scholarly journals Roads Impact Tree and Shrub Productivity in Adjacent Boreal Peatlands

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 594
Author(s):  
Saraswati Saraswati ◽  
Yubraj Bhusal ◽  
Andrew J. Trant ◽  
Maria Strack
Keyword(s):  
Radial Growth ◽  
Net Primary Productivity ◽  
Carbon Sink ◽  
Road Construction ◽  
Aboveground Net Primary Productivity ◽  
Boreal Plains ◽  
The Road ◽  
Boreal Peatlands ◽  
Vegetation Surveys ◽  
Forested Bog

Peatlands in the western boreal plains of Canada are important ecosystems as they store over two percent of global terrestrial carbon. However, in recent decades, many of these peatlands have been fragmented by access roads constructed for resource extraction and transportation, challenging their carbon storage potential. To investigate how roads have been impacting tree and shrub growth and productivity in these peatlands, this study was conducted in a forested bog and woody fen in Carmon Creek, Alberta, Canada. In 2017, vegetation surveys were conducted along 20 m transects that extended on both sides of the road with 4 m2 circular plots at 2, 6 and 20 m distance from the road and were followed by disc or core collection from woody stems. Within 20 m of the road at the bog site, we observed a shift towards significantly larger radial growth of trees in the downstream areas (t = 3.23, p = 0.006) where water table position was deeper, while at the fen site, radial growth of tall shrubs had little response to the road. Combining the effects of direct tree clearing and hydrology induced shifts in growth, aboveground net primary productivity (NPPag) post-road construction was reduced significantly in areas where vegetation was cleared during the road construction (i.e., upstream areas of the bog: t = 5.21, p < 0.0001 and downstream areas of the fen: t = 2.64, p = 0.07). Substantially lower NPPag around the road construction areas compared to reference areas shows tremendous loss of carbon sink potential of trees and shrubs after road construction through peatlands. Altogether, roads constructed through peatlands perpendicular to the water flow may shift long-term carbon sinks into sources of carbon, at least for the initial few years following road construction.

scholarly journals Annual aboveground carbon uptake enhancements from assisted gene flow in boreal black spruce forests are not long-lasting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Martin P. Girardin ◽  
Nathalie Isabel ◽  
Xiao Jing Guo ◽  
Manuel Lamothe ◽  
Isabelle Duchesne ◽  
...  
Keyword(s):  
Gene Flow ◽  
Net Primary Productivity ◽  
Black Spruce ◽  
Carbon Sink ◽  
Phenotypic Variability ◽  
Common Garden ◽  
Phylogeographic Structure ◽  
Aboveground Net Primary Productivity ◽  
Common Garden Experiments ◽  
Positive Effect

AbstractAssisted gene flow between populations has been proposed as an adaptive forest management strategy that could contribute to the sequestration of carbon. Here we provide an assessment of the mitigation potential of assisted gene flow in 46 populations of the widespread boreal conifer Picea mariana, grown in two 42-year-old common garden experiments and established in contrasting Canadian boreal regions. We use a dendroecological approach taking into account phylogeographic structure to retrospectively analyse population phenotypic variability in annual aboveground net primary productivity (NPP). We compare population NPP phenotypes to detect signals of adaptive variation and/or the presence of phenotypic clines across tree lifespans, and assess genotype‐by‐environment interactions by evaluating climate and NPP relationships. Our results show a positive effect of assisted gene flow for a period of approximately 15 years following planting, after which there was little to no effect. Although not long lasting, well-informed assisted gene flow could accelerate the transition from carbon source to carbon sink after disturbance.

Alternative method for estimating aboveground net primary productivity applied to balsam fir stands in eastern Canada

2005 ◽  
Vol 35 (5) ◽  
pp. 1193-1201 ◽  
Author(s):  
M B Lavigne ◽  
R J Foster ◽  
G Goodine ◽  
P Y Bernier ◽  
C H Ung
Keyword(s):  
Primary Productivity ◽  
Net Primary Productivity ◽  
Carbon Sink ◽  
Abies Balsamea ◽  
Substantial Effect ◽  
Balsam Fir ◽  
Aboveground Net Primary Productivity ◽  
Eastern Canada ◽  
Cross Sectional ◽  
The Difference

Aboveground net primary productivity (ANPP) was measured in three balsam fir (Abies balsamea (L.) Mill.) forests on a climatic transect extending from southern New Brunswick ("warm" study area) to central Quebec ("cool" study area). Annual foliar production was estimated with a relationship between cross-sectional area at breast height of the current-year annual xylem ring and the mass of current-year foliage, using data obtained by harvesting trees at the beginning of the study. This relationship differed among study areas. Annual branch production was determined from annual foliar production and the ratio of annual branch production to annual foliar production. The ratio of branch to foliar production was estimated from intensive measurement of a sample of branches collected at the end of the study period; it varied among years but was similar for all study areas. ANPP was 3.36 Mg C·ha–1·year–1 at the warm study area, 3.73 Mg C·ha–1· year–1 at the mid-transect study area, and 3.04 Mg C·ha–1·year–1 at the cool study area. These estimates of ANPP were greater than those estimated using a conventional method of summing up increment and litterfall. On average, the conventional estimate of ANPP was 83% of the estimate using relationships described above. Because net ecosystem productivity is the difference between NPP and heterotrophic respiration, a 17% underestimate of NPP can have a substantial effect on the estimate of carbon-sink activity of a forest.

The Political Economy of Power: Approaches to the Analysis of Relationships between the State and Business in Russia

2011 ◽  
pp. 19-33
Author(s):  
A. Oleinik
Keyword(s):  
Oil And Gas ◽  
Road Construction ◽  
Oil And Gas Industry ◽  
Retail Trade ◽  
Business Community ◽  
The Political ◽  
Economic Power ◽  
Gas Industry ◽  
The Road ◽  
Ruling Elites

The article deals with the issues of political and economic power as well as their constellation on the market. The theory of public choice and the theory of public contract are confronted with an approach centered on the power triad. If structured in the power triad, interactions among states representatives, businesses with structural advantages and businesses without structural advantages allow capturing administrative rents. The political power of the ruling elites coexists with economic power of certain members of the business community. The situation in the oil and gas industry, the retail trade and the road construction and operation industry in Russia illustrates key moments in the proposed analysis.

ABOUT THE METHOD OF THE OPTIMISATION OF STUDENTS’LEARNING ENGLISH TERMINOLOGY

2020 ◽  
pp. 73-82
Author(s):  
Л.Н. Крячко
Keyword(s):  
Foreign Language ◽  
Teaching Practice ◽  
Road Construction ◽  
National Language ◽  
The Road ◽  
Language Classes ◽  
Technical University ◽  
Training Exercises ◽  
Animal World

Постановка задачи. Изучение предмета «Иностранный язык» в техническом университете предполагает усвоение обучающимися терминологической лексики в соответствии с выбранной специальностью. Опыт преподавания показывает, что студенты испытывают трудности, связанные с запоминанием терминологических единиц и употреблением их в речи. Использование на занятиях по иностранному языку приема обучения терминологической лексике посредством опоры на внутреннюю форму данных лексических единиц позволяет оптимизировать процесс усвоения обучающимися специальных терминов. Результаты. Проведенное исследование дает основание утверждать, что анализ внутренней формы образованных семантическим способом англоязычных терминов специальности «Автомобильные дороги» позволяет выявить деривационно-ассоциативную связь терминологических единиц с лексикой общенационального языка, послужившей основой для вторичной номинации. Данные лексические единицы в большинстве случаев представляют собой хорошо знакомые студентам слова, обозначающие части тела человека и объекты, находящиеся в его близком окружении : одежду, посуду, инструменты, явления природы, представителей животного мира и т.д. Выводы. Ознакомление студентов дорожно-строительной специальности с внутренней формой изучаемых англоязычных терминов, выявление ассоциативных связей терминологических единиц со знакомыми студентам и широкоупотребительными словами общенационального языка, а также выполнение в аудитории специально разработанных тренировочных упражнений помогают снять трудности усвоения обучающимися терминологической лексики и облегчают ее запоминание. Statement of the problem. The study of the “Foreign Language” subject at a technical university involves students’ learning the terminology in accordance with the chosen specialty. The teaching practice shows that students experience the difficulties associated with memorising terminological units and using them in the speech. Applying the method of teaching the terminology based on the internal form of these lexical units at foreign language classes makes it possible to optimise the process of learning special terms by students. Results. The research that has been carried out gives reason to argue that the analysis of the internal form of the English “Automobile roads” specialty terms created in the semantic way makes it possible to reveal the derivational and associative relations of the terminological units with the national language words which served as the basis for the secondary nomination. In most cases, these lexical units are the words that are well known by the students and indicate the parts of man’s body and the objects that are present in man’s immediate environment: clothing, dishes, tools, phenomena of the nature, representatives of the animal world, etc. Conclusion. Introducing the internal form of the studied English terms to the road construction specialty students, identifying the associative relations of the terminological units with the well known to the students and widely used words of the national language, fulfilling the specially developed training exercises in the classroom help the students to overcome the difficulties of learning the terminology and to facilitate its memorization.

Features of the Harvesting and Logging Equipment Market in Russia

2020 ◽  
pp. 132-147
Author(s):  
M.A. Piskunov ◽  
Keyword(s):  
Information Technologies ◽  
Import Substitution ◽  
Road Construction ◽  
Forest Sector ◽  
Specific Information ◽  
Service Network ◽  
Russian Market ◽  
The Road ◽  
Foreign Companies ◽  
Transnational Companies

Russian forest sector forms an attractive market for harvesting and logging equipment, however the position of Russian manufacturers is extremely weak. A brief overview of the current state of the market is presented with reference to the open sources. Its features are mentioned as compared to the road construction and agricultural machinery sectors. Three transnational companies dominate the Russian market of harvesting and logging equipment: John Deere, Ponsse and Komatsu. Most of the purchased equipment falls on machines for cut-tolength technology, such as harvester and forwarder. The market volume of new machines is estimated at 330–420 forwarders, 165–300 harvesters, about 30–40 feller bunchers and the same number of skidders. There were two waves in the consolidation of the position of foreign companies in Russia. The first was connected with the delivery of equipment and the development of foreign brands in Russia against the background of still high-profile positions of Russian manufacturers in the market. The second is the takeover of enterprises having a service network and reputation by diversified transnational corporations. The main strategies of the leading companies in the current situation are the export of equipment to Russia and the development of a service network. Companies do not turn to another level associated with the opening of production sites or joint ventures for the production of harvesting and logging machines. The Russian market is characterized by the absence of a strong Russian manufacturer of harvesting and logging machines, which is ready to significantly influence or actively participate in the processes of import substitution. The position of such a manufacturer is gradually occupied by the Belarusian Amkodor Holding. The purchase of new harvesting and logging machines can afford major timber companies. The main production sites of harvesting and logging machines are located in Finland, Sweden, USA, and Canada. In order to support forestry machine engineering, in addition to economic measures of stimulation approved in other sectors, it is proposed: to organize the work of scientific forest engineering centers on the base of public-private partnership with the financial support from the major vertically-integrated timber corporate groups; to stimulate the development of Russian sector-specific information technologies for harvesting and logging; to initiate the partnership with companies from the People’s Republic of China to launch the design and production of new-generation harvesting and logging machines.

scholarly journals An investigation into the cause of road failure along Sagamu-Papalanto highway southwestern Nigeria

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ubido Oyem Emmanuel ◽  
Igwe Ogbonnaya ◽  
Ukah Bernadette Uche
Keyword(s):  
Construction Materials ◽  
Road Construction ◽  
Linear Shrinkage ◽  
Liquid Limit ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Southwestern Nigeria ◽  
Low Resistivity ◽  
The Road ◽  
Cause Of Failure

AbstractInvestigation into the cause of road failure has been carried out along a 60 km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12 to 61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1–52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2–35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17–43.9%, maximum dry density ranges from 1.51–1.74 g /cm3, specific gravity ranges from 2.52–2.64 and CBR between 3 and 12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20–138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20 m – 240 m along the profile to a depth of 7.60 m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m − 120 m along the profile to a depth of 15 m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.

scholarly journals THE PENETRATION OF ENGINEERING BY ECONOMICS: McFADDEN AND THE TRANSFORMATION OF ROAD DEMAND ESTIMATION

2021 ◽  
Vol 43 (2) ◽  
pp. 262-278
Author(s):  
Ariane Dupont-Kieffer ◽  
Sylvie Rivot ◽  
Jean-Loup Madre
Keyword(s):  
Road Network ◽  
Road Construction ◽  
Demand Estimation ◽  
Demand Modeling ◽  
The Road ◽  
Collective Decisions ◽  
The Face ◽  
Decision Making Processes ◽  
On The Road ◽  
The 1960S

The golden age of road demand modeling began in the 1950s and flourished in the 1960s in the face of major road construction needs. These macro models, as well as the econometrics and the data to be processed, were provided mainly by engineers. A division of tasks can be observed between the engineers in charge of estimating the flows within the network and the transport economists in charge of managing these flows once they are on the road network. Yet the inability to explain their decision-making processes and individual drives gave some room to economists to introduce economic analysis, so as to better understand individual or collective decisions between transport alternatives. Economists, in particular Daniel McFadden, began to offer methods to improve the measure of utility linked to transport and to inform the engineering approach. This paper explores the challenges to the boundaries between economics and engineering in road demand analysis.

scholarly journals Performance Evaluation of WMA Containing Re-Refined Acidic Sludge and Amorphous Poly Alpha Olefin (APAO)

2021 ◽  
Vol 13 (6) ◽  
pp. 3315
Author(s):  
Mansour Fakhri ◽  
Danial Arzjani ◽  
Pooyan Ayar ◽  
Maede Mottaghi ◽  
Nima Arzjani
Keyword(s):  
Resilient Modulus ◽  
Permanent Deformation ◽  
Road Construction ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Modified Bitumen ◽  
Alternative Source ◽  
The Road ◽  
Marshall Test ◽  
Alpha Olefin

The use of waste materials has been increasingly conceived as a sustainable alternative to conventional materials in the road construction industry, as concerns have arisen from the uncontrolled exploitation of natural resources in recent years. Re-refined acidic sludge (RAS) obtained from a waste material—acidic sludge—is an alternative source for bitumen. This study’s primary purpose is to evaluate the resistance of warm mix asphalt (WMA) mixtures containing RAS and a polymeric additive against moisture damage and rutting. The modified bitumen studied in this research is a mixture of virgin bitumen 60/70, RAS (10, 20, and 30%), and amorphous poly alpha olefin (APAO) polymer. To this end, Marshall test, moisture susceptibility tests (i.e., tensile strength ratio (TSR), residual Marshall, and Texas boiling water), resilient modulus, and rutting assessment tests (i.e., dynamic creep, Marshall quotient, and Kim) were carried out. The results showed superior values for modified mixtures compared to the control mix considering the Marshall test. Moreover, the probability of a reduction in mixes’ moisture damage was proved by moisture sensitivity tests. The results showed that modified mixtures could improve asphalt mixtures’ permanent deformation resistance and its resilience modulus. Asphalt mixtures containing 20% RAS (substitute for bitumen) showed a better performance in all the experiments among the samples tested.

scholarly journals Identification of geodetic risk factors occurring at the construction project preparation stage

2019 ◽  
Vol 9 (1) ◽  
pp. 14-17 ◽  
Author(s):  
Magdalena Kowacka ◽  
Dariusz Skorupka ◽  
Artur Duchaczek ◽  
Paweł Zagrodnik
Keyword(s):  
Risk Factors ◽  
Construction Projects ◽  
Expert Knowledge ◽  
Construction Project ◽  
Road Construction ◽  
Construction Process ◽  
The Road ◽  
Initial Stage ◽  
Preparation Stage

AbstractThe work contains information on the implementation of surveying works in the road construction process. The aim of the research was to identify geodetic risk factors occurring at the stage of preparation of a construction project, the presence of which can greatly disrupt the undertaking such as the road construction. The research was carried out on the basis of expert knowledge, documentation obtained from various road construction projects and the analysis of disturbances at the initial stage of works.

Assessment of changes in the state of the rangelands of Inner Mongolia, China between 1998 and 2007 using remotely sensed data

2012 ◽  
Vol 34 (1) ◽  
pp. 103 ◽  
Author(s):  
Z. M. Hu ◽  
S. G. Li ◽  
J. W. Dong ◽  
J. W. Fan
Keyword(s):  
Inner Mongolia ◽  
Vegetation Index ◽  
Net Primary Productivity ◽  
Temporal Dynamics ◽  
Remotely Sensed ◽  
The State ◽  
Mean Annual Precipitation ◽  
Aboveground Net Primary Productivity ◽  
Remotely Sensed Data ◽  
Normalised Difference Vegetation Index

The spatial annual patterns of aboveground net primary productivity (ANPP) and precipitation-use efficiency (PUE) of the rangelands of the Inner Mongolia Autonomous Region of China, a region in which several projects for ecosystem restoration had been implemented, are described for the years 1998–2007. Remotely sensed normalised difference vegetation index and ANPP data, measured in situ, were integrated to allow the prediction of ANPP and PUE in each 1 km2 of the 12 prefectures of Inner Mongolia. Furthermore, the temporal dynamics of PUE and ANPP residuals, as indicators of ecosystem deterioration and recovery, were investigated for the region and each prefecture. In general, both ANPP and PUE were positively correlated with mean annual precipitation, i.e. ANPP and PUE were higher in wet regions than in arid regions. Both PUE and ANPP residuals indicated that the state of the rangelands of the region were generally improving during the period of 2000–05, but declined by 2007 to that found in 1999. Among the four main grassland-dominated prefectures, the recovery in the state of the grasslands in the Erdos and Chifeng prefectures was highest, and Xilin Gol and Chifeng prefectures was 2 years earlier than Erdos and Hunlu Buir prefectures. The study demonstrated that the use of PUE or ANPP residuals has some limitations and it is proposed that both indices should be used together with relatively long-term datasets in order to maximise the reliability of the assessments.

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