scholarly journals A Low-Cost and Robust Landsat-Based Approach to Study Forest Degradation and Carbon Emissions from Selective Logging in the Venezuelan Amazon

2021 ◽  
Vol 13 (8) ◽  
pp. 1435
Author(s):  
Carlos Pacheco-Angulo ◽  
Wenseslao Plata-Rocha ◽  
Julio Serrano ◽  
Emilio Vilanova ◽  
Sergio Monjardin-Armenta ◽  
...  
Keyword(s):  
Carbon Emissions ◽  
Direct Method ◽  
Low Cost ◽  
Forest Degradation ◽  
Selective Logging ◽  
Managed Forests ◽  
Forest Reserve ◽  
Aboveground Carbon ◽  
Two Phases ◽  
And Function

Selective logging in the tropics is a major driver of forest degradation by altering forest structure and function, including significant losses of aboveground carbon. In this study, we used a 30-year Landsat time series (1985–2015) to analyze forest degradation and carbon emissions due to selective logging in a Forest Reserve of the Venezuelan Amazon. Our work was conducted in two phases: the first, by means of a direct method we detected the infrastructure related to logging at the sub-pixel level, and for the second, we used an indirect approach using buffer areas applied to the results of the selective logging mapping. Pre- and post-logging forest inventory data, combined with the mapping analysis were used to quantify the effects of logging on aboveground carbon emissions for three different sources: hauling, skidding and tree felling. With an overall precision of 0.943, we demonstrate the potential of this method to efficiently map selective logging and forest degradation with commission and omission errors of +7.6 ± 4.5 (Mean ± SD %) and −7.5% ± 9.1 respectively. Forest degradation due to logging directly affected close to 24,480 ha, or about ~1% of the total area of the Imataca Forest Reserve. On average, with a relatively low harvest intensity of 2.8 ± 1.2 trees ha−1 or 10.5 ± 4.6 m3 ha−1, selective logging was responsible for the emission of 61 ± 21.9 Mg C ha−1. Lack of reduced impact logging guidelines contributed to pervasive effects reflected in a mean reduction of ~35% of the aboveground carbon compared to unlogged stands. This research contributes to further improve our understanding of the relationships between selective logging and forest degradation in tropical managed forests and serves as input for the potential implementation of projects for reducing emissions from deforestation and forest degradation (REDD+).

scholarly journals Implications of Selective Harvesting of Natural Forests for Forest Product Recovery and Forest Carbon Emissions: Cases from Tarai Nepal and Queensland Australia

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 693 ◽  
Author(s):  
Bishnu Hari Poudyal ◽  
Tek Narayan Maraseni ◽  
Geoff Cockfield
Keyword(s):  
Carbon Emissions ◽  
Sustainable Forest Management ◽  
Forest Degradation ◽  
Forest Harvesting ◽  
Product Recovery ◽  
Selective Logging ◽  
Natural Forest ◽  
Forest Product ◽  
Natural Forests ◽  
Production Chain

Selective logging is one of the main natural forest harvesting approaches worldwide and contributes nearly 15% of global timber needs. However, there are increasing concerns that ongoing selective logging practices have led to decreased forest product supply, increased forest degradation, and contributed to forest based carbon emissions. Taking cases of natural forest harvesting practices from the Tarai region of Nepal and Queensland Australia, this study assesses forest product recovery and associated carbon emissions along the timber production chain. Field measurements and product flow analysis of 127 commercially harvested trees up to the exit gate of sawmills and interaction with sawmill owners and forest managers reveal that: (1) Queensland selective logging has less volume recovery (52.8%) compared to Nepal (94.5%) leaving significant utilizable volume in the forest, (2) Stump volume represents 5.5% of total timber volume in Nepal and 3.9% in Queensland with an average stump height of 43.3 cm and 40.1 cm in Nepal and Queensland respectively, (3) Average sawn timber output from the harvested logs is 36.3% in Queensland against 61% in Nepal, (4) Nepal and Queensland leave 0.186 Mg C m−3 and 0.718 Mg C m−3 on the forest floor respectively, (5) Each harvested tree damages an average of five plant species in Nepal and four in Queensland predominantly seedlings in both sites, and (6) Overall logging related total emissions in Queensland are more than double (1.099 Mg C m−3) those in Nepal (0.488 Mg C m−3). We compared these results with past studies and speculated on possible reasons for and potential implications of these results for sustainable forest management and reducing emissions from deforestation and forest degradation.

scholarly journals Carbon emissions from selective logging in the southern Yucatan Peninsula, Mexico

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Samaria Armenta-Montero ◽  
Edward A. Ellis ◽  
Peter W. Ellis ◽  
Robert Hunter Manson ◽  
Citlalli Lopez-Binnqüist ◽  
...  
Keyword(s):  
Carbon Emissions ◽  
Yucatan Peninsula ◽  
Forest Degradation ◽  
Selective Logging ◽  
Total Carbon ◽  
Collateral Damage ◽  
Forest Stewardship Council ◽  
Yucatán Peninsula ◽  
Forest Use ◽  
Forest Stewardship

Tropical forests contain approximately 40% of the carbon accumulated in terrestrial biomass. However, the loss and degradation of forests worldwide liberates this carbon and contributes 11% of total global emissions. Forest degradation is an increasing source of carbon emissions, contributing 25% in tropical forest environments; and selective logging is among the principal causes.  The central objective of this study was to evaluate biomass impacts and committed carbon emissions from selective logging in two forestry communities (ejidos with common forest use and rights) in the southern Yucatan Peninsula, Mexico. We compared emissions performance from logging operations in both ejidos, one of them certified as sustainably managed by the Forest Stewardship Council (FSC). The species of roundwood extracted as well as the number of impacted trees from harvesting were recorded and the type of collateral damage from felling, skidding, and transport of timber was quantified. Biomass of harvested timber and impacted vegetation was estimated to calculate carbon emissions using allometric equations. Results indicated that selective logging generated 1.2 Mg m-3 1.5 Mg m-3 of total carbon emissions in the Caobas and 20 de Noviembre ejidos, with 5% and 12% corresponding to collateral damage during felling, respectively.  Overall lower committed emissions and collateral damage from felling and skidding were present in Caobas, the FSC certified ejido. We discuss how forest certification, through implementation of reduced impact logging (RIL) practices can significantly reduce carbon emissions from selective logging in the region.

scholarly journals Accounting for Greenhouse Gas Emissions from Forest Edge Degradation: Gold Mining in Guyana as a Case Study

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1307
Author(s):  
Sandra Brown ◽  
Abu R. J. Mahmood ◽  
Katherine M. Goslee ◽  
Timothy R. H. Pearson ◽  
Hansrajie Sukhdeo ◽  
...  
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Carbon Emissions ◽  
Low Cost ◽  
Timber Harvest ◽  
Forest Degradation ◽  
Forest Edge ◽  
Forest Recovery ◽  
Carbon Loss ◽  
Gas Emissions

Background and Methods: Degradation of forests in developing countries results from multiple activities and is perceived to be a key source of greenhouse gas emissions, yet there are not reliable methodologies to measure and monitor emissions from all degrading activities. Therefore, there is limited knowledge of the actual extent of emissions from forest degradation. Degradation can be either in the forest interior, with a repeatable defined pattern within areas of forest, as with timber harvest, or on the forest edge and immediately bounding areas of deforestation. Forest edge degradation is especially challenging to capture with remote sensing or to predict from proxy factors. This paper addresses forest edge degradation and: (1) proposes a low cost methodology for assessing forest edge degradation surrounding deforestation; (2) using the method, provides estimates of gross carbon emissions from forest degradation surrounding and caused by alluvial mining in Guyana, and (3) compares emissions from mining degradation with other sources of forest greenhouse gas emissions. To estimate carbon emissions from forest degradation associated with mining in Guyana, 100 m buffers were located around polygons pre-mapped as mining deforestation, and within these buffers rectangular transects were established. Researchers collected ground data to produce estimates of the biomass damaged as a result of mining activities to apply to the buffer area around the mining deforestation. Results: The proposed method to estimate emissions from forest edge degradation was successfully piloted in Guyana, where 61% of the transects lost 10 Mg C ha−1 or less in trees from mining damage and 46% of these transects lost 1 Mg C ha−1 or less. Seventy percent of the damaged stems and 60% of carbon loss occurred in the first 50 m of the transects. The median loss in carbon stock from mining damage was 2.2 Mg C ha−1 (95% confidence interval: 0.0–10.2 Mg C ha−1). The carbon loss from mining degradation represented 1.0% of mean total aboveground carbon stocks, with emissions from mining degradation equivalent to ~2% of all emissions from forest change in Guyana. Conclusions: Gross carbon emissions from forest degradation around mining sites are of little significance regardless of persistence and potential forest recovery. The development of cost- and time-effective buffers around deforestation provides a sound approach to estimating carbon emissions from forest degradation adjacent to deforestation including surrounding mining. This simple approach provides a low-cost method that can be replicated anywhere to derive forest degradation estimates.

scholarly journals Drivers and their influences on variation of aboveground carbon removals in miombo woodlands of mainland Tanzania

2020 ◽  
Author(s):  
Bernardol John Manyanda ◽  
Emmanuel Fred Nzunda ◽  
Wilson Ancelm Mugasha ◽  
Rogers Ernest Malimbwi
Keyword(s):  
Carbon Emissions ◽  
Shifting Cultivation ◽  
Forest Degradation ◽  
Data Sets ◽  
Miombo Woodlands ◽  
Natural Death ◽  
Aboveground Carbon ◽  
Study Results ◽  
Assessment And Monitoring

Abstract Background Removals caused by both natural and anthropogenic drivers such as logging and fire causes substantial carbon emissions. Better insights into drivers and their variations of aboveground carbon removals is therefore needed. We assessed the drivers of aboveground carbon (AGC) removals and quantified the dynamics of removals-induced carbon emissions due to drivers using the National Forest Resources Assessment and Monitoring (NAFORMA) data sets in R software. Miombo woodlands which is the largest forest formations covering about 93% of forest land in mainland Tanzania was the case study. Results Drivers of AGC removals in miombo woodlands of mainland Tanzania in order of importance were; timber, fire, shifting cultivation, charcoal, natural death, firewood collection, poles, grazing by wildlife animals, carvings, grazing by domestic animals, and mining. The average AGC removals by drivers range from 0.0–1.273tCha− 1year− 1. Conclusions Increased mitigation efforts in addressing removals by timber, fires, shifting cultivation, charcoal and natural death would be effective in addressing forest degradation in the REDD + process in Tanzania. Since NAFORMA provides national picture on drivers and their variation on AGC removals, site-specific studies need to be conducted to bring information that would be used for local forest management. This kind of study need to be conducted in other vegetation types like Montane and Mangrove forest in Tanzania.

scholarly journals Direct measurement of stool consistency by texture analyzer and calculation of reference value in Belgian general population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kazunori Matsuda ◽  
Takuya Akiyama ◽  
Satoshi Tsujibe ◽  
Kaihei Oki ◽  
Agata Gawad ◽  
...  
Keyword(s):  
Water Content ◽  
Direct Measurement ◽  
Direct Method ◽  
Reference Value ◽  
Stool Consistency ◽  
Texture Analyzer ◽  
Simple Protocol ◽  
Stool Form ◽  
Micro Systems ◽  
And Function

AbstractStool consistency is evaluated mainly in reference to indirect indicators such as water content or the appearance of stool forms using Bristol Stool Form Scale (BSFS). Methods of measurement are limited. We thus aimed to develop a simple protocol for direct measurement of stool consistency using the TA.XTExpress Texture Analyser (Stable Micro Systems Ltd.). We developed a protocol which enables mechanical quantification of the gram-force against a cylindrical probe (ø 6 mm) pushed into the stool surface at 2.0 mm/s to 5 mm depth. The consistency of 252 stools collected from 40 healthy Belgians was evaluated by the direct method and by the indirect indicators (water content and BSFS) for comparison. The log-transformed stool consistency values measured by the texture analyzer had a negative linear correlation with the stool water contents (rrm = − 0.781) with homoscedastic variance, suggesting the appropriateness of the new protocol. They showed a similar correlation with the BSFS, but with a large variance in the consistency values of normal stool forms. This correlation was much smaller for BSFS scored by subjects (rrm = − 0.587) than by experts (rrm = − 0.789), collectively indicating BSFS as a rough indicator of stool consistency susceptible to subjective bias despite its effectiveness in clinical use. The optimized direct method using the texture analyzer enables the accurate quantification of stool consistency, which facilitates understanding of the intestinal environment and function and thus may enhance the value of the stool as a predictor of human health.

scholarly journals Design of Mechanism and Preliminary Field Validation of Low-Cost Transfemoral Rotator for Use in the Developing World

2016 ◽  
Author(s):  
Matthew L. Cavuto ◽  
Matthew Chun ◽  
Nora Kelsall ◽  
Karl Baranov ◽  
Keriann Durgin ◽  
...  
Keyword(s):  
Developing World ◽  
Low Cost ◽  
Field Studies ◽  
Field Validation ◽  
User Testing ◽  
Common Solution ◽  
Locking Mechanism ◽  
Medial Rotation ◽  
Transfemoral Amputees ◽  
And Function

Transfemoral (above-knee) amputees face a unique and challenging set of restrictions to movement and function. Most notably, they are unable to medially rotate their lower-leg and subsequently cross their legs. The best and most common solution to this issue today is a transfemoral rotator, which allows medial rotation of the leg distal to the knee through a lockable turntable mechanism. However, currently available transfemoral rotators can cost thousands of dollars, and few equivalent technologies exist in the developing world. This paper, supported by the results of field studies and user testing, establishes a framework for the design of a low-cost and easily manufacturable transfemoral rotator for use in the developing world. Two prototypes are presented, each with a unique internal locking mechanism and form. A preliminary field study was conducted on six transfemoral amputees in India and qualitative user and prosthetist feedback was collected. Both prototypes successfully allowed all subjects to complete tasks such as crossing legs, putting on pants, and tying shoes while maintaining functionality of walking and standing. Future iterations of the mechanism will be guided by a combination of the most positively received features of the prototypes and general feedback suggestions from the users.

Competency Based Curriculum: A National Survey of Teachers

1978 ◽  
Vol 72 (5) ◽  
pp. 163-169
Author(s):  
Susan Jay Spungin
Keyword(s):  
National Survey ◽  
Community Relations ◽  
Guidance And Counseling ◽  
Activity Assessment ◽  
Competency Based ◽  
Administration And Supervision ◽  
Two Phases ◽  
And Function ◽  
Visually Handicapped ◽  
Media And Technology

Presents selected findings of a national survey of teachers of the visually handicapped to measure their attitudes toward competencies in seven areas of teaching activity: Assessment and Evaluation; Educational Instructional Strategies; Guidance and Counseling; Administration and Supervision; Media and Technology; School and Community Relations; and Research. Attitudes of the 807 responding teachers in both residential and local school programs were analyzed in two phases: Phase I compared what teachers said they do with their reactions to competencies; Phase II analyzed teacher roles (rather than titles) and compared role and function with reaction to the competencies.

Limb deformity proteins: role in mesodermal induction of the apical ectodermal ridge

Development ◽  
1997 ◽  
Vol 124 (1) ◽  
pp. 133-139 ◽  
Author(s):  
J. Kuhlman ◽  
L. Niswander
Keyword(s):  
Sonic Hedgehog ◽  
Limb Development ◽  
Apical Ectodermal Ridge ◽  
Primary Defect ◽  
Limb Deformity ◽  
Normal Morphology ◽  
Fibroblast Growth Factor 8 ◽  
Skeletal Pattern ◽  
Two Phases ◽  
And Function

During early limb development, distal tip ectoderm is induced by the underlying mesenchyme to form the apical ectodermal ridge. Subsequent limb growth and patterning depend on reciprocal signaling between the mesenchyme and ridge. Mice that are homozygous for mutations at the limb deformity (ld) locus do not form a proper ridge and the anteroposterior axis of the limb is shortened. Skeletal analyses reveal shortened limbs that involve loss and fusion of distal bones and digits, defects in both anteroposterior and proximodistal patterning. Using molecular markers and mouse-chick chimeras we examined the ridge-mesenchymal interactions to determine the origin of the ld patterning defects. In the ld ridge, fibroblast growth factor 8 (Fgf8) RNA is decreased and Fgf4 RNA is not detected. In the ld mesenchyme, Sonic hedgehog (Shh), Evx1 and Wnt5a expression is decreased. In chimeras between ld ectoderm and wild-type mesenchyme, a ridge of normal morphology and function is restored, Fgf8 and Shh are expressed normally, Fgf4 is induced and a normal skeletal pattern arises. These results suggest that the ld mesenchyme is unable to induce the formation of a completely functional ridge. This primary defect causes a disruption of ridge function and subsequently leads to the patterning defects observed in ld limbs. We propose a model in which ridge induction requires at least two phases: an early competence phase, which includes induction of Fgf8 expression, and a later differentiation phase in which Fgf4 is induced and a morphological ridge is formed. Ld proteins appear to act during the differentiation phase.

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