خيارات البحث
النتائج 1 - 9 من 9
The influence of forest distribution in the landscape of Lithuania on the amount of precipitation
2014
Tiskute-Memgaudiene, D., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Ruseckas, J., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The influence of forest distribution in the landscape on precipitation in middle latitudes is poorly researched. Moreover, results of such studies are controversial. Nevertheless, most researchers agree with findings, that influence of landscape roughness formed by forests on the amount of precipitation is significant. This study aimed to extend knowledge of the interface between forest distribution and the amount of precipitation during particular periods. Database of the amount of precipitation from 31 Lithuanian meteorological stations during the period of 2002-2010 was used in this study. Findings defined statistically significant correlations in the amount of precipitation increase due to shorter Euclidean distance to the nearest forest edge in the particular landscape (r = -0.421 – -0.359), p is less than 0.05), also shorter distance of the meteorological stations to the nearest forests (r = -0.380, p is less than 0.05) and higher density of the forests, treated as a perimeter per area ratio (PAR) (r = 0.359 – 0.551, p is less than 0.05).
اظهر المزيد [+] اقل [-]Changes of dominant tree species areas over the past century in Lithuania: a mathematical approach
2014
Varnagiryte-Kabasinskiene, I., Lithuanian Research Centre for Agriculture and Forestry, Akademija, Kedainiai distr., (Lithuania);Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Kabasinskas, A., Kaunas Univ. of Technology (Lithuania);Kaunas College (Lithuania)
The changes of areas of eight tree species in Lithuania during the past century were analysed. Aiming to apply the different approaches in forest studies, the Exponential smoothing method for forecasting the changes of the tree areas for the 25 years was used. The data dating from 1922 was analyzed as a time series. The descending trend was identified for Scots pine (Pinus sylvestris L.) and European ash (Fraxinus excelsior L.) and increasing trend – for Norway spruce (Picea abies (L.) H. Karst.), common oak (Quercus robur L.), birch species (Betula pubescens Ehrh. and Betula pendula Roth), black alder (Alnus glutinosa (L.) Gaertn.), European aspen (Populus tremula L.) and grey alder (Alnus incana (L.) Moench). The Exponential Trend with Multiplicative Seasonality (ET-MS) model was fitted for almost all investigated tree species with exception of European ash. For the latter species, the Damped Trend with Multiplicative Seasonality (DT-MS) model was chosen. Mean absolute percentage error of the model in all cases did not exceed 2%.
اظهر المزيد [+] اقل [-]Morphometric and masometric parameters of the ostrich (Struthio camelus) stomach in postnatal ontogenesis
2013
Mancevica, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Mugurevics, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Stomach, as a part of the digestive canal, is important in the metabolic processes of the organism which affects the bird’s general health condition, its growth and development, consequently also the increase of the body weight. The aim of the research was to find out the dynamics of weight, length, and area of the ostrich (Struthio camelus) stomach and its parts in postnatal ontogenesis from 4 to 12 months of age. The absolute weight of stomach, length of the greater curvature of the stomach glandular part, diameter of the muscular part, thickness of stomach wall was determined. To find out the differences of the mean values between various age groups, ANOVA and Post Hoch tests were used. The increase of the stomach absolute weight continued throughout the postnatal ontogenesis period, but the stomach weight in relation to the ostrich body weight decreased, especially rapidly at the age of 6 and 8 months. At the same time, proportions of the absolute and relative weight of the stomach glandular and muscular part changed. The length of the greater curvature of the stomach glandular part, length of the deep gland region and diameter of the stomach muscular part increased during the whole observed period of ontogenesis; moreover, these parameters increased more rapidly from 6 to 8 months of age. The area of the stomach glandular and muscular part mucosa increased throughout the observed period of ontogenesis. The area of the superficial gland region in all age groups was larger than the area of the deep gland region.
اظهر المزيد [+] اقل [-]Changes of the forest land area and spatial structure in urban landscapes of Lithuania
2018
Tiskute-Memgaudiene, D., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
The territorial planning and the management of urban surfaces force the decrease of green spaces in urban landscapes. As the urbanization process during past decades of the last century was quite intensive not only in Europe but also in Lithuania, findings describing changes of forest cover as well as spatial structure of the forest land are requested. The aim of this study was as follows: first, to calculate and compare areas of the forest land in six major cities of Lithuania in 1950 and 2011, second, to evaluate the spatial structure of the forest land by investigated cities within the period of 1950 – 2011. Methods of descriptive statistical analysis and spatial analysis using ArcGIS and MS EXCEL software were used. The study was based on two geodatabases, representing the forest cover in 1950 and 2011. Results of this study revealed that areas of the forest land increased in all investigated cities excluding Panevėžys city. The increases of areas of the forest land were discovered to vary from 0.8% to 9.5%. The largest increase was found in Vilnius city (9.5%), the smallest – in Šiauliai city (0.8%). The decrease by 0.9% of the forest land was found just in Panevėžys city. No significant changes of the forest land spatial structure were found in largest cities of Lithuania, i.e. Vilnius city and Kaunas city. The spatial structure of forest land in other investigated cities tended to degrade.
اظهر المزيد [+] اقل [-]The change of forests and their area in Lithuania
2018
Ivaviciute, G., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania);Kaunas Forestry and Environmental Engineering Univ. of Applied Sciences (Lithuania)
The article presents an analysis of the existing situation of forests of the Republic of Lithuania. The situation is analysed in ten counties of the country. In the Republic of Lithuania, forests occupied 2,178,958.04 ha, country’s forest coverage – 33.38% in 2017. The highest forest coverage was established in Alytus (48.80%) and Vilnius (43.47%) counties. Only in three counties of Lithuania (Panevėžys, Telšiai and Utena) the prevailing type of ownership is private forests. In all counties of Lithuania mostly there are Group IV commercial forests, which make up 71.4% of the total forest area. The least are Group I reserved forests. Coniferous species (56.2%) prevail in the country’s forests, of which pine forests are dominant. It is crucial today to analyse the current state of forests and anticipate changes in trends, preventing potential threats. Following the analysis of Lithuanian forest change, it was determined that during the period between the years 2006 and 2017, the forest area increased by 78,616.40 ha or 3.74%. The largest forest development took place in Utena (17,324.13 ha or 7.32%) and Šiauliai (14,798.15 ha or 6.87%) counties. In order to implement the forestry development prospects, from 2018 to 2030, 106,068.87 ha of forests should be planted. In 2030, 2,285,026.91 hectares of forest would occupy Lithuania and would make up to 35% of the country’s area.
اظهر المزيد [+] اقل [-]Vertical price transmission along the potato supply chain in Lithuania
2018
Jurkenaite, N., Lithuanian Inst. of Agrarian Economics, Vilnius (Lithuania) | Paparas, D., Harper Adams Univ., Newport, Shropshire County (United Kingdom)
Potato sector is one of the competitive areas of the European Union (EU) agriculture. Although Eurostat declared that in 2015 Lithuanian share in the EU-28 harvested production was modest and composed only 0.7%, according to Food and Agriculture Organization of the United Nations (FAOSTAT), this crop remained on the list of top 10 commodities by net production value in Lithuanian agriculture. However, over the past decades the Lithuanian potato sector survived undesired transformations. The aim of this paper is to analyse the changes of the main indicators, related to the potato sector, and vertical price transmission among the chain of potatoes in Lithuania. The conducted research indicates the most important development trends of the potato sector and applies econometric techniques to investigate if there is any long-run relationship between the farm and retail prices of potatoes for the period of 2010 to 2016. Although the statistics show the shrinking production and domestic consumption of potatoes in Lithuania, the analysis of the vertical price transmission does not provide evidence of market inefficiencies. The Johansen cointegration test confirms the existence of a long-run relationship between the farm and retail prices, while the Granger causality test shows that there is a bidirectional causality between the examined series. The M-TAR model does not provide evidence of the farm and retail price asymmetry in the long run.
اظهر المزيد [+] اقل [-]Assessment of land use change scenario to increase primary productivity function at local scale
2019
Valujeva, K., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia);Wageningen Univ. and Research (Netherlands) | Nipers, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Lupikis, A., Latvian State Forest Research Inst. Silava, Salaspils, Latvia | Pilecka, J., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Schulte, R.P.O., Wageningen Univ. and Research (Netherlands)
The global population has begun to rise exponentially; therefore, the demand for bioresources including food and fibre is increasing. An increasing demand for food and fibre necessitates more sustainable use of natural resources especially for soilbased ecosystem services. In this context, Functional Land Management was developed to optimize agricultural soilbased ecosystem services to meet both agricultural and environmental targets simultaneously. The aim of the research is to evaluate unmanaged agricultural land use change impact on primary productivity function in three parishes in Latvia by using Functional Land Management framework. Evaluation of primary productivity function was accomplished for both sectors agriculture and forestry by using profit and working hours as a proxyindicators. Production of vegetables and perennial plantations has higher supply of primary productivity function comparing to other land uses. Land use changes affect all soil functions that we expect from our land, especially primary productivity function. After applying land use changes, an increase in profit is higher in Liezere parish for both areas on mineral soils (7.1%) and areas on organic soils (5.2%); while an increase in working hours is higher in Usma parish: 36.6% in areas on mineral soils and 1.0% increase in areas on organic soils. Shortterm benefits are received from agricultural land, while forest land provides long-term return which increases over time but can only be obtained after reaching the age of felling. Before applying land use changes or changes in management practices we have to consider other soil function and national commitments.
اظهر المزيد [+] اقل [-]Forest vegetation on the island of Upursala of Lake Cirišs, Latvia
2024
Straupe, Inga | Jansone, Diāna | Kozure, Alīna
Only less than one percent of the territory of Latvia is occupied by broadleaved (trees having relatively wide flat leaves) forests. The aim of the research is to assess forest vegetation in the island of Upursala of Cirišs Lake. The data is collected in four forest areas of the island. Totally 12 plots, each with an area of 200 m² (20 x 20 m) have been created. In each plot, the accounting of growing trees and deadwood is carried out. The vegetation is measured in each forest area – the projective vegetation cover and cover of each plant species by tree, shrub, herb and moss layer are determined. The research founds that the average stock of growing trees on the island of Upursala is 565.8 m³ ha⁻¹. The average amount of dead wood is 108 m³ ha⁻¹, it consists mainly of fallen deadwood. Totally 45 species are listed in the vegetation plots, of which seven are determinants of European broadleaved forests. The largest number of determinant species of European broadleaved forests has been observed in stands with mixed forests (aspen – small-leaved lime – pedunculate oak, aspen – Scots pine – pedunculate oak and Scots pine – Silver birch – aspen). It can be argued that these stands will become the European broadleaved forests in the future.
اظهر المزيد [+] اقل [-]Change in the area of Lithuanian trees and shrubs greenery in 2002–2022
2023
Ivavičiūtė, Giedrė
The topic of this article is relevant because in Lithuania the assessment of the area occupied by plantations and green spaces has shown that the area standards do not meet the requirements and recommendations of the World Health Organization. Green spaces are regulated differently in different countries of the European Union. Lithuania has also developed a legal framework for the protection, management and establishment of new plantations and green spaces. However, this legal framework is improving and new laws are being added to it. Comparative, analytical, as well as statistical, and logical analysis methods were used for the investigation. The data of the Land Fund of the Republic of Lithuania for 2002–2022 were used for comparative investigation. The aim of this article is to perform an analysis of the change in the trees and shrubs greenery area of Lithuania in 2002–2022. In Lithuania, for example, trees and shrubs occupied 84,687.48 ha in 2002. In 2022, the plantation area amounted to 208,609.48 ha. From 2002 to 2022 the area of tree and shrub plantations in Lithuania increased by 123,922.00 ha or 146.33%. The analysis shows that in the period between the years 2002 and 2022 the biggest increase in the area of shrubs and plantations took place in Utena County (32,715.83 ha or 395.27%), but the smallest increase in Tauragė County (2,642.93 ha or 37.69%) and Marijampolė County (4,581.39 ha or 72.25%). The development of plantation areas has been positively influenced by the creation of an appropriate legislative framework and the implementation of plantation programs in counties and municipalities.
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