosystems (regeneration of forest stands via reduced grazing) and those located thousands of kilometers away (deforestation to produce grain for feeding livestock). Despite their importance, these externalities are poorly known. Here we evaluated how the intensification and confinement of livestock in Spain has affected forest surface changes there and in South America, the largest provider of soybeans for animal feed to the European Union. For this purpose, we have used Spanish soybean import data from Brazil, Paraguay and Argentina and a land condition map of Spain. The area of secondary forest in Spain that has regenerated as a result of livestock stabling has been ~7000 kha for the decade 2000–2010. In the same period, 1220 kha of high value South American ecosystems (e.g. Chaco dry Forest, Amazonian rainforest or Cerrado) have been deforested. While these figures may offer a favorable interpretation of the current industrial livestock production, it is not possible to speak of compensation when comparing the destruction of well-structured ecosystems, such as primary South American forests, with the creation of secondary forest landscapes in Spain, which are also prone to wildfires. Our results highlight how evaluating land use change policies at a national or regional level is an incomplete exercise in our highly telecoupled and globalized world.

ACS Style

Jaime Martínez-Valderrama; María Sanjuán; Gabriel del Barrio; Emilio Guirado; Alberto Ruiz; Fernando Maestre. Mediterranean Landscape Re-Greening at the Expense of South American Agricultural Expansion. Land 2021, 10, 204 .

AMA Style

Jaime Martínez-Valderrama, María Sanjuán, Gabriel del Barrio, Emilio Guirado, Alberto Ruiz, Fernando Maestre. Mediterranean Landscape Re-Greening at the Expense of South American Agricultural Expansion. Land. 2021; 10 (2):204.

Chicago/Turabian Style

Jaime Martínez-Valderrama; María Sanjuán; Gabriel del Barrio; Emilio Guirado; Alberto Ruiz; Fernando Maestre. 2021. "Mediterranean Landscape Re-Greening at the Expense of South American Agricultural Expansion." Land 10, no. 2: 204.

Journal article
Published: 05 January 2021 in Sensors
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Vegetation generally appears scattered in drylands. Its structure, composition and spatial patterns are key controls of biotic interactions, water, and nutrient cycles. Applying segmentation methods to very high-resolution images for monitoring changes in vegetation cover can provide relevant information for dryland conservation ecology. For this reason, improving segmentation methods and understanding the effect of spatial resolution on segmentation results is key to improve dryland vegetation monitoring. We explored and analyzed the accuracy of Object-Based Image Analysis (OBIA) and Mask Region-based Convolutional Neural Networks (Mask R-CNN) and the fusion of both methods in the segmentation of scattered vegetation in a dryland ecosystem. As a case study, we mapped Ziziphus lotus, the dominant shrub of a habitat of conservation priority in one of the driest areas of Europe. Our results show for the first time that the fusion of the results from OBIA and Mask R-CNN increases the accuracy of the segmentation of scattered shrubs up to 25% compared to both methods separately. Hence, by fusing OBIA and Mask R-CNNs on very high-resolution images, the improved segmentation accuracy of vegetation mapping would lead to more precise and sensitive monitoring of changes in biodiversity and ecosystem services in drylands.

ACS Style

Emilio Guirado; Javier Blanco-Sacristán; Emilio Rodríguez-Caballero; Siham Tabik; Domingo Alcaraz-Segura; Jaime Martínez-Valderrama; Javier Cabello. Mask R-CNN and OBIA Fusion Improves the Segmentation of Scattered Vegetation in Very High-Resolution Optical Sensors. Sensors 2021, 21, 320 .

AMA Style

Emilio Guirado, Javier Blanco-Sacristán, Emilio Rodríguez-Caballero, Siham Tabik, Domingo Alcaraz-Segura, Jaime Martínez-Valderrama, Javier Cabello. Mask R-CNN and OBIA Fusion Improves the Segmentation of Scattered Vegetation in Very High-Resolution Optical Sensors. Sensors. 2021; 21 (1):320.

Chicago/Turabian Style

Emilio Guirado; Javier Blanco-Sacristán; Emilio Rodríguez-Caballero; Siham Tabik; Domingo Alcaraz-Segura; Jaime Martínez-Valderrama; Javier Cabello. 2021. "Mask R-CNN and OBIA Fusion Improves the Segmentation of Scattered Vegetation in Very High-Resolution Optical Sensors." Sensors 21, no. 1: 320.

Journal article
Published: 23 December 2020 in Agricultural Systems
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Rangeland productivity is strongly conditioned by the amount and temporal distribution of precipitation. Thus, the worsening of droughts with climate change could be a serious threat to their existence. This paper presents a modelling study aimed at evaluating the sensitivity of a valuable type of commercial rangelands, namely Spanish dehesas, to increases in the frequency and intensity of droughts driven by climate change. The assessment consisted in a multi-way ANOVA carried out on the basis of 5400 simulations of a multidisciplinary integrated model. It included two blocking factors linked to climate change scenarios, namely Representative Concentration Pathway and downscaling method, and two treatment factors, namely return period and severity of droughts. The levels of all factors were included as part of the simulation scenarios. The response variables constituted a summary of model's behaviour throughout one simulation. They were average profits per farmer and average stocking rate, both calculated over the entire simulation period, and remaining soil depth at the end of the simulation. The effects of the treatment factors on the response variables were small for all blocks, thereby suggesting that the sensitivity, and thus the vulnerability, of Spanish dehesas to the worsening of droughts would be low under climate change. Farmers were defined as conservative in all model simulations, that is, they minimized changes in the size of their herds and bought supplementary feed to meet shortfalls in livestock feed unless it was excessively expensive. Thus, we conclude that this group strategy could explain the adaptive capacity of Spanish dehesas to droughts. This paper shows that multidisciplinary integrated models are valuable learning tools to acquire insights into the relationships between climate, ecologic and socio-economic factors. Although there is a recurrent call for holistic studies, they are still rare in the rangeland literature. Hopefully, this paper will motivate some researchers to consider this approach.

ACS Style

J. Martínez-Valderrama; J. Ibáñez; M.A. Ibáñez; F.J. Alcalá; M.E. Sanjuán; A. Ruiz; G. del Barrio. Assessing the sensitivity of a Mediterranean commercial rangeland to droughts under climate change scenarios by means of a multidisciplinary integrated model. Agricultural Systems 2020, 187, 103021 .

AMA Style

J. Martínez-Valderrama, J. Ibáñez, M.A. Ibáñez, F.J. Alcalá, M.E. Sanjuán, A. Ruiz, G. del Barrio. Assessing the sensitivity of a Mediterranean commercial rangeland to droughts under climate change scenarios by means of a multidisciplinary integrated model. Agricultural Systems. 2020; 187 ():103021.

Chicago/Turabian Style

J. Martínez-Valderrama; J. Ibáñez; M.A. Ibáñez; F.J. Alcalá; M.E. Sanjuán; A. Ruiz; G. del Barrio. 2020. "Assessing the sensitivity of a Mediterranean commercial rangeland to droughts under climate change scenarios by means of a multidisciplinary integrated model." Agricultural Systems 187, no. : 103021.

Journal article
Published: 30 November 2020 in Forest Ecology and Management
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This study quantifies patchiness of eight types of zonal forests in three biogeographic regions of mainland Spain (Atlantic, Alpine and Mediterranean) which together occupy 1,726,578 ha. Their dominant species and European Habitat Type codes (EU Directive 92/43 EEC) are: Fagus sylvatica (9120, 9130 and 9150), Quercus robur and Q. pyrenaica (9230), Q. suber (9330), Pinus uncinata (9430), P. nigra ssp. salzmannii (9530) and P. pinea (subset of 9540). We applied the Korcak’s exponent B, which describes a hyperbolic relationship between the cumulative frequency of the number of patches and their sizes. The objectives were: 1) detect possible patch size intervals in which B varies significantly, explicitly identifying area thresholds, and 2) contribute to development of a robust forest mass fragmentation indicator. Exponent B was found by segmented regression analysis. The vector data were extracted from a filtered version of the Spanish Forest Map 1:50,000 (1997–2006). After validating the procedure by applying it to a previously published dataset, we found that in all cases the patch size range could be split into two significant intervals around relatively small threshold areas of 27–101 ha. In the one on the left, the rate at which relatively large patches become less abundant was always very slow (B = 0.017–0.094). After this threshold had been passed, the rate increased abruptly (B = 1.100–2.590). Both this high fragmentation and its lack of parsimony were unexpected in zonal forest types. General interpretations converge to the coexistence of forest patches of different ages due to human pressure events.

ACS Style

Gabriel del Barrio; Helios Sainz; Maria E. Sanjuán; Rut Sánchez de Dios; Jaime Martínez-Valderrama; Alberto Ruiz. Abrupt fragmentation thresholds of eight zonal forest types in mainland Spain. Forest Ecology and Management 2020, 482, 118788 .

AMA Style

Gabriel del Barrio, Helios Sainz, Maria E. Sanjuán, Rut Sánchez de Dios, Jaime Martínez-Valderrama, Alberto Ruiz. Abrupt fragmentation thresholds of eight zonal forest types in mainland Spain. Forest Ecology and Management. 2020; 482 ():118788.

Chicago/Turabian Style

Gabriel del Barrio; Helios Sainz; Maria E. Sanjuán; Rut Sánchez de Dios; Jaime Martínez-Valderrama; Alberto Ruiz. 2020. "Abrupt fragmentation thresholds of eight zonal forest types in mainland Spain." Forest Ecology and Management 482, no. : 118788.

Comment
Published: 11 November 2020 in Nature Food
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Food systems are driven by incentives that often lead to food being discarded before entering the market and to the degradation of natural resources. Vegetable production in the water-scarce province of Almería, Spain, illustrates this and highlights the need for policies ensuring ethical and environmental sustainability standards.

ACS Style

Jaime Martínez-Valderrama; Emilio Guirado; Fernando T. Maestre. Discarded food and resource depletion. Nature Food 2020, 1, 660 -662.

AMA Style

Jaime Martínez-Valderrama, Emilio Guirado, Fernando T. Maestre. Discarded food and resource depletion. Nature Food. 2020; 1 (11):660-662.

Chicago/Turabian Style

Jaime Martínez-Valderrama; Emilio Guirado; Fernando T. Maestre. 2020. "Discarded food and resource depletion." Nature Food 1, no. 11: 660-662.

Journal article
Published: 11 August 2020 in Land
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From its origins, the concept of desertification has been controversial. The prevailing confusion between two desertification visions, one that considers it as the expansion of deserts and another that emphasizes its anthropogenic component, has been transferred to society. Here we illustrate misunderstandings about desertification using a very illustrative case from the Tabernas-Sorbas Basin (Almeria, Spain), where striking badlands that are often used as an image of desertification coexist with an intensive olive agriculture that is irreversibly deteriorating the only oasis in continental Europe (Los Molinos spring). The olive tree is a traditional Mediterranean dryland crop and until the 1950s only about 200 ha were irrigated in this area. However, the profitability of the crop has caused irrigation to expand to 4400 ha in the last two decades. The process of intensification has been reinforced giving way to super-intensive irrigation, which involves going from 210 to 1550 trees/ha, which in a few years already occupies more than 1500 ha. The effects on the water balance of the aquifer feeding these crops have been severe, and the flow of the Los Molinos spring has gone from more than 40 L/s for the period 1970–2000 to the current 7.28 L/s. Unraveling the mechanisms of land degradation and its main drivers are the first step to propose management actions to achieve a more sustainable use of resources and to combat desertification.

ACS Style

Jaime Martínez-Valderrama; Emilio Guirado; Fernando Maestre. Unraveling Misunderstandings about Desertification: The Paradoxical Case of the Tabernas-Sorbas Basin in Southeast Spain. Land 2020, 9, 269 .

AMA Style

Jaime Martínez-Valderrama, Emilio Guirado, Fernando Maestre. Unraveling Misunderstandings about Desertification: The Paradoxical Case of the Tabernas-Sorbas Basin in Southeast Spain. Land. 2020; 9 (8):269.

Chicago/Turabian Style

Jaime Martínez-Valderrama; Emilio Guirado; Fernando Maestre. 2020. "Unraveling Misunderstandings about Desertification: The Paradoxical Case of the Tabernas-Sorbas Basin in Southeast Spain." Land 9, no. 8: 269.

Research article
Published: 29 June 2020 in Scientific Programming
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Desertification is a major global environmental issue exacerbated by climate change. Strategies to combat desertification include prevention which seeks to reverse the process before the system reaches the stable desertified state. One of these initiatives is to implement early warning tools. This paper presents SAT (the Spanish acronym for Early Warning System), a decision support system (DSS), for assessing the risk of desertification in Spain, where 20% of the land has already been desertified and 1% is in active degradation. SAT relies on three versions of a Generic Desertification Model (GDM) that integrates economics and ecology under the predator-prey paradigm. The models have been programmed using Vensim, a type of software used to build and simulate System Dynamics (SD) models. Through Visual Basic programming, these models are operated from the Excel environment. In addition to the basic simulation exercises, specially designed tools have been coupled to assess the risk of desertification and determine the ranking of the most influential factors of the process. The users targeted by SAT are government land-use planners as well as desertification experts. SAT tool is implemented for five case studies, each one of them representing a desertification syndrome identified in Spain. Given the general nature of the tool and the fact that all United Nations Convention to Combat Desertification (UNCCD) signatory countries are committed to developing their National Plans to Combat Desertification (NPCD), SAT could be exported to regions threatened by desertification and expanded to cover more case studies.

ACS Style

Jaime Martínez-Valderrama; Javier Ibáñez; Francisco J. Alcalá; Silvio Martínez. SAT: A Software for Assessing the Risk of Desertification in Spain. Scientific Programming 2020, 2020, 1 -12.

AMA Style

Jaime Martínez-Valderrama, Javier Ibáñez, Francisco J. Alcalá, Silvio Martínez. SAT: A Software for Assessing the Risk of Desertification in Spain. Scientific Programming. 2020; 2020 ():1-12.

Chicago/Turabian Style

Jaime Martínez-Valderrama; Javier Ibáñez; Francisco J. Alcalá; Silvio Martínez. 2020. "SAT: A Software for Assessing the Risk of Desertification in Spain." Scientific Programming 2020, no. : 1-12.

Comment
Published: 22 June 2020 in Nature Sustainability
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The current definition of desertification excludes hyper-arid zones given their lack of economic activity. However, the 101 million people living there, ongoing land degradation associated with the use of groundwater for intensive agriculture and climate-change-induced aridity call for a revision of this definition.

ACS Style

Jaime Martínez-Valderrama; Emilio Guirado; Fernando T. Maestre. Desertifying deserts. Nature Sustainability 2020, 3, 572 -575.

AMA Style

Jaime Martínez-Valderrama, Emilio Guirado, Fernando T. Maestre. Desertifying deserts. Nature Sustainability. 2020; 3 (8):572-575.

Chicago/Turabian Style

Jaime Martínez-Valderrama; Emilio Guirado; Fernando T. Maestre. 2020. "Desertifying deserts." Nature Sustainability 3, no. 8: 572-575.

Research article
Published: 14 May 2020 in Scientific Programming
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In the framework of coastal groundwater-dependent irrigation agriculture, modelling becomes indispensable to know how this renewable resource responds to complex (usually not conceptualized nor monitored) biophysical, social, and economic interactions. Friendly user interfaces are essential to involve nonmodeling experts in exploiting and improving models. Decision support systems (DSS) are software systems that integrate models, databases, or other decision aids and package them in a way that decision makers can use. This paper addresses these two issues: firstly with the implementation of a System Dynamics (SD) model in Vensim software that considers the integration of hydrological, agronomic, and economic drivers and secondly with the design of a Venapp, push-button interfaces that allow users access to a Vensim model without going through the Vensim modelling environment. The prototype designed, the AQUACOAST tool, gives an idea of the possibilities of this type of models to identify and analyze the impact of apparently unrelated factors such as the prices of cultivated products, subsidies or exploitation costs on the advance of saltwater intrusion, and the great threat to coastal groundwater-dependent irrigation agriculture systems.

ACS Style

Jaime Martínez-Valderrama; Javier Ibáñez; Francisco J. Alcalá. AQUACOAST: A Simulation Tool to Explore Coastal Groundwater and Irrigation Farming Interactions. Scientific Programming 2020, 2020, 1 -20.

AMA Style

Jaime Martínez-Valderrama, Javier Ibáñez, Francisco J. Alcalá. AQUACOAST: A Simulation Tool to Explore Coastal Groundwater and Irrigation Farming Interactions. Scientific Programming. 2020; 2020 ():1-20.

Chicago/Turabian Style

Jaime Martínez-Valderrama; Javier Ibáñez; Francisco J. Alcalá. 2020. "AQUACOAST: A Simulation Tool to Explore Coastal Groundwater and Irrigation Farming Interactions." Scientific Programming 2020, no. : 1-20.

Journal article
Published: 02 February 2020 in Diversity
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The honey badger (Mellivora capensis) is a medium-sized carnivore distributed throughout Africa to the Arabian Peninsula, Iran, Turkmenistan, and India. However, available information on its ecology is very scarce. We studied its feeding ecology in the remote north-western Sahara Desert, based on the contents of 125 fecal samples collected during large scale surveys. Samples were confirmed to belong to honey badgers by camera trapping and genetic analyses. Barely 18 prey species were detected. The diet primarily consisted of spiny-tailed lizards Uromastyx nigriventris and U. dispar (72% of volume in scats). Secondary prey items were arthropods (14%), small mammals (8%), other reptiles (4%), and eggs (0.8%). Some small geographic and temporal differences were related to the consumption of beetle larvae and rodents as alternative prey. Camera trapping and distance sampling surveys showed that diel activities did not overlap between honey badgers and spiny-tailed lizards, suggesting that badgers primarily dig lizards out of their burrows when inactive. Consumption of spiny lizards by other sympatric meso-carnivores was < 6.1% of occurrence (223 analyzed scats); the honey badger behaved as a trophic specialist in the Sahara, probably thanks to exclusive anatomical adaptations for digging. We discuss the role of this circumstance minimizing the exploitative competition, which could allow the survival of this large mustelid in this low productive and highly competitive environment.

ACS Style

Jose María Gil-Sánchez; Francisco Javier Herrera Sánchez; Javier Rodríguez-Siles; Juan Manuel Sáez; Miguel Ángel Díaz-Portero; Ángel Arredondo; Begoña Álvarez; Inmaculada Cancio; Jesús De Lucas; Salvador Castillo; Emil McCain; Joaquín Pérez; Gerardo Valenzuela; Jaime Martínez Valderrama; Jesús Bautista; Carlos Sarabia; Jennifer Leonard; Mariola Sánchez-Cerdá; Emilio Virgós; Abdeljebbar Qninba; Gil- Sánchez; Herrera- Sánchez. Feeding Specialization of Honey Badgers in the Sahara Desert: A Trial of Life in a Hard Environment. Diversity 2020, 12, 59 .

AMA Style

Jose María Gil-Sánchez, Francisco Javier Herrera Sánchez, Javier Rodríguez-Siles, Juan Manuel Sáez, Miguel Ángel Díaz-Portero, Ángel Arredondo, Begoña Álvarez, Inmaculada Cancio, Jesús De Lucas, Salvador Castillo, Emil McCain, Joaquín Pérez, Gerardo Valenzuela, Jaime Martínez Valderrama, Jesús Bautista, Carlos Sarabia, Jennifer Leonard, Mariola Sánchez-Cerdá, Emilio Virgós, Abdeljebbar Qninba, Gil- Sánchez, Herrera- Sánchez. Feeding Specialization of Honey Badgers in the Sahara Desert: A Trial of Life in a Hard Environment. Diversity. 2020; 12 (2):59.

Chicago/Turabian Style

Jose María Gil-Sánchez; Francisco Javier Herrera Sánchez; Javier Rodríguez-Siles; Juan Manuel Sáez; Miguel Ángel Díaz-Portero; Ángel Arredondo; Begoña Álvarez; Inmaculada Cancio; Jesús De Lucas; Salvador Castillo; Emil McCain; Joaquín Pérez; Gerardo Valenzuela; Jaime Martínez Valderrama; Jesús Bautista; Carlos Sarabia; Jennifer Leonard; Mariola Sánchez-Cerdá; Emilio Virgós; Abdeljebbar Qninba; Gil- Sánchez; Herrera- Sánchez. 2020. "Feeding Specialization of Honey Badgers in the Sahara Desert: A Trial of Life in a Hard Environment." Diversity 12, no. 2: 59.

Journal article
Published: 01 February 2020 in Science of The Total Environment
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This paper presents an integrated modelling study aimed at exploring the possible effects of drivers of change in commercial natural annual grasslands. We consider drivers as factors that affect the rangeland but are not affected by it. Thus, the stocking rate is not treated as a driver, but as an endogenous factor ultimately determined by drivers. This approach, which call for integrated multidisciplinary studies, is rare in the rangeland literature. We try to alleviate this lack by presenting and utilizing a novel multidisciplinary integrated system-dynamics model (108 equations) which represents an area of privately owned extensive farms, its farmers (their numbers and decisions), herds or flocks, herbage production, soil erosion and the linked local markets. By means of a global sensitivity analysis of this model we evaluated the sensitivities of key endogenous factors to the same percentage variation in 70 factors, including economic and climate drivers. The analysis considered the behaviours of 288,000 variants of the modelled system, each under a different 300-year driver scenario. We found that the environmental component of the model was almost exclusively sensitive to biophysical factors, whereas the socio-economic component was almost exclusively sensitive to socio-economic factors, despite the model takes account of key feedbacks connecting both components. Our results suggest that cautiously-managed commercial natural grasslands could socially and economically cope with climate change, especially in a scenario of rising prices of animal products, and also that, even though stocking rates would increase due to an increase in the demand for livestock products, the main threat to the provision of ecosystem services in the studied system would be climate change.

ACS Style

Javier Ibáñez; Jaime Martínez-Valderrama; Joaquín Francisco Lavado Contador; Manuel Pulido Fernández. Exploring the economic, social and environmental prospects for commercial natural annual grasslands by performing a sensitivity analysis on a multidisciplinary integrated model. Science of The Total Environment 2020, 705, 135860 .

AMA Style

Javier Ibáñez, Jaime Martínez-Valderrama, Joaquín Francisco Lavado Contador, Manuel Pulido Fernández. Exploring the economic, social and environmental prospects for commercial natural annual grasslands by performing a sensitivity analysis on a multidisciplinary integrated model. Science of The Total Environment. 2020; 705 ():135860.

Chicago/Turabian Style

Javier Ibáñez; Jaime Martínez-Valderrama; Joaquín Francisco Lavado Contador; Manuel Pulido Fernández. 2020. "Exploring the economic, social and environmental prospects for commercial natural annual grasslands by performing a sensitivity analysis on a multidisciplinary integrated model." Science of The Total Environment 705, no. : 135860.

Journal article
Published: 01 July 2018 in Science of The Total Environment
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In a previous paper, the Amtoudi Oasis, a remote area in the northern Sahara in southern Morocco, was chosen to model the dynamics of groundwater-dependent economics under different scenarios of water availability, both the wet 2009–2010 and the average 2010–2011 hydrological years. Groundwater imbalance was reflected by net aquifer recharge (R) less than groundwater allotment for agriculture and urban uses in the average year 2010–2011. Three key groundwater sustainability issues from the hydrologic perspective were raised for future research, which are addressed in this paper. Introducing a feasible methodology for groundwater resource modelling for sustainable use in sparse-data drylands, this paper updates available databases, compiles new databases, and introduces new formulations to: (1) refine the net groundwater balance (W) modelling for years 2009–2010 and 2010–2011, providing the magnitude of net lateral inflow from adjacent formations (RL), the largest R component contributing to the oasis; (2) evaluate the non-evaporative fraction of precipitation (P) (B) from 1973 onward as a proxy of the potential renewable water resource available for use; and (3) define the critical balance period for variables to reach a comparable stationary condition, as prerequisite for long-term modelling of W. RL was about 0.07-fold P and 0.85-fold R. Historical yearly B-to-P ratios were 0.02 for dry, 0.04 for average, and 0.07 for wet hydrological years; the average yearly P being 124 mm. A critical 17-year balance period with stable relative error below 0.1 was defined from the 44-year P and B time-series statistical study. This is the monitoring period proposed for the stationary evaluation of the variables involved in the long-term modelling of W. This paper seeks to offer a feasible methodology for groundwater modelling addressed for planning sustainable water policies in sparse-data drylands.

ACS Style

Francisco J. Alcalá; Manuel Martín-Martín; Francesco Guerrera; Jaime Martínez-Valderrama; Pedro Robles-Marín. A feasible methodology for groundwater resource modelling for sustainable use in sparse-data drylands: Application to the Amtoudi Oasis in the northern Sahara. Science of The Total Environment 2018, 630, 1246 -1257.

AMA Style

Francisco J. Alcalá, Manuel Martín-Martín, Francesco Guerrera, Jaime Martínez-Valderrama, Pedro Robles-Marín. A feasible methodology for groundwater resource modelling for sustainable use in sparse-data drylands: Application to the Amtoudi Oasis in the northern Sahara. Science of The Total Environment. 2018; 630 ():1246-1257.

Chicago/Turabian Style

Francisco J. Alcalá; Manuel Martín-Martín; Francesco Guerrera; Jaime Martínez-Valderrama; Pedro Robles-Marín. 2018. "A feasible methodology for groundwater resource modelling for sustainable use in sparse-data drylands: Application to the Amtoudi Oasis in the northern Sahara." Science of The Total Environment 630, no. : 1246-1257.

Journal article
Published: 07 April 2018 in Journal of Environmental Management
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This paper presents a modelling study that evaluated the global effectiveness of a range of group decision-making strategies for commercial farming areas in rangelands affected by temporal variations in forage production. The assessment utilised an integrated system dynamics model (86 equations) to examine the broad and long-term group decision outcomes. This model considers aspects usually neglected in related studies, such as the dynamics of the main local prices, the dynamics of the number of active farmers, the supplementary feeding of livestock, and certain behavioural traits of farmers and traders. The assessment procedure was based on an analysis of the outcomes of the model under 330,000 simulation scenarios. The results indicated that only if all the farmers in an area are either opportunistic or conservative that is, are either responsive or unresponsive to expected profits, the exploitation of the grazing resources were optimal in some senses. A widespread opportunism proved optimal only from an economic viewpoint. However, it is very unlikely that most of the farmers would agree to be opportunistic in practice. By contrast, a widespread conservatism, which in principle is perfectly feasible, proved optimal from economic, social, and ecological perspectives. Notably, it was found that the presence of a relatively small number of opportunistic farmers would suffice to considerably reduce the economic results of widespread conservatism.

ACS Style

Javier Ibáñez; Jaime Martínez-Valderrama. Global effectiveness of group decision-making strategies in coping with forage and price variabilities in commercial rangelands: A modelling assessment. Journal of Environmental Management 2018, 217, 531 -541.

AMA Style

Javier Ibáñez, Jaime Martínez-Valderrama. Global effectiveness of group decision-making strategies in coping with forage and price variabilities in commercial rangelands: A modelling assessment. Journal of Environmental Management. 2018; 217 ():531-541.

Chicago/Turabian Style

Javier Ibáñez; Jaime Martínez-Valderrama. 2018. "Global effectiveness of group decision-making strategies in coping with forage and price variabilities in commercial rangelands: A modelling assessment." Journal of Environmental Management 217, no. : 531-541.

Journal article
Published: 09 August 2017 in Science of The Total Environment
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This work illustrates the application of a simulation model to analyse how swiftly large-scale land-use changes can drive broad territories to collapse. In this sense, the economic needs of a population should not clash with the natural environment but rather be reconciled with it. Abundant literature deals with the integration of socioeconomic drivers, ecological aspects, farming management, and climatology related to Algerian rangeland degradation. The present study seeks to compare the time course of Alfa grass biomass and the livestock raised on these distinctive rangelands under two different land-use strategies. The traditional one has nomads as the main inhabitants of these lands. For centuries, their strategy for alleviating pressure on resources was to move from one area to other. The more recent sedentary land-use leads to overgrazing supported by the massive use of cheap supplemental feed. Additionally, the model was used as a platform to launch scenarios for sustainable land-use management under a competitive market-economy. A key finding for preserving grazing resources was the increment of supplemental feed prices, which is compatible with stocking rates higher than the historical ones.

ACS Style

Jaime Martínez-Valderrama; Javier Ibáñez; Gabriel Del Barrio; Francisco J. Alcalá; Maria E. Sanjuán; Alberto Ruiz; Azziz Hirche; Juan Puigdefábregas. Doomed to collapse: Why Algerian steppe rangelands are overgrazed and some lessons to help land-use transitions. Science of The Total Environment 2017, 613-614, 1489 -1497.

AMA Style

Jaime Martínez-Valderrama, Javier Ibáñez, Gabriel Del Barrio, Francisco J. Alcalá, Maria E. Sanjuán, Alberto Ruiz, Azziz Hirche, Juan Puigdefábregas. Doomed to collapse: Why Algerian steppe rangelands are overgrazed and some lessons to help land-use transitions. Science of The Total Environment. 2017; 613-614 ():1489-1497.

Chicago/Turabian Style

Jaime Martínez-Valderrama; Javier Ibáñez; Gabriel Del Barrio; Francisco J. Alcalá; Maria E. Sanjuán; Alberto Ruiz; Azziz Hirche; Juan Puigdefábregas. 2017. "Doomed to collapse: Why Algerian steppe rangelands are overgrazed and some lessons to help land-use transitions." Science of The Total Environment 613-614, no. : 1489-1497.

Journal article
Published: 26 September 2016 in Oryx
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The Endangered Cuvier's gazelleGazella cuvieriis an endemic ungulate of north-western Africa. Information on the species has been based primarily on non-systematic surveys, and the corresponding status estimates are of unknown quality. We evaluate the effectiveness and efficiency of two field methods for systematic surveys of populations of Cuvier's gazelle in arid environments: distance sampling (based on sightings) and sampling indirect sign (tracks and scats). The work was carried out in the north-western Sahara Desert, in Morocco, where what is possibly the largest population of Cuvier's gazelle persists. A logistically viable survey was conducted over a total area of c. 20.000 km2in 10 expeditions during 2011–2014. A total of 67 sites were surveyed, with 194 walking surveys (2,169 km in total). Gazelle signs were detected at 50 sites, and gazelles were sighted at 21 sites (61 individuals). We found a relationship between sightings and abundance indices based on indirect sign, which could be useful for population monitoring or ecological studies. Additionally, the data could be used in occupancy modelling. Density estimates based on distance sampling required considerable effort; however, it is possible to survey large areas during relatively short campaigns, and this proved to be the most useful approach to obtain data on the demographic structure of the population.

ACS Style

Jose María Gil-Sánchez; Francisco Javier Herrera Sánchez; Begoña Álvarez; Ángel Arredondo; Jesús Bautista; Inmaculada Cancio; Salvador Castillo; Miguel Ángel Díaz-Portero; Jesús De Lucas; Emil McCain; Joaquín Pérez; Javier Rodríguez-Siles; Juan Manuel Sáez; Jaime Martínez-Valderrama; Gerardo Valenzuela; Abdeljebbar Qninba; Emilio Virgós. Evaluating methods for surveying the Endangered Cuvier's gazelleGazella cuvieriin arid landscapes. Oryx 2016, 51, 648 -655.

AMA Style

Jose María Gil-Sánchez, Francisco Javier Herrera Sánchez, Begoña Álvarez, Ángel Arredondo, Jesús Bautista, Inmaculada Cancio, Salvador Castillo, Miguel Ángel Díaz-Portero, Jesús De Lucas, Emil McCain, Joaquín Pérez, Javier Rodríguez-Siles, Juan Manuel Sáez, Jaime Martínez-Valderrama, Gerardo Valenzuela, Abdeljebbar Qninba, Emilio Virgós. Evaluating methods for surveying the Endangered Cuvier's gazelleGazella cuvieriin arid landscapes. Oryx. 2016; 51 (4):648-655.

Chicago/Turabian Style

Jose María Gil-Sánchez; Francisco Javier Herrera Sánchez; Begoña Álvarez; Ángel Arredondo; Jesús Bautista; Inmaculada Cancio; Salvador Castillo; Miguel Ángel Díaz-Portero; Jesús De Lucas; Emil McCain; Joaquín Pérez; Javier Rodríguez-Siles; Juan Manuel Sáez; Jaime Martínez-Valderrama; Gerardo Valenzuela; Abdeljebbar Qninba; Emilio Virgós. 2016. "Evaluating methods for surveying the Endangered Cuvier's gazelleGazella cuvieriin arid landscapes." Oryx 51, no. 4: 648-655.

Journal article
Published: 01 September 2016 in Science of The Total Environment
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Mitigation strategies are crucial for desertification given that once degradation starts, other solutions are extremely expensive or unworkable. Prevention is key to handle this problem and solutions should be based on spotting and deactivating the stressors of the system. Following this topic, the Spanish Plan of Action to Combat Desertification (SPACD) created the basis for implementing two innovative approaches to evaluate the threat of land degradation in the country. This paper presents tools for preventing desertification in the form of a geomatic approach to enable the periodic assessments of the status and trends of land condition. Also System Dynamics modelling has been used to integrate bio-physical and socio-economic aspects of desertification to explain and analyse degradation in the main hot spots detected in Spain. The 2dRUE procedure was implemented to map the land-condition status by comparing potential land productivity according to water availability, the limiting factor in arid lands, with plant-biomass data. This assessment showed that 20% of the territory is degraded and an additional 1% is actively degrading. System Dynamics modelling was applied to study the five desertification landscapes identified by the SPACD. The risk analysis, implemented on these models, concluded that ‘Herbaceous crops affected by soil erosion’ is the landscape most at risk, while the Plackett-Burman sensitivity analysis used to rank the factors highlighted the supremacy of climatic factors above socioeconomic drivers.

ACS Style

Jaime Martínez-Valderrama; Javier Ibáñez; Gabriel del Barrio; María E. Sanjuán; Francisco Alcala; Silvio Martínez-Vicente; Alberto Ruiz; Juan Puigdefábregas. Present and future of desertification in Spain: Implementation of a surveillance system to prevent land degradation. Science of The Total Environment 2016, 563-564, 169 -178.

AMA Style

Jaime Martínez-Valderrama, Javier Ibáñez, Gabriel del Barrio, María E. Sanjuán, Francisco Alcala, Silvio Martínez-Vicente, Alberto Ruiz, Juan Puigdefábregas. Present and future of desertification in Spain: Implementation of a surveillance system to prevent land degradation. Science of The Total Environment. 2016; 563-564 ():169-178.

Chicago/Turabian Style

Jaime Martínez-Valderrama; Javier Ibáñez; Gabriel del Barrio; María E. Sanjuán; Francisco Alcala; Silvio Martínez-Vicente; Alberto Ruiz; Juan Puigdefábregas. 2016. "Present and future of desertification in Spain: Implementation of a surveillance system to prevent land degradation." Science of The Total Environment 563-564, no. : 169-178.

Journal article
Published: 19 July 2016 in Remote Sensing
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States of ecological maturity and temporal trends of drylands in Morocco, Algeria and Tunisia north of 28°N are reported for 1998–2008. The input data were Normalized Difference Vegetation Index databases and corresponding climate fields, at a spatial resolution of 1 km and a temporal resolution of one month. States convey opposing dynamics of human exploitation and ecological succession. They were identified synchronically for the full period by comparing each location to all other locations in the study area under equivalent aridity. Rain Use Efficiency (RUE) at two temporal scales was used to estimate proxies for biomass and turnover rate. Biomass trends were determined for every location by stepwise regression using time and aridity as predictors. This enabled human-induced degradation to be separated from simple responses to interannual climate variation. Some relevant findings include large areas of degraded land, albeit improving over time or fluctuating with climate, but rarely degrading further; smaller, but significant areas of mature and reference vegetation in most climate zones; very low overall active degradation rates throughout the area during the decade observed; biomass accumulation over time exceeding depletion in most zones; and negative feedback between land states and trends suggesting overall landscape persistence. Semiarid zones were found to be the most vulnerable. Those results can be disaggregated by country or province. The combination with existing land cover maps and national forest inventories leads to the information required by the two progress indicators associated with the United Nations Convention to Combat Desertification strategic objective to improve the conditions of ecosystems and with the Sustainable Development Goal Target 15.3 to achieve land degradation neutrality. Beyond that, the results are also useful as a basis for land management and restoration.

ACS Style

Gabriel Del Barrio; Maria E. Sanjuan; Azziz Hirche; Mohamed Yassin; Alberto Ruiz; Mohamed Ouessar; Jaime Martinez Valderrama; Bouajila Essifi; Juan Puigdefabregas. Land Degradation States and Trends in the Northwestern Maghreb Drylands, 1998–2008. Remote Sensing 2016, 8, 603 .

AMA Style

Gabriel Del Barrio, Maria E. Sanjuan, Azziz Hirche, Mohamed Yassin, Alberto Ruiz, Mohamed Ouessar, Jaime Martinez Valderrama, Bouajila Essifi, Juan Puigdefabregas. Land Degradation States and Trends in the Northwestern Maghreb Drylands, 1998–2008. Remote Sensing. 2016; 8 (7):603.

Chicago/Turabian Style

Gabriel Del Barrio; Maria E. Sanjuan; Azziz Hirche; Mohamed Yassin; Alberto Ruiz; Mohamed Ouessar; Jaime Martinez Valderrama; Bouajila Essifi; Juan Puigdefabregas. 2016. "Land Degradation States and Trends in the Northwestern Maghreb Drylands, 1998–2008." Remote Sensing 8, no. 7: 603.

Journal article
Published: 01 February 2016 in Science of The Total Environment
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An integrated dynamic model was used to evaluate the influence of climatic, soil, pastoral, economic and managerial factors on sheet erosion in rangelands of SW Spain (dehesas). This was achieved by means of a variance-based sensitivity analysis. Topsoil erodibility, climate change and a combined factor related to soil water storage capacity and the pasture production function were the factors which influenced water erosion the most. Of them, climate change is the main source of uncertainty, though in this study it caused a reduction in the mean and the variance of long-term erosion rates. The economic and managerial factors showed scant influence on soil erosion, meaning that it is unlikely to find such influence in the study area for the time being. This is because the low profitability of the livestock business maintains stocking rates at low levels. However, the potential impact of livestock, through which economic and managerial factors affect soil erosion, proved to be greater in absolute value than the impact of climate change. Therefore, if changes in some economic or managerial factors led to higher stocking rates in the future, significant increases in erosion rates would be expected.

ACS Style

J. Ibáñez; J. Francisco Lavado Contador; Susanne Schnabel; Jaime Martinez-Valderrama. Evaluating the influence of physical, economic and managerial factors on sheet erosion in rangelands of SW Spain by performing a sensitivity analysis on an integrated dynamic model. Science of The Total Environment 2016, 544, 439 -449.

AMA Style

J. Ibáñez, J. Francisco Lavado Contador, Susanne Schnabel, Jaime Martinez-Valderrama. Evaluating the influence of physical, economic and managerial factors on sheet erosion in rangelands of SW Spain by performing a sensitivity analysis on an integrated dynamic model. Science of The Total Environment. 2016; 544 ():439-449.

Chicago/Turabian Style

J. Ibáñez; J. Francisco Lavado Contador; Susanne Schnabel; Jaime Martinez-Valderrama. 2016. "Evaluating the influence of physical, economic and managerial factors on sheet erosion in rangelands of SW Spain by performing a sensitivity analysis on an integrated dynamic model." Science of The Total Environment 544, no. : 439-449.