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A methodology is proposed aimed at defining an integral index of water quality in surface waters that incorporates the information for five variables currently used to independently measure the condition of water in the Cupatítzio River, Michoacán. The variables considered were the current water quality index used by CONAGUA, the concentration of metals, biodiversity as assessed through the BMWP index, microbiological values for Escherichia coli, and the level of toxicity. The index was applied at 17 sites along the Cupatitzio riverbed in the dry season of 2017. Each variable was assigned a rank, which was standardized to a scale of 1–10 and subsequently multiplied by a weight (W) that numerically represented the degree of importance and influence that each factor had in terms of pollution. These factors depended on the anthropic condition of the area, with a value of 5 indicating the method with the most significant impact and 1 the least. The integral index of water quality (IIWQ) was calculated as the arithmetic sum of each factor considered, generating a single value. It had intervals of 15 points minimum to 150 maximum. Five water quality levels were proposed: excellent, good, fair, bad, and very bad. The results showed that, of the 17 sites studied, the majority (ten) were in the fair quality category, ranging from 69 to 95 points; six were in the good category (96 to 122 points); and only one was in the bad category (42–68 points). With the application of this methodology incorporating the information for the five variables already described, it was possible to assess the water quality conditions in the Cupatitzio River as adequate and the water as suitable for its uses in the different socioeconomic activities for which it is destined.

The objectives of this work were to use Sesuvium verrucosum to produce stable and mature compost and vermicompost and to evaluate their influence on the growth and production parameters of the Solanum lycopersicum L. crop. For the preparation of vermicompost, the earthworm Eisenia fetida (Savigny) was used. The proposed treatments were: T1 (negative control) [no organic fertilizer + urea], T2 (positive control) [bovine manure (100%) + urea], T3 (compost) [bovine manure (100%) + urea], T4 (compost) [S. verrucosum (25%) + bovine manure (75%) + urea], T5 (compost) [S. verrucosum (50%) + bovine manure (50%) + urea], T6 (compost) [S. verrucosum (75%) + bovine manure (25%) + urea], T7 (vermicompost) [bovine manure (100%) + urea], and T8 (vermicompost) [S. verrucosum (25%) + bovine manure (75%) + urea]. The results showed that all the treatments were stable, mature and rich in nutrients after 140 days. In general, treatments made from S. verrucosum showed a high pH (7.97–8.45) and electrical conductivity (3.83–8.85 dS m-1). Nonetheless, excluding T7, the treatments made from a proportion of 25% halophyte and 75% bovine manure (T8 and T4) achieved the highest morphological parameters in the different variables that were evaluated, as well as the highest yields compared to controls T1 and T2, followed by T3, T5 and T6, respectively. Therefore, it was concluded that S. verrucosum can serve as a stable and mature organic amendment, rich in nutrients, and that can be used to improve the growth and development of the S. lycopersicum crop.

The integrity of rivers is affected by anthropogenic activities at different spatial scales, from basin and landscape levels to the direct effects on the river and aquatic life. Our objective was to study these effects on the subtropical La Pasión River, analyzing environmental, geomorphological, habitat and water quality, and macroinvertebrates. We sampled the dry season (March 2022) because the river presented stable conditions. We selected the most influential variables in each spatial scale and determined their relationship with the indexes of quality characteristics and aquatic life in the river using multivariate statistics. Most sites (≈65%) had medium water and suboptimal habitat quality status, meanwhile half the sites had regular biotic integrity status; without finding coincidence in the quality of the different indexes applied, all sites indicated a high gradient of degradation from the origin to the mouth of the river. The presence of some families (e.g., Culicidae, Chironomidae, Lumbriculidae) indicated organic matter contamination. The main variables that significantly classified the river quality and integrity structure were water flow, turbidity, habitat embeddedness, and sulfates (χ2 = 0.1145, p < 0.01). It is concluded that the affected sites received wastewater without prior treatment and presented physical barriers such as irrigation channels.

Due to the strong impact of soil salination on the productivity of crops, the implementation of sustainable agricultural practices (SAPs) such as phytodesalination is intended to reverse its effects. While this practice is used in most Middle Eastern countries, Mexico has just begun envisaging its benefits and potential. This study evaluated factors promoting the adoption of phytodesalination among agricultural producers based on the municipality of Villamar, Mexico. Two hundred forty-five semistructured surveys were designed and applied to farmers who participated in various events to disseminate the practice of phytodesalination. Information was gathered on the socioeconomic/demographic characteristics and affectation levels of their parcels due to the effects of salinity. Through a logistic regression using Lasso restriction, the factors influencing the farmers’ decisions to adopt phytodesalination in their specific productive models were evaluated. The results show that more than 87% of the surveyed farmers are male, that their average age is 52 years, that more than 82% have at most an elementary or high school education, that the average plot size in the study area is roughly 4 ha, that more than 76% of the farmers are native to the area and that approximately of 84% use their production exclusively for sales. According to the model employed [prediction of 90% and AUC (area under the curve) of 0.97], the surveyed farmers are mostly influenced by institutional (advice on implementing desalination), organizational (skills and competencies to spread halophyte species in accordance with parcel length and access to halophyte plants) and economic (time to implement phytodesalination) factors. The promotion of this approach and commitment of the region’s various institutions are recommended so that farmers can extend their knowledge of SAPs through a comprehensive strategic approach that allows them to address their specific challenges.

The objective of this study was to generate an ecological niche modeling (ENM) to determine potential sites or areas where the growth and development of halophyte species are the most appropriate. To determine the number of halophyte species in the zone of study, the random quadrant method was used. The material collected per site was separated and identified. One hundred samples were taken from the soil at a depth of 20 cm for the analysis of five chemical properties. Evaporation, precipitation, and minimum and maximum temperature data were obtained from 34 meteorological stations. Geostatistical techniques were applied for the spatial prediction of the climate and soil variables. In addition, five scenes from the Sentinel-2A satellite and the digital elevation model were retrieved. Principal component analysis was performed on the 15 environmental predictors. Ten algorithms were used to conduct the ENM. The ENM results of the halophyte species were reclassified in binary maps. A species richness (PRS) map was created according to the predictions from the sum of binary maps. The PRS map was used to define the potential sites to grow and develop halophyte species of anthropogenic interest. Ten halophyte species were found in the sampled zone, of which 70% were native. The first seven principal components (95% of the cumulative variance) were used for the ENM. The AUC values of the halophyte species models ranged from 0.61 to 0.98. A total of 38% of the study area was considered suitable for potential sites of halophyte species.

The aim of this research was to evaluate the phytoremediative potential of Epipremnum aureum and Bacopa monnieri to improve the chemical properties of irrigation water exposed to the following two saline concentrations: highly saline (EC 2000 μS cm−1) and severely saline (EC 4000 μS cm−1). The artificial wetlands used in this experiment were of the free water surface type, considering a hydraulic retention time of 42 days. The evaluated treatments were configured as follows: T1 (B. monnieri [control, 300 μS cm−1]), T2 (B. monnieri [2000 μS cm−1]), T3 (B. monnieri [4000 μS cm−1]), T4 (E. aureum [control, 300 μS cm−1]), T5 (E. aureum [2000 μS cm−1]), T6 (E. aureum [4000 μS cm−1]), T7 (B. monnieri + E. aureum [control, 300 μS cm−1]), T8 (B. monnieri + E. aureum [2000 μS cm−1]), and T9 (B. monnieri + E. aureum [4000 μS cm−1]). The results showed that the species B. monnieri and E. aureum (both separately and together) showed a good ability to reduce the salinity of the irrigation water. However, B. monnieri showed a greater ability of phytoremediation, to the point of improving its chemical properties and reducing potential damage to the soil to use this water. In the highly saline group, B. monnieri accumulated 7.992 g per experimental unit and achieved to reduce of the pH from 7.96 to 7.75, EC from 2000 μS cm−1 to 670 μS cm−1, SAR from 13.54 to 3.91 and ESP from 20.17 to 5.83, which allowed it to go from (C3-S3) to (C3-S1). In the severely saline group, B. monnieri accumulated 13.494 g per experimental unit and achieved to reduce the pH from 8.14 to 7.91, EC from 4000 μS cm−1 to 1730 μS cm−1, SAR from 27.35 to 8.73, ESP from 40.35 to 13.01, which allowed it to go from (C4-S4) to (C3-S2).

The shortage of water and the increasing salinity are the main limiting environmental factors that directly affect the establishment and the development of crops. In this research, phytodesalination capacity of Sesuvium verrucosum was evaluated alone and in combination with agricultural gypsum (CaSO4·2H2O) and Polisul-C, in order to remedy a moderately saline soil at greenhouse level and under nonleaching conditions. The treatments studied were the following: T1 (soil), T2 (soil + S. verrucosum), T3 (soil +S. verrucosum + Polisul-C), T4 (soil + S. verrucosum + CaSO4·2H2O). Polyvinyl chloride (PVC) tubes filled with 8 kg of clay soil with an electrical conductivity of the saturation paste extract (ECe) of6.21 dS.m-1 were used. Soil samples were analyzed to determine the ECe, and the soluble and interchangeable cations (Na+, K+, Ca2+ and Mg2+) content. Then, the halophytic plants were divided into root and aerial parts and the content of Na+, K+, Ca2+ and Mg2+ was determined. In summary, S. verrucosum showed potential to desalinate its rhizosphere. Moreover, S. verrucosum desalination capacity significantly increases when used in combination with either of the tested amendments. This increase occurred mainly in the upper layers of the clay soil (0-30 cm). CaSO4·2H2O was shown to be the most effective amendment, since a greater gain in biomass and a large accumulation of sodium (Na+) in the aerial part of S. verrucosum was observed as a consequence of the soil improved physico-chemical properties caused by this chemical.

Apiaries must be located in areas with abundant flora as they are the nutritional base for Apis mellifera. Asteraceae is one of the most diverse plant families in Mexico and several of its species are of interest for beekeepers. The objective of this study was to determine the best sites for the placement of apiaries with the use of ecological niche models (ENM) of some Asteraceae species important for bees in two basins of the state of Michoacán, Mexico. ENM for thirty species were obtained through records of their presence, twenty abiotic variables and one biotic variable, and a map of species richness was made to determine which sites would be environmentally appropriate for apiaries. The models were statistically evaluated using the AUC_Maxent, partial_ROC and the binomial tests and were verified in the field. The first two tests’ models had values of 0.70 to 1 and the binomial test’s models had values of 1. The map showed six suitable areas with the greatest richness of species. The corroboration in the field proved ENM effective by finding twenty-two of the thirty modeled species inside the predicted areas. Our results support that ENM are a good strategy to predict the ideal habitat for species important for beekeeping, and thus determine the best places to establish apiaries in the region.

El suelo es uno de los principales recursos naturales, en el cual se sustentan los bosques y la producción de alimentos para una población que crece cada día. Contar con información actualizada sobre este recurso y su distribución facilita la planeación y clasificación de las actividades agropecuarias y de manejo de los bosques. La clasificación de suelos de la Organización de las Naciones Unidas para la Agricultura y la Alimentación (FAO) denominada Base Referencial Mundial del Recurso Suelo (WRB), ha sido mejorada con ello se aumentó su precisión. Los objetivos de esta investigación fueron actualizar la clasificación de la cartografía del Instituto Nacional de Estadística y Geografía escala 1:50,000 de los suelos del Estado de México de la clasificación FAO 1970, a la versión de suelos de la WRB 2006; además de cuantificar la superficie de las Unidades y Subunidades de sus suelos y delimitar su distribución. Los suelos dominantes en el estado son los Andosoles con 4,799.08 km2, Feozems con 4,727.18, Regosoles con 2,656.83, Vertisoles con 2,414.85 y Cambisoles con 1,960.47 km2. Se agregaron los Leptosoles que agruparon a los Rankers, Rendzinas y Litosoles; estos suelos se denominan como Leptosoles Líticos (LPli), los cuales cubren 1,749.68 km2 y tienen una profundidad menor a 10 cm. Con ello se reduce el área para la producción de cultivos.

The inventory of the geological heritage of a region is a necessary action to promote its conservation and its diffusion. We selected the Northern region of Michoacan to advance the inventory of its geological heritage, particularly in the field of volcanology, hydrology and geothermal. The term “scientific geoheritage” was used to refer to those geological features that may be susceptible to be considered as having a potential geological heritage of north Michoacan. The aim was to focus on the complex context and significance of the geological heritage, so that the protection schemes take into account its use as a natural, scientific, and cultural heritage. The Michoacan Guanajuato Volcanic Field is a highlighted geo-area with the Volcan Paricutin as an important geosite. Important hydrological sites are Lago Camecuaro and Los Chorros del Varal, which are also protected natural areas. Finally, the Azufres is a geothermal area with high economic and scientific value.

"El grado de contaminación de un sitio, debido a la deposición de mercurio proveniente de los terreros de mina, está relacionada directamente con las propiedades del suelo, ya que éstas determinan la movilidad de los contaminantes. El objetivo de este trabajo fue determinar la relación del mercurio total con las propiedades del suelo, empleando el análisis de regresión con árboles de decisión y métodos geoestadísticos. Se colectaron 102 muestras superficiales para análisis de mercurio total y 10 propiedades del suelo. El análisis de regresión con árboles de decisión mostró cuatro relaciones entre el mercurio total y las propiedades químicas: 1) pH > 8.5: mercurio total > 64 mg/kg; 2) materia orgánica > 5.5%: mercurio total > 19 mg/kg; 3) bicarbonatos > 256 mg/kg: mercurio total > 77 mg/kg; y 4) potencial redox > 171 mV: mercurio total < 49 mg/kg. Además, se encontró una correspondencia entre la regresión con árboles de decisión y los mapas elaborados con métodos geoestadísticos. Por ejemplo, en lugares con mayores concentraciones de mercurio total, hay una mayor cantidad de materia orgánica, pH y bicarbonatos, en cambio, en los lugares con menores concentraciones de mercurio total, hubo mayor nivel de potencial redox. Se concluye que: i) los altos contenidos de materia orgánica favorecen la retención del mercurio total, ii) los valores pH de neutros a alcalinos ayudan a la poca movilidad, iii) los bicarbonatos favorecen la estabilización del mercurio total y iv) un potencial redox intermedio proporciona al suelo estabilidad frente a la contaminación del mercurio total."

The aim of this study was to generate models to predict the salinity of the soils in the geothermal zone which is located in Michoacan, Mexico, over space and time. Systematic sampling was performed at locations 400 m apart with a sampling period every 48 days. At each site, two soil samples, from depths of 0–30 cm and 30–60 cm, were collected and analysed in laboratory. Regression-Kriging was used to make spatial predictions of the electrical conductivity of soil (ECs). Spherical and Gaussian theoretical models fit the experimental semivariograms. The results showed that the soil samples ranged from slightly saline (2.1–4 dS m−1) to strongly saline (8.1–16 dS m−1). In addition, the ECs was greater at a depth of 30–60 cm than it was at a depth of 0–30 cm. The ECs decreased from more than 8.0 dS m−1 to less than 4.0 dS m−1 after the first sampling period.

Landscape units are conceived as a part of the territory that share similar physical and geographic characteristics. Their delineation can contribute to identify the physical and social dynamics that emerge in the spatial environment and to propose strategies of planning and management of the territory. The main objective was to make a historical delineation of landscape units in the Duero river basin that demonstrate the dynamics of changes in the territory, the description of the actors involved, and the affectations in the natural and social environment. We analyzed the vegetation change and urban growth from 1983 to 2014, incorporating climatic, edaphic, and topographic variables. A Principal Component Analysis was performed with the information and results were used in Maximum Likelihood procedure to define different clusters based on environmental characteristics. We defined five categories from the Landsat images. Results showed landscape units with homogeneous environmental characteristics and some differences in the units’ delineation were mainly influenced by political and socioeconomic factors. Temporally there was an increased tendency of landscape units, three in 1983, nine in 1990, 1995, 2000 and 2011, and eight in 2014. This increase resulted from territory fragmentation because of berries and avocado cultivars expansion over wooded area.

el objetivo de este artículo es sustentar la conceptualización teórica y referenciar los fundamentos vinculantes y no vinculantes en la conservación de los paisajes históricos culturales para los territorios latinoamericanos. La revisión sobre las declaraciones en convenciones internacionales, tanto en Europa como América Latina, sobre las temáticas del paisaje histórico, paisaje cultural y conservación del patrimonio, abren una perspectiva de entendimiento sobre la concepciónde ideas y referencias clave que, junto al desarrollo de constructos conceptuales, guían hacia una fundamentación de nuevos caminos para la interpretación y fundamentación de la conservación del patrimonio paisajístico latinoamericano.Abstract: The main objective is to support the conceptualization and to reference the binding and non-binding documents to conserve Latin American cultural historical landscapes. The review on the declarations in international conventions, both in Europe and Latin America, on themes of historical landscape, cultural landscape and heritage conservation, they open a perspective of understanding on the conception of ideas and key references that, together with the development of conceptual constructs, they guide to think on new paths for the interpretation and basis of conservation of Latin American landscape heritage.Key words: Latin America; Culture; History; Landscape heritage; Historical-cultural landscape.

Silva-Garcia, J. T., Cruz-Cardenas, G., Ochoa-Estrada, S., Estrada-Godoy, F., Nava-Velazquez, J., & Alvarez-Bernal, D. (noviembre-diciembre, 2017). Perdida de suelo por erosion hidrica en la cuenca del lago de Chapala, Michoacan, Mexico. Tecnologia y Ciencias del Agua , 8 (6), 117-128 DOI: 10.24850/j-tyca-2017-06-08. Se cuantifico para la cuenca del lago de Chapala, porcion Michoacan, Mexico, la perdida de suelo por erosion hidrica, utilizando como metodo de medicion las parcelas de escurrimiento. Un total de 18 de ellas se instalaron por los principales usos de suelo presentes en la region: pastizal, agricultura de riego y de temporal, bosque de encino y matorral subtropical. Se realizo un muestreo mensual durante el periodo de lluvias que abarco los meses de agostooctubre de 2012. La mayor perdida de suelo se presento donde se desarrolla la agricultura de temporal con 630.7 kg ha-1, seguido de los pastizales con 87.9 kg ha-1 y en menor cantidad el bosque de encino con 3.9 kg ha-1. Considerando todos los usos de suelo, en total la perdida de suelo en la zona de estudio fue de 6 593 t ha-1 ano-1, siendo mayor en las areas de cultivo de temporal con 4 019 t ha-1 ano-1. La materia organica fue uno de los componentes del suelo que mas se perdieron durante el proceso de erosion hidrica, obteniendo valores de 24.5 y 5.1 kg ha-1 para cultivos de temporal y pastizales, respectivamente. Los macronutrientes medidos en el sedimento igualmente presentaron una correlacion con el factor anterior; los maximos valores para N, P y K se registraron en la agricultura de riego con 0.9, 0.1 y 2.1 kg ha-1, respectivamente.

The aim of this article is to analyze why there are hindrances to the development of PGI products in Mexico, based on the case study of dairy farming in the Cienega de Chapala, Michoacan. Currently, local dairy production satisfies the demand of a parastatal company, marginally supplies the local consumption of fresh milk and is the supplier of the input for the production of a typical low-value ranchero cheese with local demand. In addition, there was a negative impact of NAFTA on local products, and it persists with the recent USMCA. However, with further development of collective action of local dairy farmers, it is possible to promote PGIs for the regional market by taking advantage of the opportunity offered by the new labeling policy of the current federal government. The methodology is a combination of qualitative and quantitative; 68 interviews were conducted with dairy farmers in the study area, and MFA and ATLAS.ti software were used. The results highlight that socio-environmental problems and market failures are related to the obstacles such as the lack of collective action of dairy farmers and the absence of a local governance system that regulates the market and promotes quality, food safety and sustainable practices in the territory.

Environmental or hydrological landscape units can integrate various environmental characteristics to support proper management of natural resources. To delineate these units, quantitative methods such as ordination, clustering, and classification of abiotic factor information are used. In the present work, environmental units were delineated in the Duero River watershed of Michoacan, Mexico. This will enhance understanding of the hydrologic landscape, which is a fundamental to natural resource management. A digital elevation model was used to generate sub-basins. Climatic data were obtained from 16 meteorological stations. Sixty-nine soil and 150 water samples were collected and analyzed in the laboratory. Geostatistical methods for spatial prediction of the environmental variables were used. Mean data for each sub-basin were obtained from the environmental variable grids, generating an abiotic factor data matrix. A multivariate analysis was conducted. Exponential, linear, spherical, and Gaussian models were fit to an empirical variogram. Spatial prediction of the environmental data was done via universal and ordinary kriging. Based on principal component analysis, abiotic factors evaporation, total nitrogen, soil pH, and sodium absorption ratio of water were selected for cluster analysis. Five environmental units were delineated in the Duero watershed. One environmental unit (number 4) provided greater than 50 % of the payment for ecosystem services. The general trend is an increase of urban area. The urban surface in 1983 and 2014 was 1724 and 4750 ha, respectively, an increase of 275 %. Environmental unit 1 showed the greatest urban area growth (1336 ha) during the latter period.

Michoacan es el quinto estado con mayor diversidad de especies vegetales, sobresaliendo por su riqueza en familias, generos y especies de la flora arborea en Mexico. Por lo anterior, en este trabajo se evaluo la distribucion potencial de 12 especies de Pinaceae en condiciones actuales y escenarios futuros de cambio climatico, mediante modelos de nicho ecologico. Se utilizaron datos del clima actual, de escenarios futuros, de propiedades de suelos y el modelo digital de elevacion como predictores ambientales. El modelado se realizo con el software Maxent, 75 % de los datos de presencia de las especies se utilizo para el entrenamiento de los modelos y el 25 % restante para su validacion. Los grids de salida se clasificaron en tres categorias de areas para la distribucion de las especies: no idonea, marginal e idonea. Los modelos muestran que habra una disminucion de 16 y 40 % de areas idoneas en los horizontes 2015-2039 y 2075-2099, respectivamente. Las especies mas afectadas en la reduccion de su distribucion seran Abies religiosa , Pinus leiophylla y Pinus teocote .

In the Cienega de Chapala region of the state of Michoacan, Mexico, forage crops form a major pillar for traditional livestock systems. In this region, high soil salinity due to poor groundwater quality is a common problem. Thus, the objective of this research was to evaluate the potential of the forage species Vicia sativa L. for improved saline soil in a greenhouse and non-leaching conditions over the course of 90 days. In this experiment, three levels of NaCl salinity were tested: 5.3, 7.12 and 10.8 dS∙m–1. Samples of soil were analyzed for electrical conductivity of the saturation paste extract (ECe), soluble and interchangeable cations (Na+, K+, Ca2+ and Mg2+) content. Then, the forage species Vicia sativa L were divided into three categories (leaf, stem, and root) and their shoot biomass production and Na+, K+, Ca2+ and Mg2+ content was determined. Analysis of variance was performed to examine the effects of salinity on each of the evaluated variables; Tukey’s test was used to detect differences between the mean values of the variables per treatment. In a greenhouse experiment, the species V. sativa is confirmed to be tolerant to a moderately saline level. The high concentrations of Na+ found in both the stems and leaves of this plant confirm that it may be used for the improvement of moderately saline soils. The decrease in pH, ECe, SAR and ESP in the pots via non-leaching conditions confirmed their role in the improvement of the chemical characteristics of the soil.

The present study characterized the hydrogeochemical processes of the aquifer of Cienega de Chapala in Michoacan, Mexico. The dominant water families contained bicarbonate magnesium and sodium. In the region, water infiltrates into a fractured volcanic environment exposed in the surrounding mountains and is transmitted to the volcano-sedimentary units of the cienega, where silicate alteration and ion exchange processes occur in the clays of the subsoil. The Gibb diagrams confirm that the main evolutionary processes in the aquifer are rock-water interactions in the local flow and evaporation in the intermediate and regional flows. The molar ratios of HCO3/Na and Ca/Na are congruent with the type of volcano-sedimentary environment present in the area. Ternary mixing processes associated with three end members were also identified and were related to the flow systems in the area. The local flow contributes 77% of water to the system, and the intermediate and regional flows contribute 16% and 7%, respectively.

El modelado de la distribución de especies sinantrópicas (malezas) y los factores ambientales que determinan dicha distribución han sido poco estudiados. Physalis tiene 90 especies distribuidas en las Américas, y algunas especies en el Viejo Mundo. México alberga cerca de 70 especies y aproximadamente 35 son endémicas. La sección Angulatae incluye diez especies, todas sinantrópicas en mayor o menor grado. Las especies se concentran en la Sierra Madre Occidental, la Sierra Madre del Sur y en la Faja Volcánica Transmexicana. El objetivo de este trabajo fue modelar e identificar las variables ambientales que determinan la distribución potencial de las diez especies de Physalis sección Angulatae . Se emplearon 524 registros revisados por especialistas en la taxonomía del grupo y 20 variables ambientales; de éstas 12 fueron climáticas, tres edáficas, dos de cobertura de la vegetación y tres de atributos topográficos. Los modelos se calcularon con el algoritmo Maxent. Los resultados del modelado mostraron que el hábitat más adecuado para la persistencia de ocho especies se definió por el índice normalizado diferencial de vegetación en los meses secos del año, la materia orgánica del suelo, la altitud y el aspecto, las cuales en conjunto explicaron entre el 73 y el 9 % de la variación en su distribución. Otros factores como la precipitación total anual y la isotermalidad determinaron la distribución de P. crassifolia y de P. glabra , respectivamente. El índice normalizado diferencial de la vegetación y las propiedades de los suelos, son predictores determinantes en la distribución potencial de las especies de la sección Angulatae .

En la región de la Ciénega de Chapala porción Michoacán la mayor parte de los cultivos forrajeros son el sustento fundamental de los sistemas ganaderos tradicionales. Sin embargo, la escasez de agua y la creciente salinidad se presentan como los principales factores ambientales limitantes que afectan directamente a su establecimiento y desarrollo. En esta investigación, se evaluó la capacidad de germinación y emergencia de siete especies forrajeras en condiciones in vitro, al ser expuestas a diferentes concentraciones de NaCl. La evaluación se llevó a cabo en un período de 21 días, en el cual las semillas fueron colocadas en una incubadora sin luz a una temperatura de 25 /17°C (día / noche) respectivamente. Se utilizó el método de digestión con ácido para la extracción de los cationes Na+, K+, Ca2+ y Mg2+ a partir de las plántulas germinadas. Los tratamientos de salinidad fueron 0.0 mM, 50 mM; 100 mM; 200 mM y 400 mM. En la etapa de imbibición se observó una respuesta diferencial entre especies en condiciones de estrés salino, principalmente a 200 y 400 mM, al producir una reducción drástica en los niveles de absorción respecto a sus propios testigos y posteriormente se vio reflejado en su capacidad germinativa. Las especies H. vulgare y L. perenne mostraron una menor relación K+/Na+, ratificando con ello, ser las más tolerantes ante este nivel de concentración salina.

"En esta investigación se planteó como objetivo evaluar la percepción o conocimiento que tiene respecto al fenómeno de cambio climático la población indígena Purépecha del Municipio de Chilchota, Michoacán, México. Lo anterior, sin dejar de reconocer algunos mecanismos de adaptación basados en su cultura, tradiciones y conocimientos actuales. Como instrumento para obtener información se aplicaron encuestas. Un total de 298 fueron realizadas y distribuidas en cuatro comunidades del municipio: Zopoco (49), Tanaquillo (50), Carapan (59), Ichan (37) y la cabecera municipal Chilchota (103). Se aplicaron técnicas multivariadas para el análisis de los datos obtenidos de las encuestas, que permitieran reducir la estructura de datos y la clasificación de las variables en grupos. Los resultados muestran que la población indígena del municipio de Chilchota percibe cambios locales en el clima atribuidos a diversas acciones que el ser humano ha venido desarrollando en los últimos años (tala de árboles, quema de basura, contaminación, etc.), no asociando dichas variaciones de manera inmediata con el fenómeno de cambio climático. Como una medida de adaptación a los cambios percibidos, los calendarios agrícolas de siembra de la región se han ajustado. Estos cambios climáticos coinciden con el comportamiento cuantitativo para el periodo 1968-2007, de la temperatura media anual y de la precipitación. En dicho periodo la primera registra un incremento de 0.5 ºC, mientras que para la segunda se reportan 150 mm anuales menos."

Antes de realizar el modelado de la distribucion potencial de una especie, se recomienda hacer una preseleccion de covariables pues la redundancia o variables irrelevantes pueden inducir sesgos en la mayoria de los modelos. En este estudio, se propuso un metodo automatizado para la seleccion a priori de covariables utilizadas en el modelado. Se emplearon cinco especies tipicas de la flora mexicana (Catopheria chiapensis, Liquidambar styraciflua, Quercus martinezii, Telanthopora grandifolia y Viburnum acutifolium) y 56 covariables ambientales. Se generaron matrices de presencia-ausencia para cada especie y se analizaron empleando regresion logistica; el modelo resultante de cada especie se evaluo mediante un remuestreo bootstrap. La distribucion de las cinco especies se modelo usando el algoritmo de maxima entropia y con el empleo de tres conjuntos de covariables ambientales. La precision de los modelos generados se evaluo con intervalos de confianza de cada curva caracteristica operativa del receptor (COR). Los intervalos de confianza de las curvas COR resultantes no mostraron diferencia significativa (P < 0.05) entre los tres modelos predictivos generados; sin embargo, el modelo mas parsimonioso se obtuvo con el metodo propuesto

Mexico maintains several databases with biotic or abiotic information that enable large scale-studies (for example, at a resolution of 1 km2); unfortunately, there is no information at this resolution for soil properties. The goal of this paper was to generate a set of soil variables to address this absence. We evaluated 4400 soil samples taken on Mexican territory. The following nine soil properties were evaluated for each sample: Ca, K, Mg, Na, organic C, organic matter, electrical conductivity, sodium absorption ratio, and pH. With the use of geostatistical methods, a layer was generated for each soil property after six different semivariance models were evaluated. The kriging model (simple, ordinary, or universal) was selected as the best semivariance method with a 10-fold cross-validation approach. Exponential, pentaspherical, and spherical models were selected with ordinary and universal kriging methods to spatially predict the soil properties. Five classes for each soil map were generated. The nine soil properties were classified primarily as slightly low or medium according to their distribution throughout Mexican territory.

"La cuenca del río Duero se localiza al noroeste del Estado de Michoacán, cuenta con una superficie de 2531.3 km 2 . Se realiz ó un diagnóstico de la situación actual de la operación, calidad y cantidad de agua de manantiales de la cuenca. En total se identificaron 52, de los cuales se aforaron 49 que aportaron un gasto acumulado de 8.526 m 3 /s. Las aguas son aprovechadas principalmente para fines agrícolas, consumo urbano, acuacultura y re - creativo. El volumen de agua anual que se genera por los manantiales es de 268 876 Mm 3 , lo que satisface ampliamente las necesidades de la región. La calidad química de los manantiales es excelente para los distintos usos, no así la calidad bacteriológica. En términos de su estado de conservación y operación, s ó lo el 27 % de ellos, presenta problemas serios de un manejo eficiente, lo que pone en riesgo su sustentabilidad."

2 Posgrado en Botanica, Colegio de Postgraduados, Campus Montecillo, Texcoco, Mexico. 3 Autor para la correspondencia: gcruzc@colpos.mx Abstract: Humid Mountain Forest is one of the most important Mexican biomes due to the high fl oristic richness and endemism found within its small geographical extension. The distribution of this biome is not well known in the country; accordingly, the goal of this paper is to delimit its distribution by using potential distribution models of species characteristic to the biome as surrogates. Based on herbarium specimens housed at the National Herbarium of Mexico, a database of 78 species restricted or mostly restricted to Humid Mountain Forest was constructed. In addition, 56 environmental covariates (26 climatic, nine soil properties, nine topo- graphic attributes, and 14 remote sensing data) were assembled. Species modeling was done using MaxEnt. Twenty-three covari- ates defi ned the Humid Mountain Forest distribution in Mexico. Among these, normalized vegetation index for May, total annual precipitation, and organic carbon content in the soil were the most important. According to the models, Humid Mountain Forest in Mexico represents 7% of the total surface of the country and it is found in 25 of the 32 states. Chiapas, Guerrero, Michoacan, and Oaxaca are the most outstanding states since they collectively account for 74% of the total Humid Mountain Forest surface.

El bosque humedo de montana, tambien conocido como bosque mesofilo de montana o cloud forest, esta definido y limitado por la presencia persistente de nubes y neblina que, ademas de la lluvia, capturan las gotas de agua que se condensan sobre la vegetacion. Se reconoce ampliamente que la humedad atmosferica es el principal factor ambiental que promueve la persistencia y distribucion de este tipo de vegetacion en el mundo. Sin embargo, se carecen de analisis correlativos entre riqueza de especies del bosque humedo de montana y los factores ambientales a escalas amplias. Es de suponer que tal riqueza tiene su base en la hipotesis correlativa con variables ambientales contemporaneas, principalmente con la triada altitud-clima-suelo. El objetivo fue analizar e identificar que variables ambientales tienen asociacion significativa y cuales son las mas importantes en la prediccion de la riqueza de especies del bosque humedo de montana. Los sitios con bosque humedo de montana se ubicaron en 61 celdas de 1o latitud × 1º longitud. Mediante sistemas de informacion geografica se generaron capas ambientales que incluyeron variables bioclimaticas, de estacionalidad climatica, un modelo digital de elevacion y variables edaficas. Los resultados indican que 58% de la variacion en la riqueza de especies del bosque humedo de montana se relaciona con cinco variables: la precipitacion pluvial de los meses húmedos del ano, la altitud, la evapotranspiracion real anual, la estacionalidad de la precipitacion y el carbono organico en los suelos. En el bosque humedo de montana de Mexico existe una asociacion consistente entre la riqueza de especies y las expresiones categóricas de la relacion agua-energia.

In this work, aggregate stability was evaluated as a quality indicator in soils of tropi- cal dry deciduous forests (TDF) with relation to land use, the sampling position in the hillslope and the sampling season. The study was done on a representative morpho-edaphological unit of the tropical dry ecosystems (hillslope on granite with eutric regosol) on the coast of the state of Jalisco, Mexico. The evaluated soil ag- gregation indexes were: Aggregate stability index (ASI)test, maximum stability, minimum stability, relative index of variability, and the index of quality of aggrega- tion change. These indexes showed differences in soil aggregation resulting from changes in land use (conserved TDF, grazed TDF, and cultivated pasture). The in- dexes showed that there is greater stability of the aggregates during the rainy season than in the dry season; as well as in the higher part of the slope than in the lower one. The relationship of the edaphic properties with the ASItest indicator was mainly with radical volume, and less so with exchangeable bases (calcium and magnesium), clay, and organic carbon. The proposed soil aggregation indexes allowed monitoring spatiotemporal changes in soil structure.

Map units directly related to properties of soil-landscape are generated by local soil classes. Therefore to take into consideration the knowledge of farmers is essential to automate the procedure. The aim of this study was to map local soil classes by computer-assisted cartography (CAC), using several combinations of topographic properties produced by GIS (digital elevation model, aspect, slope, and profile curvature). A decision tree was used to find the number of topographic properties required for digital cartography of the local soil classes. The maps produced were evaluated based on the attributes of map quality defined as precision and accuracy of the CAC-based maps. The evaluation was carried out in Central Mexico using three maps of local soil classes with contrasting landscape and climatic conditions (desert, temperate, and tropical). In the three areas the precision (56 %) of the CAC maps based on elevation as topographical feature was higher than when based on slope, aspect and profile curvature. The accuracy of the maps (boundary locations) was however low (33 %), in other words, further research is required to improve this indicator. Mapas de solos locais gerado unidades do mapa diretamente relacionadas às propriedades de solo-paisagem. Portanto, para ter em conta o conhecimento dos agricultores é fundamental para automatizar o processo. O objetivo deste estudo foi realizar a cartografia assistida por computador (CAC) das classes de solos locais, por meio de várias combinações de atributos topográficos produzidos em GIS (modelo numérico do terreno, aspecto, declividade e curvatura do perfil). O método da árvore de decisão foi utilizado para localizar o número de atributos topográficos necessários à produção de cartografia digital das classes de solo. Os mapas produzidos foram avaliados usando o atributo de qualidade do mapa, definido como sua precisão e exatidão dos mapas produzidos pelo CAC. A avaliação foi realizada no centro do México, com três mapas de classes de solos locais com diferentes paisagens e condições climáticas: árida, temperada e tropical. Os resultados mostraram que, nas três áreas estudadas, os mapas produzidos pelo CAC, usando o atributo de elevação como característica topográfica, obtiveram a maior precisão (56 %). No entanto, a exatidão dos mapas (localização dos limites) foi menor: 33 %. Isso significa que a precisão dos mapas produzidos ainda permanece baixa, havendo necessidade de novas pesquisas para melhorar esse indicador.

The objective of this research is to evaluate the precision and accuracy of local soil class maps generated with four computer algorithms: minimum distance, parallelepiped, maximum likelihood, and artificial neural networks, using digital elevation models and spectral signatures of local soil classes as input data. The study was done in the states of Mexico, San Luis Potosi, and Veracruz. Statistical binomial proportion tests were done to compare the difference between maps' precision and accuracy. The conclusion was that the combination of reflectance and elevation improved the quality of soil class maps produced by CAC, due to the reflectance variation of local soil classes according to altitude, which helped to better identify them. The best precision was 84% and the best accuracy was 30%.

"Los modelos de balance hidrológico de cuencas son herramientas que permiten describir procesos dinámicos y predecir, a través de la simulación, escenarios del impacto de las actividades productivas de una región. En el presente trabajo se determinó el balance hídrico y las cargas de contaminantes por actividades agrí- colas en la subcuenca del lago de Chapala mediante la herramienta de evaluación de agua y suelo SWAT (2012). Se configuró el modelo con datos de altimetría, con información del tipo de suelo (incorporando los resultados de análisis de laboratorio en cada horizonte) y uso del suelo y vegetación que se actualizó a 2010 por medio de datos de sensores remotos y con el programa Explorafor, así como con las ba- ses de datos climáticas obtenidas del programa EricIII-CONAGUA. Se estructuró un concentrado de fertilizantes y plaguicidas que se utilizan en la subcuenca de Chapala derivadas de 550 encuestas que se aplicaron a los productores agrícolas. La simulación con el modelo SWAT se realizó de 1999 a 2001. El balance hídrico resultó negativo por un margen de 300 %. Esto se puede relacionar con que se trata de una subcuenca abierta, ya que el principal afluente es el río Lerma. En cuanto a los herbicidas, se estima con el modelo una aplicación promedio anual de 408 g/ha de los diferentes principios activos, con una degradación de 342 g/ha. Para los plaguicidas se obtuvo un valor de 533 g/ha con una degradación de 532 g/ha. El total de los herbicidas y plaguicidas disueltos fueron del orden de 1.7 g/ha y los adsorbidos por el sedimento de 11 g/ha."

Prior to modeling the potential distribution of a species it is recommended to carry out analyses to reduce errors in the model, especially those caused by the spatial autocorrelation of presence data or the multi-collinearity of the environmental predictors used. This paper proposes statistical methods to solve drawbacks frequently disregarded when such models are built. We use spatial records of 3 species characteristic of the Mexican humid mountain forest and 2 sets of original variables. The selection of presence-only records with no autocorrelation was made by applying both randomness and pattern analyses. Through principal component analysis (PCA) the 2 sets of original variables were transformed into 4 different sets to produce the species distribution models with the modeling application in Maxent. Model precision was higher than 90% applying a binomial test and was always higher than 0.9 with the area under the curve (AUC) and with the partial receiver operating characteristic (ROC). The results show that the records selected with the randomness method proposed here and the use of the PCA to select the environmental predictors generated more parsimonious predictive models, with a precision higher than 95%, and in addition, the response variables show no spatial autocorrelation.

"El concepto de vulnerabilidad acuífera se define como la probabilidad de que el agua subterránea se contamine con alguna sustancia en concentraciones por arriba de la normatividad para agua de consumo humano o de los valores recomendados por la Organización Mundial de la Salud. Aunque inicialmente se le relacionaba sólo a aspectos cualitativos de contaminación, actualmente puede incluir aspectos cuantitativos, mediante la aplicación de diferentes métodos. El objetivo de este estudio, fue determinar los niveles de vulnerabilidad acuífera para el agua subterránea en la cuenca del río Duero, Michoacán, mediante la utilización del método SINTACS. La cuenca, se localiza al noroeste del estado de Michoacán, dentro de la Región Hidrológica No. 12, Lerma-Santiago, específicamente en la Zona Hidrológica Río Lerma-Chapala. En la región, prevalece un ambiente volcánico sedimentario, destacando estructuras de tipo estratovolcán, depósitos aluviales y lacustres. La economía se sustenta en la producción de frutillas, muy demandante del recurso agua, lo cual hace que la extracción de agua subterránea se realice mediante la operación de aproximadamente 805 pozos, generando sobrexplotación en los valles principales. El comportamiento hidráulico de los acuíferos en la cuenca varía de libre a semiconfinado. Se determinaron primordialmente dos niveles de vulnerabilidad: baja, en el rango de 80-105 puntos, que cubre la mayor parte de la cuenca (50 %) y que se asocia con un acuífero en condiciones de semiconfinado constituido por los materiales arcillosos de baja conductividad hidráulica; y vulnerabilidad media (105-140 puntos) con el 25 % del área, para acuíferos en condición hidrogeológica de libres, asociados a depósitos aluviales. Sólo existen pequeñas porciones con vulnerabilidad muy baja y alta. La obtención de información enfocada hacia este ámbito, coadyuva en el establecimiento de políticas públicas orientadas a la protección del agua subterránea, zonificando sitios potenciales a ser contaminados por actividades antrópicas no planificadas."

The cartography of farmland classes allows generating land maps, using a methodology based on local knowledge, rapidly and at low cost, and with a greater number of cartographic units than conventional soil surveys maps. However, the results found when producing these maps with automated cartography techniques are contrasting. Precision and accuracy were evaluated in 324 computer generated farmland class (FLC) maps by applying the Inverse Distance Weighted (IDW) interpolation model. These maps were obtained by varying the sample size for the training, its spatial design, and the Power value of the interpolator. Moreover, the effort needed to obtain maps with acceptable reliability was quantified. The procedure was applied to FLC maps obtained from surveys with producers from three contrasting environmental zones in Mexico. The results show that the best sampling scheme in the three areas is the systematic sampling, and Power 8, giving the maps with the highest reliability. Through the criterion of map reliability and effort needed for sampling, the recommended sample size is 10% to 25% of the total plots.

Rendimiento de naranja, mineralogía, cartografía de suelos, criterios locales, criterios técnicos.