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Distinguishing between the effect of seed material and forest type on Scots pine stand productivity
2005
Jansons, A.(Latvian Forestry Research Inst. Silava, Salaspils (Latvia))E-mail:arisjansons@navigator.lv
Due to large diversity of site conditions suitable for Scots pine growth in Latvia, it is important to evaluate their influence on growth and survival of particular Scots pine families. To do so, open pollinated progenies from phenotypically selected plus trees of 35 at the age of 32 years have been evaluated in 2 forest types (Cladinosa-callunosa and Hylocomyosa). Investigation revealed that forest type and family influence had a great significance to height, diameter at breast height, and diameter of thickest branch up to 2 meters' height (alpha is less than 0.001), but clone influence had lower significance (alpha=0.008). Proportion of influence to height growth caused by tree family was 70% at the age of 6 years and 17% at the age of 32 years. Proportion of influence on survival caused by tree family was 57% and 44% respectively. The corresponding influence of forest type was 12% and 28% to height, 15% and 39% to survival. Diameter at breast height at the age of 32 years was equally influenced by forest type and family (~11%). Equal breeding effect - but not with the same families - can be reached both in fertile and poor soils. In group (20%) selection this effect was ~8% for height, 11% for diameter, and 30% for survival; in individual selection ~10% for height, and ~17% for diameter.
Afficher plus [+] Moins [-]Generation of a test reference year for Liepāja, Latvia
2016
Ruduks, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lesinskis, A., Riga Technical Univ. (Latvia)
Actual and reliable meteorological data are necessary for building performance analysis. Since meteorological conditions vary significantly from year to year, there is a need to create a test reference year (TRY), to represent the long-term weather conditions over a year. In this paper TRY data model was generated by analysing every 3-hour weather data for a 30-year period (1984 – 2013) in Liepāja, Latvia, provided by the Latvian Environment Geology and Meteorology Centre (LEGMC). TRY model was generated according to standard LVS EN ISO 15927-4. The generated TRY contains from typical months that are included in TRY from a number of different years. The data gathered from TRY was compared with the climate data from the Latvian Cabinet of Ministers regulation No. 379, Regulations Regarding Latvian Building Code LBN 003-15. Average monthly temperature values in LBN 003-15 were lower than the TRY values that indicate on climate changes in this location. The results of this study may be used in building energy simulations and heating-cooling load calculations for selected region. TRY selection process should include the latest meteorological observations and should be periodically renewed to reflect the long-term climate change.
Afficher plus [+] Moins [-]Training guide: gender and climate change research in agriculture and food security for rural development
2012
Food and Agriculture Organization of the United Nations
It is widely accepted that agricultural development will be severely curtailed without addressing the risks and capitalizing on the opportunities posed by climate change (FAO, 2010b). The agriculture sector must adapt to the impacts of climate change in order to provide food security to the world’s growing population. At the same time agriculture must mitigate its contributions to climate change (13.5 percent of global greenhouse gas emissions) in order to slow the progression of this global challenge (FAO, 2009). Concurrently, it is internationally recognized that addressing gender issues in agriculture reduces hunger and poverty. In fact, it is estimated that more than 100 million people could be lifted out of poverty if women had the same access to and control of resources as men (FAO, 2011a). Although they are important food producers and providers, women presently have limited access to and control of resources. However, to date, these ideas – that climate change and gender issues are integral parts of agricultural development – have not been implemented in an effective way. This guide seeks to fill that gap by supporting work to investigate the gender dimensions of responding to climate change in the agriculture and food security sectors. The final goals are to improve food production, livelihood security and gender equality in the context of the changing climate.
Afficher plus [+] Moins [-]Influence of nitrogen fertilizers, previous crops and soil texture on spring wheat yield
2001
Jermuss, A. (Latvia Univ. of Agriculture, Skriveri (Latvia). Research Centre "Skriveri")
In 1999-2000 the field trials with spring wheat 'Munk' on optimisation of a nitrogen fertilizers were established at the Skriveri Research Centre of the Latvia University of Agriculture. The field trials were conducted on two different kinds of Luvisol soil: loam and loamy sand. As the influence of the previous crops-grass, grain and potatoes on efficiency of different (0; 50; 100; 150; 200; 250 kg ha*[-1)) nitrogen fertilizers was investigated. Is stated, that as well as predecessor, and mechanical structure of soil considerably influence efficiency of use of ammonium saltpetre by spring wheat. Some relevant soil properties at the beginning of the experiment were: in loam pH (KCl) 6.3; available phosphorus (DL-method) 100 mg P2O5 kg*[-1), available potassium (DL-method) 135 mg K2O kg*[-1); and soil organic matter (Tyurin's method) 2.3% in sandy loam pH (KCL) - 5.7; available phosphorus - 142 mg P2O5 kg*[-1); available potassium - 92 mg K2) kg(-1); and soil organic matter - 2.2%. The data mathematical processing was done using the General Linear Model criterion Tukey of the program SPSS.
Afficher plus [+] Moins [-]Changes of biology of the potato late blight pathogen Phytophthora infestans in last years. Review
2002
Bimsteine, G. (Latvia Univ. of Agriculture, Jelgava (Latvia))
Potato is the second important crop in Latvia. The area covered with potato is about 50 thousand hectares. Potato late blight caused by Phytophthora infestans (Mont.) de Bary is the most serious potato disease. Weather conditions in Latvia are very favourable for the development of potato late blight and it is occuring almost every year. The biology of P.infestans was the subject of a number of authors - plant pathologists. Research results about P.infestans population biology and epidemiology are presented in this review, especially focusing on the changes of pathogen biology.
Afficher plus [+] Moins [-]Natural and economic risk factors in Estonian agriculture
2002
Astover, A. | Roostalu, H. | Vingissaar, V. (Estonian Agricultural Univ., Tartu (Estonia))
Agriculture more than any other branch of production is influenced by various natural, anthropogenic and economic risk factors on which the profitability of production and preservation of the environment in rural areas depend. The prerequisite of prevention or alleviation of risks is their all-round knowledge and consideration. In order to understand the nature of risks, they will be dealt with in the present study on the example of the cultivation of the most common cereal in Estonia - barley. The difference in barley yields, resulting from the pedoclimatic coditions of Estonia, may be 2-4-fold in different regions and in different years. At the same time, differences in the profitability of barley cultivation, depending on economic factors and on the specificity of production, may be up to 6-fold.
Afficher plus [+] Moins [-]Training guide. Gender and Climate Change Research in Agriculture and Food Security for Rural Development
2011
Nelson, S. | Chaudhury M | Tranberg H | Lambrou Y | Tapio-Bistrom, M.L. | Kristjanson, Patricia M.
The purpose of this guide is to promote gender-responsive and socially-sensitive climate change research and development in the agriculture and food security sectors through participatory approaches. The guide focuses on the household and community level. It provides users with resources and tools for collecting, analysing and sharing gender-sensitive information about agricultural communities, households and individual household members who are facing climatic changes.
Afficher plus [+] Moins [-]Carbon stock of deciduous forests on organic soils in Latvia
2023
Bičkovskis, Kārlis | Samariks, Valters | Liepiņš, Jānis | Šņepsts, Guntars
Forests play a significant role in the mitigation of climate change through carbon storage and sequestration. However, a forest’s capacity to absorb carbon is influenced by a number of factors, such as soil characteristics, the selection of tree species, and the application of silvicultural practices. A study in Latvia was conducted to evaluate the carbon stock and sequestration potential of birch, common aspen, black alder and grey alder growing on periodically waterlogged and drained organic soils. Empirical data of forest resources were obtained from the National Forest Inventory (NFI) from 2016 to 2020. The findings indicate that black alder may thrive in both soil types, as it showed the best increase in carbon stock in periodically waterlogged soils, reaching a maximum of 129 t C haE−1 at the age of 61–70 years. Greater carbon sequestration in tree biomass occurs on drained soils compared to periodically waterlogged. Birch, aspen, and black alder stands may store between 106 and 119 t C haE−1 at age of 61 and 70 years, which is similar to grey alder stands at ages of 31–40 (114 ± 0.73 t C haE−1). Therefore, a short rotation for grey alder growing on drained organic soils could maximize carbon accumulation and add substitution value. These results suggest that different types of deciduous trees have varying capacities for carbon storage and sequestration, and that it’s important to consider site-specific factors, rotation age and silvicultural practices when aiming to maximize carbon sequestration in tree biomass.
Afficher plus [+] Moins [-]CCAFS approach for climate information services inspired a rural development program in Burkina Faso
2017
CGIAR Research Program on Climate Change, Agriculture and Food Security
The CCAFS Climate Information Services in West Africa project, in collaboration with meteorological services, radio stations, and mobile phone companies, was instrumental to the development of a component dedicated to the use and dissemination of climate information for VALPAPE program in Burkina Faso. A study tour to was organised to the Climate-Smart Villages of Tibtenga (Burkina) and Cinzana (Mali), made up of a group of 20 people from local communities, agricultural services, farmers' associations, national extension services and agricultural research.
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