Magnetic and pedological characterisation of a paleosol under aridic conditions in Spain

Francisco Bautista, Maria Felicidad Bógalo, Antonio Sánchez Navarro, Avto Goguitchaichvili, María José Delgado Iniesta, Ruben Cejudo, Purificación Marín Sanleandro, Juana María Gil y Elvira Díaz-Pereira
RESUMEN. The systematic use of magnetic techniques for the characterization of soils is still scarce despite its great potential for the identification of pedogenetic processes. The main objective of this study is to analyze the magnetic properties of a soil profile with contrasting horizons and try to relate them to the properties determined through conventional techniques. The horizons of a soil profile located in a tectonic depression in Murcia, Spain are described and their physical, chemical, and mineralogical properties analyzed with conventional techniques. The following magnetic properties are included in the study: the mass-specific magnetic susceptibility, frequency-dependent susceptibility, continuous thermomagnetic curves at low field, isothermal remanent magnetization acquisition and the estimation of magnetic hardness (coercitivity) through the parameter S-200. Detailed description of the soil profile and the results of conventional analyses allowed the identification of a mollic horizon, an argic horizon, and a calcic horizon, as well as a textural discontinuity. Apparently, pedogenic magnetite occurs in the A horizon and is responsible for the magnetization in most cases. The magnetic carriers in the Bt horizons are superparamagnetic particles and they are related to the high percentage of clay. High coercivity minerals (hematite and probably goethite) were detected in different concentrations in all soil horizons. The amount of ferrimagnetic minerals decreases with depth. The magnetic properties allowed a better characterization of the diagnostic horizons. The results and information derived from the analysis of the magnetic properties could not be obtained using conventional soil analysis only. (ver)

 

Retrieving air humidity, global solar radiation, and reference evapotranspiration from daily temperatures: development and validation of new methods for Mexico. Part III: reference evapotranspiration

P. Lobit, A. Gómez Tagle, F. Bautista, J. P. Lhomme
RESUMEN. We evaluated two methods to estimate evapotranspiration (ETo) from minimal weather records (daily maximum and minimum temperatures) in Mexico: a modified reduced set FAO-Penman-Monteith method (Allen et al. 1998, Rome, Italy) and the Hargreaves and Samani (Appl Eng Agric 1(2): 96–99, 1985) method. In the reduced set method, the FAOPenman-Monteith equation was applied with vapor pressure and radiation estimated from temperature data using two new models (see first and second articles in this series): mean temperature as the average of maximum and minimum temperature corrected for a constant bias and constant wind speed. The Hargreaves-Samani method combines two empirical relationships: one between diurnal temperature range ΔT and shortwave radiation Rs, and another one between average temperature and the ratio ETo/Rs: both relationships were evaluated and calibrated for Mexico. After performing a sensitivity analysis to evaluate the impact of different approximations on the estimation of Rs and ETo, several model combinations were tested to predict ETo from daily maximum and minimum (ver)

 

Índices de adsorción de metales pesados en suelos urbanos: el caso de Morelia, Michoacán

Francisco Bautista, Elsy Campuzano, Carmen Delgado, Avto Goguitchaichvili
RESUMEN. Due to rapid urban growth and significant increase of human activities such as industrialization, use of motor vehicles and the generation of urban solid waste a large amounts of heavy metals are systematically released into the environment contributing to the pollution of urban soils. However, the ability of soil to adsorb heavy metals is still poorly studied. The aim of this investigation was the evaluation and / or development of three heavy metal adsorption indices and their mathematical validation using decision trees for classification purposes. The sampling was carried out within the urban area of the city of Morelia, State of Michoacan, Mexico. In total 100 samples of topsoil were collected and the content of organic matter, pH, cation exchange capacity, percentage of clay, structure, stoniness and bulk density were analyzed. The Lehmann index was evaluated and two new indices were developed, the modified Lehmann index and the Bautista-Campuzano index. The mathematical validation and development of decision trees were performed using the WEKA software. The Lehmann index took into account mainly the percentage of clays, aggregates and stoniness. The modified Lehmann index used the cation exchange capacity, organic matter, stoniness and pH. Finally the Bautista-Campuzano index considered the pH, organic matter, clays, stoniness and bulk density. The three indices showed congruence between soil properties and adsorption classes of heavy metals with a Kappa coefficient greater than 0.7. However, the Bautista-Campuzano index showed greater theoretical consistency according to the decision tree for classification purpose. This study reveals the importance of the mathematical and theoretical evaluation of the indices using decision trees for classification. For this reason, we consider that the Bautista-Campuzano index is the most efficient methodology for generating information and decision-making related to the improvement of soils in urban areas to increase the adsorption of heavy metals. (ver)

 

Are changes in remotely sensed canopy cover associated to changes in vegetation structure, diversity, and composition in recovered tropical shrublands?

Alma Juliana Lomelí Jiménez, Diego Rafael Pérez-Salicrup, Blanca Lorena Figueroa Rangel, Manuel E. Mendoza-Cantú, Ramón Cuevas Guzmán, Ellen Andresen, Jorge Eduardo Morfín Ríos
RESUMEN. The recovery of vegetation cover is a process that has important implications for the conservation of biodiversity and ecosystem services. Generally, the recovery of vegetation cover is documented over large areas using remote sensing, and it is often assumed that ecosystem properties and processes recover along with remotely sensed canopy cover. Here we analyze and compare the structure, composition, and diversity of trees and shrubs among plots established in a stratified random sampling design over four remotely sensed canopy cover change (CCC) categories defined according to a gradient in the percent of canopy cover. Plots were located in the Lake Cuitzeo basin (Mexico), where canopy recovery associated with agricultural abandonment has occurred in recent decades (1975–2000). We found that diversity measures, basal area, tree and shrub density, ground-truthed canopy cover, and mean plant height increased with increasing CCC category. However, Shannon index (H′) was lower in the CCC category with the most closed canopy cover category than in plots apparently not affected by agriculture. Furthermore, ordination analyses showed that composition of dominant species were not associated with CCC categories. Our results suggest that canopy closure in our study area is not associated with the recovery of species diversity, and does not result in similar species dominance as in sites not affected by agriculture. (ver)

 

Digital soil map of Quintana Roo, Mexico

Patricia Fragoso-Servón, Alberto Pereira Corona, Francisco Bautista Zúñiga, Gonzalo de Jesús Zapata Buenfila
RESUMEN. A digital soil map of Quintana Roo was compiled at a 50 m pixel resolution using a geomorphopedological approach to produce a map that reflects a synoptic view of the geomorphology, environmental conditions and associated soils. Initially, it was developed using a geopedological approach and then converted to a digital map. The map was derived from soil-forming factors using mathematical methods to infer information in places where data were not available. Its compilation included three stages; the first two follow the geopedological approach that consists of a synthesis of data from the characterization of the geomorphological landscapes (vertical dissection, karst geomorphometrics, failures, geology) and soils, and the third stage incorporating environmental components (climate and vegetation) and related variables through various methods of statistical analysis (cluster, principal components and classification analysis) to obtain the pattern of soil distribution and to develop a model for the digital soil map of the study area. (ver)

 

How social capital enables or restricts the livelihoods of poor peri-urban farmers in Mexico

Yadira Méndez-Lemus, Antonio Vieyra
RESUMEN. Poor farmers in peri-urban territories are subjected to the gradual transmutation of their livelihoods while they try to escape from poverty and adapt to an increasingly urban environment. Social capital seems to influence the outcomes of such livelihoods, and might expand chances and choices to improve poverty status, but also to follow their own paths. This article explores the mechanisms through which this capital enables or restricts such livelihoods in two peripheral municipalities in Mexico. The findings highlight the importance of informal institutional and non-institutional mechanisms in regulating access to, and distribution of, resources in peri-urban territories... (ver)

 

Potential distribution of mountain cloud forest in Michoacan, Mexico: Priorization for conservation in the context of landscape connectivity

Correa Ayram, C., M.E. Mendoza, A. Etter y D.R. Pérez Salicrup
RESUMEN. Landscape connectivity is essential in biodiversity conservation because of its ability to reduce the effect of habitat fragmentation; furthermore is a key property in adapting to climate change. Potential distribution models and landscape connectivity studies have increased with regard to their utility to prioritizing areas for conservation. The objective of this study was to model the potential distribution of Mountain Cloud Forests (MCF) in the Transversal Volcanic System, Michoacán (TVSMich) and to analyze the role of these areas in maintaining landscape connectivity. Potential distribution was modeled for the MCF based on the maximum entropy approach using 95 occurrence points and 17 ecological variables at 30m spatial resolution. Potential connectivity was then evaluated by using a probability of connectivity (PC) index based on graph theory. The percentage of variation (dPCk) was used to identify the individual contribution of each potential area of MCF in overall connectivity. The different ways in which the potential areas of MCF can contribute to connectivity were evaluated by using the three fractions derived from dPCk (dPCintrak, dPCfluxk and dPCconnectork). We determined that 37,567 ha of the TVSMich are optimal for the presence of MCF. The contribution of said area in the maintenance of connectivity was low. The conservation of MCF is indispensable, however, in providing or receiving dispersal flows through TVSMich because of its role as a connector element between another habitat types. The knowledge of the potential capacity of MCF to promote structural and functional landscape connectivity is key in the prioritization of conservation areas (ver)

 

Cambio de cobertura y uso de suelo en cuencas tropicales costeras del Pacifico Central Mexicano

Alejandro Jalmacin Nené Preciado, Gaspar González Sansón, Manuel Eduardo Mendoza, Francisco de Asís Silva Bátiz,
RESUMEN. En los últimos años los humedales costeros de Jalisco han sufrido transformaciones en las confluencias y en las cuencas a las que están asociados. El esquema de la gestión costera sugiere incluir la zona de estudio y las áreas adyacentes en un mismo sistema. Por lo tanto, este trabajo plantea analizar los procesos de cambio de cobertura y uso del suelo en dos cuencas costeras, Arroyo Seco (CAS) y María García (CMG). Se consideraron dos periodos, 1971-1996 y 1996-2014. En total, en la CAS los bosques tropicales perdieron 4 000 ha y en la CMG 7 100 ha. Por otro lado, los usos agropecuarios aumentaron el 55% y el 175%, respectivamente. Hay dos factores detonantes de cambio: en la CMG la construcción del distrito de riego 093 generó importantes pérdidas de bosques tropicales; en la CAS el desarrollo turístico modificó las estructuras del paisaje en las confluencias de la laguna Barra de Navidad. Los principales procesos observados fueron la deforestación y la transición forestal, recuperándose solo el 30% de las superficies de bosques tropicales. Mediante la aplicación de un modelo lineal generalizado se encontró que la deforestación, a diferencia de la transición forestal, está influenciada por valores más bajos de pendientes, altitud, distancia a localidades y a vías de comunicación, pero el modelo que mejor explica este proceso incluye las variables altitud, cuenca y periodo, debido a las características intrínsecas de cada periodo y cada cuenca. (ver) (pdf)

 

Paisajes Geomorfológicos: Base para el levantamiento de suelos en Tabasco, México

Joel Zavala-Cruz, Raquel Jiménez Ramírez, David Jesús Palma-López, Francisco Bautista Zúñiga, Francisco Gavi Reyes
RESUMEN. La cartografía de suelos contribuye a la planificación de los sistemas agropecuarios, pero el nivel de reconocimiento con que se cuenta en México está desactualizado. El objetivo del estudio fue actualizar el mapa de paisajes geomorfológicos del estado de Tabasco y analizar sus relaciones con los grupos de suelos. Con base en la cartografía sobre geomorfología, geología y suelos, el análisis de mapas topográficos, ortofotomapas, modelo digital de elevación de INEGI, en la verificación de campo, se zonificó el estado de acuerdo al enfoque geopedológico. El estado de Tabasco se ubica en tres ambientes morfogenéticos: la Planicie Costera del Golfo Sur (PCGS), la Península de Yucatán (PY) y la Sierra de Chiapas y Guatemala (SCHG), los cuales representan el 85.1, 9.0 y 6.0 %; se subdividen en 12 paisajes geomorfológicos, sobresaliendo las terrazas costeras, las planicies palustre, fluvial activa y fluviodeltaica inactiva en la PCGS. Los paisajes geomorfológicos influyen en la distribución geográfica de los grupos de suelos y las características a nivel de horizontes, propiedades, materiales de diagnóstico y calificadores, que inciden en factores limitantes para la capacidad agropecuaria. Destacan los grupos de suelos Arenosol, Solonchak, Histosol, Gleysol, Fluvisol y Vertisol, en las planicies; Alisol, Acrisol y Luvisol en las terrazas costeras, lomeríos y montañas sobre rocas detríticas; y Leptosol, Vertisol y Cambisol en paisajes kársticos. (ver)

 

El carbono orgánico en Leptosols con distribución discontinua en la península de Yucatán

Carmen Delgado-Carranza, Francisco Bautista-Zúñiga, Luz Ma. Calvo-Irabien, Yameli Guadalupe Aguilar-Duarte, Jazmín Guadalupe Martínez-Tellez
RESUMEN. La estimación del COS requiere cuantificar la fracción gruesa (piedras y gravas), la densidad aparente (DA) y la profundidad. Pero el inventario de suelos del INEGI no reporta los dos primeros, en consecuencia los mapas de COS generan grandes dudas. El objetivo fue evaluar la variabilidad espacial del carbono orgánico del suelo a distancias cortas, así como los contenidos del carbono orgánico por unidad de área en suelos Leptosols del norte de la península de Yucatán. Se tomaron 102, el carbono orgánico se analizó con la técnica del dicromato de potasio; se separaron los fragmentos gruesos (grava gruesa, grava mediana y grava fina) de la tierra fina; el color se registró en seco y húmedo; la DA se midió con la cantidad de tierra fina en un volumen de 10x10 cm de superficie por una profundidad variable hasta encontrar la roca. El análisis geoestadístico se realizó mediante kriging ordinario. Estos Leptosols presentaron valores de COS por debajo de las 100 t ha-1 reportados para esta zona, con valores medios de 32.85, 37.57, 43.72 y 61.93 t ha-1, para suelos pardos obscuros, pardos muy obscuros, negros y grises muy obscuros. Los fragmentos gruesos varían de 6.7 a 96.4 %, con un promedio de 71.15 %. Los valores de carbono orgánico del suelo obtenidos son menores a los reportados en unidad de superficie. Además se comprobó la alta discontinuidad y variabilidad a distancias cortas. (ver)

 

IVAKY: Índice de la vulnerabilidad del acuífero kárstico yucateco a la contaminación

Y. Aguilar-Duarte, F. Bautista, M. E. Mendoza, O. Frausto, T. Ihl, C. Delgado
RESUMEN. Se propone el índice de la vulnerabilidad del acuífero kárstico yucateco (IVAKY). El IVAKY se construyó con base en un mapa geomorfopedológico escala 1:50000, que contiene la densidad y tipología de las depresiones kársticas y las asociaciones edíficas en cada unidad geomorfopedológica. El factor clima es incluido a través de la longitud del periodo de lluvias que considera cantidad, distribución e intensidad de la lluvia. Los tres factores (relieve, suelos y clima) se ponderaron con el proceso de análisis jerárquico (AHP, por sus siglas en inglés) utilizando ArcGis 9.1. Se identificé que el Anillo de cenotes y parte de la zona noreste del estado de Yucatán presentan el nivel extremo de vulnerabilidad, donde predominan dolinas en contacto con el acuífero y suelos como los Nudilithic Leptosols, Lithic Leptosols y Rendzic Leptosols, ocupando 19% de la superficie estatal. Los niveles bajos y muy bajos de vulnerabilidad se ubican en el sur de Yucatán en áreas de igual o mayor a 50 msnm, con una densidad baja a media de depresiones kársticas (úvalas y poljes) y Luvisols, Vertisols y Stagnosols, asociados con Leptosols (12% de la superficie estatal)(ver)

 

Anthropogenic impact on habitat connectivity: A multidimensional human footprint index evaluated in a highly biodiverse landscape of Mexico

Camilo A. Correa Ayrama, Manuel E. Mendoza, Andrés Etter, Diego R. Pérez Salicrup
RESUMEN. Evaluating the cumulative effects of the human footprint on landscape connectivity is crucial for imple-menting policies for the appropriate management and conservation of landscapes. We present anadjusted multidimensional spatial human footprint index (SHFI) to analyze the effects of landscape trans-formation on the remnant habitat connectivity for 40 terrestrial mammal species representative of theTrans-Mexican Volcanic System in Michoacán (TMVSMich), in western central Mexico. We adjusted theSHFI by adding fragmentation and habitat loss to its original three components: land use intensity, timeof human landscape intervention, and biophysical vulnerability. The adjusted SHFI was applied to fourscenarios: one grouping all species and three grouping several species by habitat spatial requirements.Using the SHFI as a dispersal resistance surface and applying a circuit theory based approach, we analyzedthe effects of cumulative human impact on habitat connectivity in the different scenarios. For evaluat-ing the relationship between habitat loss and connectivity, we applied graph theory-based equivalentconnected area (ECA) index. Results show over 60% of the TMVSMichhas high SHFI values, considerablylowering current flow for all species. Nevertheless, the effect on connectivity of human impact is higherfor species with limited dispersal capacity (100–500 m). Our approach provides a new form of evaluatinghuman impact on habitat connectivity that can be applied to different scales and landscapes. Further-more, the approach is useful for guiding discussions and implementing future biodiversity conservationinitiatives that promote landscape connectivity as an adaptive strategy for climate change.(ver)

 

Density of Karst Depressions in Yucatán state, Mexico

Yameli Aguilar, Francisco Bautista, Manuel E. Mendoza, Oscar Frausto, Thomas Ihl
RESUMEN. The abundance of karst depressions in Yucatán has been widely recognized, but they have not been classified or quantified despite their importance in land-use planning. Our objective was to study the types and areas of the sinkholes, uvalas, and poljes and identify their patterns of spatial distribution. (ver)

 

Modelling with stakeholders - Next generation

Alexey Voinov, Nagesh Kolagani, Michael K. McCall, Pierre D. Glynn, Marit E. Kragt, Frank O. Ostermann, Suzanne A. Pierce, Palaniappan Ramu
RESUMEN. This paper updates and builds on ‘Modelling with Stakeholders’ Voinov and Bousquet, 2010 which demonstrated the importance of, and demand for, stakeholder participation in resource and environmental modelling.(ver)

 

Environmental Modelling & Software: Preface to this Virtual Thematic Issue: Modelling with Stakeholders II

Alexey Voinov, Nagesh Kolagani, Michael K. McCall
RESUMEN. Five years ago when the first Environmental Modelling and Software (EMS) Thematic Issue on “Modelling with Stakeholders” was published (Bousquet, Voinov, 2010), we were quite optimistic that stakeholder involvement in the modelling process was growing and that such a bottom-up approach could lead to better decision-making. (ver)

 

Beyond ‘‘Landscape” in REDD+: The Imperative for ‘‘Territory”

Michael K. McCall
RESUMEN. This paper problematizes the use of the ‘‘landscape” concept as the perspective in forest governance and REDD+ discourse, especially as it affects ownership claims and management of forest space. This study advocates the contrasting concept of ‘‘territory” as essential to spatial justice in community-held forest lands and for effectivity in REDD+ projects. Whereas landscape in REDD+ discourse is a basic unit of resolution for biophysical, especially conservationist, analysis; territory refers to spatial units embedded in tenurial entitlements, and thus in governance and the execution of management.(ver)

 

Participatory Mapping of the Geography of Risk: Risk Perceptions of Children and Adolescents in Two Portuguese Towns

Isabel Preto, Michael K. McCall, Mário Freitas, Luís Dourado
RESUMEN. This study identifies, characterizes, and represents children’s and adolescents’ perceptions of urban risks, using participatory mapping and Participatory Geographic Information Systems.(ver)

 

Moving from Measuring, Reporting, Verification (MRV) of Forest Carbon to Community Mapping, Measuring, Monitoring (MMM): Perspectives from Mexico

Michael K. McCall, Noah Chutz, Margaret Skutsch
RESUMEN. There have been many calls for community participation in MRV (measuring, reporting, verification) for REDD+. This paper examines whether community involvement in MRV is a requirement, why it appears desirable to REDD+ agencies and external actors, and under what conditions communities might be interested in participating.(ver)

 

Software for Land Evaluation (Soil, Water and Climate)

Francisco Bautista1 , Carmen Delgado2, Ángeles Gallegos3 , Aristeo Pacheco3
RESUMEN. The study of soil organic carbon by its relationship to fertility, climate change and payment for environmental services is currently one of the main topics of interest international. The ability of a soil to act as a reservoir of organic carbon depends on its properties, use and management. Furthermore; is common to find erroneous calculations of carbon due to inaccuracies in selection of the soil properties to be measured and the use of inadequate units. The aim of this work was the development of a software for managing large volumes of information to calculate the organic carbon content of the soil. The tools used for development are: Eclipse as a programming interface, Derby as management system database and Java as programming language. The input variables were: volume of coarse fragments (%), thickness of horizons (cm), bulk density (g cm-3) and organic carbon content of the soil (%) for each horizon of the soil profile. Soil & Environment (S & E) is a software useful for debugging and increase reliability in the calculations of carbon, this tool provides a graphical user-friendly interface, a database of properties of the soil profile and an interpretation results. The software allows expressing the content of soil organic carbon in t ha-1. S&E to estimate the carbon content simulating the horizons loss by soil degradation.(ver)

 

Soil & Environment as a tool for soil environmental functions evaluation (en ruso)

Ángeles Gallegos-Tavera, Dubrovina I.A., Francisco Bautista
RESUMEN. Soil degradation is a part of total ecological crisis due to the fact that soil is the link of any ecosystem. The soil loses its environmental functions (EF) under the comprehensive loads. One of the key topics of nature protection in the last decade is the evaluation and accounting ecosystem services in human economic activity. Therefore, the search and development of spatial planning tools for areas based on their EF is very important. The article considers the software for evaluation of EF using TUSEC algorithms (Technique for Soil Evaluation and Categorization). The technique implies a score evaluation of basic environmental functions of natural and anthropogenic soils. EF evaluation allows keeping a balance of benefits and losses at a spatial planning as a result of lower environmental impacts on soil functions. The central component of the software is a relational DBMS Derby designed in Java using IDE Eclipse. Data on the site, field description and analysis of soil profiles are stored in the database using input tools. Intermediate calculations and evaluation of EF is based on input data by TUSEC algorithms. The forcasting modeling tool allows calculating the change of EF ranks for different types of land use. The evaluation results of EF and predictive models can be presented by graphs. Export of tabular and graphical information is possible as well as the spatial reference data into the GIS. Friendly interface for data input and output and database management is designed for users who do not know SQL query language.(ver)

 

Climatic responses of Pinus pseudostrobus and Abies religiosa in the Monarch Butterfly Biosphere Reserve, Central Mexico

Teodoro Carlón Allendea, Manuel E. Mendoza, Diego R. Pérez-Salicrup, José Villanueva-Díaz, Antonio Lara
RESUMEN. Understanding of the effects of climate on the growth of trees is important to project the response of forests to climate change. Dendrochronological analysis offers a "proxy" source for the effects of climatic variation on tree growth at different spatial and temporal scales. This study combines radial growth patterns of forest trees in the Monarch Butterfly Biosphere Reserve (MBBR), central Mexico, with temperature and precipitation variables from instrumental records to examine influences of temperature and precipitation on radial growth of Pinus pseudostrobus and Abies religiosa. Dendrochronological samples were collected as cross-sections and increment cores, using a chainsaw and increment borers, respectively. Total ring-width chronologies were developed for each site. Principal Component Analyses (PCA) were used to identify common temperature, precipitation and tree growth variation patterns. Correlation and response function analyses between chronologies and records of temperature and precipitation were used to evaluate the relation of climate variables on tree growth. Low precipitation years related to low growth and high precipitation years to higher radial increase. Months during which tree growth was most strongly affected by precipitation were January, February, April, and May, and in some chronologies May’s average monthly maximum temperature was negatively correlated with tree growth. PCA and comparison of PCA factor scores of climatic variables and chronologies showed no significant differences between northern, central or southern portions of the MBBR. Winter-spring rainfall was most influential on growth of both studied tree species. Clearly, tree growth in the MBBR is reduced in years of low January-May precipitation combined with high summer (May) temperatures, a scenario which is likely to occur as a consequence of global climatic change. (ver)

 

Habitat connectivity in biodiversity conservation: A review of recent studies and applications

Camilo A. Correa Ayram, Manuel E. Mendoza, Andrés Etter, Diego R. Pérez Salicrup
RESUMEN. The study of landscape connectivity in conservation has increased considerably since the early part of the 21st century. While the implications of landscape connectivity are self-evident for conservation, they are also important for Physical Geography since a proper understanding of landscape patterns and processes allows for better landscape management practices, which are at the core of Geography. This paper presents a review of the literature based on 162 publications from 2000 to 2013, in which we evaluated the current state and recent advances in the integration of landscape connectivity in the identification and planning of conservation areas. The literature review and data analysis were based on a database organized into five categories: General information, study areas, research objectives, research methods in connectivity studies, and integration of connectivity with conservation. We found a substantial increase in the number of publications relating to connectivity and conservation from 2008 to 2013. Least cost analysis was the method most commonly applied. We found no implementation of landscape connectivity proposals generated by the studies (e.g. potential corridors) into real landscape elements to ensure the permanence and functionality of ecosystems. We identified four important niches for potential future research projects: a) connectivity and climate change, b) contribution of connectivity studies to restoration planning, c) connectivity and land cover/land use change modeling and planning, d) contribution of connectivity analysis in the provision of ecosystem services across landscapes. (ver)

 

Organic carbon content and water retention in soils of a cloud forest in Michoacán, México

Carlos A. Anayam Manuel E. Mendoza, Mercedes Rivera, Rosaura Páez, Luis Daniel Olivares Martínez
RESUMEN. Cloud Forests (CFs) in Michoacan, Mexico face strong pressures due to logging and the change of land use to agriculture, which can affect the ecological functions of the soil. This study identifies the main soils of a CF in Michoacan, Mexico, and evaluates its amounts of Organic Carbon in the soil (OCS) and water-retention capacity. The sampling design was stratified, considering different slope positions. Eight profiles of soils of 1 m in depth were characterized using standard methods. The soil groups identified - Andosol, Alisol, Umbrisol - displayed high degrees of weathering, high to neutral acidities, and a low saturation of bases. The OCS content fluctuated between 92 and 152 Mg ha-1; 55 % of this was distributed in the first 30 cm, and no differences were observed between soil groups. Water retention at high tension (HT, 1500 kPa) and low tension (LT, 30 kPa) varied from 98 to 284 L m-2 , and from 249 to 510 L m-2, respectively. At a depth of 60 cm, where fine roots concentrate, the available water (AW) fluctuated between 107 and 167 L m-2, with no differences between soil groups. Water retention at HT has a negative correlation with the proportion of sands and the apparent density, whereas LT had a positive correlation with the concentration of OCS, and a negative one with apparent density. The AW had a positive correlation with the OCS concentration. The investigation confirms the importance of the CF in the storage of OCS and indicates that the OCS is determinant in the availability of water. Given the accumulation of OCS on the soil surface, carbon and water retention can be very sensitive to anthropogenic disturbances. (ver)

 

Modelación espacial del tiempo de intervención antrópica sobre el paisaje: un caso de estudio en el sistema volcánico transversal de Michoacán, México

Camilo A. Correa Ayram, Manuel E. Mendoza, Andrés Etter, Diego Pérez Salicrup
RESUMEN. En este estudio se presenta un modelo espacial del tiempo de intervención humana sobre el paisaje (TI), construido como componente integral de un índice de huella espacial humana aplicado al Sistema Volcánico Transversal de Michoacán (SVTMich). Para elaborar el modelo espacial de TI se llevó acabó una recopilación de datos históricos georreferenciados acerca del proceso de ocupación del territorio y las actividades humanas principalmente antes del periodo prehispánico. Estos datos se incorporaron a un modelo de uso potencial del suelo relativo a la topografía (Pendiente, elevación, sistema hídrico y distancia a cuerpos de agua) como limitante de las actividades humanas en el pasado. El modelo se clasificó según el tiempo de intervención antrópica en 6 categorías de acuerdo a los años de duración de las actividades humanas sobre el paisaje (0 años, 0-40 años, 40-200 años, 200-500 años, 500-1500 años, >1500 años). Según los resultados, el 53% del SVTMich ha estado sujeto continuamente a la influencia humana durante más de 500 años, mientras que un 43% ha sido intervenido desde hace 40 años. La estimación de la duración en años en que el paisaje ha estado sometido a la actividad humana es crucial para entender el nivel de impacto antrópico sobre el mismo y de esta forma mejorar las decisiones sobre su manejo.(ver)

 

Dinámica espacio-temporal del bosque nublado y su estado sucesional en el estado de Michoacán, México

Yolotzin Martínez Ruiz, Manuel E. Mendoza, Gerardo E. Santana Huicochea, Vicente Salinas Melgoza, Erna Martha López Granados
RESUMEN.El bosque nublado es un ecotono entre las comunidades tropicales y templadas caracterizado por presentar condiciones de humedad, atribuyéndole una gran diversidad biológica y un importante papel como fuente de recursos hídricos. En el Estado de Michoacán, el conocimiento de ese sistema es limitado; este trabajo contribuye a la generación de información que pueda servir como criterios de decisión sobre su restauración y/o conservación. El objetivo del estudio fue evaluar los cambios de cobertura vegetal y uso del suelo que apoyen en la identificación del estado sucesional y posibles asociaciones entre especies de tres fragmentos de Bosque nublado. El trabajo se basó en la interpretación de ortofotos (1994) y de una imagen SPOT 5 (2009). La caracterización del estado sucesional de los fragmentos se basó en la elaboración de muestreos cualitativos (transectos y punto-cuadrante) y se calculó el índice de valor de importancia de cada especie. La tasa de cambio de esta vegetación. Los géneros Pinus y Senecio presentaron los mayores valores de importancia ecológica, lo que indica que este ecosistema se encuentra perturbado. Los resultados indicaron que existen asociaciones positivas entre las especies Styrax argenteus - Ternstroemia lineata, Quercus crassifolia - Cornus disciflora y Pinus lawsonii - Quercus sp. (ver)

 

The App SOC plus a tool to estimate and calculate organic carbon in the soil profile

Francisco Bautista, Eduardo García, Ángeles Gallegos
RESUMEN. In the world, researchers are working very intensively in the development of soil organic carbon (SOC) inventories. Soil organic carbon is very important because it constitutes the largest reservoir of carbon in terrestrial ecosystems.(ver)

 

Paisajes geomorfológicos: Base para el levantamiento de suelos en Tabasco, México.

Joel Zavala-Cruz, Raquel Jiménez Ramírez, David Jesús Palma-López, Francisco Bautista Zúñiga, Francisco Gavi Reyes
RESUMEN. La cartografía de suelos contribuye a la planificación de los sistemas agropecuarios, pero el nivel de reconocimiento con que se cuenta en México está desactualizado. El objetivo del presente estudio fue actualizar el mapa de paisajes geomorfológicos del estado de Tabasco y analizar sus relaciones con los grupos de suelos.(ver)

 

Further evidence for magnetic susceptibility as a proxy for the evaluation of heavy metals in mining wastes: case study of Tlalpujahua and El Oro Mining Districts

Juan Morales, María del Sol Hernández-Bernal, Pedro Corona-Chávez, Avto Gogichaishvili y Francisco Bautista
RESUMEN. Magnetic susceptibility is nowadays used in most areas of environmental research as a proxy for heavy metal pollution in industrial and urban areas. Although the relationship between magnetic susceptibility and concentration of toxic elements in different environments has been pointed out in several studies, mining wastes (tailings) have hardly been investigated by magnetic methods. We report the relationships between magnetic susceptibility and potentially toxic elements monitored at 12 vertical ground profiles of the Tlalpujahua and El Oro mining districts, western Mexico.(ver)

 

Componentes del paisaje como predictores de cubiertas de vegetación: estudio de caso del estado de Michoacán, México

Luis Fernando Gopar Merino y Alejandro Velázquez
RESUMEN. El estado de Michoacán alberga una yuxtaposición de riquezas culturales y naturales destacable que se entrelazan entre condiciones geológicas, geográficas y ecológicas. Este patrimonio natural y cultural está hoy día amenazado, por ende, los tomadores de decisiones buscan información de línea base para restaurar y reorientar las acciones de desarrollo. El objetivo de este artículo, por tanto, fue predecir los patrones de cubierta vegetal oriunda a través de un método replicable. La predicción se basó en atributos climáticos, geológicos, geomorfológicos y ecológicos, jerárquicamente yuxtapuestos a través de un sistema de información geográfica (SIG).(ver)

 

Análisis espacial del paisaje como base para muestreos dendrocronológicos: El caso de la Reserva de la Biosfera Mariposa Monarca, México

Teodoro Carlón-Allende, Manuel E. Mendoza, José Villanueva-Díaz y Diego R. Pérez-Salicrup
RESUMEN. El análisis espacial del paisaje, con técnicas de Percepción Remota (PR) y herramientas de Sistemas de Información Geográfica (SIG), es un procedimiento poco usado en la identificación de sitios potencialmente idóneos para el muestreo dendrocronológico. En el presente trabajo se diseñó un protocolo para identificar áreas con árboles climáticamente sensibles, empleando un análisis espacial de variables biofísicas. El diseño consistió en el análisis de la pendiente del terreno, la orientación de laderas y la distribución de Cobertura Vegetal y Uso de Suelo (CVUS), mediante el uso de técnicas de PR y herramientas de SIG. El protocolo se validó mediante un muestreo dendrocronológico en dos sitios adyacentes. Los análisis estadísticos del ancho de anillos de crecimiento se realizaron mediante los programas COFECHA y dplR. Los resultados indicaron que 18% de la Reserva de la Biosfera Mariposa Monarca presenta características aptas para
colectar muestras dendrocronológicas sensibles a variación climática. Los análisis estadísticos indican que existen diferencias entre los dos sitios en edad de árboles, diámetro y ancho de los anillos. La propuesta del diseño de muestreo permitió ubicar sitios con árboles longevos y sensibles, lo que se traduce en alta variación interanual en el ancho de anillos. El análisis espacial de variables biofísicas previas al muestreo dendrocronológico, contribuye a la identificación de sitios con árboles sensibles y a eliminar menos muestras. El protocolo propuesto es eficiente y puede ser replicable en otras áreas. (ver)

 

Actualización del mapa de suelos del Estado de Yucatán México: Enfoque Geomorfopedológico y WRB.
Francisco Bautista, Oscar Frausto, Thomas Ihl, Yameli Aguilar
RESUMEN. El objetivo del trabajo fue identicar las relaciones entre los ambientes geomorfológicos, geoformas y suelos del estado de Yucatán. Se elaboró un modelo digital de elevación, utilizando 58 mapas topográcos digitales a escala 1:50 000, un mapa altimétrico con curvas de nivel de 10 m, y 401 perles de suelo. Se identicaron los elementos del relieve al interior de las geoformas con imágenes de satélite (SPOT y LANDSAT). El mapa geomorfopedológico del estado de Yucatán se generó con base en la cartográca geomorfologica a escala 1:50 000. Se identicaron cinco ambientes geomorfológicos: marino litoral, palustre, pseudopalustre, kárstico y tecto-kárstico. En cada uno de ellos se identicaron las geoformas (planicies y lomeríos) y suelos. El enfoque geomorfopedológico permitió la identicación y descripción de los paisajes geomorfológicos costeros y las planicies pseudopalustres. En el karst, a mayor altitud y con un clima más húmedo, la disolución de la caliza ocasiona depresiones con suelos de mayor profundidad que los Leptosoles. Esta situación se intensica en zonas con diferente tiempo de emersión de las plataformas. En las planicies kársticas de 10 a 100 msnm los suelos muestran mayor desarrollo en las zonas de mayor altitud con climas más húmedos.Los factores formadores más importantes, en este caso, fueron: la altitud media al nivel del mar, el clima y el tiempo de emersión. (ver)

 

Geodiversity of a Tropical Karst Zone in South-East Mexico
P. Fragoso-Servón, A. Pereira, O. Frausto and F. Bautista
Abstract The Yucatan Peninsula in south-eastern Mexico is the largest karstic area of the country; however, there are very few studies on the geodiversity of the region. The objective of this study is the identification and qualification of the diversity of elements of the relief, considering geomorphology, geology, hydrology and soil properties as components of geodiversity. To calculate the geodiversity, a simple additive model of thematic diversity was used, following Jacˇková and Romportl (2008). The geodiversity in the east of the Yucatan Peninsula manifests as a north to south banding. The geodiversity of coastal portion presents values ranging from medium to very high, in the central portion it ranges from medium to very low and in the western portion, where are the oldest geological formations, have high and very high values. (ver)

 

Correlación entre elementos potencialmente tóxicos y propiedades magnéticas en suelos de la Ciudad de México para la identificación de sitios contaminados: definición de umbrales magnéticos
Rubén Cejudo-Ruíz, Francisco Bautista, Patricia Quintana, María del Carmen Delgado-Carranza, Daniel Aguilar, Avto Goguitchaichvili y Juan Julio Morales-Contreras
RESUMEN La Ciudad de México no cuenta con un sistema de monitoreo ambiental que permita determinar de forma rápida y confiable la calidad de suelo en términos de concentración de elementos potencialmente tóxicos (EPT). Diversos estudios en suelos muestran correlaciones entre elementos potencialmente tóxicos y diversos parámetros magnéticos; sin embargo, muy pocos estudios han propuesto valores umbral para parámetros magnéticos que permitan identificar cuándo un suelo se encuentra contaminado. El propósito de este trabajo fue identificar aquellos parámetros magnéticos que manifiestan una correlación con la concentración de EPT en suelos y establecer un valor umbral que permitan detectar de forma rápida y confiable suelos contaminados. Se recolectaron 88 muestras de suelo superficial de la Ciudad de México; dado que la ciudad se encuentra construida en dos tipos de ambientes geológicos, las muestras fueron separadas en dos grupos (37 de la zona lacustre y 51 de la zona volcánica)....(ver)

 

Concentración de elementos tóxicos en suelos del área metropolitana de la Ciudad de México: análisis espacial utilizando kriging ordinario y kriging indicador.
Thomas IHL, Francisco BAUTISTA, Fredy Rubén CEJUDO RUÍZ, María del Carmen DELGADO, Patricia QUINTANA OWEN, Daniel AGUILAR Avto GOGUITCHAICHVILI
ABSTRACT In order to generate relevant information for decision-makers to protect the inhabitants of the Metropolitan Area of Mexico City, 89 samples of topsoil were collected in urban zones to assess the concentration of toxic elements. For this purpose, the concentration of Cr, Cu, Ni, Pb, V and Zn were quantified with X-ray fluorescence. To evaluate the pollution, we considered the maximum permissible limits, the contamination factor and the pollution load index. The spatial distribution was analyzed by geostatistical methods. Ordinary and indicator Kriging were applied to estimate the values at unmeasured sites and the proportion of the values exceeding the critical concentration for each element within a region. The study revealed that the Metropolitan Area of Mexico City has excessive environmental problems related to pollution. The concentrations of Cr and V are apparently not anthropic, while the high amounts of Cu, Zn and Pb are largely due to human activities. The pollution of Ni exhibits two single spots, while Cu and Zn contents are distributed from the city center towards the northern suburbs. The presence of Pb is spread evenly through the entire urbanized area. The probability maps clearly identify the most contaminated areas, which requires immediate action by local decision-makers. (ver)