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Pollution analysis of surface (rain) water from pig-breeding enterprise production territory
2015
Miseviciene, S., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
Pollution of surface (rain) wastewater forming in the production territory of a pig-breeding enterprise was investigated in the period 2007–2011. The surface water is collected from the production territory from yards with a hard covering and from roofs, enters the rain sewerage, and is released untreated into the natural environment. The aim of this work is to find out what influence on the environment is exerted by surface wastewater released into the natural environment from the production territory of pig-breeding enterprises. Surface wastewater pollution indices and the research frequency were identified according to the requirement to carry out surface water monitoring: surface wastewater samples are collected three times per year. Because of the uneven rainfall distribution during the year, less surface wastewater runoff occurred during the cold period; however, concentrations of indices were higher compared to the end of the warm period (TSS – 18 %, BOD7 – 39 %, Ntotal – was unchanging, oil products – 12.5 %). Only Ptotal concentrations were higher in the end of the warm period in 14 %. The organic pollution in surface wastewater was increased by total suspended solids. The increased concentrations of TSS and biochemical oxygen demand (BOD7 ) were related to a higher precipitation level. The indices’ TSS, BOD7 , Ntotal, Ptotal and oil products concentrations in the surface wastewater runoff from the pig breeding enterprise‘s production territory complied with the requirements for surface water which is collected from this area and released into the environment.
Afficher plus [+] Moins [-]Quality assessment of electronic learning materials
2015
Kazaine, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Information and communication technology combined with multimedia and networking has enabled development of e-learning. E-learning opportunities expand access to education, without the learner’s social, economic and geographical barriers. The main question in this situation has to take into account the quality of e-learning materials. The aim of this research was to explore the definition of the quality and scientific research literature on e-learning quality, and identify the quality influencing factors. This article looks at quality standards and summarizes the existing literature on the quality aspects of electronic materials. During the research was analyzed the literature of the last 13 years. Findings showed that the quality evaluation model covers a wide scale — from one e-course to e-learning system implementation quality aspects. The quality of electronic learning material can be measured by technical, pedagogy and content criteria. The technical quality of the e-material (text, picture, video, sound recording, visual presentation, multimedia, etc.) is influenced by many factors and specifying for each type. The research should be continued to indicate the quality criteria for each type of e-materials including the degree of importance.
Afficher plus [+] Moins [-]Information literacy in community development
2015
Holma, B., University of Latvia, Riga (Latvia) | Pakalna, D., University of Latvia, Riga (Latvia)
The purpose of this paper is to describe the information literacy of people as essential competencies required for the generation of social capital and use of social capital in sharing and obtaining information, which in its turn, is considered to be an important resource in the community’s development. The paper analyses the terms: social capital, information literacy and their mutual influence, as well as describes the research where informational literacy of the population of Latvia, its levels and the determined groups of knowledge and skills, which need to be improved in order to contribute to the generation and use of the social capital, through various methods (population surveys, focus group discussions, information literacy knowledge assessment questionnaires and performing practical tasks) were assessed. The research is based on the UNESCO Media and Information Literacy (MIL) Competency Matrix and UNESCO MIL Assessment Framework. The main conclusions of research are the following: information literacy is an important competence for developing social capital; but based on the completed research there are skills of information literacy – processing of information, critical assessment of information resources, legally correct use of information sources, as well as effective use of information technologies – which should be improved. The research was conducted within the framework of the European Social Fund project ‘Development of Innovative Diagnostic Instruments for Regional Growth’ (No.2013/0057/1DP/1.1.1.2.0/13/APIA/VIAA/065).
Afficher plus [+] Moins [-]Quality assessment of European ash Fraxinus excelsior L. genetic resource forests in Latvia
2015
Puspure, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Gerra–Inohosa, L., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Arhipova, N., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
In Latvia, two European ash (Fraxinus excelsior) genetic resource forests (GRF) have been designated in Skrīveri and Bērvircava. However, as the degree of damage of ash by the pathogenic fungus Hymenoscyphus fraxineus has increased, many stands have died and many do not comply anymore with minimum requirements for GRF. The aim of the present research was to evaluate and examine the quality of ash GRFs. In each forest unit, one 20×20 m plot was established, and the first (E3) and second (E2) layer projective cover of each species was determined in August 2014. All undergrowth and advance regeneration species were counted and the degree of ash damage by H. fraxineus was determined along a diagonal 25×1 m transect in each plot. In total, 101 plots were established. Quality evaluation was carried out according to the basic criteria for selection of GRF as well as based on criteria cited in other research. Their variation was established by using principal component analysis. Ash in layer E3 was better maintained in Skrīveri, but ash regeneration there was worse, as well as a higher degree of damage by H. fraxineus was observed. Ash regeneration density is significantly influenced by its cover on layers E3 and E2 as well as by tree species dominating the growth. The most valuable GRFs have been maintained in Skrīveri where 50% of units were rated of average quality and few of bad quality. In Bērvircava, 56% of forest units were of bad and very bad quality.
Afficher plus [+] Moins [-]Edge effects on epiphytic lichens in unmanaged black alder stands in southern Latvia
2015
Liepa, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Straupe, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
The emergence of human–induced edges in forested landscapes has caused major threat for the existence of habitat specialists. Woodland key habitat (WKH) concept has been created in the Baltic and Fennoscandian forests to preserve small forest parcels with a high biodiversity value in the production forests. In this study we investigated the occurrence of epiphytic lichen indicator species in black alder WKHs in Southern Latvia. In total 30 black alder WKHs with age of 84 to 129 years were chosen for analysis including stands adjacent to young, middle–aged and mature stands. Sample plots were placed at three distances from the forest edge. Our results indicate significant differences in number of species per sample plots adjacent to stands of different age. Lichen indicator species were considerably more common in habitats adjacent to mature forest stands and further (40–50 m) from the edge. From four lichen indicator species found in this study, sample plots adjacent to young stands hosted only two species. We argue that the indicator species response to human–induced edges is species specific and some of them are resistant to microclimatic changes near the edges.
Afficher plus [+] Moins [-]Grey alder Alnus incana (L.) Moench additional growth changes after thinning in Aegopodiosa site type
2015
MiezIte, O., Latvia Univ. of Agriculture, Jelgava (Latvia) | Liepa, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Sereiko, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Luguza, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
Grey alder stands Alnus incana (L.) Moench have a number of distinctive features. In fertile soils it successfully forms productive forest stands without any human intervention. Therefore, relatively few publications can be found on the thinning effects on stand reaction after thinning. It is possible that due to the highly intensive circulation of substances in the ecosystems of grey alder (high photosynthesis and canopy thinning, withering and breaking off of the lower branches, litter decomposition within a few years, thereby ensuring a continuous and stable plant mineral nutrition substance complementarity in the soil) response reaction of the remaining trees and management of grey alder forest stands could be different comparing to other tree species. The study analyses stock volume additional increment dynamics during 10-year period after the thinning in 24-year-old grey alder pure stands in Aegopodiosa site type. Thinning of grey alder forest stands have caused a moderate positive reference reaction – during 10 years, in addition to the total increase, 3.17 m**3 haE-1 have been added. During the valuation interval response reaction differs among the years. In the first four years it is relatively small as accumulation of the growing potential is taking place. From the fifth to seventh year after felling an intensive growing takes place, which results in repeatedly additional annual increment. Starting from the eighth year, the trees show tendency to return to a steady state as it was before the thinning.
Afficher plus [+] Moins [-]Influence of post-fire management on regeneration of Scots pine (Pinus sylvestris L.) in north-western Latvia
2015
Zadina, M., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Donis, J., Forest Competence Centre, Riga (Latvia) | Jansons, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Fire is a frequent disturbance in hemiboreal forests that in Latvia affects mostly Scots pine (Pinus Sylvestris L.) stands. Increased forest fire risk is predicted in future as a result of climatic changes. Therefore the aim of our study was to assess Scots pine regeneration after forest fire in different forest types and with different regeneration methods. Tree height was measured and browsing damage assessed seven years after the forest fire in six different forest types, where planting and natural regeneration (in a clearcut and without management) occurred in compartments randomly selected from a list of stands severely affected by forest fire. The height of Scots pine was significantly affected both by forest type and regeneration method. Notable advantages of planting based on tree height were found in wet mineral soils and peat soils. Trees on poor (dry, wet, peat) soils were higher in natural regeneration after clearcut than in natural regeneration without clearcut. The density of Scots pine trees was significantly affected by the forest type but not by regeneration method (planting, natural regeneration, natural regeneration after the clearcut). The most abundant tree species in natural regeneration after clearcut in all forest types was silver birch (Betula pendula Roth.). The height of silver birch exceeded that of Scots pine in all analyzed soils in clearcut areas except Vaccinososphagnosa forest type, emphasizing the importance of thinning to ensure a successful development of Scots pine stands.
Afficher plus [+] Moins [-]Leaching and durability of copper treated Scots pine (Pinus sylvestris L.) wood
2015
Meija-Feldmane, A., Latvian State Inst. of Wood Chemistry, Riga (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia)
Scots pine (Pinus sylvestris L.) is the most common wood species in Latvia. It is classified as not durable, therefore additional protection against microorganisms is needed prior its use outdoors. Presently Cu-containing wood preservatives are commonly used, but the biggest drawback is the poor Cu fixation, therefore raising concerns about the impact on the environment. Three types of specimens were used to carry out the experiments – untreated, Latvian originated Scots pine; Scots pine commercially treated with preservatives that belong to a group of Cu-boron-triazole (CBA) products; and Scots pine, impregnated with micronized-Cu solution using a standard full cell process. In order to make sure that all of the specimens are equal in their components, elemental analysis was performed and content of nitrogen (1.2 – 2.5 g kgE-1), carbon (485.5 g kgE-1), oxygen (456.0 g kgE-1) and hydrogen (55.6 g kgE-1) was determined. The treated specimens were leached according to the European standard EN 84. For micronized-Cu impregnated Scots pine the total Cu content in leachates obtained by atomic absorption spectroscopy was 0.15 mg gE-1 of wood, and 0.06 mg gE-1 of absolute dry matter with CBA preservative impregnated Scots pine wood. Subsequently, according to the European standard EN 113, treated Scots pine blocks were exposed to brown-rot fungus Coniophora puteana and to white-rot fungus Trametes versicolor for 16 weeks. Mass loss for wood treated with micro-Cu was 48.4% (484 g kgE-1) and 1.5% (15 g kgE-1) respectively, but for CBA – 49.5 % (495 g kgE-1) and 1.2% (12 g kgE-1). Both samples proved to be inappropriate for outdoor use (use class 3).
Afficher plus [+] Moins [-]Effect of thermal modification on wood colour
2015
Cirule, D., Latvian State Inst. of Wood Chemistry, Riga (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Kuka, E., Latvian State Inst. of Wood Chemistry, Riga (Latvia)
Colour and colour homogeneity are of special importance for establishing the quality of wood products. In the present study the effect of thermal treatment at 140 °C and 170 °C on colour and its homogeneity was studied for aspen (Populus tremula L.), grey alder (Alnus incana Moench) and ash (Fraxinus excelsior) wood. Wood colour was monitored and evaluated by spectrophotometrical measurements of reflectance spectra and colour parameter calculations using CIELAB colour model with L* as the lightness, and a* and b* as the chromatic parameters. Wood colour changed substantially and all studied types of wood acquired quite similar colour due to the thermal treatment with greater discolouration and almost the same colour detected for treatment at 170 °C. The average colour difference within a board surface as well as among boards of one species was found to be less than 3 DEab units for all thermally treated specimens which can be regarded as hardly perceptible colour difference. However, noticeable differences in colour were detected between the surface and inner layers of thermally treated wood boards. Greater colour heterogeneity throughout the depth of a board was detected for woods treated at 140 °C.
Afficher plus [+] Moins [-]Development of local food systems in Latvia
2015
Melece, L., Latvian State Inst. of Agrarian Economics, Riga (Latvia) | Krievina, A., Latvian State Inst. of Agrarian Economics, Riga (Latvia)
Although there is no consensus among scholars and professionals regarding the definition of the local food system, nevertheless, the local food systems or alternative food networks are no less important and suitable tool for solving environmental, economical (farmers’ and rural inhabitants’ income increasing) and social issues, and encouraging the further sustainable development of rural areas and communities. The aim of study is to assess the state and recent characteristics of the local food systems and its development in Latvia. The paper presents results of a study of the typology and categorisation of both the producers and distribution channels, and development of the local food systems as a whole, especially in Latvia. Various sources of materials and data have been used: the academic literature, legislation, reports and recommendations, as well as web pages, the internet and data from Food and Veterinary Service (FVS). The typology and categories of local food systems as well as short food supply chains are characterised, and its existence in Latvia is given. Besides, it is essential that the different kind of its merging organizations and projects supporting distribution of local food is implemented. The development of consumer groups for local food purchasing is important. While the requirements for small farmers–food producers are the same as those for large producers, the results suggest that during the recent years an increasing number of home-made food producers is observed.
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