scholarly journals Transpiration of Anatolian black pine and sessile oak forest stands in a sub-humid region of Turkey

2021 ◽  
Vol 64 (1) ◽  
pp. 111-128
Author(s):  
Mehmet Said Ozcelik ◽  
Kamil Sengonul
Keyword(s):  
Management Practices ◽  
Regression Equations ◽  
Black Pine ◽  
Forest Stands ◽  
Flow Measurements ◽  
Stand Transpiration ◽  
Sessile Oak ◽  
Wide Range ◽  
Model Equations ◽  
Anatolian Black Pine

Transpiration is a key component of the watershed water budget. Therefore, determining the transpiration of forest stands with different characteristics have been of interest for watershed hydrology and forest management practices in a wide range of environments. The objectives of this study were to compare transpiration of Anatolian black pine (Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe) and sessile oak (Quercus petraea (Matt.) Liebl.) tree stands and to model transpiration based on the measured climatic factors. Stand transpirations were calculated from sap flow measurements made by the trunk heat balance method. We conducted an exploratory factor analysis (PCR) to detect affecting meteorological factors of stand transpiration, and we developed linear regression equations to predict transpiration of pine and oak stands. Mean daily and yearly canopy transpiration (Ec) were 1.05 mm day-1 and 378.3 mm year-1 for the pine stand and 3.52 mm day-1 and 801.7 mm year-1 for the oak stand. There was a highly positive correlation between daily stand transpiration and wind speed, global radiation, air vapour pressure deficit and air temperature, but a negative correlation with relative humidity for both stands. Soil water potential had little effect on stand transpiration. The model equations accounted for 81% of the variations in transpiration for the pine stand and 85% for the oak stand. Therefore, the transpiration of forest stands should be considered for effective vegetation management practices, as model equations to estimate the transpiration of pine and oak stands in the region.

scholarly journals The Effect of Herb Layer on Nocturnal Macrolepidoptera (Lepidoptera: Macroheterocera) Communities

2013 ◽  
Vol 9 (1) ◽  
pp. 43-56
Author(s):  
Bálint Horváth ◽  
Viktória Tóth ◽  
Gyula Kovács
Keyword(s):  
Plant Species ◽  
Management Practices ◽  
Vascular Plant ◽  
Quercus Petraea ◽  
Species Number ◽  
Herb Layer ◽  
Forest Stands ◽  
Forest Diversity ◽  
Sessile Oak ◽  
The Difference

Abstract Vegetation beneath the canopy might be an important factor for macromoth community composition in forest ecosystems, strongly determined by forest management practices. Herein, we compared nocturnal macrolepidoptera communities and herb layers in young and old sessile oak (Quercus petraea) dominated forest stands in the Sopron Mountains (Western Hungary). The investigation of Lepidoptera species was performed 15 times from the end of March to the end of October in 2011. Portable light traps were used, and a total of 257 species and 5503 individuals were identified. The Geometridae family was the most abundant, followed by Noctuidae and Notodontidae. To investigate vascular plant species in the herb layer, circular plots with a 10-m radius around the moth traps were used. In each plot, we estimated the abundance of plant species in 20 sub-plots with a 1-m radius from May to July of 2011. The abundance of macromoth species was higher in the old forest stand, which might be influenced by the trees’ higher foliar biomass. However, the mean abundance of herbs was lower in the old forest. Diversity of both the herb layer and the moth community were significantly higher in the young forest. However we found higher species richness of moths in the old forest. For additional analyses, moths feeding on plants in the herb layer were selected, but neither the difference in species number, neither mean abundance between the young and old forest were significant. Our results suggest that the herb layer is not a key factor for macrolepidoptera communities in Hungarian sessile oak forest stands.

Estimating crown fuel loading for calabrian pine and Anatolian black pine

2008 ◽  
Vol 17 (1) ◽  
pp. 147 ◽  
Author(s):  
Ömer Küçük ◽  
Ertuğrul Bilgili ◽  
Bülent Sağlam
Keyword(s):  
Total Biomass ◽  
Regression Equations ◽  
Black Pine ◽  
Fire Behaviour ◽  
Fuel Loading ◽  
Crown Length ◽  
Crown Width ◽  
Calabrian Pine ◽  
Anatolian Black Pine ◽  
Fine Branch

Fuels are of great importance in fire behaviour prediction. This paper deals with the prediction of aboveground foliage and branch biomass of calabrian pine (Pinus brutia Ten.) and Anatolian black pine (P. nigra J.F. Arnold subsp. nigra var. caramanica (Loudon) Rehder). The study was based on a total of 418 destructively sampled calabrian and black pine trees and saplings. As a result of the analyses, several regression equations were developed for predicting foliage, fine branch (<0.6 cm), medium branch (0.6–1.0 cm), active fuels (foliage + fine branch), thick branch (1.0–2.5 cm), and total fuel loading. The relationships between fuel biomass and tree properties were determined by multiple linear regressions, considering tree properties as the independent variables, and foliage, branch, active fuel and total biomass as the dependent variables. Tree properties included tree height, crown length, crown width, diameter at breast height and root collar diameter. Results indicated that foliage, branch and total biomass could all be accurately predicted based on the readily measurable and/or predictable tree characteristics. Of the fuel characteristics, crown length, crown width, and height were the three most significant predictors of fuel biomass. The results of this study will not only contribute to the prediction of fire behaviour, but will also be of invaluable use in other forestry disciplines.

Impression management and legitimacy strategies: The BP case

2013 ◽  
pp. 35-64 ◽  
Author(s):  
Giovanna Michelon
Keyword(s):  
Impression Management ◽  
Management Practices ◽  
Legitimacy Theory ◽  
British Petroleum ◽  
Wide Range ◽  
Management Techniques ◽  
Disclosure Tone ◽  
The Empirical Analysis ◽  
A Company ◽  
Texas City

The aim of this paper is to study if and how impression management varies during different phases of the legitimation process, in particular during the legitimacy building and legitimacy repairing phases (Suchman, 1995). We aim at understanding whether and how the disclosure tone adopted by a company in the two different moments is diverse and thus functional to the intrinsic objective of the each phase. The empirical analysis focuses on the case of British Petroleum Plc. We investigated the impression management practices undertaken by the company both during the preparation of the rebranding operation, i.e. a situation in which the company is trying to build legitimacy; and during the happenings of two legitimacy crises, like the explosion of the refinery in Texas City and the oil spill in the Gulf of Mexico. The evidence appears in line with the theoretical prediction of legitimacy theory. Results show that while the company tends to privilege image enhancement techniques during the legitimacy-building phase, it uses more obfuscation techniques when managing a legitimacy-repairing process. Moreover, the analysis suggests that the company makes more extensive use of impression management techniques in the disclosures addressed to shareholders, investors and other market operators than in the disclosures addressed to the wide range of other stakeholders.

scholarly journals Fitness of Herbicide-Resistant Weeds: Current Knowledge and Implications for Management

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 469 ◽  
Author(s):  
Vila-Aiub
Keyword(s):  
Life History ◽  
Herbicide Resistance ◽  
Management Practices ◽  
Current Knowledge ◽  
Resistance Management ◽  
Fitness Cost ◽  
Plant Fitness ◽  
Resistance Mutations ◽  
Fitness Costs ◽  
Wide Range

Herbicide resistance is the ultimate evidence of the extraordinary capacity of weeds to evolve under stressful conditions. Despite the extraordinary plant fitness advantage endowed by herbicide resistance mutations in agroecosystems under herbicide selection, resistance mutations are predicted to exhibit an adaptation cost (i.e., fitness cost), relative to the susceptible wild-type, in herbicide untreated conditions. Fitness costs associated with herbicide resistance mutations are not universal and their expression depends on the particular mutation, genetic background, dominance of the fitness cost, and environmental conditions. The detrimental effects of herbicide resistance mutations on plant fitness may arise as a direct impact on fitness-related traits and/or coevolution with changes in other life history traits that ultimately may lead to fitness costs under particular ecological conditions. This brings the idea that a “lower adaptive value” of herbicide resistance mutations represents an opportunity for the design of resistance management practices that could minimize the evolution of herbicide resistance. It is evident that the challenge for weed management practices aiming to control, minimize, or even reverse the frequency of resistance mutations in the agricultural landscape is to “create” those agroecological conditions that could expose, exploit, and exacerbate those life history and/or fitness traits affecting the evolution of herbicide resistance mutations. Ideally, resistance management should implement a wide range of cultural practices leading to environmentally mediated fitness costs associated with herbicide resistance mutations.

scholarly journals Environmental Drivers and Age Trends in Site Productivity for Oak in Southern Poland

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 209
Author(s):  
Luiza Tymińska-Czabańska ◽  
Jarosław Socha ◽  
Marek Maj ◽  
Dominika Cywicka ◽  
Xo Viet Hoang Duong
Keyword(s):  
Nitrogen Deposition ◽  
Management Practices ◽  
Additive Model ◽  
Climatic Conditions ◽  
Environmental Indicators ◽  
Environmental Drivers ◽  
Site Productivity ◽  
Site Factors ◽  
Wide Range ◽  
Si Model

Site productivity provides critical information for forest management practices and is a fundamental measure in forestry. It is determined using site index (SI) models, which are developed using two primary groups of methods, namely, phytocentric (plant-based) or geocentric (earth-based). Geocentric methods allow for direct site growth modelling, in which the SI is predicted using multiple environmental indicators. However, changes in non-static site factors—particularly nitrogen deposition and rising CO2 concentration—lead to an increase in site productivity, which may be visible as an age trend in the SI. In this study, we developed a geocentric SI model for oak. For the development of the SI model, we used data from 150 sample plots, representing a wide range of local topographic and site conditions. A generalized additive model was used to model site productivity. We found that the oak SI depended predominantly on physicochemical soil properties—mainly nitrogen, carbon, sand, and clay content. Additionally, the oak SI value was found to be slightly shaped by the topography, especially by altitude above sea level, and topographic position. We also detected a significant relationship between the SI and the age of oak stands, indicating the long-term increasing site productivity for oak, most likely caused by nitrogen deposition and changes in climatic conditions. The developed geocentric site productivity model for oak explained 77.2% of the SI variation.

scholarly journals A Cross-sectional Survey of the North American Skull Base Society: Current Practice Patterns of Vestibular Schwannoma Evaluation and Management in North America

2017 ◽  
Vol 79 (03) ◽  
pp. 289-296 ◽  
Author(s):  
Jamie Van Gompel ◽  
R. Wiet ◽  
Nicole Tombers ◽  
Anand Devaiah ◽  
Devyani Lal ◽  
...  
Keyword(s):  
North America ◽  
Skull Base ◽  
Vestibular Schwannoma ◽  
North American ◽  
Management Practices ◽  
Current Practice ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Number Of Patients ◽  
Wide Range

Background Very few studies have examined vestibular schwannoma (VS) management trends across centers and between providers. The objective of this study is to examine current practice trends, variance in treatment philosophies, and nuanced or controversial aspects of VS care across North America. Methods This is a cross-sectional survey of North American Skull Base Society (NASBS) members who report regular involvement in VS care. Results A total of 57 completed surveys were returned. Most respondents claimed to have over 20 years of experience and the majority reported working in an academic practice with an affiliated otolaryngology and/or neurosurgery residency program. Sixty-three percent of respondents claimed to evaluate VS patients in clinic with both an otolaryngologist and neurosurgeon involved. Eighty-six percent of respondents claimed to operate on VS with both an otolaryngologist and neurosurgeon involved, while only 18% of neurosurgeons and 9% of otolaryngologists performed surgery alone. There was a wide range in the number of cases evaluated at each center annually. Similarly, there was wide variation in the number of patients treated with microsurgery and radiation at each center. Additional details regarding management preferences for microsurgery, stereotactic radiosurgery, stereotactic radiotherapy, and conservative observation are presented. Conclusion VS management practices vary between providers and centers. Overall, most centers employ a multidisciplinary approach to management with collaboration between otolaryngology and neurosurgery. Overall, survey responses concur with previous studies suggesting a shift toward conservatism in management.

Control of properties and structure of steel vessels by cooling in various media at the outlet of rolling and pressing lines

2021 ◽  
pp. 34-38
Author(s):  
R. L. Shatalov ◽  
V. A. Medvedev
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Metal Structure ◽  
Machine Building ◽  
Regression Equations ◽  
Wide Range ◽  
Industrial Mineral ◽  
Cooling Media ◽  
Technological Limitations ◽  
Non Destructive

When controlling the mechanical properties and structure of vessels made of carbon structural steels manufactured by hot deformation on rolling and pressing lines (PPL) of machine-building enterprises of Russia, such cooling media as water, I20 industrial mineral oil, air are used. The applied cooling media are able to provide the workpieces with a given structure with a wide range of mechanical properties. However, the cooling media have a number of technological limitations and conditions of the use, non-compliance with which leads to reject. When cooled in oil, the probability of ignition is high; when cooled in water, hardening cracks may form, and air is not always able to provide the required rate and uniformity of heat transfer to the environment. The efficiency of control of physical and mechanical properties and structure of deformed vessels made of 50 steel by cooling in TERMAT polymer aqueous solutions in different concentrations on PPL of the plant of JSC NPO Pribor was studied. The effect of varying the concentration from 2 to 9% of TERMAT polymer on the formation of metal structure, as well as physical and mechanical properties of hot-deformed vessels was studied. The results of testing the strength and plastic characteristics of vessels by destructive and non-destructive control methods are presented. According to the results of physical and mechanical properties, regression equations were obtained with at least 95% reliability of R2, which establish the relationship between the controlled plastic and strength parameters of the vessel metal`s properties. The conducted researches allowed to compare the indicators of the main physical and mechanical properties of steel vessels at the PPL outlet and to propose methods of inhomogeneity control that reduce time and material costs by 5–10% during the tests.

scholarly journals Applying Nitrogen Site-Specifically Using Soil Electrical Conductivity Maps and Precision Agriculture Technology

2001 ◽  
Vol 1 ◽  
pp. 767-776 ◽  
Author(s):  
E.D. Lund ◽  
M.C. Wolcott ◽  
G.P. Hanson
Keyword(s):  
Electrical Conductivity ◽  
Case Studies ◽  
Crop Yield ◽  
Soil Texture ◽  
Precision Agriculture ◽  
Management Practices ◽  
N Availability ◽  
Soil Electrical Conductivity ◽  
Variable Yield ◽  
Wide Range

Soil texture varies significantly within many agricultural fields. The physical properties of soil, such as soil texture, have a direct effect on water holding capacity, cation exchange capacity, crop yield, production capability, and nitrogen (N) loss variations within a field. In short, mobile nutrients are used, lost, and stored differently as soil textures vary. A uniform application of N to varying soils results in a wide range of N availability to the crop. N applied in excess of crop usage results in a waste of the grower’s input expense, a potential negative effect on the environment, and in some crops a reduction of crop quality, yield, and harvestability. Inadequate N levels represent a lost opportunity for crop yield and profit. The global positioning system (GPS)-referenced mapping of bulk soil electrical conductivity (EC) has been shown to serve as an effective proxy for soil texture and other soil properties. Soils with a high clay content conduct more electricity than coarser textured soils, which results in higher EC values. This paper will describe the EC mapping process and provide case studies of site-specific N applications based on EC maps. Results of these case studies suggest that N can be managed site-specifically using a variety of management practices, including soil sampling, variable yield goals, and cropping history.

scholarly journals Predictive Regression Equations of Flowmetric and Spirometric Peak Expiratory Flow in Healthy Moroccan Adults

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Khalid Bouti ◽  
Iliass Maouni ◽  
Jouda Benamor ◽  
Jamal Eddine Bourkadi
Keyword(s):  
Peak Flow ◽  
Adult Population ◽  
Cross Sectional Study ◽  
Regression Equations ◽  
Anthropometric Parameters ◽  
Cross Sectional ◽  
Flow Measurements ◽  
Predictive Regression ◽  
Final Sample ◽  
Main Determinants

Introduction. PEF has never been characterized among healthy Moroccan adults. The objective of this study is to describe the values of PEF among healthy Moroccan adults, to study its relationship with anthropometric parameters (gender, age, height, and weight), to compare spirometric and flowmetric PEF, to establish the prediction equations for PEF, and to study the correlation between PEF and FEV1. Methods. Cross-sectional study conducted between May and June 2016. It involved healthy nonsmoking volunteers living in Tetouan, Morocco, gathered through a mobile stand realization of spirometry and peak flow measurements. Results. Our final sample concerned 313 adults (143 men and 170 women). For both men and women, age and height were the main determinants of PEF, and a positive correlation was found between PEF and FEV1. Conclusion. Our study has established the PEF predictive equations in the Moroccan adult population. Our results allow us to conclude that the PEF can be a reliable alternative of FEV1 in centers not equipped with spirometry.

Sign in / Sign up

Export Citation Format

Share Document