Ruling Frameworks and Fire Use‐Conflicts in Tropical Forests of Chiapas, Mexico: A Discourse Analysis

The use of fire within tropical forests to settle agriculture and livestock systems has long been causing a bottle-neck for governmental and environmental development agencies, especially in natural forested areas with local population. An international strategy followed since many years ago is the decree of special territories with vast forests as natural protected areas (NPA). In Mexico, environmental laws can run contrary to customs and practices of natural resource-dependent communities which still use fire to farm their lands as unique livelihood activity. The chapter examines two conflicting frameworks of resource management (forest and soil) and governance in a forest village’s efforts to comply with federal policies against fires in a NPA of Chiapas, Mexico. Forest and soil management is a key locus in California village, where governance structures come into conflict with hierarchical State power. Participatory workshops and semi-structured interviews were primary research instruments for data collection and discovery of community front and backstage. Ethnography and discourse analysis were used as main tools for the analysis of information. While the State leads the conservation efforts and limits cultural activities and local actions through coercive laws, the land use and resource-dependent communities defend their access rights, and they also determine how to individual or collectively manage fires in daily activities. Finding collective solutions with horizontal-dialogue strategies represent an important issue and a pending task for the development and preservation agencies focused on forested areas. Backstage dialogue is a tool for village self-preservation when livelihood strategies are at odds with protectionist conservation efforts

Biomass Accumulation and Carbon Storage in Pinus maximinoi, Quercus robur, Quercus rugosa, and Pinus patula from Village- Forests of Chiapas, Mexico

The Frailesca region (Chiapas, Mexico) presents a lack of forest studies and its environmental contribution. This chapter displays a first case study with preliminary research information regarding the identification of main forest trees and rural villages with best potential for biomass production and carbon storage management. Twenty two plots of 500 m2 were selected in 11 villages of the region, in order to identify the main and dominant forest trees species and then to estimate the biomass production and carbon storage in pine (Pinus maximinoi), oak (Quercus robur), holm oak (Quercus rugosa) and Mexican weeping pine (Pinus patula) species. This study shows that the largest accumulation of both biomass and carbon occurred in the pine forests and the lowest in the oak forests. Pine trees showed carbon storage of 516.75 Mg ha−1, followed by holm oaks, with 297.21 Mg ha−1; the species with the lowest value was oak, with 75.02 Mg ha−1. The forests of the 24 de Febrero villages had the highest potential for carbon storage. Deep studies are being conducted in relation to the aboveground biomass, carbon contents in trees stem, branches and leaves, and the relation to biomass dynamics and carbon stocks and other ecological aspects of village-forests

El carbono de la biomasa aérea medido en cronosecuencias: primera estimación en México

Abstract The negotiation of carbon capture projects under REDD+ and CDM mechanisms carried out in the different land and vegetation uses requires knowing the storage capacity (capture) that ecosystems have under current conditions and the approximate maximum level they can reach in the future. Because of this, the temporal variations of the different compartments (aerial biomass, standing woody material, litter-mulch-fallen woody material, underground biomass and soil) as they can contribute as CO2 sinks must be studied. The purpose of this work is to collect, review and synthesize the information available in Mexico about the carbon contents studied in a chronosequences approach. Results of the carbon contents of aerial biomass were found only for 21 types of vegetation of 50 represented in Mexico. The information on the temporal variations in the five carbon stores, can be used as reference to establish buying-selling commitments of carbon bonds in terms of amount and time in which mitigation and adaptation to climate change goals are met.Resumen La negociación de proyectos de captura de carbono bajo mecanismos REDD+ y MDL requiere estimar la capacidad y nivel máximo de almacenamiento de CO2 de los ecosistemas bajo las condiciones actuales y futuras. Para lo anterior debe considerarse la variación temporal, como sumideros de carbono de los compartimientos de biomasa aérea, material leñoso en pie, hojarasca-mantillo, material leñoso caído, biomasa subterránea y suelo. Se recopiló, revisó y sintetizó la información disponible de los contenidos de carbono de los ecosistemas terrestres de México con un enfoque de cronosecuencias. Los compartimentos más investigados en 90 estudios fueron la biomasa viva sobre el suelo y la biomasa muerta en piso y mantillo. Se presentan resultados del contenido de carbono de la biomasa aérea para 21 tipos de vegetación, de los 50 reconocidos para México. La información de la variación temporal del carbono en México, en sus cinco almacenes, será referencia para establecer los compromisos de compra-venta de bonos de carbono en términos de cantidad y tiempo en que se conseguirían las metas de mitigación y adaptación al cambio climático

FOREST LITTER PRODUCTION VARIES WITH SEASON AND ELEVATION GRADIENT IN CHIAPAS, MEXICO

Background. Forest litterfall is a fundamental process of ecosystem nutrient cycling, also, it is a source of energy for the development and propagation of wildfire. Understanding the temporal dynamics of litter production and storage is critical for sustainable management and conservation of forest ecosystems. Objective. To quantify the monthly production and storage of forest litter in an elevation gradient. Methodology. We selected forest sites at three elevations: 670, 775, and 1010 masl, corresponding to pine, oak, and tropical lowland forest ecosystems in Nambiyugua hill, Chiapas, Mexico. Sixteen sampling sites with a radius of 11.28 m were established for tree measurements, and 48 litter traps of 0.50 m2 were installed to collect monthly litterfall for a year. To sample ground litter eight 30 by 30 cm2 quadrats were used in each site. The fallen woody material was measured with the planar intersection method. Litter samples were oven-dried at 60 °C for 72 h and separated into leaves and other plant parts. One-way ANOVA was used to test the significant differences between forests. Results. The highest total loads of litter and fallen woody material were obtained in the pine forests of upper elevation with 29.01 t ha-1. The highest litter production was obtained in January and April, with a mean of 1.34 ± 0.19 and 0.74 ± 0.13 t ha-1 respectively in pine forests. In the oak forest, the highest production occurred in March, with 1.08 ± 0.25 t ha-1; while the lowland forest reached the highest production in January with 0.85 ± 0.26 t ha-1, with a decreasing trend in June. Implications. Understanding the seasonal variability in litter production and forest fuel loads is crucial for forest productivity, carbon sequestration, and wildfire prevention Conclusions. The production of forest fuels was different among the ecosystems representing the elevation gradients. The highest monthly production of litter was registered during the January-May period for the pine and oak ecosystems but in November - January in tropical lowland forests

Composición botánica y calidad de la dieta de bovinos en un sistema silvopastoril intensivo

Se realizó un estudio para evaluar la composición botánica y calidad de la dieta seleccionada para bovinos pastoreando un sistema silvopastoril intensivo (50,000 árboles ha-1) de Leucaena (Leucaena leucocephala) asociado con Chontalpo (Brachiaria decumbens) y Estrella africana (Cynodon plectostachyus) (T1), en comparación al sistema de solamente gramíneas (T2). Se utilizaron ocho becerros en crecimiento de raza Jersey en cada tratamiento. La composición botánica se conoció a través de la técnica de micriohistología en heces, mientras que la calidad de la dieta fue a través de la estimación de proteína cruda (PC), cenizas (Ce) y materia orgánica (MO), y fibra detergente neutro (FDN) y fibra detergente ácido (FDA). Los datos se analizaron mediante un modelo completamente al azar y la comparación de medias se realizó a través de la prueba de Tukey. El T1 presentó un consumo de 68.41% de la gramínea y 31.59% de la arbórea y para el T2 la dieta contenía 100% de la gramínea. Respecto a la calidad de la dieta seleccionada, se encontraron diferencias estadísticas (P<0.05) para el caso de PC (T1= 11.9%, T2= 7.8%). Se concluye que la presencia de la arbórea Leucaena en el sistema, mejora la calidad de la dieta seleccionada de los bovinos en función de una composición botánica más diversa

Captura de carbono en la biomasa aérea de la palma de aceite en Chiapas, México

Chiapas, Mexico, occupies the first place in surface and production of oil palm, as an alternative to mitigate climate change, for the potential of perennial crops to fix in their biomass the carbon (C) that is released in the form of environmental CO2. The objective of this work was to measure the carbon captured in the aerial fraction of the oil palm plant (Elaeis guineensis Jacq.). The study was conducted from January 2016 to June 2017 in three producing regions; where to twenty-one plants of twelve years on average, the stipe biomass was determined using the truncated cone technique, while for the leaves the equivalence of 65% of the biomass of the stipe was used. With these data, a descriptive statistic was made to know the biomass values. The amount of C was determined by the Walkley and Black method modified by UV spectrophotometry. The accumulated biomass per plant was 1877.30 kg, representing 268.45 t/ha with an average density of 143 plants/ha. 49.35% and 44.15% were carbon in stipe and leaves, respectively; therefore, the quantity of this element was 877.64 kg of carbon per plant, which represented 125.5 t/ha. An allometric equation was generated estimating the biomass from the volume of the stipe (y = 243.86 + 990.61x), as well as for the amount of carbon from the biomass (y = 149.07 + 0.39x). Two allometric models were determined with the data obtained from oil palm cultivation, which is suggested to be evaluated in the field to determine the degree of reliability in the estimation of biomass and carbon stored under the agroclimatic conditions similar to those of the present study.Chiapas, México, ocupa el primer lugar en superficie y producción de palma de aceite, se puede considerar como alternativa de mitigación del cambio climático, por el potencial de los cultivos perennes para fijar en su biomasa el carbono (C) que se libera en forma de CO2 ambiental. El objetivo de este trabajo fue medir el carbono capturado en la fracción aérea de la planta de la palma de aceite (Elaeis guineensis Jacq.). El estudio se realizó de enero del 2016 a junio del 2017 en tres regiones productoras; donde a veintiún plantas de doce años en promedio se les determinó la biomasa del estípite mediante la técnica del cono truncado, mientras que, para las hojas se utilizó la equivalencia del 65% de la biomasa del estípite. Con estos datos se realizó una estadística descriptiva para conocer los valores de biomasa. La cantidad de C se determinó por el método de Walkley y Black modificado por espectrofotometría de UV. La biomasa acumulada por planta fue de 1877,30 kg, que representó 268,45 t/ha con una densidad promedio de 143 plantas/ha. El 49,35% y 44,15% fue carbono en estípite y hojas, respectivamente; por tanto, la cantidad de este elemento fue 877,64 kg de carbono por planta, que representó 125,5 t/ha. Se generó una ecuación alométrica que estima la biomasa a partir del volumen del estípite (y = 243,86 + 990,61x), así como para la cantidad de carbono a partir de la biomasa (y = 149,07 + 0,39x). Se determinaron dos modelos alométricos con los datos obtenidos del cultivo de palma de aceite, los cuales se sugiere sean evaluados en campo para determinar el grado de confiabilidad en la estimación de biomasa y el carbono almacenado bajo condiciones agroclimáticas similares a las del presente estudio

Composición botánica y calidad de la dieta de bovinos en un sistema silvopastoril intensivo

Se realizó un estudio para evaluar la composición botánica y calidad de la dieta seleccionada por bovinos pastoreando un sistema silvopastoril intensivo (50,000 árboles por hectárea) de Leucaena (Leucaena leucocephala) asociado con Chontalpo (Brachiaria decumbens) (T1) en comparación al sistema monocultivo de la misma gramínea (T2). Se utilizaron seis becerras en crecimiento de raza Jersey en cada tratamiento. La composición botánica se realizó siguiendo la técnica descrita por González (1990), en la calidad de la dieta, para el caso de Proteína Cruda (PC), Ceniza (Ce) y Materia Orgánica (MO) con la técnica de AOAC (1990), Fibra Detergente Neutra (FDN) y Fibra Detergente Ácida (FDA) fueron determinadas según la técnica de Van Soest (1983). Los datos se analizaron mediante un modelo completamente al azar y la comparación de medias se realizó a través de la prueba de Tukey. El T1 presentó un consumo del 68.41 % de la gramínea y 31.59 % de la arbórea, para el T2, la dieta contenía 100 % de gramíneas. Respecto a la calidad de la dieta seleccionada, se encontraron diferencias estadísticas (P<0.05) para el caso de proteína cruda (T1= 11.9, T2= 7.8 %). Se concluye que la presencia de la arbórea Leucaena en el sistema, mejora la calidad de la dieta seleccionada de los bovinos en función de una composición botánica más diversa

BIOMASS PRODUCTION AND CHEMICAL COMPOSITION OF Tithonia diversifolia BY THE DATE OF HARVESTING AT DIFFERENT CUTTING HEIGHTS

Background: The use of Tithonia diversifolia foliage can improve the quality of animal feed because its crude protein content doubles that of tropical grasses. However, plant response regarding biomass production to frequent harvest disturbances are not known well. Objective: To evaluate the effect of different cutting heights and repeated harvests on biomass production and nutrient content of T. diversifolia in fodder banks under warm sub-humid climate. Methodology: We used a completely randomized design with a factorial arrangement; the treatments consisted of six harvest dates: Mar, May, July, September, November 2019 and January 2020; and three harvest heights: 40, 60 and 80 cm from the ground level. After each harvest date, the biomass was separated into different components, weighed and dried. Samples were taken to analyse the chemical composition of the forage. Results: The highest yield of leaves was found in the month of January, while tender stems in November. The Senescent material and total biomass were lower in September. The cutting height influenced leaf yield. Crude protein content was higher in September at a cutting height of 60 cm. Neutral detergent fiber was higher in the month of November for all cutting heights. Likewise, the highest contents of acid detergent fiber were in November for all cutting heights and in January for the cutting height of 60 cm. Lignin content was similar for all treatments. Implications: These results contribute to the development sustainable livestock production by providing alternatives to reduce grassland degradation from overgrazing. Conclusion: Biomass yield and chemical composition of T. diversifolia are affected by harvest date and heights, so it is necessary to consider it in the management strategies for optimal use of forage resources, incorporation in silvopastoral systems and the development of sustainable livestock production

Dinámica temporal de combustibles forestales y efecto del incendio en Cerro Nambiyugua, Chiapas, México

Forest fuel is one of the main carbon pools, but is also considered a factor involved in the occurrence and intensity of forest fires. The objective of this study was to analyze the temporal dynamics of forest fuel storage and the effect of fire in a pine (Pinus oocarpa Schiede) forest. The measurement of fresh and decomposed litter, and woody materials was carried out from 2010 to 2021 at four sites of a pine forest in the Cerro Nambiyugua, Villaflores, Chiapas, with the National Forest and Soil Inventory method. At each site, eight 30 x 30 cm2 quadrants were used to collect litter samples. To dry the samples, paper bags were used and placed in an oven at 70°C for 72 hours. The fallen woody material was sampled with the line intersection method. Fresh and decomposed litter load increased gradually over time. The highest litter loads were obtained in 2018 with 12.67 t ha−1 . After the forest fire in 2019, the litter load decreased to 5.67 t ha−1 , and by 2021 it increased to 8.65 t ha−1 . The accumulation trend of fallen woody material varied according to the category of ignition hours. The results of this study have fundamental implications in the strategies and periodicity of forest fuel load management and carbon storage, since a greater frequency of forest fires is expected with climate change.Los combustibles forestales son uno de los principales reservorios de carbono, pero también se consideran un factor involucrado en la ocurrencia e intensidad de incendios forestales. El objetivo de este estudio fue analizar la dinámica temporal de almacenamiento y efecto del incendio sobre los combustibles forestales en bosque de pino (Pinus oocarpa Schiede). La medición de hojarasca, mantillo y materiales leñosos se realizó de 2010 a 2021 en cuatro sitios de un bosque de pino del Cerro Nambiyugua, Villaflores, Chiapas con el método del Inventario Nacional Forestal y de Suelos. En cada sitio, se utilizaron ocho cuadrantes de 30 x 30 cm2 para colectar las muestras de hojarasca y mantillo. Para el secado de las muestras, se utilizaron bolsas de papel estraza y se colocaron en estufa a 70°C durante 72 horas. El material leñoso caído se determinó con la metodología de intersección planar. La carga de hojarasca y mantillo aumentó gradualmente con el tiempo. Las mayores cargas de hojarasca se obtuvieron en el año 2018 con 12.67 t ha−1 . Después del incendio forestal del año 2019, la carga de hojarasca disminuyó a 5.67 t ha−1 , y para el 2021 aumento a 8.65 t ha−1 . La tendencia de acumulación de material leñoso caído varió según la categoría de horas de ignición. Los resultados de este estudio tienen implicaciones fundamentales en las estrategias y periodicidad del manejo de carga de combustibles forestales y almacenamiento de carbono ya que con el cambio climático se espera mayor frecuencia de incendios forestales

BIOMASS ACCUMULATION IN FORESTS WITH HIGH PRESSURE OF FUELWOOD EXTRACTION IN CHIAPAS, MEXICO

ABSTRACT Tropical forests plays a vital role in mitigating atmospheric CO2 but the retention capacity of such ecosystems has changed greatly due to increasing anthropogenic pressures, of which firewood extraction is the main one activity in rural areas. The purpose of this research was to evaluate the biomass stocks of pine and oak forests with different pressure of fuelwood extraction in Chiapas, Mexico. The study was carried out in four locations in the state of Chiapas, southern Mexico; two of them with high extraction levels and the other two with lower extraction levels. Pine and Oak forests are the predominant forest types in the region. A total of sixteen plots of 400 m2 were established to measure the biomass stocks of the trees with > 7.5 cm DBH. Published allometric equations were used to quantify the biomass stocks. The average biomass of the pine forest with low fuelwood extraction was 213.4 Mg ha-1, and that of the oak forest was 189.5 Mg ha-1. On the other hand, the biomass stocks of the pine forest with high fuelwood extraction was 138.2 Mg ha-1, and that of the oak forest was 92.0 Mg ha-1. Communities with agricultural diversification like apiculture and agroforestry practices were found more effective in forest biomass conservation when compared to those who are only dedicated to Milpa cultivation and extensive bovine livestock production. The adoption of silvopasture systems, the use of crop residues and the use of ecological cooking stoves can be the alternatives to reduce forest fuelwood extraction