BackgroundCuatrociénegas is a region of unique biological, geological, geographical and evolutionary importance. It is part of the Chihuahua Desert, its current population is mestizo; however, it has a high historical, cultural and tourist relevance. It has been cataloged as a Flora and Fauna by Mexican law, as well as a High Protection site by the World Wildlife Fund and UNESCO. Because of its complex biological and sociocultural characteristics, we consider it important to know, determine, identify and analyze the traditional ethnobotanical knowledge and practices in this region.MethodsBetween 2016 and 2019, seven field trips were made to document the knowledge and use of flora. Cuatrociénegas is a protected area, collecting botanical material is regulated, so specimens were photographed and collected in neighboring communities, and in public and private gardens. Later permission was obtained to complete the collection of specimens (2019-2020). The plants were identified and entered into the flora database of the state of Coahuila, and deposited in the Herbarium of the Faculty of Forest Sciences, Autonomous University of Nuevo León, Mexico. One hundred and ten local residents (50 men and 60 women) aged between 27 and 91 years were interviewed (semi-structured interviews). The cultural importance of ethnobotanical resources (cultural significance index) and its significance with respect to ethnobotanical richness in other Biosphere Reserves in Mexico (Mann-Whitney test) ware evaluated.Results and DiscussionThe ethnobotanical information registers 158 species and 132 genera in 57 vascular and non-vascular families, documenting a greater knowledge and use of cultivated species (84) with respect to wild species (74). The diversity of plants reported, compared to other ethnobotanical studies carried out in Biosphere Reserves, is similar. The people local pay special attention to medicinal and ornamental plants. The species that presented the highest use values are Larrea tridentata, Jatropha dioica and Machaeranthera pinnatifida, three characteristic species of the desert region.ConclusionsThe particular diversity of wild flora in Cuatrociénegas Valley, combined with the varied introduced flora, is an important multifunctional resource. Special attention to introduced species is associated with use restrictions; as well as the high value of ornamental species, difficult to maintain in desert areas. The extensive knowledge and use of ethnobotany are an example that biocultural diversity (at the conceptual level) is also, strongly associated with socio-ecological system with mestizo groups and semi-urban rural landscapes, ceasing to be exclusive to indigenous regions.

Los incendios forestales en México han tenido gran relevancia después de la temporada de incendios en 1998 debido a su contribución directa a la deforestación, el cambio en la estructura y composición del bosque. Además recientemente se considera su participación directa en el incremento de bióxido de carbono en la atmósfera. Sin embargo,  es muy escaso el conocimiento que se posee acerca de los efectos de los incendios sobre la estructura, composición y dinámica de los bosques de la Sierra Madre Oriental (SMO). En este trabajo, se presenta una cronosecuencia de incendios forestales (134 años) determinada a través del análisis de anillos de crecimiento en cohortes post-incendio con diferentes edades. Los objetivos del estudio fueron: (1) establecer y determinar el rango histórico de la ocurrencia de incendios forestales, (2) evaluar parámetros dendrométricos para conocer la estructura presente y así establecer sitios de referencia para programas de restauración ecológica y (3) incrementar nuestro conocimiento en los procesos de disturbio en los bosques mixtos de pino-encino en la SMO. El estudio revela que existieron diferencias significativas entre las cohortes post incendios en términos de riqueza de especies, composición y estructura del rodal. La estructura forestal fue menos diversa en rodales jóvenes comparados con los intermedios, maduros y sobremaduros. Una alta diversidad de especies arbóreas fue generalmente encontrada en rodales jóvenes, mientras que en los rodales intermedios y maduros mostraron la diversidad más baja.

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Patrones de distribución espacial del arbolado en un bosque mixto de pino-encino del noreste de México Spatial distribution patterns of trees in a mixed pine-oak forest of Northeastern Mexico

Water availability and salt excess are limiting factors in Mexican mixed pine-oak forest. In order to characterise the acclimatation of native species to these stresses, leaf water (W w ) and osmotic potentials (W s ) of Juniperus flaccida, Pinus pseudostrobus and Quercus canbyi were measured under natural drought and non-drought conditions under two different aspects in the Sierra Madre Oriental. Factorial ANOVA revealed significant differences in W w and W s between two aspects, species and sampling dates. In general, all species showed high predawn and low midday values that declined progressively with increasing drought and soil-water loss. Seasonal and diurnal fluctuation of W w and W s were higher for J. flaccida and Q. canbyi than for P. pseudostrobus. Leaf W w and W s were mainly correlated with soil water content, while W s of P. pseudostrobus were hardly correlated with environmental variables. Thus, species have different strategies to withstand drought. P. pseudostrobus was identified as a species with isohydric water status regulation, while J. flaccida and Q. canbyi presented water potential patterns typical for anisohydric species. The type of water status regulation may be a critical factor for plant survival and mortality in the context of climate change. Nevertheless, for precise conclusions about the advantages and disadvantages of each type, further long-term investigations are required.

Background Cuatrociénegas, part of the Chihuahuan Desert, is a region of unique biological, geological, geographical, and evolutionary importance. Its current population is mestizo; nevertheless, it has high national historical, cultural, and touristic relevance in Mexico. It has been cataloged as nationally significant for its flora and fauna by Mexican law, as well as being designated a High Protection site by the World Wildlife Fund and UNESCO. Because of its diverse and complex biological and sociocultural characteristics, we considered it important to determine, identify, and analyze various aspects of the traditional ethnobotanical knowledge and practices in this region. Methods Between 2016 and 2019, seven field trips were made to document the knowledge and use of flora. Cuatrociénegas is a protected area, collecting botanical material is regulated, so specimens were photographed and collected in neighboring communities, and in public and private gardens. Later permission was obtained to complete the collection of specimens (2019–2020). The plants were identified and entered into the flora database of the state of Coahuila, and deposited in the Herbarium of the Faculty of Forest Sciences, Autonomous University of Nuevo León, Mexico. One hundred ten local residents (50 men and 60 women), aged between 27 and 91 years, were interviewed (semi-structured interviews). The cultural importance of ethnobotanical resources (cultural significance index) and its significance with respect to ethnobotanical richness in other Biosphere Reserves in Mexico (Mann-Whitney test), and similarities in the diversity of exotic species (Sørensen index) were studied. Results and discussion The ethnobotanical information registers 158 species and 132 genera in 57 vascular and non-vascular families, documenting a greater knowledge and use of cultivated species (84) with respect to wild species (74). The diversity of plants reported is compared to other ethnobotanical studies carried out in Mexican Biosphere Reserves. These results are highly relevant, in spite of unique exotic species. The people local pay special attention to medicinal and ornamental plants. The species that presented the highest use values are Larrea tridentata, Jatropha dioica, and Machaeranthera pinnatifida, three species characteristic of the desert region. Conclusions The particular diversity of wild flora in Cuatrociénegas Valley, combined with the varied introduced flora, is an important multifunctional resource. Special attention to introduced species is associated with harvesting use restrictions in the protected area as well as the high value of ornamental species that are difficult to maintain in desert areas. The extensive use of ethnobotanical knowledge is an example that biocultural diversity (at the conceptual level) is also strongly associated with socio-ecological systems incorporating mestizo groups and semi-urban rural landscapes, thus ceasing to be an exclusive focus of indigenous communities and regions.

Se desarrolló un diagrama de manejo de densidad (DMD) para el género Pinus en un predio bajo manejo del ejido Pueblo Nuevo, Durango, cuyo objetivo es la producción de madera para aserrío. Los datos se obtuvieron del inventario forestal de la Umafor 1008, en El Salto, Durango y consta de 196 sitios de muestreo, de los cuales se estimó el número de árboles por hectárea N, la altura dominante H0, el diámetro medio cuadrático dg y el volumen V. El diagrama se desarrolló con dos ecuaciones base, en las que se representó el diámetro medio cuadrático y el volumen. El Índice de espaciamiento de Hart-Becking IH, se calculó como referencia en la planeación de cortas; las ecuaciones base fueron ajustadas a través de la regresión no lineal de la función nls en el software estadístico R project 3.4.0. Rstudio 1.0.143, a través de un proceso iterativo; el ajuste simultáneo de las ecuaciones se realizó por el método de FIML (full information maximum likelihood). El sistema de ecuaciones fue ajustado simultáneamente mediante el procedimiento MODEL del sistema estadístico SAS/ETS®. La bondad de ajuste de los estadísticos arrojó un coeficiente de determinación R2 = 0.7074 y un error medio cuadrático RMSE = 2.7563 para la ecuación de dg y de R2 = 0.9947 y RMSE = 7.9114 para el volumen. Las isolíneas del Índice de Hart adquirieron valores mínimos y máximos en porcentaje de la densidad de 16 de 56, respectivamente. Se planteó un esquema de cortas de acuerdo al objetivo de producción: madera con dimensiones para aserrío.

The use and consumption of wood has always captured the attention of forest researchers, mainly from the point of view of forest management and the sustainable processing of raw materials. For this reason, the wood industry has not only been concerned with the maintenance of forests, but also with efficient processing. The objective was to identify, analyse and discuss the main elements that influence the efficient use of natural timber resources at a global, regional and local level, providing a historical and current perspective of the industrial forestry sector in Mexico. Historically, the wood industries worldwide have been concerned with applying intensive silvicultural treatments in native and artificial forest stands, in search of satisfying the demand of a growing market. In this context, industries evolved as processes needed to be more efficient. Therefore, efforts were made to reduce and take advantage of forest residues, at the same time various historical events generated additional needs. At present, the integration of silviculture and forest transformation allow to increase and improve the quality of the products generated. Through the application of intensive silvicultural treatments, products of a single species are obtained. However, it is possible to direct production to a specific market as the forest mass develops. For its part, selective treatments in uneven-aged forests maintain a constant production of diverse products for different specialized markets. In Mexico, it is imperative to analyse and generate innovative or competitive products derived from wood to improve the efficiency of forest harvesting.