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Gailite A.,Latvian State Forestry Research Institute Silava | Gaile A.,Latvian State Forestry Research Institute Silava | Gaile I.,Latvian State Forestry Research Institute Silava | Voronova A.,Latvian State Forestry Research Institute Silava | And 3 more authors.
Proceedings of the Latvian Academy of Sciences, Section B: Natural, Exact, and Applied Sciences | Year: 2013

Rye (Secale cereale L.) is an important grain crop in Latvia, where it is mainly used for baking rye bread, which is a popular staple. However, the area under rye cultivation in Latvia is small, and the majority of varieties planted are foreign. In 1937, almost 290 000 ha of rye were planted, while in 2011, only 28 000 ha were planted, or ∼5% of the area planted with cereals. The Latvian rye genetic resources collection contains nine accessions, including old and new cultivars, landraces and one repatriated accession, which was previously held in the N. I. Vavilov Research Institute of Plant Industry collection. A set of descriptors has been developed for rye, and field evaluations of the Latvian rye collection have been started. A set of simple sequence repeat (SSR) markers has been utilised for genetic fingerprinting of the collection. The initial genetic results indicate that the Latvian rye collection contains a high degree of genetic diversity. Analyses are continuing in order to more fully characterise the collection both phenotypically and genetically.

Howlett S.J.,Latvian State Forestry Research Institute silava | Stafford R.,Bournemouth University | Waller M.,Global Vision International Seychelles | Antha S.,Seychelles National Parks Authority | Mason-Parker C.,Global Vision International Seychelles
Journal of Marine Biology | Year: 2016

Marine protected areas can be designated for a number of reasons, but exactly how they provide benefits is only recently being understood. We assessed the effect of protection on the size and distribution of six common species of grouper in a coral reef ecosystem. Data on live coral cover, coral genus diversity, and coral colony structure type were also compared to give an indication of reef quality between sites. A significant interaction was found for Aethaloperca rogaa and Cephalopholis nigripinnis, indicating that protected areas held greater numbers of smaller and median sized fish of these species than unprotected areas. Similar but nonsignificant trends were found for Cephalopholis miniata and Cephalopholis argus. For Anyperodon leucogrammicus, MPAs held significantly more fish than unprotected sites, but as the increase was equal between size categories there was no interaction. The last species Epinephelus fasciatus, which was one of the smallest species, had no significant interaction, similar mean counts between protected and unprotected areas, and no obvious strong favouritism for particular sites with values indicating better reef quality, indicating intraspecies competition. The results of this study indicate that while the MPAs in this study are likely too small to benefit large groupers, the improvements to habitat quality have indirect benefits to groupers, especially at their earlier life stages. © 2016 Samantha J. Howlett et al.

Spalvis K.,Latvian State Forestry Research Institute Silava | Daugaviete M.,Latvian State Forestry Research Institute Silava | Platace R.,Latvian Academy of Sciences | Daugavietis U.,Latvian State Forestry Research Institute Silava
International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM | Year: 2014

In the northern hemisphere Norway spruce (Picea abies Karst.) as one of the most productive and fast-growing conifer species has long been cultivated over vast areas. According to the literature data the spruce plantations in Europe take up some 6 to 7 million hectares. In the territory of present-day Latvia pure stands of spruce were established in woodlands already in the 19th century. Starting with the 1980s, spruce plantations for short rotation cultivation (till the age of 40 years) were on a larger scale established also in abandoned agricultural lands. Between 2000 and 2012, the area under similar plantations has reached 28,700ha. At first commercial thinnings at the age of 15 years the number of trees in the plantations is normally reduced to 1,500 stems•ha-1. In such a situation the major challenge is how to utilize the biomass thinned out. In the given study we have investigated the structure and amount of woody biomass that may be recovered in thinning 15-year pure stands of spruce. According to the field data, the weight of above-ground biomass of one tree in 15-year pure stands of spruce is on average 142.9kg (100%), of which stemwood makes 65.7 kg (46.0%) and tree foliage 76.9kg (53.9%), respectively. The biomass of green branches comprises the fraction of needles (38.1 kg or 49.5%) and young shoots (7.2kg or 9.4%), which in biomass studies is known as tree foliage. In 21 to 25-year pure stands of spruce the above-ground biomass of one tree weighs on average 372kg (100%), of which stemwood is 244.5 kg (65.7%) and tree foliage 117kg (31.5%), respectively In similar spruce plantations the number of trees removed in the first commercial thinnings is 1,210 trees ha-1 with the yield of pulpwood 27.1m3ha-1, or stem biomass 21.5t ha-1, and tree foliage 17.8t ha-1. When thinning 21to 25-year plantations, on average 877 trees ha-1 are thinned out, with the yield of pulpwood 109m3ha-1, or stem biomass 86.3t ha-1, and tree foliage 21.6t ha-1. The profit calculations, when utilizing also tree foliage, show that in thinning 15 to16-year spruce plantations the gross profit is 1.8 times higher, compared to the case when only pulpwood is utilized. For 21 to 25- year plantations this increase in gross profit is 1.2 times higher compared to utilizing pulpwood alone. © 2014, SGEM. All Rights Reserved.

Jansons A.,Latvian State Forestry Research Institute Silava
Research for Rural Development | Year: 2010

The effect of growing conditions, age and stocking density on the amount of deadwood in the pine forest stands of Latvia was analyzed in this research. The material for studies was collected within the framework of the National Forest inventory of Latvia in the period 2004 to 2008. From databases of the National forest inventory the data about 1627 sample plots dominated by pine were selected and analysed. The total amount of deadwood (m3 ha-1) was compared among five forest edaphical rows - forests on dry mineral soils, forests on wet mineral soils, forests on wet peat soils, forests on drained mineral soils and forests on drained peat soils. Deadwood was also analysed in five age groups - young, middle age, premature, mature and over-mature stands, as well as in six groups of stocking density - small-density, sparse-density, middle-density, high-density, full-density and over-density stands. It was found out, that the growing conditions (p = 0.000 < α = 0.05), stand age (p = 0.000) and stocking density (p = 0.000) have significant influence on the amount of deadwood in pine forest stands. The highest amount of deadwood is in the pine stands on wet mineral soils - 18.6 ± 2.09 m3 ha-1. With increase of the stand age the amount of deadwood also increases and in the mature pine stands the amount of deadwood is 17.8 ± 1.58 m3 ha-1. The amount of deadwood in the pine forest stands also increases with stocking density and in the over-density stands it is 21.6 ± 2.50 m3 ha-1.

Libiete-Zalite Z.,Latvian State Forestry Research Institute Silava | Zalitis T.,Latvian State Forestry Research Institute Silava
Research for Rural Development | Year: 2010

Large proportion of 30-50 years old spruce stands originated from overstocked plantations can be characterized by low growth potential and present serious problem to forest managers. Although according to legislation unproductive spruce stands can now be clearcut, possible alternative solution allowing a forest owner to remove only trees with the worst growth potential would be also welcome. To be able to recommend any silvicultural measures, information on the inner structural development of the stands is necessary. The aim of this study was to analyze temporal structure of several spruce stands that have originated from overstocked plantations and now belong to the 2nd (increased risk stands) or 3rd (unpromising stands) growth potential groups. Data for the study from seven sample plots located in Forest Research Station 'Kalsnava' and thinned with different intensity were used. Tree diameter distribution, volume accumulation patterns and tree mortality were analyzed. Correlation between tree diameter and tree diameter difference in the observation period from 2000 to 2006 was weaker than in the observation period from 2006 to 2009, indicating further decline of growth potential. In most cases the major part of the volume was accumulated in the middle of the diameter class distribution. For most of the trees one or both sawlogs were of good or average quality. In order to develop optimal and profitable stand management model, the effect of different thinning methods in spruce stands of low growth potential should be studied in the future.

Zalitis T.,Latvian State Forestry Research Institute Silava | Libiete-Zalite Z.,Latvian State Forestry Research Institute Silava
Research for Rural Development | Year: 2010

Both forestry theory and practice have proved that amelioration favours the growth of forest stands significantly. The growing stock increases even 10 times, if the amelioration system is well-functioning. Joint Stock Company "Latvia State Forests" that is managing half of forests in Latvia has started renovation of old amelioration systems aiming to improve the productivity of state owned forests in Latvia. In order to evaluate the impact of the renovation of the old amelioration systems, a tree ring width in 7 pine stands, 5 spruce stands and 3 birch stands was analysed. This study shows that the renovation itself has not affected the productivity of mature pine, spruce and birch significantly 3-4 years after the renovation. Authors have come to a conclusion that the reason for that could be too short observation period or particularities of a stand structure and age.

Gailis A.,Latvian State Forestry Research Institute Silava | Jansons A.,Latvian State Forestry Research Institute Silava
Research for Rural Development | Year: 2010

Black alder wood is suitable for production of high quality veneer and other uses, but doe to its small share in total forest area (3%) in Latvia its genetic improvement have not been a priority. Set of progeny tests, together 22.8 ha, have been established only in the last decade. First of them have reached the age of 8 to 10 years and are suitable for first assessment. Aim of our study was to evaluate potential of improvement of black alder using selection, based on progeny testing. Data from 4 open pollinated progeny tests of phenotypically selected black alder plus trees, located in central part of Latvia, each containing from 15 to 21 families, are evaluated, using breeding value as a criterion. Results reveal that selection of parent trees with the practically possible intensity (10%) yields notable improvement in height at the age of 8 to 10 years: from 10 to 32%. Parent trees of open-pollinated families S9, S14, S16 and 84115 that have superior productivity and above-average quality can be recommended for establishment of second-round seed orchard. Estimates of genetic parameter suggest that selection in black alder trials could be carried out with high accuracy and improvements are possible both in productivity and quality (branch thickness, stem straightness, occurrence of spike knots).

Lazdins A.,Latvian State Forestry Research Institute Silava | Lazdina D.,Latvian State Forestry Research Institute Silava | Liepa I.,Latvia University of Agriculture
Research for Rural Development | Year: 2010

Reduction of agricultural production has led to abandonment of farmlands in Latvia. According to the Central Statistical Bureau, 1.4 million ha of lands, including 0.6 million ha of farmlands were set aside in 2008. Most of them transform into forests; however, information about the afforestation has been limited until recent years. The first field measurement based evaluation of forest stands on abandoned farmlands was implemented within the scope of the National statistical forest inventory (NSFI). The NSFI covers forests, farmlands, settlements, wetlands and other lands, providing valuable information about the land use and forest resources. According to the NSFI, total area of naturally afforested farmlands is 257,850 ± 3,606 ha with growing stock of 2,870.364 ± 239,088 m3. Naturally afforested lands occupy 4% of the total country area. The highest share of naturally afforested lands is in Ludza (11% of the total area) and Krāslava districts (9% of the total area). Birch (Betula pendula Roth) and grey alder (Alnus incana (L.) Moench) are the most common dominant tree species in naturally afforested areas (77,092 ± 1,861 ha and 40,285 ± 1,395 ha, respectively). In relation to the Kyoto protocol it is important to separate lands afforested before and after 1990. The total area of lands afforested after 1990 in Latvia is 170,890 ± 2,862 ha with total growing stock of 1,367.427 ± 125,482 m3 and annual increment of timber volume - 122,530 ± 10,513 m3.

Baumanis J.,Latvia University of Agriculture | Ozolins J.,Latvian State Forestry Research Institute Silava
Research for Rural Development | Year: 2010

The number of the most important game animals of artiodactyla species (moose, red deer, roe deer, wild boar) has been increasing in Latvia during the last 10 years. At the same time, the number of hunting districts where the census of these game animals is taken is also increasing, whereas the average area of the districts is diminishing. The studies show that at present the area of many hunting districts is notably smaller than the individual territory inhabited by these species. This particular study aims at establishing whether there is a relationship between the area of a hunting district on which a census is taken and the number of animals counted, as well as whether the number of animals is really increasing or the increase in the number is attributed to an increase in the census unit number. It was established that in respect of the four species there is a significant correlation between the area of the hunting district and the density of animals in the district. The number of moose and red deer may be assessed more objectively in the districts with an area exceeding 5,000 hectares. The census of roe deer and wild boars is notably influenced by the area of the territory where the census is taken, but the analysis does not explicitly show whether the number of roe deer and wild boars is under-assessed in large districts or over-assessed in the small ones.

Skipars V.,Latvian State Forestry Research Institute Silava | Baumanis I.,Latvian State Forestry Research Institute Silava | Rungis D.,Latvian State Forestry Research Institute Silava
Research for Rural Development | Year: 2010

Scots pine (Pinus sylvestris) is Latvia's most economically important tree species. It accounts for 38% of the total forest area of Latvia. One of diseases affecting P. sylvestris is root rot caused by the fungus Heterobasidion annosum, which causes large economic losses. There is some evidence of Scots pine trees with higher levels of resistance but no absolutely resistant tree clones have been described so far. Many genes encoding peptides and proteins with direct or indirect antifungal activity have been described in various plant species, but only few of them have been studied in conifers. In our study we have utilised various approaches to research genetic aspects of Scots pine resistance to H. annosum. Here we present our initial results. Initially, H. annosum infection was determined in 300 trees and in a subset of twenty seven trees representing fifteen families (progeny of one mother tree) infection levels were quantitatively characterised. Candidate-genes were selected based on previously published research. Gene copy number variation (CNV) analyses were performed on selected samples. Copy number variation polymorphism was detected for a gene encoding a thaumatinlike protein analogues of which are described as potent antifungal proteins in other plants. As increased gene copy number can lead to increased gene product amounts in cells it is possible that an increased copy number of thaumatin-like protein is beneficial to the pine tree in respect to resistance against H. annosum and other pathogens. Further experiments need to be performed to investigate this in more detail.

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