Paisajes geomorfológicos relacionados con la clasificación de los suelos en planicies y terrazas de Tabasco, México:

Introducción: Las selvas albergan más de la mitad de las especies del planeta, a pesar de la biodiversidad que poseen son los ambientes más amenazados, principalmente por actividades antrópicas, y su complejidad con relación a la altitud alberga vacíos de información a pesar de los valores que representa. Objetivo: Describir la estructura y diversidad de árboles en un gradiente altitudinal. Métodos: En cinco estratos altitudinales (EA) se establecieron 21 unidades de muestreo (UM) de 20 x 50 m: seis en el EA1, cinco en EA2, cuatro en EA3, tres en EA4 y 5. La estructura se caracterizó mediante las categorías diamétricas y de altura, y de los índices de valor de importancia (IVI) y forestal (IVF). La diversidad se analizó con los índices de Shannon-Wiener (H´) y Simpson (S), mientras la semejanza florística con el coeficiente de Sørensen (IS). Resultados: Se registraron 209 especies, ocho registradas en la Norma Oficial Mexicana-059-Secretaría de Medio Ambiente y Recursos Naturales-2010 (NOM-059-SEMARNAT-2019). Las especies con los mayores IVI e IVF fueron: Haematoxylum campechianum y Manilkara zapota en EA1; Rinorea guatemalensis y Pouteria reticulata en EA2; M. zapota y Brosimum alicastrum en EA3; Guatteria anomala y Pseudolmedia spuria en EA4; y Terminalia amazonia y Pouteria durlandii en EA5. En los cinco EA se identificaron tres rangos de altura y seis de diámetro, el mayor número de individuos se encontró en la primera categoria diamétrica. La diversidad de las especies fue menor a mayor altitud. En los EA 2 y 3 se presentó la mayor semejanza (IS = 58.7 %). Conclusión: La estructura y diversidad de las especies arbóreas, presentan mayores cambios en intervalos altitudinales más amplios, relacionados con la necesidad ambiental de cada especie.

Scolitine bark beetles of the genus Tomicus (Coleoptera: Curculionidae: Scolytinae) include some forestry pests of major importance worldwide, with the capacity for invading new habitats and threatening native forest populations and are considered as exotic species for America. However, Tomicus piniperda L. the common pine shoot beetle has invaded North America recently and specimens of T. minor Hart have been intercepted in the United States. The possibility for an invasion of Mexico grows day by day. A preventive strategy to evaluate the invasion by exotic species is ecological niche modeling. Using bioclimatic variables, distributional data, entropy algorithm, and modeling software, the ecological niche of three Tomicus species was calculated and projected to Mexico. Results of this analysis showed potential environmental suitability in Mexico for T. destruens (small and dispersed areas in the Altiplano Norte biogeographic province and an isolated area in the Tamaulipeca biogeographic province) and T. minor (high suitability in the biogeographical provinces of Baja California, California, Sonorense, Altiplano Norte and Altiplano Sur, Tamaulipeca and small areas in eastern Eje Volcánico.). For T. piniperda, no environmental suitability was projected in Mexico. Additional ecological requirements, host preferences, and local fauna competition, as factors influencing the potential invasion of T. minor in Mexico, are discussed. Our work has an important impact because Mexico is one of the most important countries with high pine diversity in the world and shows an important impact on pine´s hot spots.

Objective: The objective of this study was to evaluate the edaphic suitability of Elaeis guineensis at a semi-detailed scale (1:50000), in the Plains and Terraces of Tabasco, Mexico (PTT). Design/Methodology/Approach: The edaphic requirements consisted of a semi-detailed soil map. The evaluation of the edaphic suitability was based on the agroecological zoning methodology proposed by FAO and the final 1:50000 scale map was developed using the algebra mapping tool with the ArcGis® Geographic Information System. Results: The Gleysols, Fluvisols, Luvisols, and Lixisols groups dominate the PTT, with 65.1, 16.2, 6.3, and 4%, respectively. Most of the soils (79.95%) have zero suitability for oil palm. Study Limitations/Implications: Oil palm is the eighth most important perennial crop (over cocoa) for the economy of southeastern Mexico. In this scenario, the expansion of plantations in the country is a possibility; therefore, complying with internal regulations and carry is important. Findings/Conclusions: The internal drainage of Gleysols soils limits the establishment of E. guineensis plantations in the plains and terraces of Tabasco, Mexico.