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Forest certification is a private, voluntary and market-driven instrument designed to promote responsible forest management. This paper focused on the FSC and the NOM NMX-AA-143-SCFI-2008 schemes used in Mexico for the certification of sustainable forest management. In this paper we used the analytical hierarchical process (AHP) to study the factors that determine the main impacts of forest certification in México. A panel of 30 experts was selected as decision-makers to find which principles, criteria and indicators are considered as the most relevant while implementing forest certification. For decision-makers, the environmental principle occupied the first place with 40.26% of importance in the implementation of forest certification, followed by the social principle, and the economic principle with 32.15% and 27.59% of importance, respectively. Regarding the criteria, forest management and production, biodiversity, and forest protection were considered to be the most relevant. Regarding the indicators, the results indicated that forest certification in Mexico can have a positive impact on the existence of educational institutions, community services such as water, energy, medical services and drainage, the quality of the forest management plans, investment in forest management, machinery and equipment, environmental services, recreation, tourism, research, development and community education, planning for the conservation of biological diversity, and planning for biodiversity conservation. [ABSTRACT FROM AUTHOR]

Facing a dramatic depletion of forests in the Viceroyalty of New Spain, throughout the last decades of colonial rule (between the mid-eighteenth and early nineteenth centuries) the Bourbon administration wrote and published a considerable number of laws, reports, surveys, and ordinances on forest management and conservation. In this paper we examine discourses of forest conservation and the measures applied to preserve this critical resource by colonial official and experts. Drawing on forest laws, ordinances, and reports from national archives in Mexico City, we argue that conservation became part of the concepts which defined how forests were conceptualized and managed, but also that conservation was intrinsic to colonial processes of state-making and territorialization. This paper aims to approach Bourbon officials' understanding of conservation as a complex interrelation between renewed discourses of nature and the practices of colonial forest administration through the idea of indeterminacy. Likewise, it sheds light on patterns that have defined the ways in which forest conservation has been constituted in modern Mexico, addressing a little-studied period in forest management in this country. • Forest conservation was contentious questioning the universality of colonial laws. • Conservation became a site of experimentation to know, govern, and produce forests. • Conservation provides insights into the colonial state's territorial actualization. • Colonial forest laws played an important role in defining the context of depletion. [ABSTRACT FROM AUTHOR]

Abies hidalgensis is an endemic species from the state of Hidalgo, Mexico, that has been registered only in nine fragmented relict populations that have a total of 1 000 individuals among them. Intensive forest management takes place in five of the populations under specific programs focused on Pinus spp. Still, it is necessary to know the impact of these activities on the genetic diversity of the threatened species, if restoration and conservation strategies are to be proposed. The aim of this work was to estimate the effect of forest management on the genetic structure of A. hidalgensis using seven nuclear molecular markers developed for A. guatemalensis (Ab07, Ab08, Ab09, Ab12, Ab15, Ab20, Ab23). The species was sampled growing under two different conditions; (i) areas under forest management and (ii) conserved areas. Two indexes of genetic diversity were evaluated, observed and expected heterozygosity. The genetic structure was determined by an analysis of molecular variance and a Bayesian assignment model. A bottleneck analysis was also carried out. The populations were found to have a common genetic base (differentiation coefficient FST = 0.056, number of migrants per generation Nm = 43), which suggests recent fragmentation of the distribution, which in turn increases the bottleneck effect in managed areas (Wilcoxon probability Wp = 0.007 and 0.016). This explains the apparently high heterozygous level (He = 0.69) and low inbreeding. Our results are important as they may be used to design strategies for management and conservation of A. hidalgensis. [ABSTRACT FROM AUTHOR]

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.)

Forest management modifies tree cover, directly influencing various ecosystem services, such as water regulation. Evapotranspiration, water interception, surface runoff, stemflow, and throughfall are among those processes that depend on tree cover. The objective of this study was to evaluate the changes in water yield, defined as the difference between precipitation and evapotranspiration, after the application of silvicultural treatments in a temperate forest ecosystem in northern Mexico. Fifteen experimental plots were established in which the following treatments were applied: intensive management (clearcutting), semi-intensive management (selection, tree cutting of 59–61% of basal area), conservative management (selection, tree cutting of 29–31% of basal area), and no treatment (control group). Incident precipitation, throughfall, stemflow, net precipitation, interception, and surface runoff were analyzed. Results show that conservative management treatments increase water yield between 2 to 3.6 mm per m-2 ha-1 of tree basal area removed. Water flow distribution, in relation to the incident precipitation, ranged from 72.3 to 91.8% for throughfall, 0.2 to 0.4% for stemflow, 72.7 to 91.8% for net precipitation, 8.19 to 27.42% for interception or evaporation, and 0.54 to 1.93% for surface runoff. The conservative management treatment was the most viable alternative for increasing water yield without compromising timber harvesting and loss of soil due to hydric erosion. [ABSTRACT FROM AUTHOR]

Temperature and precipitation influence insect distribution locally and drive large-scale biogeographical patterns. We used current and future climate data from the CHELSA database to create ensemble species distribution models for three Atta leaf-cutting ant species (Atta cephalotes, A. mexicana, and A. texana) found in Mexico. These models were used to estimate the potential impact of climate change on the distribution of these species in the future. Our results show that bioclimatic variables influence the distribution of each Atta species occupying a unique climatic niche: A. cephalotes is affected by temperature seasonality, A. mexicana by isothermality, and A. texana by the minimum temperature of the coldest month. Atta texana and A. mexicana are expected to decline their range by 80% and 60%, respectively, due to rising temperatures, decreased rainfall, and increased drought. Due to rising temperatures and increased humidity, Atta cephalotes is expected to expand its range by 30%. Since Atta species are important pests, our coexistence with them requires knowledge of their ecological functions and potential future distribution changes. In addition, these insects serve as bioindicators of habitat quality, and they can contribute to the local economy in rural areas since they are eaten as food for the nutritional value of the queens. In this sense, presenting a future perspective of these species' distribution is important for forest and crop management. Education programs also are necessary to raise awareness of the importance of these ants and the challenges they face because of climate change. Our results offer a perspective of climate change studies to define conservation and adaptation strategies for protecting vulnerable areas such as high-elevation remnant forests. [ABSTRACT FROM AUTHOR]

The Puuc Biocultural State Reserve (PBSR) is a unique model for tropical dry forest conservation in Mexico. Preserving forest biodiversity and carbon within the PBSR depends on maintaining low-impact productive activities coordinated by multiple communal and private landowners. In this study, we used state-of-the-art remote sensing data to investigate past spatial patterns in forest clearing dynamics and their relation to forest carbon density and forest plant species richness and diversity in the context of the forest conservation goals of the PBSR. We used a Landsat-based continuous change detection product for the 2000–2021 period and compared it to carbon density and tree species richness models generated from ALOS-2 PALSAR 2 imagery and national scale forest inventory data. The estimated error-adjusted area of detected annual forest clearings from the year 2000 until the year 2021 was 230,511 ha in total (±19,979 ha). The analysis of annual forest clearing frequency and area suggests that although forest clearing was significantly more intensive outside of the PBSR than within the PBSR during the entire 2000–2021 period, there is no evidence suggesting that the frequency and magnitude of forest clearing changed over the years after the creation of the PBSR in 2011. However, an emergent hotspot analysis shows that high spatiotemporal clustering of forest clearing events (hotspots) during the 2012–2021 period was less common than prior to 2011, and these more recent hotspots have been confined to areas outside the PBSR. After comparing forest clearing events to carbon density and tree species richness models, the results show that landowners outside the PBSR often clear forests with lower carbon density and species diversity than those inside the PBSR. This suggests that, compared to landowners outside the PBSR, landowners within the PBSR might be practicing longer fallow periods allowing forests to attain higher carbon density and tree species richness and hence better soil nutrient recovery after land abandonment. In conclusion, our results show that the PBSR effectively acted as a stabilizing forest management scheme during the 2012–2021 period, minimizing the impact of productive activities by lowering the frequency of forest clearing events and preserving late secondary forests within the PBSR. We recommend continuing efforts to provide alternative optimal field data collection strategies and modeling techniques to spatially predict key tropical forest attributes. Combining these models with continuous change detection datasets will allow for underlying ecological processes to be revealed and the generation of information better adapted to forest governance scales. [ABSTRACT FROM AUTHOR]

The National Forestry Commission of Mexico continuously monitors forest structure within the country's continental territory by the implementation of the National Forest and Soils Inventory (INFyS). Due to the challenges involved in collecting data exclusively from field surveys, there are spatial information gaps for important forest attributes. This can produce bias or increase uncertainty when generating estimates required to support forest management decisions. Our objective is to predict the spatial distribution of tree height and tree density in all Mexican forests. We performed wall‐to‐wall spatial predictions of both attributes in 1‐km grids, using ensemble machine learning across each forest type in Mexico. Predictor variables include remote sensing imagery and other geospatial data (e.g., mean precipitation, surface temperature, canopy cover). Training data is from the 2009 to 2014 cycle (n > 26,000 sampling plots). Spatial cross validation suggested that the model had a better performance when predicting tree height r2 =.35 [.12,.51] (mean [min, max]) than for tree density r2 =.23 [.05,.42]. The best predictive performance when mapping tree height was for broadleaf and coniferous‐broadleaf forests (model explained ~50% of variance). The best predictive performance when mapping tree density was for tropical forest (model explained ~40% of variance). Although most forests had relatively low uncertainty for tree height predictions, e.g., values <60%, arid and semiarid ecosystems had high uncertainty, e.g., values >80%. Uncertainty values for tree density predictions were >80% in most forests. The applied open science approach we present is easily replicable and scalable, thus it is helpful to assist in the decision‐making and future of the National Forest and Soils Inventory. This work highlights the need for analytical tools that help us exploit the full potential of the Mexican forest inventory datasets. [ABSTRACT FROM AUTHOR]

Sectional equations and mathematical volume models are a reliable way to estimate carbon sequestration and storage, which is a key foundation for forest management and conservation. The objective of this study was to assess stem volume and form factor through the classical sectional method to then, using five regression models commonly used for forest management, identify the most suitable mathematical model to estimate the stem volume in a commercial forest plantation (CFP) of Pinus pseudostrobus Lindley in the Comunidad Indígena de Nuevo San Juan Parangaricutiro, Michoacán, in Western Mexico. By using 10, 15 and 20 yr.-old sampling points and two sampling methods (destructive and nondestructive), we found a form factor 0.42, 0.48 and 0.51 and stem volume of 0.098 m3, 0.400 m3 and 0.804 m3 for the three ages assessed, which presented diameter classes (DC), from 10 to 45 cm. The mathematical models identified that age of plantation determines stem volume and form factor, and the models that best fit volume estimation were the Schumacher-Hall model and the Australian model with an R2adj range between 0.89 and 0.99. Estimation of stem volume is of vital importance to assess the income generated by the timber industry, and relevant for forest conservation, management, and carbon sequestration studies. [ABSTRACT FROM AUTHOR]

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.)

Litter, LS, is the organic material in which locates in the top A soil horizon, playing key ecological roles in forests. Models, in contrast to common allocation factors, must be used in LS assessments as they are currently absent in the scientific literature. Its evaluation assess the mass, input and flux of several bio-geo-chemicals, rainfall interception as one component of the local hydrology, and wildfire regimes, among others, hence its importance in forestry. The aim of this study was to: (i) develop models to assess LS, accumulation, and loss rates; and (ii) assess rainfall interception and fire regimes in 133 northern forest plantations of Mexico. Two developed techniques: the statistical model (SMLS) and the mass balance budget model (MBMLS) tested and validated local and regional LS datasets. Models use basal area, timber, aboveground tree biomass, litter fall, accumulation, and loss sub-models. The best fitting model was used to predict rainfall interception and fire behavior in forest plantations. Results showed the SMLS model predicted and validated LS datasets (p = 0.0001; r2 = 0.82 and p = 0.0001; r2 = 0.79) better than the MBMLS model (p = 0.0001; r2 = 0.32 and p = 0.0001; r2 = 0.66) but the later followed well tendencies of Mexican and World datasets; counts for inputs, stocks, and losses from all processes and revealed decomposition loss may explain ≈40% of the total LS variance. SMLS predicted forest plantations growing in high productivity 40-year-old stands accumulate LS > 30 Mg ha−1 shifting to the new high-severity wildfire regime and intercepting ≈15% of the annual rainfall. SMLS is preliminarily recommended for LS assessments and predicts the need of LS management in forest plantations (>40-year-old) to reduce rainfall interception as well as the risk of high-severity wildfires. The novel, flexible, simple, contrasting and consistent modeling approaches is a piece of scientific information required in forest management. [ABSTRACT FROM AUTHOR]

Biometric systems are the basis of forest management and consist of a set of equations that describe the relationships between forest attributes and dendrometric variables. A systematic review of the state of the art of biometric systems in Mexico was carried out by a Mexican consortium (10 researchers), covering a period of 50 years ca (1970–2019), using the main scientific literature delivered by a systematic search (WoS, Scopus, Scielo, Redalyc) and a targeted search (theses, technical reports, etc.). A single selection criterion was established for the inclusion of information in the analysis: the document had to present at least one of the equations of interest. We found 376 documents containing 2524 equations for volume (69%), diameter (11%), height (9%) and site index (11%). These equations were developed for forest species mainly from temperate regions (88%), such as pine (66%) and oak (9%). Consequently, the Mexican states with the highest number of equations were Durango (28%), Chihuahua (17%), Hidalgo (13%) and Oaxaca (8%). Although large, the number of equations identified concentrated on a relatively small number of models: Schumacher & Hall and Fang et al. for volume; Chapman-Richards and Schumacher for site index and diameter; and Chapman-Richards and the allometric equation for height. An analysis of model fit, measured through R2, showed that, on average, the volume, diameter and site index models show high fit (R2 = 0.96), although this pattern was more consistent in the volume models. Publication bias was evaluated by means of a funnel plot analysis, with no apparent bias identified. A limitation of our study is that the information obtained is not updated to the present year; however, the 50-year trends allow us to assume that no recent significant changes in the patterns exist. Finally, we highlight the need to assess the predictive ability of the models to ensure accurate estimates to support better forest management decisions. [ABSTRACT FROM AUTHOR]

Since 2007 many developing countries have laid groundwork for Reducing Emissions from Deforestation and forest Degradation and sustainable management and conservation of forests (REDD +) under the auspices of the United Nations Framework Convention on Climate Change (UNFCCC). REDD + is aimed at incentivizing forest conservation and management in developing countries through policy programmers and local projects, which should in theory enhance the participation of very diverse actors in forest policy and governance. Here we explore the early years of REDD + in Mexico focusing on the alleged "participatory" nature of the REDD + initiative. Based on interviews and field observations with those involved in drafting the REDD + national strategy and in the implementation of small-scale pilot project activities, we investigate the meaning of participation for REDD + actors, their aspirations in this regard, and how procedural justice issues are being considered in early policy implementation. We demonstrate that the process set in motion to draft the strategy did not sufficiently involve sub-national governance levels, thus reducing the legitimacy of REDD + efforts, particularly in rural communities. We suggest that rural local actors should be further involved in REDD + decision-making forums, be provided with more information for a good understanding of REDD + implementation (e.g., pilot projects), and most importantly, be given a real chance to implement REDD + activities grounded on their own institutions and land-use practices. [ABSTRACT FROM AUTHOR]

Extreme events such as hurricanes repeatedly affect coastal areas in several tropical regions of the world. The economic and biodiversity losses caused by these extreme events are considerable. Mexico's coasts are exposed to hurricanes annually. A hydrological characterization and regionalization of the storms caused by the rain fields generated by all the hurricanes that touched the Mexican coast from 1966 to 2017 were carried out. Adimensional Huff curves are proposed to get precipitation hyetograms from which the erosion factor of a storm is obtained, using the universal soil loss equation (USLE). The results made it possible to get the typical precipitation hyetograms in the forests and protected areas before, during, and after the impact of a hurricane. The proposed hydrological regionalization made it possible to estimate the rainfall intensity in 30 min to characterize the start of rain erosion. The method proposed in this research was applied in the 177 natural protected areas (25,628,239 ha) as well as in the 370 voluntarily designated areas for conservation (399,643 ha) in Mexico. It is concluded that, with the regionalization and the proposed equations, it is possible to get typical hurricane precipitation hyetograms, which would allow us to detail the forest management plans in forests, ecological reserves, and protected areas of Mexico. [ABSTRACT FROM AUTHOR]