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Background: Drought periods are major evolutionary triggers of wood anatomical adaptive variation in Lower Tropical Montane Cloud Forests tree species. We tested the influence of historical drought events on the effects of ecological stress memory on latewood width and xylem vessel traits in two relict hickory species (Carya palmeri and Carya myristiciformis) from central-eastern Mexico. We hypothesized that latewood width would decrease during historical drought years, establishing correlations between growth and water stress conditions, and that moisture deficit during past tree growth between successive drought events, would impact on wood anatomical features. We analyzed latewood anatomical traits that developed during historical drought and pre- and post-drought years in both species. Results: We found that repeated periods of hydric stress left climatic signatures for annual latewood growth and xylem vessel traits that are essential for hydric adaptation in tropical montane hickory species. Conclusions: Our results demonstrate the existence of cause‒effect relationships in wood anatomical architecture and highlight the ecological stress memory linked with historical drought events. Thus, combined time-series analysis of latewood width and xylem vessel traits is a powerful tool for understanding the ecological behavior of hickory species. [ABSTRACT FROM AUTHOR]

We describe a new fossil wood genus of Anacardiaceae with two species from the Tepetate Formation (upper Eocene), Baja California Sur State, Mexico. The first species has distinct growth ring boundaries, vessels solitary and in radial multiples; alternate intervessel pitting, and the vessel-ray parenchyma pits with reduced borders. Its other features are: non-septate and septate fibers, axial parenchyma rare, and rays mostly uniseriate except for those with radial canals. The second species has distinct growth ring boundaries, vessels solitary and in radial multiples (a higher percentage of solitary vessels than the first species), vessel-ray pits with a horizontal to round shape, all fibers nonseptate, vasicentric axial parenchyma, heterocellular rays and radial canals in some multiseriate rays. The diagnostic traits in both woods allow us to erect in a new fossil genus, Pericuxylon with two species in the Anacardiaceae family. The occurrence of Anacardiaceae in the late Eocene of southern Baja California Sur confirms its long geological history and importance in forests of northern Mexico. • Key words: Baja California Peninsula, eudicots, fossil woods, Sapindales. [ABSTRACT FROM AUTHOR]

In tropical dry forests, studies on wood anatomical traits have concentrated mainly on variations in vessel diameter and frequency. Recent research suggests that parenchyma and fibers also play an important role in water conduction and in xylem hydraulic safety. However, these relationships are not fully understood, and wood trait variation among different functional profiles as well as their variation under different water availability scenarios have been little studied. In this work, we aim to (1) characterize a set of wood anatomical traits among six selected tree species that represent the economic spectrum of tropical dry forests, (2) assess the variation in these traits under three different rainfall regimes, and (3) determine the relationships between wood anatomical traits and possible functional trade-offs. Differences among species and sites in wood traits were explored. Linear mixed models were fitted, and model comparison was performed. Most variation occurred among species along the economic spectrum. Obligate deciduous, low wood density species were characterized by wood with wide vessels and low frequency, suggesting high water transport capacity but sensitivity to drought. Moreover, high cell fractions of carbon and water storage were also found in these tree species related to the occurrence of abundant parenchyma or septate fibers. Contrary to what most studies show, Cochlospermum vitifolium, a succulent tree species, presented the greatest variation in wood traits. Facultative deciduous, high wood density species were characterized by a sturdy vascular system that may favor resistance to cavitation and low reserve storage. Contrary to our expectations, variation among the rainfall regimes was generally low in all species and was mostly related to vessel traits, while fiber and parenchyma traits presented little variation among species. Strong functional associations between wood anatomical traits and functional trade-offs were found for the six tree species studied along the economic spectrum of tropical dry forests. [ABSTRACT FROM AUTHOR]

1. There is little information on tropical dry forests regarding cerambycids and their relationship with seasonality, vertical stratification, and physical characteristics of the wood they require to develop. 2. In this work, we determined whether cerambycids in a tropical dry forest of central Mexico differed in the selection of oviposition sites in two different strata throughout two seasons; the relationship between the time of exposure of branches and the emergence of cerambycids; the emergence of these insects in relation to the physical characteristics of the wood and its relationship with stratification and seasonality; and if there was a seasonal shift between strata by cerambycids. Branch segments from 81 woody plant species were cut and exposed to allow the cerambycids to oviposit; the branches were harvested in four 2‐month periods and placed in emergence chambers. For each plant species, we measured the density, decomposition rate, and offered volume of wood. 3. There was a greater quantity of generalist species of stratum (15) and season (12), and we found six important habitat indicator species: three species were significantly associated with the canopy and the dry season, two species preferred the dry season but not strata, and one species preferred both strata in the dry season and the ground during the rainy season. Cerambycid species generally selected soft and ephemeral wood resources. 4. Branch selection by cerambycids in Central Mexico is not random choice; it is determined by season, stratum, density, and especially by host type, decomposition, and volume. Finally, there is a greater abundance of cerambycids in the ground and a greater richness of species in the canopy. [ABSTRACT FROM AUTHOR]

Cactus species are well represented in arid and semiarid environments, where they sometimes even dominate the landscape, forming true cactus forests. In this review, we summarize for the first time the importance of cactus species as a wood resource for a neglected saproxylic (dead wood-dependent) entomofauna associated with decomposing and decomposed tissues in arid and semiarid environments. The complex decomposition process of cactus species is discussed in depth. We provide a checklist of the entomofauna living in decaying and decayed cacti, in which insects represented 93% of the species recorded. In particular, Coleoptera (41.5%) and Diptera (43.8%) orders together represented 85% of the insect species recorded. The family Drosophilidae made up 50% of studied Diptera species because the drosophilid–cactus–yeast complex has been widely studied during recent decades. However, we found that during the last 2 decades, there has been increasing interest in investigating the diversity of arthropods in this saproxylic habitat in Mexico, with a special focus on Syrphidae (Diptera) and Coleoptera, the former for their role in the decomposition process. Disentangling the role of the insects associated with decaying cactus is a challenge when it comes to understanding the function of xeric saprophagous insects in this environment. One frontier in this research area is to find whether decomposed stems in xeric soils would act as "islands" of fertility due to the amount of nitrogen which could be recuperated from these microecosystems. Further research is needed to understand the ecological succession of the entomofauna playing a role in the decomposition process of cactus species in semiarid environments. Graphical Abstract [ABSTRACT FROM AUTHOR]

The generation of biomass residues in different productive activities of rural communities in Mexico represents an area of opportunity for the generation of bioenergy for various purposes. Solid biofuels (SBF), for example, are an alternative for the exploitation of these residues. The present study shows a comprehensive proposal for the analysis of residues of Pinus spp. generated by the artisanal sector of a rural community in Mexico. The proposal is based on four stages: a) characterization of the physico-chemical and functional properties of the residues, by Scanning Electron Microscopy (SEM), Infrared (FTIR) and Raman Spectroscopy, Thermogravimetry (TGA-DTG), determining the calorific coefficient and polymeric compounds present by fiber analysis; (b) spatial, temporal and dimensional analysis of the waste generated in the town studied; (c) assessment of the energy potential available in space and time; (d) definition of guidelines for the management of solid biofuels for the community through collection, processing and final disposal centers. The results of the assessment of timber residue from 50 artisan workshops that represent 25% of the total in the community show that the identified heating value of the dry residue ranges from 17.6 MJ/kg to 18.1 MJ/kg, attributed to the presence of polymeric compounds such as cellulose, hemicellulose and lignin, the latter in the order of 28%, which contributes to a high energy potential, and whose compounds were identified by TGA-DTG analysis, FTIR, SEM and fiber analysis. The energy potential was estimated at approximately 7 TJ/year for the analyzed workshops. In which case, the economic savings obtained from unburned firewood would amount to about $20,000 USD/year. As regards the reduction in firewood consumption due to the use of residues for energy purposes, about 350 Tn/year would be mitigated, which would reduce the community's emissions by more than 76 TnCO2/year. A strategic management proposal was also established, aimed at providing spaces for the collection, processing and final disposal of solid biofuels from wood residues, which in sum represent an energy alternative that is sustainable in environmental, economic and social terms, for the same community. [ABSTRACT FROM AUTHOR]

Copyright of Biotropica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: To achieve optimal balance among wood's support, storage, and transport functions, tree species present adaptive variation in wood anatomical traits. Oaks (Quercus) are woody plants that are dominant in many ecosystems, possess wide variation in wood traits, and can tolerate water stress in diverse habitats. Mountain regions contain steep climatic gradients that exert strong environmental pressures on wood traits. The aims of this study were: (1) to quantify the anatomical variation in 21 oak species distributed along an environmental gradient and (2) to analyze the interspecific variation among the studied species. Fibres and parenchyma fractions were the most abundant cell types. We found a trade-off between total fibre fraction and total parenchyma fraction modulated by the precipitation during the warmest quarter in which oak species in drier areas invested more in support cells. The 21 oak species studied showed vasicentric tracheids, which could be essential to compensate for the transport system in drier areas. Wood density was negatively correlated with the axial parenchyma fraction and fibre lumen width. Oak species have high interspecific variation in the total vessel fraction and vessel diameter. Anatomical variation in oak species along a climatic gradient showed a broad continuum of fibre characteristics from wide to narrow wall and lumen, abundant to scarce parenchyma, and wide to narrow vessels. These variations imply a diversification of ecological strategies within the genus that includes the vascular design of the stem to define the tolerance and competitiveness of the oak species. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

BACKGROUND: Here we report the residual efficacy of the neonicotinoid insecticide clothianidin against pyrethroid-resistant Aedes aegypti. We first conducted a range-finding evaluation of clothianidin on three different substrates (wall, wood, cloth) using three doses (100, 300 and 600 mg a.i. m−2) and conducting World Health Organization (WHO) cone bioassays to assess acute (24 h) and delayed (up to 7 days) mortality. In experimental houses located in Merida (Mexico) and using free-flying pyrethroid-resistant Ae. aegypti females, we quantified the acute and delayed mortality after a 24-h exposure to the targeted indoor residual spraying (TIRS) of two clothianidin doses (100 and 300 mg a.i. m−2). RESULTS: Range-finding studies with WHO cones showed low (<50%) acute mortality for all surfaces, doses and times post spraying. Delayed mortality was higher, with average values above or close to the 60% mark (and 95% confidence interval estimates crossing 80% for the 600 mg a.i. m−2 dose). In experimental houses, a similar low acute mortality was quantified (range of mortality across 12 months was 2–44% for 100 mg a.i. m−2 and 8–61% for 300 mg a.i/m²). However, delayed mortality showed a strong effect of clothianidin on free-flying Ae. aegypti, with values above 80% up to 7 months post-TIRS. CONCLUSION: Novel residual insecticide molecules have a promising outlook for Ae. aegypti control and can contribute to the expansion and adoption of TIRS in urban areas. clothianidin can contribute to the control of resistant Ae. aegypti and provide residual control for up to 7 months after application. [ABSTRACT FROM AUTHOR]

Ips apache Lanier is a bark beetle that is a potential risk to biodiversity and the coniferous wood industry. In Mexico, the insect is associated with various tree species of the genus Pinus. This work is the first published report on infestation by I. apache in Pinus devoniana Lindley in southern Jalisco, Mexico. [ABSTRACT FROM AUTHOR]

Summary: The paleofloras of Central America are little known, and on this occasion, woods from the Miocene of Chalatenango, El Salvador, are reported. The identification was carried out from the elaboration of thin sections that allowed observation of anatomical patterns. Later, they were compared with woods of current and fossil taxa already described in the literature. The fossil specimens presented characteristics shared by several current genera of Lauraceae, so they were assigned to this family. However, since the variability of the woods between the genera of Lauraceae is low, it was uncertain to assign them to the current genera without having other plant organs. We recognize five new species in three fossil genera: Argapaloxylon salvadorensis , Laurinoxylon scalariforme , Mezilaurinoxylon miocenica , M. americana , and M. draconis. In addition, we assign a wood to an already described species, L. chalatenangensis. In Central America and southern Mexico, there is a great diversity and dominance of lauraceous plants in forests and jungles. The specimens described here represent new evidence suggesting that this vegetation type may have existed for approximately 15 million years. However, that current genera cannot be recognized even at this time is striking. A more detailed history of the lineages involved requires a closer comparison of existing plants with extinct ones. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lilloa is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work presents new data on the life cycle impact assessment of various lignocellulosic biomass types in Mexico. A comparative life cycle assessment model of biomass densification systems was conducted. An integrated approach that incorporated various process variables, such as technology and variations in feed properties, within the analysis was employed to evaluate the environmental impact of producing 1 MJ of energy-containing densified fuel. The results show that the densification unit and curing (fuel drying) have the highest impact on the life cycle's operational energy and the total life cycle energy, respectively. Of all the 33 biomass types from the 17 species sources considered in this study, sweet sorghum and sandbur grass have the highest global warming potential, 0.26 and 0.24 (kg CO2-eq), and human toxicity 0.58 and 0.53 (kg 1,4-dichlorobenzene-eq), respectively, while coffee pulp and cooperi pine wood have the least impact in both categories, with values of 0.08 and 0.09 (kg CO2-eq), and 0.17 and 0.16 (kg 1,4-dichlorobenzene-eq), respectively. Chichicaxtla sawmill slabs also have a low environmental impact, and cooperi pine and Ceiba wood have the lowest ozone depletion and ecotoxicity potential. A sensitivity analysis indicated the effects of the transportation system and energy source on the life cycle's environmental impact. Adequate feed preparation, the blending of multiple feeds in the optimum ratio, and the careful selection of densification technology could improve the environmental performance of densifying some of the low-bulk-density feed biomass types. [ABSTRACT FROM AUTHOR]

Wood encodes environmental information that can be recovered through the study of tree-ring width and wood anatomical variables such as lumen area or cell-wall thickness. Anatomical variables often provide a stronger hydroclimate signal than tree-ring width, but they show a low tree-to-tree coherence. We investigate the sources of variation in tree-ring width, lumen area, and cell-wall thickness in three pine species inhabiting sites with contrasting climate conditions: Pinus lumholtzii in wet-summer northern Mexico, and Pinus halepensis and Pinus sylvestris in dry-summer north-eastern Spain. We quantified the amount of variance of these three variables explained by spring and summer water balance and how it varied among trees. Wood anatomical variables accounted for a larger inter-individual variability than tree-ring width data. Anatomical traits responded to hydroclimate more individualistically than tree-ring width. This individualistic response represents an important issue in long-term studies on wood anatomical characteristics. We emphasized the degree of variation among individuals of the same population, which has far-reaching implications for understanding tree species' responses to climate change. Dendroclimatic and wood anatomical studies should focus on trees rather than on the mean population series. [ABSTRACT FROM AUTHOR]

Wood decomposition in tropical forests is strongly linked to the terrestrial carbon cycle. Our understanding of the successional changes in wood decomposition in diverse tropical forests is still limited. In this study, we tested the hypothesis that fine wood decomposition rates decline with the increasing age of successional forests due to the interspecific variation in wood density and changes in species composition. We studied fine wood decomposition in a chronosequence of tropical forests representing four successional phases in southern Mexico. Wood segments (1–7.5 cm diameter) from 30 dominant species (wood density range 0.34–0.83 g cm−3) were left on the ground for decomposition, and samples were recollected at different time intervals for three years. We used a modified negative exponential model by introducing the power parameter (p) that allowed for a time-dependent decomposition rate (k). Average k within a successional phase ranged from 0.22 to 0.39 yr−1 and declined gradually with the increase in forest age. We found a significant negative correlation between wood density and decomposition rate constants. The kspecies ranged from 0.07 to 1.11 yr−1, whereas p-parameters varied between 0.65 and 1.42. Trees such as Bursera simaruba, and Cascabela gaumeri decomposed faster, while Eugenia ibarrae, and Pouteria reticulata decomposed slower. Average fine woody debris inputs ranged from 1.2 to 3.7 Mg ha−1 yr−1 which increased with forest age. Increasing production and declining decomposition rates during succession contribute to the higher accumulation of deadwood in primary forests. The results on generalized, age- and species-specific wood decay parameters have important implications in simulating carbon dynamics of the changing tropical forests. [ABSTRACT FROM AUTHOR]

Gullies in volcanic deposits are among the first signs of erosion that can be observed during or immediately after the volcanic activity and reflective of unstable conditions of newly formed deposits. Gully formation and erosion pulses may well continue to occur long after the initial landform was created, mostly as a result of torrential rainfall and/or land‐use changes. Yet, proper understanding of erosion dynamics and its relations with environmental drivers remains challenging as long‐term observations are, especially in volcanic terrain. Here we applied dendrogeomorphic approaches to (i) analyse both microscopic and macroscopic disturbances in tree roots exposed by gully erosion in a young volcanic landform of central Mexico and to (ii) quantify the evolution of erosion in the volcanic deposits of Paricutin Volcano. To this end we analysed 154 cross‐sections of 30 living, exposed roots of Pinus pseudoestrobus Lindl., of which 25 were used for anatomical and 129 for macroscopic analysis. Wood anatomical – or microscopic – disturbances were mostly in the form of strong growth reductions (~50%) in lumen area of earlywood tracheids, substantial increases in ring widths (mostly stemming from eccentric growth) and the increased formation of latewood cells. We observe major erosion pulses in 2010, 2012, 2015, 2016, 2017 and 2018, triggered primarily by torrential rainfall (with >100 mm 24 h−1 for the maximum intensity event: standard precipitation index values ≥ 2). Along the gully, the lower sector formed between 2009 and 2017, whereas the central sector exhibited important phases of exposure from 2012 to 2018. In the upper, most recent sector of the gully, erosion started only in 2017. Erosion rates in the lower and upper sectors are smaller with a channel widening rate of 6 to 16 cm yr−1. Around the main knickpoint found in the central part of the gully, retreat rates are up to 60 cm yr−1 and gully incision is 30 cm yr−1. The methods applied in this research are novel and can be applied to other volcanic environments with intense gully erosion, so as to provide baseline data for land‐use and environmental management plans. [ABSTRACT FROM AUTHOR]

Summary: We describe two new fossil woods from the San Carlos Formation (Upper Cretaceous), Chihuahua State, Mexico. The first wood resembles the fossil genus Metcalfeoxylon in having solitary vessels, scalariform perforation plates, vessel-ray parenchyma pits of similar size as the intervessel pits, axial parenchyma apotracheal diffuse and diffuse in aggregates, and heterocellular multiseriate rays with long, uniseriate tails. The second wood is a new fossil genus, and it is characterized by having diffuse porous wood, vessels predominantly solitary, vessel outlines oval and tending to be of two diameter classes, simple perforation plates, minute alternate intervessel pits, vessel-ray parenchyma pits similar to intervessel pits in size and shape, vasicentric tracheids, non-septate fibers, homocellular rays, and exclusively uniseriate and biseriate rays. This combination of features supports its placement in Myrtales (?Myrtaceae), in a new fossil-genus named Lazarocardenasoxylon. These two new records provide more information about the floristic composition of the Late Cretaceous flora of the San Carlos Formation and its relationship with those from the southern USA. However, a definitive picture of the floristic relationship of these Cretaceous floras of northern Mexico and southern USA remains elusive. [ABSTRACT FROM AUTHOR]

Sawmills are economically important in Mexico due to the generation of added value in forest species Mexico due to the transformation of round wood to sawn wood, the sawmill industry is located in all agro ecological regions and states. These units are source of employment for women and men in remote areas inhabited by the poor and extreme poverty population, the objective of the was to quantify the monetary value that the sawmill industry contributes to the forest economy, for which statistical data from INEGI was used and SEMARNAT, the first with valuable information and the second on production in m3r; a 25-years horizon was considered: 1995-2019, which was broken down into four six-year terms and the first year of the current administration to know, the behavior, trend and participation of the economic value of the sawmill in various macroeconomic aggregates. The methodology consisted of using current (market) values and constant (deflated) values, with the base year 2013 (according to INEGI and in thus make the data comparable, know trends and quantify their variations with the statistical function average annual growth rate (tmca). In real terms, the importance of the value in the Mexican economy of the sawmill industry during the period of analysis was very scarce since at the country level it represented on average of the 25 years considered, only 0.09% of the national GDP and at the sector level primary (agriculture, livestock, forestry, hunting and fishing) increased its share to 2.81% of primary GDP. [ABSTRACT FROM AUTHOR]

Secondary forests recovering after disturbances currently comprise about half of the world′s tropical forests. A better understanding of the recovery of species composition, stand structure, and biomass stocks of these secondary forests is critical for the sustainable management of these ecosystems. The main objective of this research was to develop the successional trends in forest biomass, tree diversity, and species composition recovery. We monitored the changes in tree species composition, stand structural characteristics, and biomass growth in a chronosequence of tropical secondary forests in the Yucatan Peninsula of Southeastern Mexico. We used both linear and non-linear regressions to develop biomass growth models during forest succession. We calculated tree species diversity and similitude indices between forest successional groups (young, medium-aged, and old-growth forests). The aboveground biomass stocks ranged from 5.2 to 121 Mg C ha-1, which increased gradually with forest age. We observed a divergent trend of biomass accumulation between soft- and densewood species during succession. The contribution of densewood species on tree biomass stock increased (from 32 % to 81 %) with the increasing forest ages. However, the tree diversity indices did not change significantly with forest age and were a poor predictor of aboveground biomass growth during succession. Secondary forests (SFs) of advanced age were more similar to old-growth forests (OF) in their species composition compared to young ones, as evidenced by the Chao-Jaccard index. However, it may take more than a century for these secondary forests to recover to OF-level species composition. Furthermore, the structural equation model allowed us to infer the relative importance of forest age, tree diversity, soil properties, and stand structural attributes, including wood density on biomass growth along the forest chronosequence. Forest age-mediated effect of species composition shift and stand structural changes was a better predictor of biomass accumulation than the changes in tree diversity or soil properties during succession. However, the soil properties as a construct (latent variable), had a significant positive covariance with stand structure, indirectly influencing biomass growth. These biomass and species composition recovery models could be useful in forest management for biodiversity conservation, landscape restoration, and ecosystem services, including carbon sequestration. • Divergent trends of biomass accumulation between soft- and densewood species during succession. • Secondary forests take more than 100 years to restore their original species composition and biomass stocks. • The tree diversity index was a poor predictor of aboveground biomass storage during succession. • Wood traits and stand structural properties predicted the change in biomass stocks. • Soil properties covaried positively with forest structure and composition, indirectly influencing biomass change. [ABSTRACT FROM AUTHOR]

This study describes the exploitation of wood waste (Pinus spp.) in the form of sawdust and shavings generated during the production of furniture and artisanal items in a community in the state of Michoacán, western Mexico. A process is described to densifying this raw material, to produce solid-type biofuel briquettes that can be used to satisfy the need to generate low-power heat for residential sectors. Briquette production involved six stages: (a) gathering samples of sawdust and shavings from artisanal workshops in the community; (b) proximal characterization of the samples; (c) elaborating the briquettes; (d) physicochemical characterization of the briquettes; (e) evaluation of the physical-thermal combustion of the briquettes; and (f) an economic evaluation of briquette production to determine viability. Finally, we performed a comparative analysis of the energy, economic, and environmental indicators of the briquettes produced and conventional pine and oak firewood (Pinus spp., Quercus spp.) in the study community. The results show the viability of using biomass residues to make briquettes, which are efficient, economic and easy to make and use. [ABSTRACT FROM AUTHOR]

Anatomical and subcellular characteristics of juvenile and adult wood of seven species (Manilkara zapota (L.) P. Royen, Platymiscium yucatanum Standl., Lonchocarpus castilloi Standl., Roseodendron donnell-smithii (Rose) Miranda, Terminalia buceras (L.) Wright, Tabebuia rosea (Bertol.) DC., Lysiloma latisiliquum (L.) Benth. from Mexico, including a histometric evaluation, were investigated by light microscopy with a digitized image analysis system and by X-ray diffractometry using the SilviScan® system. The topochemical distribution of lignin and phenolic deposits in the tissue was studied by means of cellular UV-microspectrophotometry (UMSP). Extractive contents (acetone/water and water) were determined gravimetrically. The results of the structural and topochemical analyses were compared with the interrelations of certain anatomical and subcellular structures as well as the topochemical composition with regard to the physical and mechanical properties of the timbers investigated. The objective was to provide a detailed cellular and subcellular description of the heartwood of seven lesser-known timbers from Central America. All examined tree species show significant differences between juvenile and adult heartwood. For individual species, however, the differences vary greatly and have to be individually assessed in addition to general trends observed for all studied species. It has been shown that vessel size, fibre length, size of fibre lumina, and height and width of rays, as well as the content of extractives and topochemical composition of the cell walls, are suitable indicators for the differentiation of the two heartwood types. The results also contribute to a better understanding of the wood properties of the investigated timbers in relation to their utilization and added value increase. [ABSTRACT FROM AUTHOR]

• Sensibility to precipitation by tree ring growth is reported as tree species specific. • In consequence some species ring growth is uncoupled to the rain season. • This response is driven by adaptations in anatomical traits in roots and trunk. • These traits permited the access to restricted water sources in oak but not in pine. • The uncoupling of ring growth limits its capacity to reconstruct past climate. Reconstruction of past precipitation cycles using tree ring growth is a common practice to study climatic conditions from the past. However, several studies have attested that not all tree species provide with the same accuracy to reconstruct past climate and in particular precipitation. In this study, we present evidence that anatomical and morphological differences in trunk and root traits of two forest species provide different capacities to access restricted water sources, these explains the different sensitivities of tree-ring growth to annual precipitation by the species. To test this suggestion, we examined trunk anatomy, root distribution, tree-ring growth, natural isotopic label of tree rings (δ13C) as well as the water use efficiency (WUE) and leaf water potential (Ψ leaf) for two tree species (oak - Quercus potosina and pine - Pinus cembroides) from a semiarid forest in central México. Results showed large differences in stem and root anatomy between species, with oak fine roots equipped with a triple layer of epidermal tissue containing calcium oxalate crystals (druses). These root characteristics permitted oak to explore deeper rock fractures and crevices reaching additional water sources, whereas pine fine roots were mostly distributed in the first 10 cm of the topsoil. Oak also possess trunk structural anatomy of specialized tissue formed by fiber tracheid's connecting vessel tissue to water storing, which is used during particular drought periods. Oak tree-ring growth and their δ13C values that corresponded with wet conditions were observed in years below average precipitation. In comparison, the same variables in pine changed accordingly to precipitation variability, since pine did not have traits helping to access additional water sources during drought. [ABSTRACT FROM AUTHOR]

Global climate change will alter forests by shifting species ranges, which has implications for their ecological functions. Annual tree-ring widths andwood density are useful proxies for carbon cycle studies across a range of species. Here, using a dendroecological approach we sought to understand the carbon accumulation rates of two representative pine species growing on contrasting wet (P. arizonica) and dry (P. cembroides) sites and reveal how such species cope with climate variability. Although the rate of carbon gain was not significantly different across sites, we found that variations in carbon accumulation responded differently to specific hydroclimate drivers, site conditions, or to functional features of each species, which are still to be explored. Overall, annual carbon accumulation (C) was less sensitive to climate variability than ring width and wood density. Annual C was more sensitive to rainfall in the cold season (P. arizonica) and to the start of spring (both species). Our species-specific approach provided a suitable basis for modeling projections in the long-term carbon balance in these forests. Using speciesspecific tree-ring data has the potential to yield better estimations given that tree rings reflect fine spatial and temporal resolution, thereby reducing the uncertainty in forest carbon budgets. [ABSTRACT FROM AUTHOR]

Objective. To determine prevalence trends of using Wood as the Main Cooking Fuel (WMCF) in Mexico and household characteristics that predict its use. Materials and methods. Estimates were obtained from the 1990, 2000 and 2010 censuses and from a national survey performed in 2012 and 2013. Results. In 2012-2013, 9.5% of the 66 321 surveyed households and 10.9% of their 252 011 residents used WMCF. Prevalence was higher in rural (40.5%) than urban areas (1.5%), p<0.0001. From 1990 to 2013 wood use decreased by 53% overall and by 28.6% in rural areas, gas use increased respectively by 17.5 and 52.7%. Predictors of using WMCF were living in rural or suburban areas and those associated with low socioeconomic status. Conclusion. Use of WMCF has decreased substantially in Mexico but at a slower pace in rural areas. Improving household characteristics and socioeconomic status may decrease use of WMCF at a higher rate. [ABSTRACT FROM AUTHOR]

Background: Vegetation structure is defined as the temporal and spatial distribution of plant species in a particular site. Vegetation structure includes vertical and horizontal distribution and has been widely used as an indicator of successional changes. Ecological succession plays an essential role in the determination of the mechanisms that structure plant communities under anthropogenic disturbances. After an anthropogenic disturbance, such as grazing, forests follow changes in the original composition and vegetation structure, which eventually could restore some of their attributes to become mature forests again. To know how the time of abandonment affects woody plant communities, we ask the following questions: (1) How does the species richness, diversity, and vertical structure (A index) change concerning the time of abandonment? (2) Are species similarities among woody vegetation communities determined by land abandonment? (3) Which woody species have the highest ecological importance in each successional stage?, Methods: We explored how successional stages after land abandonment mediated the species richness, species diversity (alpha and beta), and ecological importance value index on four areas of Tamaulipan thornscrub. We selected four areas that differed in time of abandonment: 10, 20, 30, and >30 years. The first three areas were used for cattle grazing, whereas the >30-year area was selected as a control since it does not have a record of disturbance by cattle grazing or agriculture. During the summer of 2012, we randomly established four square plots (40 m × 40 m) in each area, separated at least 200 m from each other. In each plot, we recorded all woody individuals per species with a basal diameter ≥1 cm at 10 cm above ground level. We estimated species richness indices, species diversity (alpha and beta), and ecological importance value index., Results: We recorded 27 woody species belonging to 23 genera and 15 families. Fabaceae accounted for 40% of the species. Acacia farnesiana was the most important and abundant species in the first three successional stages. We suggested that older successional stages of Tamaulipan thornscrub promote woody plant communities, characterized by a higher complex structure than younger communities. We observed the highest species similarity between the sites with a closer time of abandonment, while the lowest similarity was shown between the sites with extreme time of abandonment. We conclude that Tamaulipan thornscrub shows a similar trend of ecological succession to other dry forests and the time of abandonment has a high mediation on plant dynamics in the Tamaulipan thornscrub. Also, we stand out the importance of secondary forests for Tamaulipan thornscrub woody plant communities. Finally, we recommended future studies include aspects of regeneration speed, the proximity of mature vegetation, and the interactions of plants with their seed dispersers., Competing Interests: The authors declare that they have no competing interests., (© 2023 Alanis et al.)

San Pedro Atlapulco is a rural indigenous community located in the state of Mexico together with the Insurgente Miguel Hidalgo y Costilla national park. By the time, the population had worked principally as peasants and sold natural resources, but unfortunately the community has never received any support from the government sector. Nowadays, the principal economy is based on tourism because of the availability proximity of conifer wood which makes a suitable environment in the valleys for people who manages tourist activities such as horse riding, All Terrain Vehicle (ATV) riding, hiking, Picnicking, etc. There is some effect necessary to be evaluated in order to preserve and take advantage for eco-tourism and the need to research the opportunities for its sustainable use and adequate management. The main objective of this investigation is to evaluate the sustainability of the recreative tourism activity through social indicators and the possibility of incorporating this resource to the tourism activity with the aim of proposing an eco-tourism alternative for the community of San Pedro Atlapulco, State of Mexico which would allow strengthening of the tourism product and consequently would present opportunities for the improvement of the quality of life for the residents. The methodology of the current study was modeled to evaluate the Management of the Natural Resources System Incorporating Indicators for Sustainability (MESMIS), this consists of integrating experiences and recommendations of different institutions, which have been working on the development of methodologies to evaluate the sustainability management of natural resources. [ABSTRACT FROM AUTHOR]

The present study was undertaken with the goal of analyzing the morphology and variability of leaf length, width, petiole length, and total leaf length, fresh and dry weight of individual leaves of 14 species native to Northern Mexico. The native species Cordia boissieri, Condalia hookeri, Sargentia greggii, Diospyros texana, Zanthoxylum fagara, Sideroxylon celastrinum, Karwinskia humboldtiana, Celtis pallida, Guaiacum angustifolium, Prosopis laevigata, Celtis laevigata, Parkinsonia texana, Forestiera angustifolia and Havardia pallens where chosen due to their ecological and economic importance to the rural villages as well as large variability in morphological characteristics between them. Descriptive statistical analyses showed that there was large variability in these leaf traits between the different species. Principal component analysis (PCA) revealed that it was possible to produce two axes that can explain more than 83% of the observed variation and could therefore be used in the future for separating tree species in ecological guilds and to study. Species and vegetation community level response to perturbations or individual performance in the field or under experimental conditions between the different species of this study. This suggests that similar advances are possible for other species for the same traits both in the region of study but also elsewhere. [ABSTRACT FROM AUTHOR]

Charcoal particles vary in size and form, but they can preserve morphological characteristics used to infer the type of vegetation being burnt. To deduce potential fuel and fire type, we reconstructed local fire activity analyzing macrocharcoal morphologies and pollen data of the sediment core CHA08-V from Lake Chalco from the sub-stage MIS 5a to MIS 3, with CHAR data and Z-Score analysis. We identified the following fuel types: i) wood , characterized by blocky and quadrilateral morphologies with solid, foliated or striated surface textures; ii) grass , represented by rectangular-porous and rectangular-latticed morphologies; and iii) herbs , characterized by long-thin filaments and polygonal porous particles. Arboreal pollen components were associated to wood morphotypes whereas non-arboreal pollen related to herbs and grass morphotypes, indicating that variation in vegetation composition was important regulating factor determining fire types in the Basin of Mexico. This study provides the first long-term record of charcoal morphotypes for Mexico region to emphasize the importance of charcoal morphotypes analyses to complement paleoenvironmental interpretation of past fire regimes. • The first long-term record of charcoal morphotypes in Mexico to determine the fuel combusted. • Identification of twelve charcoal morphotypes associated with the burning of wood, leaves, grasses and herbaceous material. • Mixed morphotypes associated with surface fires occasionally transitioning to crown fires in the Basin of Mexico. [ABSTRACT FROM AUTHOR]

The article discusses the history of the extraction and exportation of wood from Carmen Island and Campeche, Mexico by foreign colonists in the 19th century. The authors comment on commerce between Mexico and the United States and Europe, the construction of social networks, and 19th century commercial activity. The conquistador and discoverer of various colors of Campeche wood Marcos Ayala is mentioned. Other topics mentioned include French merchants and colonists such as the Anizan brothers Francisco and Benito and international trade.

Studies of air pollution and cognition often rely on measures from outdoor environments. Many individuals in low- and middle-income countries are exposed to indoor air pollution from combustion of solid cooking fuels. Little is known about how solid cooking fuel use affects cognitive decline over time. This study uses data from the 2012, 2015, and 2018 Mexican Health and Aging Study (n = 14 245, age 50+) to assess how use of wood or coal for cooking fuel affects cognition of older adults relative to use of gas. It uses latent change score modeling to determine how using solid cooking fuel affected performance in Verbal Learning, Verbal Recall, Visual Scanning, and Verbal Fluency. Solid cooking fuel was used by 17% of the full sample but was more common in rural areas. Solid fuel users also had lower socioeconomic status. Compared to those using gas, solid fuel users had lower baseline scores and faster decline in Verbal Learning (β = -0.18, p < 0.05), Visual Scanning (β = -1.00, p < 0.001), and Verbal Fluency (β = -0.33, p < 0.001). Indoor air pollution from solid cooking fuels may represent a modifiable risk factor for cognitive decline. Policy should focus on facilitating access to clean cooking fuels., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This work presents a study on the use of wood and plastic wastes generated in abundance in Merida, Mexico, to help to reduce them in order to mitigate environmental deterioration. The use of these wastes is proposed to obtain a low-cost building material. So, the escalation process (i.e., extrusion) at the pilot level to obtain a prototype of a wood-plastic composite (WPC) corrugated sheet to evaluate the technical feasibility to make a low-cost product is reported. A corrugated sheet with recycled high-density polyethylene (R-HDPE) was produced. The R-HDPE was collected from Merida's Separation Plant. The wood came from the trimmings of different varieties of trees and shrubs that are periodically pruned. WPC sheets with virgin HDPE were prepared to assess its effect on the materials' mechanical performance. The wood/HDPE weight ratio was 40/60. The performance of the WPC sheets was compared with that of commercial products with similar characteristics, namely acrylic and polyester sheets reinforced with fibreglass, and black asphalt-saturated cardboard sheets. Thus, the effect of natural weathering on the maximum tensile tearing force and on the maximum flexural load of the different types of sheets was evaluated. Although the mechanical performance of the WPC sheets was lower than that of the acrylic and polyacrylic sheets, their performance was much better than that of the cheap black asphalt-saturated cardboard sheets. So, they are a good option to be used as low-cost temporary roofing.

Premise: Photosynthetic stems represent a source of extra carbon in plants from hot and dry environments, but little is known about how leaves and photosynthetic stems differ in terms of photosynthetic capacity, trait coordination, and responses to seasonal drought in subtropical systems., Methods: We studied photosynthetic, hydraulic, morphometric (specific leaf area [SLA], wood density [WD]), and biochemical (C and N isotopes) traits in leaves and photosynthetic stems of 12 plant species from a sarcocaulescent scrub in the southern Baja California Peninsula, Mexico, in wet and dry seasons., Results: Leaves and stems had similar mean photosynthetic capacity, as evaluated by chlorophyll fluorescence traits, indicating similar investment in leaf and stem photosynthesis. We did not find a relationship between stem hydraulic conductivity and leaf or stem photosynthetic traits. However, we found resource allocation trade-offs, between WD and both stem hydraulic conductivity and SLA. Leaf and stem photosynthetic traits did not change with season, but specific stem area was one of the few traits that changed the most between seasons-it increased during the dry season by as much as 154% indicating substantial water storage., Conclusions: Our results indicate the same proportional investment in photosynthetic capacity and dry matter in both leaves and photosynthetic stems across all 12 species. We identified multiple strategies at this seasonal site, with species ranging from high WD, low SLA, low hydraulic conductivity, and high specific bark area on one end of the spectrum and opposite traits on the other end., (© 2020 Botanical Society of America.)

Despite its high ecological importance, the commensal interactions at community level are poorly studied. In tropical dry forests (TDF) there is a great diversity of species adapted to the high seasonality that characterizes them; however, little is known regarding how the spatial and temporal availability of resources generates changes in the pattern of commensal interactions. We experimentally studied changes in the diversity, composition, and pattern of interactions in spatio-temporal associations between the saproxylophagous beetles and their host trees in a TDF in Morelos, Mexico. A total of 65 host tree species were selected, from which 16 wood sections were obtained per species. These sections were exposed in the field to allow oviposition by the cerambycids under four different (spatio-temporal) treatments. We analyzed the network structure and generated indices at species level (i.e., specialization, species strength, and effective partners) and those related to physical characteristics of the wood (hardness and degradation rate) and the cerambycids (body size). In total, 1,323 individuals of 57 species of cerambycids emerged. Our results showed that, independently of the space and time, the network presented a nested and modular structure, with a high specialization degree and a high turnover of cerambycid species and their interactions. In general, we found that the cerambycids are mostly associated with softwood species with a lower decomposition rate of wood, as well as with the most abundant host species. The commensalistic interactions between the cerambycids and their host trees are highly specialized but are not spatio-temporally static. The high turnover in the interactions is caused by the emergence patterns of cerambycids, which seem to restrict their use to certain species. The knowledge of the spatio-temporal variation in Cerambycidae-host tree interactions allows us to predict how environmental and structural changes in the habitat can modify the species ensemble, and therefore its interactions., Competing Interests: The authors have declared that no competing interests exist.

Extreme climatic and weather events are increasing in frequency and intensity across the world causing episodes of widespread tree mortality in many forested ecosystems. However, we have a limited understanding about which local factors influence tree mortality patterns, restricting our ability to predict tree mortality, especially within topographically complex tropical landscapes with a matrix of mature and secondary forests. We investigated the effects of two major local factors, topography and forest successional type, on climate-induced tropical tree mortality patterns using an observational and modeling approach. The northernmost Neotropical dry forest endured an unprecedented episode of frost-induced tree mortality after the historic February 2011 cold wave hit northwestern Mexico. In a moderately hilly landscape covering mature and secondary tropical dry forests, we surveyed 454 sites for the presence or absence of frost-induced tree mortality. In addition, across forty-eight 1 ha plots equally split into the two forest types, we examined 6,981 woody plants to estimate a frost-disturbance severity metric using the density of frost-killed trees. Elevation is the main factor modulating frost effects regardless of forest type. Higher occurrence probabilities of frost-induced tree mortality at lowland forests can be explained by the strong influence of elevation on temperature distribution since heavier cold air masses move downhill during advective frosts. Holding elevation constant, the probability of frost-induced tree mortality in mature forests was twice that of secondary forests but severity showed the opposite pattern, suggesting a cautious use of occurrence probabilities of tree mortality to infer severity of climate-driven disturbances. Extreme frost events, in addition to altering forest successional pathways and ecosystem services, likely maintain and could ultimately shift latitudinal and altitudinal range margins of Neotropical dry forests., (© 2019 John Wiley & Sons Ltd.)

Natural history collections are increasingly valued as genomic resources. Their specimens reflect the combined efforts of collectors and curators over hundreds of years. For many rare or endangered species, specimens are the only readily available source of DNA. We leveraged specimens from a historical collection to study the evolutionary history of wood-partridges in the genus Dendrortyx. The three Dendrortyx species are found in the highlands of central Mexico and Central America south to Costa Rica. One of these species is endangered, and in general, Dendrortyx are secretive and poorly represented in tissue collections. We extracted DNA from historical museum specimens and sequenced ultraconserved elements (UCEs) and mitochondrial DNA (mtDNA) to assess their phylogeny and divergence times. Phylogenies built from hundreds to thousands of nuclear markers were well resolved and largely congruent with an mtDNA phylogeny. The divergence times revealed an unusually old avian divergence across the Isthmus of Tehuantepec in the Pliocene around 3.6 million years ago. Combined with other recent studies, our results challenge the general pattern that highland bird divergences in Mesoamerica are relatively young and influenced by the Pleistocene glacial cycles compared to the older divergences of reptiles and plants, which are thought to overlap more with periods of mountain formation. We also found evidence for monophyletic genetic lineages in mountain ranges within the widespread D. macroura, which should be investigated further with integrative taxonomic methods. Our study demonstrates the power of museum genomics to provide insight into the evolutionary histories of groups where modern samples are lacking., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The aim of this work was to evaluate wood chips from vineyard prunings (VPs) as a potential substrate in cultures of Ganoderma spp. Biological efficiency (BE), production rate (PR), yield, and protein and fat contents of basidiomes increased when the wild strains G. oerstedii and G. subincrustatum, which were isolated from the Sonoran Desert, were cultivated on VPs. The mineral content of the basidiomes varied depending on the strain and substrate. The carbohydrate and phenol contents of the different substrate combinations and of the basidiomes were similar among strains. However, the carbohydrate and phenol contents of the substrates did not correlate with an increase in BE. Conversely, the high availability of protein, fat, and hemicellulose in VPs positively correlated with increases in BE, in yield, and in the protein and fat contents of the basidiomes of the wild strains. Our results clearly demonstrate that, in comparison with the traditional substrate of oak wood, VPs improve the production and biochemical composition of basidiomes. Therefore, cultivation of Ganoderma spp. on VPs is an environmentally friendly strategy for increasing their nutritional value and for cultivating these mushrooms for other biotechnological applications.

Household use of fuelwood represents a socio-ecological condition with important health effects mainly in rural areas from developing countries. One approach to tackle this problem has been the introduction of efficient wood-burning chimney stoves. The aim of this study was to assess the impact of the introduction of Patsari stoves on the respiratory health of young children in highlands Michoacán, Mexico. A total of 668 households in six rural communities in a fuelwood using region were selected and randomized to receive an improved stove (Patsari) or rely entirely on the traditional wood fire until the end of the follow-up including 10 monthly visits. Adherence to the intervention was variable over the follow-up time. The actual use of the Patsari stove as reported by the mother showed a protective effect mainly on the upper and lower respiratory infection duration (IRR URI 0.79, 95% CI 0.70-0.89, and LRI 0.41, 95% CI 0.21-0.80) compared to households that used only an open fire. Fewer days of child's ill health represents saved time for the woman and avoided disease treatment costs for the family, as well as a decrease in public health costs due to a reduction in the frequency of patient visits.