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WORLD ATLAS OF DESERTIFICATION Third Edition Rethinking land degradation and sustainable land management

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... Para dar seguimiento al ODS 15.3.1, la UNCCD planteó tres subindicadores clave: 1) tendencia en la cubierta terrestre, 2) la productividad de la tierra y 3) reservas de carbono orgánico por encima y por debajo del suelo (Shen et al., 2023;Rotllan et al., 2021). Por lo tanto, medir la PT es fundamental para evaluar la degradación y desertificación de tierras (Shen et al., 2023;Cherlet et al., 2018). ...
... El Atlas Mundial de la Desertificación propuso medir la PT anual a lo largo del tiempo para determinar la dinámica de la productividad de la tierra (DPT) mediante la estimación de tres métricas adimensionales: tendencia, estado y rendimiento. Su finalidad es determinar si la PT ha mejorado, es estable o se ha degradado a través del tiempo (Sims et al., 2021;Cherlet et al., 2018). La determinación de la dinámica de la productividad (DPT) se ha utilizado en los últimos años para tener claridad sobre el estado que guarda la PT a gran escala, debido a su alta confiabilidad (Rotllan et al., 2021;Sims et al., 2021). ...
... La prevalencia de la condición estable de la métrica de tendencia y estado de la dinámica de la PT, en más de 80% de la superficie nacional, nos indica que, bajo esa condición, no hubo cambios significativos en la productividad a largo plazo, y que la productividad de los últimos cuatro años del periodo de evaluación (2015-2019) fue similar a la productividad histórica (2000-2014) (Cherlet et al., 2018). Estos resultados fueron similares a los datos globales que reportó la UNCCD (2017) en el periodo 1999-2013, donde la condición estable en la tendencia y estado de la productividad fue mayor que la disminución e incremento de la PT. ...
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La productividad de la tierra (PT) es un indicador fundamental para medir la degradación y desertificación de este recurso. En México aún no se cuenta con un estudio a escala nacional que cuantifique y analice el indicador PT en áreas con condiciones similares (cobertura de la tierra y características bioclimáticas). El objetivo de esta investigación es cuantificar el indicador de PT a escala nacional mediante la determinación de la dinámica de la productividad de la tierra (DPT) para el periodo 2000-2019. El análisis tomó como base ocho regiones climáticas dominantes con cobertura vegetal similar donde se calculó la productividad primaria neta (PPN) mediante la radiación fotosintéticamente activa incidente (MJm-2 año-1), la fracción de la radiación fotosintéticamente activa interceptada por los tejidos verdes y la eficiencia en el uso de la radiación solar (gMS MJ-1). Posteriormente se determinó la PT a través de un análisis multitemporal de la PPN para calcular tres métricas: tendencia, estado y rendimiento. Se evaluó la dinámica de la productividad de la tierra (DPT) con la combinación de las tres métricas anteriores y se obtuvieron cinco clases: mejora, estable, estresado, moderadamente degradado y degradado. Por último, se identificaron los usos de suelo y vegetación según la dinámica y degradación de la PT en las ocho regiones climáticas. El análisis de datos se realizó utilizando el lenguaje R (v4.2.3) integrado en el sistema de información geográfica QGIS (v3.28). La PPN promedio anual varió en todo el país, desde menos de 500 g m-2 año-1 en la región climática árida, hasta poco más de 3000 g m-2 año-1 en la región muy húmeda del país. La métrica de tendencia estable se encontró en 86% del territorio nacional. La métrica de estado de PT presentó condición estable en casi 88% del territorio, mientras que la métrica de rendimiento de PT tuvo una condición degradada en 53.2% de la superficie del país. La DPT fue estable en 78% del territorio nacional. En poco más de 70% de la superficie ocupada por tipo de uso de suelo y vegetación no hubo cambios de la DPT. Los resultados obtenidos en este estudio contribuyen a tener información cuantitativa del indicador de productividad de la tierra que puede ser de utilidad para futuras investigaciones que midan la degradación y desertificación de tierras en México.
... Secondary salinization affects 77 million hectares, mainly in cultivable and irrigated areas of countries like India, China, Pakistan, Iran, and Iraq. Primary salinization affects nearly 1 billion hectares worldwide (Cherlet et al., 2018) [27] , with irrigationinduced salinization observed in countries such as Spain, Hungary, France, Southern Italy, and several Northern European countries (Daliakopoulos et al., 2016) [31] . In India alone, around 6.73 million hectares are currently affected, with projections indicating a rise to 20 million hectares by 2050. ...
... Increasing salinity also affects water quality, particularly in northwestern Indian states such as Punjab, Haryana, and Rajasthan. Globally, improper water management poses a significant risk of salinization in regions like Australia, the Middle East, the Mediterranean Basin, Northern Africa, and Central Asia (Cherlet et al., 2018) [27] . Future degradation of water quality is expected due to intensive irrigation practices and the strain on natural resources to meet the food demands of a growing population (Sharma and Singh, 2015) [163] . ...
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Soil health is paramount for sustainable agriculture, impacting crop production, nutrient cycling, and ecosystem stability. The microbial communities inhabiting diverse environments, termed microbiomes, play crucial roles in soil health and ecosystem functions. Among various stresses affecting plant growth, salinity stress poses significant challenges, resulting from high concentrations of soluble salts in the soil. This stress disrupts physiological processes in plants, impeding growth and productivity. Globally, extensive areas of agricultural lands face salinity issues, leading to substantial economic losses. Physiological responses of plants to salinity stress include osmotic and ionic stresses, as well as oxidative stress. Halophytes, adapted to high salt concentrations, contrast with glycophytes, which are more susceptible to salinity stress. The impact of salinity stress on plants extends from osmotic stress to ionic toxicity, affecting nutrient uptake, photosynthesis, and reproductive development. This review paper focuses on microorganisms, particularly salt tolerant plant growth promoting rhizobacteria (ST-PGPRs), which employ various strategies to mitigate salinity stress in plants. These strategies encompass cellular adjustments, salt-in approaches, osmolyte accumulation, and direct and indirect mechanisms for plant growth promotion. Direct mechanisms include nitrogen fixation, phosphorous solubilization, ammonia production, and the production of plant hormones. Indirect mechanisms involve the synthesis of ACC deaminase, Trehalose, siderophores, antioxidant enzymes, Hydrogen cyanide, Exopolysaccharide, Nitric oxide, ion homeostasis and compartmentalization, and biofilm formation. Understanding these microbial strategies is crucial for developing sustainable agricultural practices in saline soils, ultimately enhancing soil health and agricultural productivity in salt-affected regions.
... Another key parameter for model development is the Aridity Index (AI), which quantifies the ratio of precipitation to potential evapotranspiration. This metric indicates moisture availability, helping to assess climate dryness (Maggi et al., 2018). Higher aridity values are linked to greater suspended sediment concentrations and lower sensitivity of sediment concentration to changes in discharge. ...
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Widely adopted models for estimating hydraulic geometry attributes rely on simplistic power‐law equations, which can introduce inaccuracy due to their inability to capture spatial variability. This study introduces a new model for predicting channel geometry utilizing advanced tree‐based Machine Learning (ML) algorithms. The research enhances the quality of the extensive HYDRoacoustic data set supporting Surface Water Oceanographic Topography (HYDRoSWOT) through a proposed preprocessing method. Observations of bankfull and mean‐flow conditions at each gauge site are identified and extracted as target variables for model development. HYDRoSWOT‐extracted attributes, along with other predictors from various sources, such as National Hydrography Data set Plus (NHDPlusV2.1), are used to train and validate predictive models. The models achieve average R² values of 0.85 for channel width and 0.69 for channel depth, demonstrating high accuracy in capturing spatial variability in hydraulic geometry attributes. Independent evaluations further test the models' performance in predicting reach‐averaged conditions at locations outside the training and testing data sets. The results show that the proposed model significantly outperforms existing regional hydraulic geometry relations, with accuracy improvements of 30% for bankfull width and 76% for bankfull depth. The proposed model is then utilized to generate channel width and depth under bankfull and mean‐flow conditions data set across approximately 2.7 million streams within NHDPlusV2.1 data set across the CONtiguous United State (CONUS). This data set is a valuable resource for water‐related sciences, including hydrology, geomorphology, flood modeling, water quality assessment, and flood management.
... Mientras que los dos primeros resultan de una revisión crítica el tercer apartado se lleva a cabo a través del análisis documental y la realización de investigación en campo, mediante la aplicación de cuestionarios y entrevistas semiestructuradas en localidades in�uenciadas por tales procesos de cambio. El contexto particular de las zonas áridas en SLP se re�ere no solo porque son ecosistemas que han recibido una atención particular en la agenda internacional entorno al desarrollo sostenible, debido a que la deserti�cación que atraviesan se replica a escala planetaria (WAD, 2018). Esencialmente, como espacios estratégicos de acumulación de capital se encuentran sujetas a procesos contradictorios entre las formas productivas, investidas como sostenibles para la producción energética (solar y eólica) y agroindustrial (agricultura protegida) (Ortega y Morán, 2020), y múltiples procesos de desatención de la vida. ...
Conference Paper
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Resumen: En América Latina, el despojo territorial para la acumulación y producción del capital, ha asumido un papel central en la liberación de espacios estratégicos para el extractivismo y la privatización de los bienes comunes (Borde y Torres-Tovar, 2017), dejando como huella la destrucción de la naturaleza y consecuencias sobre las formas de vivir, de enfermar y de morir... https://conferenciaclacso.org/programa/resumen_ponencia.php?&ponencia=Conf-1-1408-66333&eje=5
... Gianoli et al. 2023). This conceptual framework has been employed in environmental science, particularly in conjunction with satellite remote sensing data(Ivits et al. 2013, Cherlet et al. 2018, Martínez-Valderrama et al. 2022. As for the additional indicators of the study, they refer to but are not limited to population density and change, groundwater table decline, acidification and eutrophication(Gianoli et al. 2023). ...
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One of the major processes that affect land is its degradation. The term "land" contains all natural resources contributing to agricultural production, including forestry and livestock production. This definition includes landforms, climate, water resources, soils, and vegetation (forests and grasslands). This scoping document, in the context of the Soils for Europe - SOLO project, makes state of the art related to land degradation studies. It highlights that its complex profile needs a combination of monitoring and assessment schemes, due to the multiple dimensions, scales and perspectives, as well as to its transitional character, with multiple drivers and actors.
... The measurements were conducted in July 2021 during the early morning, prior to the onset of direct sunlight hours, under stable clear sky conditions. The area has a relatively high level of humidity compared to the Mediterranean climate [49]. The mean air temperature is 13 • C, the mean annual rainfall is 1403 mm (ranging from 131 mm in summer to 517 in winter), and the average annual evapotranspiration (ETo) is 1077 mm. ...
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In the face of ongoing climatic changes, understanding the species’ sap flow responses is of crucial importance for adaptation and resilience of ecosystems. This study investigated diurnal variability and radial sap flux density (Js) in a natural Juniperus drupacea forest on Mt Parnon and determined the climatic factors affecting its total sap flow (Qs). Between July 2021 and March 2022, Granier-type sensors and automatic weather stations monitored Js of J. drupacea trees and environmental factors. Utilizing a multi-point sensor for Js radial profile variability, correction factors were applied to calculate (Qs), ranging from 4.78 to 16.18 L day⁻¹. In drier months of the study period (July–September), Qs progressively increased with increasing PAR and soil temperature, reaching a plateau at maximum values (app. 600 µmol m⁻² s⁻¹ and 26 °C respectively) indicating partial stomatal closure. Whereas, during the wetter period (October–March), when water was no longer a limiting factor, VPD and PAR emerged as significant controllers of stand transpiration. In this period, Qs responded positively to increasing soil water content (θ) only on days with high VPD (>0.5 kPa). The studied J. drupacea stand demonstrated adaptability to varying environmental conditions, crucial for the species’ survival, considering anticipated climate change scenarios.
... The northern Sahel region is defined by the 150 and 600 mm isohyets as its boundaries, while for the southern Sudanian zone the MAP varies between 600 and 1,000 mm (Karlson & Ostwald, 2016). This region comprises mainly arid, semi-arid and dry subhumid aridity subtypes, as determined from the aridity index (AI; Figure 1), which is closely related to long-term climatic water deficits and is defined as the long-term averaged ratio of precipitation to atmospheric water demand (potential evapotranspiration) (Cherlet et al., 2018). ...
Article
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Interannual variability in climatic drivers can have a strong impact on dryland ecosystem functioning globally. While interannual variations in dryland ecosystem processes are mainly driven by rainfall, other global change drivers such as CO2 fertilization and rising temperatures can play an increasingly important role for these ecosystems. Yet, the high complexity of dryland ecosystems makes it difficult to unravel the individual and interactive impacts of these different drivers. In this work we study the impacts of interannual climatic variability on the dryland ecosystems of the Sudano‐Sahel region for the period 1950–2022. By using a dynamic vegetation model (LPJ‐GUESS v4.0), we show that the year‐to‐year variability in dryland ecosystems that originates from interannual variability in rainfall is modulated by effects of CO2 fertilization, which can strongly impact woody encroachment and resource competition between vegetation types. In contrast, we found that increased temperatures had a relatively low influence at the ecosystem level. We also show that this response varies with aridity subtype, depending on the amount and type of woody cover. By untangling the impacts of climatic drivers on dryland vegetation, this study helps us to understand the different sensitivities of dryland ecosystems to climatic variability under global change.
... For example, a positive anomaly in temperature indicates that the expected temperature will be warmer than the baseline, while a negative anomaly indicates that the expected temperature will be cooler than the baseline. (ii) Climate types were classified based on the aridity index (Cherlet et al. 2018) crops), respectively, is expected to transition to other FS, i.e. FS5, FS14, FS11, and FS7, it is expected that farmers from other systems also transition to these systems. ...
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Developing countries are considered extremely vulnerable to climate change, due to their socioeconomic context (high levels of poverty) and high dependence of their livelihoods on natural resources. Rural areas in these countries concentrate most of the poorest and food-insecure people in the world, with farmers being among the most vulnerable to climate change. The impacts of climate change are expected to be spatially heterogeneous. In this sense, this paper aims at exploring the direct, marginal effect of climate change on farming system choice and its implications to food security in Mozambique, using a space-for-time approach. Our results suggest that major changes are to be expected in farming system choice and their spatial distribution due to climate change, which will potentially impact the livelihoods and food security status of smallholder farmers. Farming systems including food/cash crops and/or livestock, which are among the most food secure, will tend to be replaced by other systems in all climate scenarios. Mixed farming systems (including food and livestock) and livestock-oriented systems, mostly food insecure, predominant in arid areas are expected to expand with climate change. Food security and innovation stress maps were sketched out from the modelling results, identifying priority areas for public intervention. We also highlight how our approach can be an effective and easily replicable framework to address this type of issues in other developing regions facing similar problems.
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Regenerative Agriculture (RA) has emerged as an environment-centric agriculture that prioritises reducing synthetic inputs, emphasising holistic management focussed on sustainability. However, evidence linking RA practices to desired sustainable outcomes remains inconclusive, and today’s modern conventional agriculture (MCA) prioritises similar aspects. This scoping review explores RA’s origins and how its proponents perceive sustainable outcomes. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses—extension for Scoping Reviews guidelines, our review searched peer-reviewed articles from Scopus and Web of Science, along with a Google Scholar snowball search, up to July 2024. Of the 71 articles reviewed in detail, 46 explicitly discussed RA, and 25 addressed sustainability or holistic management relevant to RA. Key research gaps identified include: (1) Despite varying definitions and uncertain outcomes, growing interest in RA warrants further research into farmers’ preferences for RA over MCA. (2) There is insufficient evidence on how farmers balance the interconnected elements in the economic, social, and environmental domains for sustainable outcomes. (3) RA practices are often unclear and overlap with other production methods, necessitating clearer definitions of input systems and strategies used to comprehend RA’s biophysical and economic outcomes. A conceptual framework is proposed to guide future research and inform agricultural sustainability programmes.
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Soil is a critical component of terrestrial ecosystems, playing an invaluable role in supporting plant growth, regulating water and nutrient cycles, filtering pollutants, and providing habitat for soil organisms. However, increasing pressures from human activities, including intensive agriculture, deforestation, urbanization, and climate change are degrading soils across the world. Therefore, sustainable management of soil resources is imperative to ensure continued provisioning of ecosystem services, promote sustainable development outcomes, and help us to achieve the UN Sustainable Development Goals (SDGs). This paper reviews literature across multiple disciplines to examine the vital links between soil and realization of the SDGs. Soil properties influence productivity and food security, water availability and quality, climate regulation through carbon storage, biodiversity conservation, and human health. Degraded soils undermine these ecosystem services, exacerbating poverty, hunger, and inequality. Research shows ecosystem-based approaches that prioritize soil health, including conservation agriculture, agroecology, and regenerative systems, can sustainably intensify agriculture while restoring multi-functionality. Additionally, nature-based solutions utilizing plant-soil interactions for restoration have demonstrated cost-effectiveness. Achieving land degradation neutrality is now an explicit target under the United Nations Convention to Combat Desertification (UNCCD), emphasizing the need to scale soil-focused initiatives within the SDG framework. Therefore, protecting and restoring global soil assets can serve as a nexus in policy frameworks to simultaneously advance progress across multiple SDGs.
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