scholarly journals Constructing single-entry stem volume models for four economically important tree species of Greece

2021 ◽  
Vol 48 (2) ◽  
pp. 136-146
Author(s):  
Panagiotis P. Koulelis ◽  
Kostas Ioannidis
Keyword(s):  
Tree Species ◽  
National Level ◽  
Sustainable Use ◽  
Information Criterion ◽  
Cost Effective ◽  
Volume Estimation ◽  
Stem Volume ◽  
Nonlinear Regression Models ◽  
Cubic Polynomial ◽  
Two Parameter

Abstract Three different nonlinear regression models were tested for their ability to predict stem volume for economically important native tree species in Greece. Τhe models were evaluated using adjusted R square (Adj Rsqr) root mean square error (RMSE) and Akaike information criterion (AICc), where necessary. In general, the quadratic polynomial and cubic polynomial models and the two-parameter power models fit the data well. Although the two-parameter power function fit best for fir, oak, and beech trees, the cubic polynomial model produced the best fit statistics for black pine. Making forest inventory estimates often involves predicting tree volumes from only the diameter at breast height (DBH) and merchantable height. This study covers important gaps in fast and cost-effective methods for calculating the volume of tree species at national level. However, the increasing need for reliable estimates of inventory components and volume changes requires more accurate volume estimation techniques. Especially when those estimates concern the national inventory, those models must be validated using an entire range of age/diameter and site classes of each species before their extended use across the country to promote the sustainable use of forest resources.

scholarly journals Comparison of Volumes Estimated from Breast Height and Stump Diameters: Application to Tectona grandis Data

2020 ◽  
Vol 66 (5) ◽  
pp. 551-555
Author(s):  
Onyekachi Chukwu ◽  
Friday N Ogana ◽  
Juliet U Nwatu
Keyword(s):  
Growth Model ◽  
Tectona Grandis ◽  
Information Criterion ◽  
Volume Estimation ◽  
Stem Volume ◽  
Model Assessment ◽  
Significance Level ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Stump Diameter

Abstract Models estimating tree volume from stump diameter are important forest-management tools when volume estimation is needed postharvest, and dbh values are unavailable, for example the incidence of timber trespass. However, the use of stump diameter as the only independent variable for predicting tree volume has been limited. Therefore, in this article, stump diameter was used to estimate stem volume of Tectona grandis Linn. f, and this was compared with volume estimated from diameter at breast height. Five functions were considered each for the two stem diameters: simple linear, semilogarithmic, zero-intercept, power, and growth. Model assessment was based on least values of the root mean square error and Akaike information criterion. The results showed that the growth model had the best overall performance for both sets of volume models. A paired-sample t-test was used to compare volume estimated by stump diameter and volume estimated by diameter at breast height at 5 percent significance level. The results showed that there were no significant differences (P = .087) between timber volumes estimated from both stem diameters. Therefore, both diameters can be used interchangeably for modeling tree volume.

scholarly journals 101 Evaluation of Growth Curve Functions for predicted weight in small holder crossbred dairy cattle in Tanzania

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 79-80
Author(s):  
Chinyere Ekine ◽  
Raphael Mrode ◽  
Edwin Oyieng ◽  
Daniel Komwihangilo ◽  
Gilbert Msuta ◽  
...  
Keyword(s):  
Growth Curve ◽  
Model Comparison ◽  
Predictive Ability ◽  
Nonlinear Least Squares ◽  
Information Criterion ◽  
Dairy Farms ◽  
Exponential Model ◽  
Males And Females ◽  
Small Holder ◽  
Two Parameter

Abstract Modelling the growth curve of animals provides information on growth characteristics and is important for optimizing management in different livestock systems. This study evaluated the growth curves of crossbred calves from birth to 30 months of age in small holder dairy farms in Tanzania using a two parameter (exponential), four different three parameters (Logistic, von Bertalanffy, Brody, Gompertz), and three polynomial functions. Predicted weights based on heart girth measurements of 623 male and 846 female calves born between 2016 and 2019 used in this study were from the African Dairy Genetic Gains (ADGG) project in selected milk sheds in Tanzania, namely Tanga, Kilimanjaro, Arusha, Iringa, Njomba and Mbeya. Each function was fitted separately to weight measurement of males and females adjusted for the effect of ward and season of birth using the nonlinear least squares (nls) functions in R statistical software. The Akaike’s information criterion (AIC) and Bayesian information criterion (BIC) were used for model comparison. Based on these criteria, all three polynomial and four parameter functions performed better and did not differ enough from each other in both males and females compared to the two-parameter exponential model. Predicted weight varied among the models and differed between males and females. The highest estimated weight was observed in the Brody model for both males (278.09 kg) and females (264.10 kg). Lowest estimated weight was observed in the exponential model. Estimated growth rate varied among models. For males, it ranged from 0.04 kg-0.08 kg and for females, from 0.05 kg-0.09 kg in the Brody model and logistic model respectively. Predictive ability across all fitted curves was low, ranging from 25% to approximately 29%. This could be due to the huge range of breed compositions in the evaluated crossbred calves which characterizes small holder dairy farms in this system and different levels of farm management.

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.

scholarly journals Challenges for Evaluation of the Safety of Engineered Nanomaterials

2021 ◽  
Vol 43 (1) ◽  
pp. 4-7
Author(s):  
Linda J. Johnston ◽  
Norma Gonzalez-Rojano ◽  
Kevin J. Wilkinson ◽  
Baoshan Xing
Keyword(s):  
Rapid Development ◽  
Sustainable Use ◽  
Cost Effective ◽  
Engineered Nanomaterials ◽  
Full Potential ◽  
Effective Strategies ◽  
Toxicological Studies ◽  
Regulatory Guidelines ◽  
Significant Effort ◽  
Safe By Design

Abstract Nanotechnology has developed rapidly in the last two decades with significant effort focused on the development of nano-enabled materials with new or improved properties that offer solutions for current world challenges. The commercialization of products containing engineered nanomaterials (ENM) has progressed much more rapidly than the development of practical approaches to ensure their safe and sustainable use. The lack of adequate detection and characterization techniques and reproducible and validated methods for toxicological studies have been identified as major limitations. The rapid development of ENM of increasing complexity and diversity and concerns over the adequacy of existing regulations also contribute to safety concerns with these materials. The full potential of nanotechnology can only be realized when feasible, cost-effective strategies to ensure a safe-by-design approach, effective risk assessment approaches and appropriate regulatory guidelines are in place.

scholarly journals Special Issue on “Bioenergy Systems, Material Management, and Sustainability”

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 590
Author(s):  
Fernando V. Lima ◽  
Gerardo J. Ruiz-Mercado
Keyword(s):  
Sustainable Use ◽  
Cost Effective ◽  
Special Issue ◽  
Material Management ◽  
Environmental Challenges ◽  
Material Sources ◽  
Bioenergy Systems

The growing worldwide demand for energy and resources, combined with the stringent environmental challenges and regulations, means that the efficient, cost-effective, and sustainable use of energy and material sources, including bio-based, has become increasingly important [...]

scholarly journals Brazilian Mangroves: Blue Carbon Hotspots of National and Global Relevance to Natural Climate Solutions

2022 ◽  
Vol 4 ◽  
Author(s):  
Andre S. Rovai ◽  
Robert R. Twilley ◽  
Thomas A. Worthington ◽  
Pablo Riul
Keyword(s):  
Carbon Sequestration ◽  
National Level ◽  
Cost Effective ◽  
Woody Biomass ◽  
Carbon Stocks ◽  
Blue Carbon ◽  
Carbon Accumulation ◽  
Amazon Forest ◽  
Nationally Determined Contributions ◽  
Natural Climate

Mangroves are known for large carbon stocks and high sequestration rates in biomass and soils, making these intertidal wetlands a cost-effective strategy for some nations to compensate for a portion of their carbon dioxide (CO2) emissions. However, few countries have the national-level inventories required to support the inclusion of mangroves into national carbon credit markets. This is the case for Brazil, home of the second largest mangrove area in the world but lacking an integrated mangrove carbon inventory that captures the diversity of coastline types and climatic zones in which mangroves are present. Here we reviewed published datasets to derive the first integrated assessment of carbon stocks, carbon sequestration rates and potential CO2eq emissions across Brazilian mangroves. We found that Brazilian mangroves hold 8.5% of the global mangrove carbon stocks (biomass and soils combined). When compared to other Brazilian vegetated biomes, mangroves store up to 4.3 times more carbon in the top meter of soil and are second in biomass carbon stocks only to the Amazon forest. Moreover, organic carbon sequestration rates in Brazilian mangroves soils are 15–30% higher than recent global estimates; and integrated over the country’s area, they account for 13.5% of the carbon buried in world’s mangroves annually. Carbon sequestration in Brazilian mangroves woody biomass is 10% of carbon accumulation in mangrove woody biomass globally. Our study identifies Brazilian mangroves as a major global blue carbon hotspot and suggest that their loss could potentially release substantial amounts of CO2. This research provides a robust baseline for the consideration of mangroves into strategies to meet Brazil’s intended Nationally Determined Contributions.

scholarly journals COMPATIBLE STEM VOLUME AND TAPER EQUATIONS FOR FIVE MAJOR TREE SPECIES IN NORTHEAST CHINA

2020 ◽  
Vol 18 (5) ◽  
pp. 6295-6308
Author(s):  
A. HUSSAIN ◽  
M.K. SHAHZAD ◽  
S.D. XIN ◽  
L.C. JIANG
Keyword(s):  
Tree Species ◽  
Northeast China ◽  
Stem Volume ◽  
Taper Equations

scholarly journals Description of blackberry fruit growth by nonlinear regression models

2020 ◽  
Vol 42 (2) ◽  
Author(s):  
Édipo Menezes da Silva ◽  
Maraísa Hellen Tadeu ◽  
Victor Ferreira da Silva ◽  
Rafael Pio ◽  
Tales Jesus Fernandes ◽  
...  
Keyword(s):  
Statistical Models ◽  
Regression Models ◽  
Least Squares Method ◽  
Growth Curves ◽  
Gompertz Model ◽  
Information Criterion ◽  
Financial Return ◽  
Nonlinear Regression Models ◽  
Small Fruit ◽  
Small Producers

Abstract Blackberry is a small fruit with several properties beneficial to human health and its cultivation is an alternative for small producers due to its fast and high financial return. Studying the growth of fruits over time is extremely important to understand their development, helping in the most appropriate crop management, avoiding post-harvest losses, which is one of the aggravating factors of blackberry cultivation, being a short shelf life fruit. Thus, growth curves are highlighted in this type of study and modeling through statistical models helps understanding how such growth occurs. Data from this study were obtained from an experiment conducted at the Federal University of Lavras in 2015. The aim of this study was to adjust nonlinear, double Logistic and double Gompertz models to describe the diameter growth of four blackberry cultivars (‘Brazos’, ‘Choctaw’, ‘Guarani’ and ‘Tupy’). Estimations of parameters were obtained using the least squares method and the Gauss-Newton algorithm, with the “nls” and “glns” functions of the R statistical software. The comparison of adjustments was made by the Akaike information criterion (AICc), residual standard deviation (RSD) and adjusted determination coefficient (R2 aj). The models satisfactorily described data, choosing the Logistic double model for ‘Brazos’ and ‘Guarani’ cultivars and the double Gompertz model for ‘Tupy’ and ‘Choctaw’ cultivars.

scholarly journals Novel Nested-Seq Approach for SARS-CoV-2 Real-Time Epidemiology and In-Depth Mutational Profiling in Wastewater

2021 ◽  
Vol 22 (16) ◽  
pp. 8498
Author(s):  
Margaritis Avgeris ◽  
Panagiotis G. Adamopoulos ◽  
Aikaterini Galani ◽  
Marieta Xagorari ◽  
Dimitrios Gourgiotis ◽  
...  
Keyword(s):  
Real Time ◽  
Nested Pcr ◽  
Mutational Analysis ◽  
National Level ◽  
Rna Stability ◽  
3D Structure ◽  
Cost Effective ◽  
Clinical Samples ◽  
Sequencing Data ◽  
Alpha Variant

Considering the lack of effective treatments against COVID-19, wastewater-based epidemiology (WBE) is emerging as a cost-effective approach for real-time population-wide SARS-CoV-2 monitoring. Here, we report novel molecular assays for sensitive detection and mutational/variant analysis of SARS-CoV-2 in wastewater. Highly stable regions of SARS-CoV-2 RNA were identified by RNA stability analysis and targeted for the development of novel nested PCR assays. Targeted DNA sequencing (DNA-seq) was applied for the analysis and quantification of SARS-CoV-2 mutations/variants, following hexamers-based reverse transcription and nested PCR-based amplification of targeted regions. Three-dimensional (3D) structure models were generated to examine the predicted structural modification caused by genomic variants. WBE of SARS-CoV-2 revealed to be assay dependent, and significantly improved sensitivity achieved by assay combination (94%) vs. single-assay screening (30%–60%). Targeted DNA-seq allowed the quantification of SARS-CoV-2 mutations/variants in wastewater, which agreed with COVID-19 patients’ sequencing data. A mutational analysis indicated the prevalence of D614G (S) and P323L (RdRP) variants, as well as of the Β.1.1.7/alpha variant of concern, in agreement with the frequency of Β.1.1.7/alpha variant in clinical samples of the same period of the third pandemic wave at the national level. Our assays provide an innovative cost-effective platform for real-time monitoring and early-identification of SARS-CoV-2 variants at community/population levels.

scholarly journals National mapping and estimation of forest area by dominant tree species using Sentinel-2 data

2020 ◽  
Author(s):  
Johannes Breidenbach ◽  
Lars T. Waser ◽  
Misganu Debella-Gilo ◽  
Johannes Schumacher ◽  
Johannes Rahlf ◽  
...  
Keyword(s):  
Tree Species ◽  
Deciduous Forest ◽  
National Level ◽  
National Forest Inventory ◽  
Forest Area ◽  
Forest Resource ◽  
Species Specific ◽  
Minimum Numbers ◽  
Generate Model ◽  
Sentinel 2

Nation-wide Sentinel-2 mosaics were used with National Forest Inventory (NFI) plot data for modelling and subsequent mapping of spruce-, pine- and deciduous-dominated forest in Norway at a 16m×16m resolution. The accuracies of the best model ranged between 74% for spruce and 87% for deciduous forest. An overall accuracy of 90% was found on stand level using independent data from more than 42,000 stands. Errors mostly resulting from a forest mask reduced the model accuracies by approximately 10%. The produced map was subsequently used to generate model-assisted (MA) and post stratified (PS) estimates of species-specific forest area. At the national level, efficiencies of the estimates increased by 20% to 50% for MA and up to 90% for PS. Greater minimum numbers of observations constrained the use of PS. For MA estimates of municipalities, efficiencies improved by up to a factor of 8 but were sometimes also less than 1. PS estimates were always equally as or more precise than direct and MA estimates but were applicable in fewer municipalities. The tree species prediction map is part of the Norwegian forest resource map and is used, among others, to improve maps of other variables of interest such as timber volume and biomass.

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