Se realizó un inventario florístico de la SMsC del centro de Veracruz, México, mediante el muestreo de67 parcelas de 100 m2 distribuidas en 5 sitios de estudio ubicados en el muncipio de Jalcomulco, región central deVeracruz. En total se registraron 230 especies de plantas vasculares, distribuidas en 174 géneros y 68 familias. Lasfamilias más diversas fueron Fabaceae, Euphorbiaceae, Rubiaceae y Acanthaceae. El 42% de las especies registradasfueron árboles, seguidas por hierbas (23%), arbustos (19%) y trepadoras (14%). El análisis de similitud demostróimportantes diferencias entre los sitios de estudio. La riqueza fue de 35.6±9.5 especies/100 m2 y se presentarondiferencias significativas entre los sitios muestreados. Las especies más frecuentes fueron Aphanante monoica,Brosimum alicastrum y Resinanthus aromaticus en el estrato superior; Mosannona depressa, Coccoloba barbadensisy Malpighia glabra en el estrato medio; Comocladia engleriana, Hyperbaena jalcomulcensis, Yucca guatemalensis,Acalypha villosa y Psychotria erythrocarpa en el estrato inferior; Anthurium schlechtendalii, Dorstenia contrajerva yLasiacis sloanei en el estrato herbáceo y en las trepadoras Hippocratea celastroides y Petrea volubilis. El predominiode especies arbóreas y el bajo número de especies de Asteraceae y Poaceae indican que se trata de vegetación primariabien conservada.

Introduction: Drought is a slow evolution phenomenon drastically affecting the environment and human activities. Nowadays, there are several indices to study drought. They can be based on in-site measurements of meteorological stations or remote perception data. However, Mexico’s number of functioning meteorological stations from the National Meteorological Service (NMS) is steadily decreasing. Nevertheless, the NMS reports drought conditions through the Mexican Drought Monitor (MDM), which uses different methods to estimate drought levels. These reports are provided every 15 days for each municipality. However, the methods the NMS utilizes are unknown to the general public. Thus, in-situ studies which try to estimate drought are limited by the MDM data constrictions. Consequently, remote perception is an alternative to solve the lack of stations and the MDM data restrictions, depending on the region. Therefore, this research aims to: 1) Develop a methodology to quantify drought intensity based on the Normalized Difference Drought Index (NDDI) with Landsat 8 multispectral images in the municipalities of the central zone of the Gulf of Mexico for drought and no drought periods. 2) Analyze and compare the NDDI behavior against the MDM from the NMS during the same periods.Methods: The methodology consisted of estimating the NDDI by using Landsat 8 multispectral images. Further on, NDDI drought values were compared with the MDM.Results: Results showed that NDDI values increase from July to October during a drought period, coinciding with months when precipitation is low, and temperature is high. Additionally, it was found that the NDDI coincides with the MDM data in 46% of the municipalities having drought conditions when temperatures increased 2.1°C and precipitations decreased by 668 mm. Furthermore, the NDDI coincided in 16% of the municipalities during no drought periods with the maximum increases in temperatures at 1.4°C and precipitation reduced by 386 mm.Discussion: The NDDI estimated by Landsat 8 images can determine drought behavior in the study zone during periods with limited reduced precipitation and temperature increases.

Agriculture and raising livestock are human activities highly affected by drought. In Mexico, the Veracruz territory is seriously affected by this phenomenon. Our study had two objectives: (1) to analyze the drought evolution through the Standardized Precipitation Index (SPI) and the maximum temperature in the central zone of the state of Veracruz for the period 1980–2018; and (2) to describe the relationship between the yield of corn grain and cattle, and the SPI, in the study area. The methodology consisted of calculating the SPI to estimate the drought conditions in the mentioned area. Subsequently, we determined the relationship of these conditions with the maximum temperature increase and the presence of El Niño/La Niña events. The results showed that the drought has intensified during 1980–2018, having a presence in almost 50% of the area. Additionally, the maximum temperature increased by approximately 6 °C. As a result, the cultivation of corn grain under rain conditions showed reductions in 48% of the analyzed municipalities. Concerning livestock variables, lower reductions were reported (42–32%) for the same period. Therefore, we can conclude that the drought has intensified in recent years due to an increase in the maximum temperature and El Niño/La Niña events, and these factors have had a higher impact on the agricultural sector.

Hydrometeorological hazards are considered the most important phenomena affecting crop production in the Eastern regions of Mexico, where the State of Veracruz is located. However, more information about their consequences on these sites needs to be studied. This research aims to determine the effects of hydrometeorological phenomena on the most important crops cultivated in the State of Veracruz. The methodology involved analyzing the State’s crop production database from 2001 to 2020 and comparing this data with the National Hydrometeorological Disaster Declarations database. Multivariable correlation analysis and geographic information systems were applied to geographically analyze 42 rainfed crops plus the five most valuable ones in the State to determine their production related to climatic phenomena. The results found that the most affected crops are corn, soy, sorghum, beans, and rice, with more than 10,000 lost hectares. Droughts caused total damage to corn, soy, and beans and decreased productivity in corn, orange, lemon, wheat, coffee, and sesame. For the most valuable crops, tropical cyclones caused the highest production decrements in corn, sugar cane, and pineapple, while droughts caused the same effects in lemon and orange. We conclude that tropical cyclones are the most critical phenomena negatively impacting Veracruz, with high implications on the agrifood system.

Antecedentes y Objetivos: El estudio de las selvas tropicales es de gran interés debido a su alta biodiversidad, relacionada con la variabilidad del ambiente, que incrementa la diversidad y la especificidad de sus componentes. Este estudio presenta una evaluación de la estructura, riqueza y diversidad de especies de angiospermas leñosas de la selva mediana subcaducifolia (SMsC) en el centro de Veracruz, con el objetivo de contribuir al conocimiento de sus características e identificar áreas de alto valor para la conservación de los escasos fragmentos de vegetación primaria que aún existen en la zona.Métodos: Se delimitaron 67 parcelas de muestreo de 100 m2, distribuidas en cinco sitios de estudio en los municipios Jalcomulco y Tlaltetela. En cada parcela se registraron y midieron todos los individuos con DAP ≥5 cm y se estimaron sus valores de cobertura, densidad, área basal y altura, así como los valores de diversidad α (riqueza total, riqueza por parcela e índice α de Fisher) y los valores de diversidad β (matriz de similitud con coeficiente de Jaccard y porcentaje de similitud), además de la importancia ecológica de las especies mediante el Valor de Importancia Relativa de Curtis (VIR).Resultados clave: Se registraron 98 especies de plantas leñosas, agrupadas en 83 géneros y 35 familias de angiospermas. Las familias más diversas fueron Fabaceae y Euphorbiaceae. La forma biológica predominante (75.5%) fueron los árboles. La selva tropical mostró una alta riqueza y elevada tasa de recambio de especies. Las especies dominantes de acuerdo con el VIR fueron Resinanthus aromaticus y Brosimum alicastrum, aunque el conjunto de las seis especies dominantes fue muy variable entre los sitios de estudio.Conclusiones: La presencia de especies clave como Brosimum alicastrum, Resinanthus aromaticus y Sapranthus microcarpus permitió identificar los elementos característicos de la SMsC y sus ecotonos con la selva mediana subperennifolia y la selva baja caducifolia.