It is well known that tree growth is strongly affected by climate at high elevations, but it is still unclear how climate variability influences the distribution of montane forest ecosystems, particularly tree line species. To advance knowledge in this field, we combined temporal (tree ring measurements) and spatial data (remotely sensed variables), to quantify how forests responded to climatic variability across altitudinal gradients in Central Mexico. Normalized difference vegetation index (NDVI), tree‐ring chronologies, and site‐level climatic data were used in a vegetation trend analysis of greenness and browning and to reconstruct canopy vigor for the last century. Although a common ring width chronology was developed, we found significant site‐dependent forest growth response, where young trees (<100 years) exhibited heterogeneous growth trends, without an altitudinal pattern. However, mature trees (100–200 years) showed a common growth decline during the middle twentieth century, regardless of their altitude. Annual maximum NDVI anomalies did not show a general greening effect at high‐elevations. The forest showed both greening and browning zones denoting spatial variability in tree vigor. Furthermore, temperature from the previous year had a positive effect on both NDVI and ring width index but negative at beginning of the growing season. The significant relationship between winter‐spring NDVI (December to March) and ring width index (r = 0.64, p < 0.05), was useful to reconstruct the canopy vigor for the last 151 years. Thus, the greening effect derived from NDVI should be carefully interpreted as a direct forest growth increase. These results highlight the potential of integrating remotely sensed and dendrochronological methods to improve predictions of forest ecosystem responses.

An interdisciplinary approach is needed for understanding tree physiology and forest biogeochemical cycles undergoing climate change and rising atmospheric CO₂. We combined tree ring time series, wood isotope signatures, remotely sensed variables, and climatic data to perform a spatiotemporal scaling analysis of tree physiology and high‐elevation forest responses to rising CO₂. The main question addressed is how tree physiological performance of dominant trees can be combined with satellite‐derived information of stand‐level productivity to understand how the landscape shapes the relationship between forest structure and function. Annually resolved tree ring carbon and oxygen isotopic ratios (δ¹³C and δ¹⁸O), carbon isotope discrimination from CO₂ to wood (Δ¹³C), and intrinsic water‐use efficiency (iWUE) of dominant Pinus hartwegii Lindl. trees were sampled and compared against stand‐level normalized difference vegetation index (NDVI) time series from 2000 to 2016. Linear mixed‐effects models tested the effects of elevation, aspect, and time. Carbon and oxygen isotope ratios were correlated with NDVI mainly for the previous fall‐winter season and for the beginning of the growing season. Wood δ¹³C decreased over time regardless of spatial position, whereas wood δ¹⁸O varied as a function of altitude and time. Although Δ¹³C did not vary with elevation, aspect, or time, a notable decline in Δ¹³C and peak in iWUE during a severe drought event was evident. Results highlight the link between remotely sensed data, tree ring isotopic composition, and tree physiology as the determining factors to determine spatiotemporal variability in dendroecological studies.

This study aimed to determine the population fluctuation of Scolytinae (Coleoptera: Curculionidae) in orchards of avocado Persea americana var. Hass, located in the municipalities of Nuevo San Juan Parangaricutiro (SJ), Uruapan (UR), and Ziracuaretiro (ZR), Michoacán, México. The study was carried out from July 2016 to June 2018. The insects were captured using a-copaene, ethanol and querciverol + ethanol lures, which were placed in bottle traps. The population fluctuation of Scolytinae, during both years and sampling sites, presented its maximum peak during July and August. In ZR, the highest abundance of Scolytinae were recorded during July and October in the 2016-2017 cycle, and during September and October in the 2017-2018 cycle. The population abundance of Scolytinae was higher during the 2016-2017 cycle in SJ and UR, and in ZR the highest population abundance corresponded to the 2017-2018 cycle. The most abundant species of Scolytinae in SJ were Microcorthylus invalidus (43.28%), Araptus schwarzi (28.68 %) and Corthylus detrimentosus (23.02 %), in UR, were A. schwarzi (41.40%) and M. invalidus (14.75%) and ZR were Premnobius cavipennis (26.04%), Hypothenemus crudiae (17.75 %) and Corthylus flagellifer (16.17%). At the three sites, the maximum population coincided with the periods with higher rainfall and higher relative humidity percentages, conditions that favored a greater availability of food resources at the sites, which were used by the species for their establishment.

El programa anual de fertilización juega un papel importante en el manejo del huerto y de su eficiencia dependen, en gran medida, la producción y calidad de los frutos. Una fertilización balanceada considera la cantidad de nutrientes disponibles en el suelo, incluyendo los que utiliza el árbol para su desarrollo y los que son removidos por la producción de fruto, lo que asegura el suministro adecuado de macro y micro elementos. El objetivo de esta investigación fue evaluar el efecto del programa de fertilización sobre los cambios en las variables relacionadas con la maduración y calidad de frutos de mango ‘Kent’, a partir de un experimento instalado en un huerto de comercial enAcaponeta, Nayarit, México, donde se aplicaron tres niveles de fertilización ((g árbol-1): normal (381 de N, 367deP2O5,296deK2O,688deCa,84deMg,14deFe,9 de Mn, 5 de Zn y 45 de B), alta (50% más de cada elemento de la dosis normal) y control (sin fertilización). Las dosis de fertilización afectaron la concentración nutrimental del fruto. Se presentaron diferencias en los perfiles de la intensidad respiratoria, firmeza, sólidos solubles totales (SST), ácido cítrico, ácido ascórbico y relación azúcar/ácido, asimismo, la presencia de nitrógeno en los niveles de fertilización normal y alta, aumentó la tonalidad verde del color de fondo de los frutos. Se concluyó que, la calidad y vida de anaquel de los frutos fue afectada por los niveles de fertilización aplicados.

Photosynthetica covers wide range of photosynthesis research or research including photosynthetic parameters of both experimental and theoretical nature.

Los árboles de jacaranda son comunes en áreas urbanas del valle de México y se desarrollan frecuentemente bajo condiciones de estrés nutricional o hídrico, lo que restringe el crecimiento del arbolado. El suministro de carbohidratos a través del sistema vascular recientemente se ha recomendado como una opción para mejorar el crecimiento y vitalidad. Por lo anterior, el objetivo del trabajo fue evaluar el efecto de la glucosa sobre crecimiento y vitalidad de árboles de Jacaranda mimosifolia inyectada al tronco en cuatro concentraciones: 0 (testigo), 30, 55 y 80 g L-1 Se midieron incrementos en diámetro (cm) y altura (m), se monitoreó la condición de copa y producción de follaje y además se evaluó el contenido de carbohidratos en brotes, troncos y raíces, así como la fluorescencia de la clorofila (Fv/Fm). Se encontraron diferencias significativas (P≤0.05) en el incremento en diámetro y altura con la aplicación de 80 g L-1 de glucosa. La condición de copa mostró valores significativamente más altos en densidad y bajos en transparencia, así como una buena producción de follaje, con la concentración más alta del carbohidrato (80 g L-1). Su contenido presentó diferencias significativas (P≤0.05) en tronco, no así en brotes, raíces, ni en valores de fluorescencia de la clorofila. Las inyecciones de glucosa al tronco tienen un efecto significativo en el crecimiento de árboles de esta especie y afectan en menor medida la vitalidad del arbolado.