Mónica de la Cruz Vargas-Mendoza

Los agroecosistemas se han desarrollado junto a los asentamientos humanos a lo largo de la historia, caracterizados por la inclusión de labores culturales que intervienen las dinámicas territoriales (DT), lo que hace necesario comprenderlas para fortalecer el desarrollo de una región. La presente propuesta de reflexión, bajo un enfoque sistémico pretende dimensionar los agroecosistemas tropicales desde el reconocimiento de las DT como parte fundamental de las innovaciones técnico-científicas que se aplican al territorio. Esta investigación está dirigida a considerar aquellos elementos que distinguen la dimensión ambiental desde el sistema socioecológico que atraviesa sus componentes socioculturales, económico-productivos, político-institucionales implícitos en los agroecosistemas de frutas tropicales, los cuales normalmente se han abordado de manera aislada. En conclusión, esta propuesta aporta herramientas innovadoras al modelo de análisis que permiten abordar los agroecosistemas tropicales desde una perspectiva sistémica, interpretando las modificaciones en las relaciones que suceden al interior del territorio agrícola, pertinentes para la toma de decisiones que buscan el bien común, aportando nuevas miradas en la construcción y fortalecimiento de la agricultura alternativa.

The continuous changes and increase of land use into ranching and agriculture have caused shifts in the composition and structure of dung beetle communities due to the modification of vegetation structure. The impact of these changes can be approached using dung beetles as ecological indicators. Agricultural, ranching, and forestry are often integrated into the same farm in different proportions (landscape level), and their degree of integration with habitats changes over time and space. We assessed if different habitat proportions of crop, pasture, and forest land on three farms affect the structure and diversity of dung beetle (Coleoptera: Scarabaeinae) communities. Farms included from three to four habitat conditions each (plantations of timber species, banana-coffee plantation, living fences, pastures, secondary and riparian forest). Pitfall traps with dung and carrion as bait were placed across each habitat condition of each farm during three different sampling periods. Across all samplings, 1,198 dung beetle individuals belonging to 21 species were captured. Species diversity and composition vary according to the type of farm and the main factor that modifies this tendency is the proportion of pasture land composing the farm. Farms with a lower proportion of grazing land (11.96% for forestry farms and 32.19% for agricultural farms) and denser vegetation canopy, which cast more shadows, had greater beetle diversity. Conversely, farms having a greater proportion of grazing land had low diversity and a dominant tendency in the species abundance curve. Umbraphile species dominated the forest farm, indicating a strong affinity for shaded environments such as the one provided there, while species displaying no habitat preference exhibited higher abundance in the ranching farm. Additionally, a notable prevalence of small-sized species was observed in the ranching farm, contrasting with a relatively even distribution of sizes in the remaining landscapes. These tendencies suggest that shade positively influences biodiversity conservation. Riparian vegetation, living fences, and banana-coffee plantations are important connectivity elements in agricultural landscapes for shade-adapted dung beetle species.

Background. Climate change models have projected an increase in the distribution of certain crop pests of economic importance by forecasting more favorable future conditions for these organisms. In citrus farming, Huanglongbing is one of the most devastating diseases worldwide, since it has caused the death of millions of trees. Objetive. The objective of this study was to estimate the current and future distribution of Candidatus Liberibacter asiaticus in Mexico, under the climate change scenarios SSP2 4.5 and SSP5 8.5, for the years 2050 and 2070. Methodology. Distribution models were generated with MaxEnt and R, using uncorrelated bioclimatic variables from eight General Circulation Models (GCM) derived from CMIP6 and disease presence data. Results. The results indicate that the current suitability is 44.6 %. The future distribution depended on how model predictions were pooled. An optimistic approach that considered the intersection of all models showed a small reduction of 4.1% while, considering the union of all the GCM models, the increase will vary from 12.3 to 20.1 % of the Mexican territory depending on the particular scenario and time projection. Implications. The zones of potential occurrence of Candidatus Liberibacter asiaticus include most of the citrus-growing areas in Mexico. Conclusion. In some regions, future scenarios show a reduction in the potential occurrence of the species in citrus plantations. However, the risk remains because its surroundings include suitable areas that can be sources of dissemination of the disease.

El zacahuil, alimento ancestral, símbolo de identidad de la Huasteca, es elaborado y consumido hasta la fecha en esta región de México. El objetivo fue conocer cómo el proceso de elaboración del zacahuil es aprendido y la relación de sus insumos con los agroecosistemas de la Huasteca. Se entrevistaron 130 personas de tres municipios de la región huasteca, expertas en elaborar zacahuil, utilizando una guía de entrevista semiestructurada. Se encontró que el zacahuil es elaborado por adultos y jóvenes, principalmente para venta al público. El aprendizaje del proceso de elaboración ocurre principalmente en contextos familiares. Los ingredientes y materiales más importantes para su elaboración son el maíz, la carne de cerdo, la papatla y la leña, los cuales provienen de los agroecosistemas locales; estos insumos marcan diferencias entre municipios. Se concluye que los elementos locales que dan origen a las diferencias en ingredientes y materiales entre municipios, al estar en relación estrecha con los recursos específicos de cada lugar, y sus agroecosistemas, contribuyen a la prevalencia del zacahuil como una comida con identidad local y regional de la Huasteca.

Background. Plants in the neotropical region provide different ecological services and sustain entomofauna biodiversity. The butterfly, Morpho helenor montezuma, has high economic value worldwide, derived from recreational activities. To enhance its sustainable use, it is important to know the spatial relationship of this species with its host-plants. Objective. To estimate the potential geographical areas in Mexico of three host-plants: Bauhinia divaricata, Andira inermis and Pterocarpus rohrii and their spatial relationship with M. helenor montezuma. Methodology. Distribution models of the species were generated using MaxEnt, employing predictive variables based on temperature and precipitation, and records of presence data. Subsequently, a joint analysis of layers was performed to determine the overlap in the distributions. Results. The models were appropriate as the area under the curve ranged from 0.86 to 0.96. The broadest potential host-plant distribution was for B. divaricata (30%), followed by A. inermis (21%) and P. rohrii with 7% of the country. In general, the joint distribution of the plant species is neotropical, and can be found in Veracruz, Tabasco, Chiapas and Oaxaca. Implications. The knowledge of the distributions of the plants allows their prioritization for conservation management and entomotourism. Conclusion. The joint distribution of B. divaricata against that of M. helenor montezuma had the greatest overlap (61%), with regard to the type of climate the highest concordance was found with P. rohrii. Pertinence to entomotourism and conservation planning is discussed.