scholarly journals Patterns of Density and Production in the Community Forests of the Sierra Madre Occidental, Mexico

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 307 ◽  
Author(s):  
Jaime Roberto Padilla-Martínez ◽  
José Javier Corral-Rivas ◽  
Jaime Briseño-Reyes ◽  
Carola Paul ◽  
Pablito Marcelo López-Serrano ◽  
...  
Keyword(s):  
Sustainable Use ◽  
Basal Area ◽  
Future Research ◽  
Stem Density ◽  
Large Set ◽  
Sierra Madre Occidental ◽  
Forest Diversity ◽  
Community Forests ◽  
Forest Density ◽  
Sierra Madre

The Mexican Sierra Madre Occidental (SMO) represents a region where hundreds of plant species reach the limits of their northern or southern range. The SMO also features a unique cultural diversity, and many communities living within the forest or in its close vicinity depend on the products and services that these forests provide. Our study was based on a large set of remeasured field plots placed in the forests of Durango which are part of the SMO. Using hierarchical clustering, three distinctly different forest types were identified based on structural differences and the relation between stem density and basal area. Maximum forest densities were estimated using a 0.975th quantile regression. Forest production (expressed as current periodic volume increment per unit of area and time) was estimated based on number of stems, forest density, mean height, and forest diversity. Forest density is the principal factors affecting periodic volume production. The discussion presented recommendations for the sustainable use of this unique natural resource. Maintaining minimum levels of residual density is key to ensuring the continued viability of the forests of the Mexican SMO. Future research is needed to identify optimum residual structures, productive residual densities, and desirable levels of biodiversity.

scholarly journals Forest Vegetation and Dynamics Studies in India

2021 ◽  
Author(s):  
Madan Prasad Singh ◽  
Manohara Tattekere Nanjappa ◽  
Sukumar Raman ◽  
Suresh Hebbalalu Satyanatayana ◽  
Ayyappan Narayanan ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Life ◽  
Climatic Variability ◽  
National Level ◽  
Warning System ◽  
Basal Area ◽  
Evergreen Forest ◽  
Stem Density ◽  
Forest Diversity ◽  
Research And Education

Forests across the globe have been exploited for resouces, and over the years the demand has increased, and forests are rather exploited instead of sustainable use. Focussed research on vegetation and forerst dynamics is necessary to preserve biodiversity and functioning of forests for sustanence of human life on Earth.This article emphasis that the India has a long history of traditional knowledge on forest and plants, and explorations from 17th century on forests and provided subsequent scientific approach on classification of forests. This also explains the developments of quantitative approach on the understanding of vegetation and forest diversity. Four case studies viz., Mudumalai, Sholayar, Uppangala, Kakachi permanent plots in the forests of Western Ghats has been explained in detail about their sampling methods with a note on the results of forest monitoring. In the case of deciduous forests, the population of plant species showed considerable fluctuations but basal area has been steadily increasing over time, and this is reflecting carbon sequestration. In Sholayar, a total of 25390 individuals of 106 woody species was recorded for < 1 cm diameter at breast height in the first census of the 10 ha plot in the tropical evergreen forest. In Uppangala, 1) a 27- year long investigation revealed that residual impact of logging in the evergreen forests and such forests would take more time to resemble unlogged forests in terms of composition and structure; 2) across a similar temporal scale, the unlogged plots trees < 30 cm gbh showed a more or less similar trend in mortality (an average of 0.8% year-1) and recruitment (1%). The Kakachi plot study revealed that 1) endemic species showed least change in stem density and basal area whereas widely distributed species showed greater change in both; 2) The overall recruitment of trees was 0.86 % per year and mortality 0.56% per year resulting in an annual turnover of 0.71% ; 3) majority of the gap species had high levels of recruitment and mortality resulting in a high turnover.Such studies can be used as early warning system to understand how the response of individual plants, species and forests with the climatic variability. In conclusion, the necessity of implementation of national level projects, the way forward of two such studies: 1) impact of climate change on Indian forests through Indian Council of Forestry Research and Education (ICFRE) colloborations and 2) Indian long term ecological observatorion, including the sampling protocols of such studies. This will be the first of its kind in India to address climate change issues at national and international level and helps to trace footprints of climate change impacts through vegetation and also reveals to what extent our forests are resilient to changes in the climate.

STABLE ISOTOPE COMPOSITIONS OF MODERN SURFACE WATER IN THE SIERRA MADRE OCCIDENTAL, MEXICO

2020 ◽  
Author(s):  
Jordan M. Foote ◽  
◽  
Majie Fan ◽  
Aaron J. Martin ◽  
Lu Zhu
Keyword(s):  
Surface Water ◽  
Stable Isotope ◽  
Sierra Madre Occidental ◽  
Sierra Madre

scholarly journals A Regional Review of Genetic Resource Access and Benefit Sharing – Key Issues and Research Gaps

2021 ◽  
pp. 1-24
Author(s):  
Clare Morrison ◽  
Fran Humphries ◽  
Charles Lawson
Keyword(s):  
Intellectual Property ◽  
Traditional Knowledge ◽  
Biological Diversity ◽  
National Level ◽  
Sustainable Use ◽  
Benefit Sharing ◽  
Comparative Approach ◽  
Future Research ◽  
Access And Benefit Sharing ◽  
Legal Mechanism

Countries are increasingly using access and benefit sharing (ABS) as a legal mechanism to support the conservation and sustainable use of the world’s biological diversity. ABS regulates collection and/or use of genetic resources/traditional knowledge and sharing benefits from their use with the provider. The purpose of this review is to assess the trends, biases and gaps of ABS literature using a regional comparative approach about the key topics of concern between each region. It analyses four key topic groupings: (1) implementation of international, regional and national ABS policy and law; (2) intellectual property and ABS; (3) traditional knowledge; and (4) research, development and commercialisation. Findings included gaps in: (1) analysing effectiveness of national level implementation; (2) addressing apparent conflicts between support for intellectual property promoting exclusivity for traditional knowledge and challenges to intellectual property exclusivity for patents; (3) examining traditional knowledge of local communities (in contrast to Indigenous Peoples); and (4) lack of practical examples that quantify benefit sharing from research and commercialisation outcomes. We conclude that future research addressing the identified gaps and biases can promote more informed understanding among stakeholders about the ABS concept and whether it is capable of delivering concrete biological conservation, sustainable use and equity outcomes.

Exploring the Recruitment Dynamics of Sugar Maple and Yellow Birch Saplings into Merchantable Stems Following Harvesting in the Acadian Forest Region of New Brunswick, Canada

2021 ◽  
Author(s):  
Alex Noel ◽  
Jules Comeau ◽  
Salah-Eddine El Adlouni ◽  
Gaetan Pelletier ◽  
Marie-Andrée Giroux
Keyword(s):  
New Brunswick ◽  
Sugar Maple ◽  
Basal Area ◽  
Stem Density ◽  
Yellow Birch ◽  
Probability Of Occurrence ◽  
Silvicultural Treatment ◽  
Forest Region ◽  
Wide Range ◽  
Acadian Forest

The recruitment of saplings in forest stands into merchantable stems is a very complex process, thus making it challenging to understand and predict. The recruitment dynamics in the Acadian Forest Region of New Brunswick are not well known or documented. Our objective was to draw an inference from existing large scale routine forest inventories as to the different dynamics behind the recruitment from the sapling layer into the commercial tree size layer in terms of density and occurrence of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britt.) following harvesting, by looking at many factors on a wide range of spatial and temporal scales using models. Results suggest that the variation in density and probability of occurrence is best explained by the intensity of silvicultural treatment, by the merchantable stem density in each plot, and by the proportion of merchantable basal area of each group of species. The number of recruits of sugar maple and yellow birch stems tend be higher when time since last treatment increases, when mid to low levels of silvicultural treatment intensity were implemented, and within plots having intermediate levels of merchantable stem density. Lastly, our modeling efforts suggest that the probability of occurrence and density of recruitment of both species tend to increase while its share of merchantable basal area increases.

Post-Oligocene river incision, southern Sierra Madre Occidental, Mexico

Geomorphology ◽  
2003 ◽  
Vol 55 (1-4) ◽  
pp. 235-247 ◽  
Author(s):  
David R. Montgomery ◽  
Jorge López-Blanco
Keyword(s):  
Sierra Madre Occidental ◽  
River Incision ◽  
Sierra Madre

Tree density, basal area and species diversity in a disturbed dry tropical forest of northern India: implications for conservation

2006 ◽  
Vol 33 (3) ◽  
pp. 256-262 ◽  
Author(s):  
R. SAGAR ◽  
J.S. SINGH
Keyword(s):  
Species Diversity ◽  
Tropical Forest ◽  
Basal Area ◽  
Tree Density ◽  
Dry Forest ◽  
Conservation Strategies ◽  
Stem Density ◽  
Dry Tropical Forest ◽  
Number Of Species ◽  
Northern India

Dry tropical forest communities are among the world's most threatened systems and urgent measures are required to protect and restore them in degraded landscapes. For planning conservation strategies, there is a need to determine the few essential measurable properties, such as number of species and basal area, that best describe the dry forest vegetation and its environment, and to document quantitative relationships among them. This paper examines the relationships between forest basal area and diversity components (number of species and evenness) for a disturbed dry tropical forest of northern India. Data were collected from five sites located in the Vindhyan dry tropical forest of India, selected on the basis of satellite images and field observations to represent the entire range of conditions in terms of canopy cover and disturbance regimes. These sites represented different communities in terms of species composition. The forest was poorer in species richness, and lower in stem density and basal area than wet forests of the tropics. Across sites (communities), the diversity components and tree density were positively related with total tree basal area. Considering basal area as a surrogate of biomass and net production, diversity is found to be positively associated with productivity. A positive relationship between basal area, tree density and species diversity may be an important characteristic of the dry forest, where recurring disturbance does not permit concentration of biomass or stems in only a few strong competitors. However, the relationships of basal area with density, alpha diversity and evenness remain statistically significant only when data from all sites, including the extremely disturbed one, are used in the analysis. In some sites there was a greater coefficient of variation (CV) of basal area than in others, attributed to patchy distribution of stems and resultant blanks. Therefore, to enhance the tree diversity of these forests, the variability in tree basal area must be reduced by regulating local disturbances. Conservation activities, particularly fuelwood plantations near human settlements, deferred grazing and canopy enrichment through multi-species plantations of nursery-raised or wild-collected seedlings of desirable species within the forest patches of low basal area, will be needed to attain restoration goals, but reforestation programmes will have to be made attractive to the forest-dwelling communities.

scholarly journals Sentiment Analysis of Suicide Notes: A Shared Task

2012 ◽  
Vol 5s1 ◽  
pp. BII.S9042 ◽  
Author(s):  
John P. Pestian ◽  
Pawel Matykiewicz ◽  
Michelle Linn-Gust ◽  
Brett South ◽  
Ozlem Uzuner ◽  
...  
Keyword(s):  
Preliminary Analysis ◽  
The Other ◽  
Future Research ◽  
Large Set ◽  
Biomedical Domain ◽  
Shared Task ◽  
Clinical Text ◽  
Evaluation Measures ◽  
Suicide Notes ◽  
Data Production

This paper reports on a shared task involving the assignment of emotions to suicide notes. Two features distinguished this task from previous shared tasks in the biomedical domain. One is that it resulted in the corpus of fully anonymized clinical text and annotated suicide notes. This resource is permanently available and will (we hope) facilitate future research. The other key feature of the task is that it required categorization with respect to a large set of labels. The number of participants was larger than in any previous biomedical challenge task. We describe the data production process and the evaluation measures, and give a preliminary analysis of the results. Many systems performed at levels approaching the inter-coder agreement, suggesting that human-like performance on this task is within the reach of currently available technologies.

scholarly journals New locality of the endangered Sierra Madre Sparrow (Xenospiza baileyi) from the State of Durango, Mexico, and recommendations for its conservation

2018 ◽  
Vol 34 (1) ◽  
pp. 1-6 ◽  
Author(s):  
José Hugo Martínez-Guerrero ◽  
Jorge Nocedal ◽  
Daniel Sierra-Franco ◽  
Samuel Ignacio Arroyo-Arroyo ◽  
Martín Emilio Pereda-Solís
Keyword(s):  
The State ◽  
Reproductive Season ◽  
Livestock Grazing ◽  
Rainfed Agriculture ◽  
Sierra Madre Occidental ◽  
Sierra Madre ◽  
Protection Area ◽  
Northwestern Mexico ◽  
The City ◽  
Special Protection

The Sierra Madre Sparrow (Xenospiza baileyi) is an endemic species of Mexico that is threatened with extinction. Its distribution is reported in two areas: One in the Transvolcanic Belt of central Mexico (La Cima) near Mexico City and the other in the Sierra Madre Occidental in northwestern Mexico (Ejido Ojo de Agua El Cazador) near the city of Durango, in the state of Durango. The habitat is the same in these two areas, and consists of sub-alpine grassland that is located in shallow valleys or shallows. In our case, "El Bajío la Cantera" of approximately 55 hectares, is mostly used in rainfed agriculture, protected from livestock grazing with wire fences, which in turn represents protection for remnants of grassland where they are the birds. “El Bajío la Cantera" belongs to Ejido 12 de Mayo, Municipality of San Dimas, Durango, where 28 males were detected singing along a 500 meter transect. This finding represents the population of the healthiest Sierra Madre Sparrow currently known, so it would be necessary to document their population trend over time. This information can help to evaluate and propose the creation of a special protection area for the species that involves joint government actions and ejidatarios tending to conserve the habitat during the reproductive season in order to increase and / or maintain the size of the population.

scholarly journals Thinning Response and Potential Basal Area in a Mixed Sub-humid Low-elevation Oak-Hornbeam Forest

2021 ◽  
Author(s):  
Mathias Neumann ◽  
Hubert Hasenauer
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Climatic Conditions ◽  
Diameter Distribution ◽  
Stem Density ◽  
Growing Stock ◽  
A Site ◽  
Water Nutrients ◽  
Related Mortality

Abstract Competition for resources (light, water, nutrients, etc.) limits the size and abundance of alive trees a site can support. This carrying capacity determines the potential carbon sequestration in alive trees as well as the maximum growing stock. Lower stocking through thinning can change growth and mortality. We were interested in the relations between stand structure, increment and mortality using a long-unmanaged oak-hornbeam forest near Vienna, Austria, as case study. We expected lower increment for heavy thinned compared to unmanaged stands. We tested the thinning response using three permanent growth plots, whereas two were thinned (50% and 70% basal area removed) and one remained unmanaged. We calculated stand structure (basal area, stem density, diameter distribution) and increment and mortality of single trees. The heavy thinned stand had over ten years similar increment as the moderate thinned and unthinned stands. Basal area of the unthinned stand remained constant and stem density decreased due to competition-related mortality. The studied oak-hornbeam stands responded well even to late and heavy thinning suggesting a broad “plateau” of stocking and increment for these forest types. Lower stem density for thinned stands lead to much larger tree increment of single trees, compared to the unthinned reference. The findings of this study need verification for other soil and climatic conditions.

scholarly journals Adolescencia rural indígena, escuela y masculinidades

2018 ◽  
Vol 13 (1) ◽  
pp. 69
Author(s):  
Lourdes Consuelo Pacheco-Ladrón de Guevara
Keyword(s):  
Sierra Madre Occidental ◽  
Sierra Madre

Tanto la niñez como la adolescencia se consideran construcciones socioculturales enmarcadas en contextos específicos. De ahí que lejos de establecer parámetros genéricos sobre la adolescencia, su estudio particular permite especificar las formas de ser adolescente en situaciones concretas. En el presente documento se aborda la construcción de las masculinidades rurales indígenas desde la comunidad y la escuela telesecundaria, para lo cual se realizaron grupos focales y entrevistas a estudiantes indígenas de telesecundaria de la Sierra Madre Occidental durante los años 2010 y 2011. Se discute la importancia de abordar la construcción de las masculinidades adolescentes en el marco de la irrupción de la escuela telesecundaria en la zona indígena en función de que la escuela telesecundaria se ha convertido en el espacio de la adolescencia indígena rural. Se concluye que la escuela tiene posibilidades de convertirse en un espacio de discusión de las propuestas comunitarias tradicionales si es capaz de replantear la funcionalidad de las masculinidades en los contextos específicos a partir de las condiciones del grupo cultural.

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