خيارات البحث
النتائج 1461 - 1470 من 2,098
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.
اظهر المزيد [+] اقل [-]Birch growth responses to the insect injury simulations
2015
Araminiene, V., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania) | Varnagiryte-Kabasinskiene, I., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr. (Lithuania)
The tree growth compensation followed by insect damage is important for tree survival. Insect damage by making 3 and 6 holes per each leaf, and clipping one third of a leaf were simulated for one-year old silver birch (Betula pendula Roth) seedlings once, at the beginning of the vegetation season. The height, aboveground and root biomass, root length, stem diameter and leaf area were measured for all damaged and control seedlings. The aim of the study was to examine the effects of different insect-damage simulations on silver birch growth. Our study demonstrated that leaf dry mass decreased in response to leaf perforations and clipping one third of leaf. However, at the end of the experiment, the cumulative dry mass reached the level of the control. We found no statistically significant effect on the aboveground and total biomass of damaged seedlings compared to the control. The leaf clipping decreased the leaf area and stem diameter compared both to the treatment with hole-damaged seedlings and the control. The induced birch growth response showed that tree seedlings were able to compensate their growth up to the control level after the insect damage in eight weeks.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Manufacturing and application studies of Sots pine bark pellets
2015
Spalvis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Daugavietis, U., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
This paper describes the use of Scots pine (Pinus sylvestris L) bark humus and fine fractions for animal litter pellet manufacture, and the efficacy of various additives in improving absorbency. In Latvia is no researches about litter pellet manufacture of pine bark, and possibilities of increasing water absorbency; in internationals research papers there is also no information about the possibilities of improving water absorbency of pine bark pellets with various additives. The additives tested were fresh and fallen leaves, tree needles, dried hogweed and sawdust. Pellets were manufactured with a ZLSP200B granulator at Adazi city, Latvia, in 2014. The results indicated that production of small diameter pine bark pellets could be problematic. Absorbency of the pellets was tested both by rinsing and soaking the pellets, and results were compared to woodchip particle litter pellets. It was found that the best absorbency was achieved with adding up to 30% sawdust, which increased pellet absorbency both by rinsing and soaking. The results indicate that it is possible to manufacture pellets using Scots pine (Pinus sylvestris L.) bark humus and fine fraction with good absorbency which can be disposed of in sewerage systems.
اظهر المزيد [+] اقل [-]Absorption of EU funds and the development of rural areas in Latvia and Poland
2015
Stawicki, M., Warsaw Univ. of Life Sciences (Poland)
The article presents the findings of research aiming to discover the links between absorption of European funds and the development of rural areas in Latvia and Poland. Based on statistical data and Latvian territorial development index at local level, the value of index for Polish local communities was calculated showing a slightly bigger difference in local development in Poland. Absorption of EU funds was rather concentrated in both countries and its highest level was connected with major infrastructural projects as construction of roads, motorways, etc. The use of EU funds under Cohesion Policy is not correlated with the level of development, neither in Latvia nor in Poland. The only significant negative correlation can be observed between the development and the use of funds under Common Agricultural Policy and Fisheries Policy in Latvia.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]The impact of plot spatial properties on the conversion of arable land into brushwood
2015
Maasikamaee, S., Estonian Univ. of Life Sciences, Tartu (Estonia) | Mandel, M., Estonian Univ. of Life Sciences, Tartu (Estonia)
Land use change has caught scientist’s attention all over the world and in the perspective of globalisation the pressures on agricultural land are increasing. However, the agricultural land abandonment is still evident. This phenomenon has no single definition and its driving forces are varying among different regions and countries. In this paper agricultural land is considered as abandoned while there is evidence of shrub and bushes on agricultural land according to the orthophoto and Estonian base map comparison. The aim of this paper was to test the impact of arable land plot spatial properties: plot area, ratio of arable land area in the surrounding of plot and plot compactness. General hypothesis is that brushwood will more likely occur on the arable land plots with poor spatial properties than on arable land plots with good ones. The study was conducted in 15 rural municipalities across Estonia. Results are showing some impact of the spatial properties on the arable land plots conversion into brushwood. In nine municipalities out of 15, there was an arable plot area without brushwood larger than plots with brushwood and the percentage of arable land area surrounding plots without brushwood was higher in other 9 studied municipalities. As expected, the uncompact arable land plots tend to have more likely brushwood on them than the compact ones. Study results show that the impact of plot area and the ratio of arable land in surroundings of plots on the conversion of arable land plots into brushwood need further studies.
اظهر المزيد [+] اقل [-]Rural community public project valuation applying TOPSIS multi-criteria method
2015
Baranauskiene, J., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Mazure, G., Latvia Univ. of Agriculture, Jelgava (Latvia) | Alekneviciene, V., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The primary goal of public projects is to create social benefits for the community. The prepared public project usually has more than one option. In order to choose the most efficient option, it is necessary to take into consideration all social benefits. For this reason multi-criteria methods may be applied since they provide a possibility to assess quantitatively social benefits which are measured in many different quantitative and qualitative indicators. The problem of the research stems from a variety of social benefits indicators of public projects, the problematic establishment of their value and the need of their complex valuation. The paper presents a methodology for TOPSIS multi-criteria method adapted for the valuation of public projects in order to select investment option and the empirical research makes it possible to look at the problems of public project valuation from the practical approach. The research of the paper is aimed at revealing the advantages and limitations of TOPSIS multi-criteria method used for public projects valuation.
اظهر المزيد [+] اقل [-]Social dimension of the measurement for regional development
2015
Rasnaca, L., University of Latvia, Riga (Latvia) | Bela, B., University of Latvia, Riga (Latvia)
The article addresses the problem of social dimension measurement of for regional development. Authors’ discus approaches of definition of social dimension. There is some discord how social dimension could be understood in more broader or narrowed sense and how it is characterized in international and national social policy documents. Authors focus attention on contiguity of social dimension and social security. The measurement of social dimension demands multidimensional approach. The authors use theoretical analysis and document analysis, as well as analysis of statistical data on key elements of social dimension of regional development (differences of employment rate; GINI coefficient, and the number of people at risk-of-poverty threshold). The main conclusions are that social dimension is more or less covered in development planning documents, but the progress indicators are inadequate. Especially disparities in social dimension of regional development are formally addressed and closer analysis of key indicators shows necessity to elaborate both – policy instruments as well as policy progress measurement.
اظهر المزيد [+] اقل [-]The role of EU funds in diversification of rural economy in Latvia
2015
Ozolins, J., Corporate Management Experts Bureau, Riga Latvia | Veveris, A., Latvian State Inst. of Agrarian Economics, Riga (Latvia) | Benga, E., Latvian State Inst. of Agrarian Economics, Riga (Latvia)
Promotion of non-agricultural activities in Latvian rural areas is highly important for diversification of rural economy due to decrease in agricultural and forestry employment. So far too little attention has been paid to this aspect. Although EAFRD is the only EU fund directly supporting rural development, only 14% of its public financing for projects in 2007-2013 was invested in non-agricultural entrepreneurship, half of this in financially demanding energy production projects. By total eligible accepted project expenses, approximately 60% of rural entrepreneurship projects were financed by EAFRD. ERDF was also important in which a smaller number of higher value investment projects was implemented. Although EU funds have some importance in activating rural entrepreneurship, so far the direct impact on creation of jobs and value added has been small. The impact could be increased by setting forth specific job creation requirements for the beneficiaries. It is also suggested to avoid supporting expensive projects which do not create a substantial number of jobs. In view of rural entrepreneurs improvements in entrepreneurial environment, including taxing policy are more important than direct support. It especially concerns operation of small companies. Development of small companies in rural areas is of high importance because in many territories there is no capacity and rationale to develop large projects.
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