Caracterización de las estructuras diamétricas de los bosques naturales del noroeste de Durango, México

The diameter distribution of 44 permanent plots (conifers and broadleaf trees) was modeled using the three-parameter Weibull and Johnson's SB probability density functions (PDFs) in Santiago Papasquiaro, Durango. Four different methods of fitting parameters were used: maximum likelihood (ML), moments (MM), non-linear regression by ordinary least squares (ONLS) and percentiles (MP). The best method of fitting parameters for conifers and broadleaf trees was the method of moments. In modeling the Weibull PDFs, it was assumed that the location parameter (ε) corresponds to the minimum measurable diameter. The scale parameter (λ) was modeled using the method of prediction parameter (PPM) through a linear regression relating to the quadratic mean diameter and dominant height of the stand. Finally, the shape parameter (γ) was indirectly recovered by the method of moments through prediction of the average diameter of the stand. According to the Kolmogorov-Smirnov test (P= 0.05), 71 % of the plots for the group of conifers and 68 % of the plots for the group of broadleaf species come from a population that follows the fitting distribution functionLa distribución diamétrica de 44 parcelas permanentes (coníferas y latifoliadas) se modeló a través de las funciones de densidad de probabilidad (FDP) Weibull de tres parámetros y SB Johnson, en el municipio de Santiago Papasquiaro, Durango. Para ello, se emplearon cuatro métodos de ajuste de parámetros: máxima verosimilitud, momentos, regresión no lineal por mínimos cuadrados ordinarios y percentiles. El mejor método de ajuste para las especies de coníferas y latifoliadas fue el método de momentos. En el modelado de la FDP Weibull se asumió que el parámetro de localización (ε) corresponde al diámetro mínimo inventariable de la distribución. El parámetro de escala (λ) se modeló con el procedimiento de predicción de parámetros a través de un modelo de regresión lineal simple que relaciona γ con el diámetro cuadrático medio y la altura dominante del rodal. Finalmente, el parámetro de forma (γ) fue recuperado indirectamente por el método de momentos a través de la predicción del diámetro medio del rodal. De acuerdo con la prueba de Kolmogorov-Smirnov (P = 0.05), 71 % de las parcelas del grupo de especies de coníferas y 68 % de las parcelas del grupo de latifoliadas provienen de una población que sigue la función de distribución ajustadaS

Compatible Taper and Volume Systems Based on Volume Ratio Models for Four Pine Species in Oaxaca Mexico

Estimating tree volume components is an essential element in sustainable forest management. Compatible taper and merchantable outside-bark volume systems based on volume ratio models were globally fitted to four pine species (reduced models) with the aim to select the best reduced model and to fit it with dummy variables and additive effects using Pinus pseudostrobus Lindl as a base species. The study was carried out in the northern mountains of Oaxaca, Mexico. To fit the taper, merchantable volume, stem volume, branch volume, and total tree volume (stem volume and branch volume) equations, a taper dataset of 222, 230, 245, and 333 trees of Pinus douglasiana Martínez (Pd), Pinus oaxacana Mirov (Po), Pinus patula Schltd (Pp), and Pinus pseudostrobus Lindl (Pps), respectively, was used. In general, the compatible systems explained more than 97% in the observed variability for the four studied components: outside-bark diameter (d), merchantable outside-bark volume (Vm), stem outside-bark volume (Vs), and total tree volume (Vt). Alternatively, more than 52% of the observed variability for branch volume (Vb) was also explained. The developed compatible systems based on volume ratio models are a simple and consistent alternative for estimating the outside-bark diameter and variable outside-bark volume, as well as the components of commercial species for uneven-age and mixed-species forests in Oaxaca, MexicoThis study was partially financed by the CONAFOR—CONACYT funding for the project called Biometric system for the planning of sustainable forest management of ecosystems with timber potential in MexicoS

Evaluación de modelos de diversidad-abundancia del estrato arbóreo en un bosque de niebla

Los modelos de diversidad-abundancia pueden emplearse para detectar impactos o perturbaciones en ecosistemas forestales que han sido aprovechados. Se compararon cuatro modelos en cuanto a la distribución-abundancia de especies arbóreas en dos parcelas de observación con diferente historial de manejo en el bosque mesófilo de montaña “El Cielo”, Tamaulipas, México. Se probaron dos esquemas de muestreo para evaluar su eficiencia en colectar la información requerida para el ajuste de estos modelos. Los resultados sugieren que las parcelas de observación se encuentran en un estadio sucesional entre las etapas pioneras y tardías, donde dominan las especies con abundancia intermedia. El esquema de muestreo en transectos resultó ser más adecuado para colectar el tipo de información requerida para el ajuste de los modelos. La parcela que fue previamente sometida a cortas selectivas se encuentra en una etapa de sucesión más temprana que aquella sin intervención, ya que en esta última la abundancia relativa de especies se ajustó al modelo normal logarítmico, mientras que los datos de la primera no se ajustaron. Contrario a estudios en los que no se recomienda el uso de modelos de abundancia de especies para detectar impactos o perturbaciones en ecosistemas forestales después de haber sido intervenidos, esta investigación indica que dichas ecuaciones son herramientas útiles para evaluar y cuantificar tales cambios

An Analysis of Non-State and State Approaches for Forest Certification in Mexico

The first author expresses thanks to CONACYT for her doctoral-awarded scholarship (Grant 362184)Mexico has had a non-state forest certification system under the Forest Stewardship Council (FSC) since it was initiated in 1993, and developed a new state-sponsored Mexican Forest Certification System (MFCS) that began in 2008. Several analyses have been made of FSC forest certification in Mexico, but none have summarized the new MFCS system or compared its standards with FSC. We compare the implementation of the non-state FSC market forest certification with the state-sponsored MFCS system in Mexico, and review literature on forest certification, focusing on all studies in Mexico. MFCS has had substantial enrollment of more than 902,802 ha by 2016, compared to 900,388 ha for the more-established FSC program. MFCS can be acceptable for stand-alone forest certification, and might be viewed as a stepwise path to FSC certification. The merits of both systems are analyzed in terms of standard content, likely sustainable forestry practices, access to markets, and community forestry enterprises.S

Non-small cell lung cancer diagnosis aid with histopathological images using Explainable Deep Learning techniques

Background: Lung cancer has the highest mortality rate in the world, twice as high as the second highest. On the other hand, pathologists are overworked and this is detrimental to the time spent on each patient, diagnostic turnaround time, and their success rate. Objective: In this work, we design, implement, and evaluate a diagnostic aid system for non-small cell lung cancer detection, using Deep Learning techniques. Methods: The classifier developed is based on Artificial Intelligence techniques, obtaining an automatic classification result between healthy, adenocarcinoma and squamous cell carcinoma, given an histopathological image from lung tissue. Moreover, a report module based on Explainable Deep Learning techniques is included and gives the pathologist information about the image’s areas used to classify the sample and the confidence of belonging to each class. Results: The results show a system accuracy between 97.11 and 99.69%, depending on the number of classes classified, and a value of the area under ROC curve between 99.77 and 99.94%. Conclusions: The classification results obtain a substantial improvement according to previous works. Thanks to the given report, the time spent by the pathologist and the diagnostic turnaround time can be reduced.Andalusian Regional I+D+i FEDER Project DAFNE US-138161

Modelos de volumen específicos y regionales para 12 especies forestales en el estado de Durango, México

Introduction: Estimating the volume of individual trees is an important aspect in dendrometry and in the conducting of forest inventories. Objective: Significant differences were evaluated in additive equation systems for estimating the total volume of individual trees in nine species of the genus Pinus (P. cooperi, P.durangensis, P. arizonica, P. leiophylla, P. teocote, P. engelmannii, P. lumholtzii, P.strobiformisand P. herrerae), and three of the genus Quercus (Q. sideroxyla, Q. durifoliaand Q. rugosa), and among regional forest management units (UMAFOR) when dealing with the same species. Materials and methods: To evaluate whether equation systems are different among tree species of the same genus and among the UMAFORs for the same species, two complementary statistical analyzes were used based on the fitting of a reduced and a full equation system: the F test of nonlinear extra sum of squares method, and the parameter significance analysis. Results and discussion: For most of the species studied, equation systems are significantly different. The need to use regional models in 10 of the 12 tree species, except for P. strobiformis and Q. rugosa, is also reported. Conclusion: The use of a state model for P. strobiformis and Q. rugosa is recommended.Introducción: La estimación del volumen de árboles individuales es un aspecto relevante en la dendrometría y en la realización de inventarios forestales. Objetivo: Se evaluaron diferencias significativas en sistemas de ecuaciones aditivas para la estimación de volumen total de árboles individuales en nueve especies de Pinus (P. cooperi, P. durangensis, P. arizonica, P. leiophylla, P. teocote, P. engelmannii, P. lumholtzii, P. strobiformis y P. herrerae), y tres de Quercus (Q. sideroxyla, Q. durifolia y Q. rugosa), y entre unidades de manejo forestal regional (UMAFOR) cuando se trata de una misma especie. Materiales y métodos: Para evaluar si el sistema de ecuaciones difiere entre especies de un mismo género y entre las UMAFOR para una misma especie, se utilizaron dos análisis estadísticos complementarios basados en el ajuste de un sistema reducido y un sistema completo de ecuaciones: la prueba F asociada al método de la suma adicional de cuadrados no lineales y el análisis de significancia de los parámetros. Resultados y discusión: Para la mayoría de las especies estudiadas, los sistemas de ecuaciones son significativamente diferentes. Se reporta la necesidad de utilizar modelos regionales en 10 de las 12 especies, exceptuando a P. strobiformis y Q. rugosa. Conclusiones: Se recomienda el empleo de un modelo estatal para P. strobiformis y Q. rugosa.We thank the Program Fomento a la Organización Social,Planeación y Desarrollo Regional Forestal (PROFOS) of CONAFOR for funding the collection of the data used in this studyS

Desarrollo de un modelo de perfil de copa para Pinus cooperi Blanco en la UMAFOR 1008, Durango, México

A crown profile model for Pinus cooperi Blanco in UMAFOR 1008 (El Salto, Pueblo Nuevo, Durango) was developed from data corresponding to 92 sampled trees. Trees with well-formed crowns were selected from stands varying in age, density and site quality. Diameter at breast height, total height, crown width, crown length, and crown profile were measured in each tree. To predict the crown profile, basic geometric shapes and several mathematic models were evaluated. The model developed by Hann (1999) best described the experimental data of the total crown, light crown, and shaded crown, accounting for over 92 % of the observed variability.Se desarrolló un modelo de perfil de copa para Pinus cooperi Blanco a partir de 92 árboles en la UMAFOR 1008 (Región El Salto, Pueblo Nuevo, Durango). Se seleccionaron individuos con una copa bien conformada y de diferente edad, densidad y calidad de estación. En cada uno de los individuos se midieron las variables diámetro normal, altura total, diámetro, longitud y perfil de copa. Tanto formas geométricas sencillas como algunos modelos matemáticos se analizaron para predecir el perfil de la copa. El mejor modelo para describir el perfil de copa de P. cooperi fue el de Hann (1999), ya que tuvo mejor ajuste para la copa entera, copa de luz y copa de sombra, explicando más de 92 % de la variabilidad de los datos.S

Allometric Equations for Estimating Biomass and Carbon Stocks in the Temperate Forests of North-Western Mexico

This paper presents new equations for estimating above-ground biomass (AGB) and biomass components of seventeen forest species in the temperate forests of northwestern Mexico. A data set corresponding to 1336 destructively sampled oak and pine trees was used to fit the models. The generalized method of moments was used to simultaneously fit systems of equations for biomass components and AGB, to ensure additivity. In addition, the carbon content of each tree component was calculated by the dry combustion method, in a TOC analyser. The results of cross-validation indicated that the fitted equations accounted for on average 91%, 82%, 83% and 76% of the observed variance in stem wood and stem bark, branch and foliage biomass, respectively, whereas the total AGB equations explained on average 93% of the total observed variance in AGB. The inclusion of total height (h) or diameter at breast height2 × total height (d2h) as a predictor in the d-only based equations systems slightly improved estimates for stem wood, stem bark and total above-ground biomass, and greatly improved the estimates produced by the branch and foliage biomass equations. The predictive power of the proposed equations is higher than that of existing models for the study area. The fitted equations were used to estimate stand level AGB stocks from data on growing stock in 429 permanent sampling plots. Three machine-learning techniques were used to model the estimated stand level AGB and carbon contents; the selected models were used to map the AGB and carbon distributions in the study area, for which mean values of respectively 129.84 Mg ha−1 and 63.80 Mg ha−1 were obtained.This study was financially supported by the Mexican National Council for Science and Technology (CONACyT) and by the State of Durango Government (Project FOMIX- DGO-2011-C01-165681)S

Assessing the natural durability of different tropical timbers in soil-bed tests

Ground contact speeds up timber decay because of the large number of microorganisms in soil. This study, we assessed the natural durability of seven tropical species using the European standard EN 807 (2001). We embedded samples of Dalbergia granadillo, Cordia elaeagnoides, Swietenia humillis, Tabebuia donell-smithii, Hura polyandra, Enterolobium cyclocarpum and Tabebuia rosea and temperate species Fagus sylvatica (as a control) in sandy, clay-sandy-loam and clay-loam for 8, 16, 24 and 32 weeks. We evaluated durability of the samples by determining the mass loss and modulus of elasticity (MOE) loss. The results varied significantly (p < 0.001) depending on timber species and soil type considered. The D. granadillo and C. elaeagnoides were the most durable, with mass losses of 4.5%, 6.5% and MOE losses of 4.5%, 20.5%, respectively. F. sylvatica, T. rosea and E. cyclocarpum samples were the least durable, with mass losses of 22.3-25% and MOE losses of 35.8-59.8%, respectively. Decay was most aggressive in sandy-clay-loam soil followed by the clay-loam soil and finally the sandy soil