Please login first

List of accepted submissions

 
 
Show results per page
Find papers
 
  • Open access
  • 12 Reads
Effects of the geographical scale in hybrid detection at extensive contact zones between Quercus faginea and Q. pyrenaica.

In the present climate change scenario, the question of to what extent horizontal gene flow among interbreeding species is of adaptive value represents an intriguing research topic. The aim of this study is to illustrate the importance of an accurate selection of the study scale for the correct identification of two oak species widely distributed in the Western Mediterranean (Q. faginea and Q. pyrenaica) and their hybrids. To this aim, we selected three plots each representing either an apparent monospecific assembly of one of the parentals or of hybrid individuals (through visual identification), distributed at three different geographic scales (fine/medium/large). We used AFLPs (Amplified Fragment Length Polymorphism) to investigate species limits and population structure through multivariate and Bayesian methods. In a first step, the three plots corresponding to each geographical scale level were analyzed separately, to be then treated as a unique data set in a second step. The obtained results revealed incongruence between both approaches and strong effects of scale. We then tested for spatial autocorrelation through Mantel tests and encountered that our data taken altogether show a pattern of isolation by distance. A subsequent Spatial Autocorrelation Analyses confirmed that the average genetic distance between pairs of individuals is smaller than random expectations when individuals are separated by distances <65 km. Although aware of the fact that our study represents just a preliminary approach, we demonstrate: (i) to our knowledge, for the first time, that introgressive homoploid hybridization is active and has historically modelled the evolution of the studied taxa; (ii) the necessity of including methodological improvements that may allow overcoming the limitations of assigning individuals to genetic categories when study-plots are selected for studies aimed to evaluate responses of oaks to environmental changes along geographic gradients.

  • Open access
  • 18 Reads
The use of microsatelliets markers in molecular characteristisc of hybrids between Pulsatilla species

Pulsatilla x hakelii Pohl. is the most common hybrid between Pulsatilla patens and Pulsatilla pratensis. It occurs in the natural environment, most often in sites together with parental forms. Pulsatilla × hackelii is morphologically intermediate between the pure Pulsatilla species. Separation of hybrid individuals from pure Pulsatilla species requires a whole set of morphological features. Completed plastid genome provide molecular evidence for the hybrid origin of Pulsatilla × hackelii. In our study we presents the – genotypic characteristics of Pulsatilla x hakelii based on microsatellites markers developed for Pulsatilla vulgaris. A specimen of the hybrid was found in the Świętokrzyskie Mountains, near Bocheniec village, in the vicinity of a forest road in a fresh mixed coniferous forest (Querco roboris-Pinetum (W.Mat. 1981) J.Mat. 1988). We amplified a set of 10 microsatellites in two multiplex PCR reactions. From the 10 analyzed loci, we successfully amplified eight. The analyzed microsatellites in population studies of three Pulsatilla species showed some species specific alleles. In case of the Pulsatilla x hakelii sample, we obtained PCR products in the case of 5 loci developed for P. vulgaris, but successfully crossamplified in P. patens and P. pratensis. Additionaly we obtained results for 2 loci, which crossamplified only for Pulsatilla patens and 1 only for Pulsatilla pratensis. Among the investigated markers, 2 were monomorphic and the remaining six were polymorphic, what making them highly informative in population studies for pasque-flower species as Pulsatilla patens, P. pratensis and P. vernalis. The obtained results indicated that analized microsatellites markers can be used for hybrids identification, although there is a need for further research on a larger number of hybridized individuals.

  • Open access
  • 14 Reads
Migration and multiplication of pathogenic Bursaphelenchus xylophilus isolates of diverse geographic origins

Adverse pine wilt disease expansion forecasts must be met with rapid advances in tools to fight against this disease, such as genetic breeding. The optimal approach for breeding more resistant trees to B. xylophilus, causative agent of this disease, is to use the most virulent isolates in inoculation assays.

Different inoculation experiments were conducted on Botrytis cinerea cultures, along with P. pinaster and P. radiata branch sections and seedlings. Seven virulent isolates of diverse geographic origin (USA745 from USA, KA4 and S10 from Japan, Pt52T and Pt72CH from Portugal, SpPO1 and SpSA1from Spain) were used in the experiments. The main aim of this work is to investigate differences among the seven isolates.

Results from the experiments showed significant differences among B. xylophilus isolates. On fungal culture, the isolate from USA showed the highest multiplication rate. Both seedling inoculation and branch sections experiments pointed to the Portuguese isolate Pt52T and the Spanish SpPo1 as the most virulent to P. pinaster. Conversely, higher numbers of Pt72CH isolate passed through P. pinaster branch sections. The most virulent isolate for P. radiata was the Japanese S10, though it only showed significant differences in mortality when compared to the Spanish SpSA1. These results suggest that B. xylophilus have differential host specificity.

  • Open access
  • 12 Reads
Validation of catenary based methods for cable road layout planning

Cable-based technologies have been a backbone for harvesting on steep slopes. Computing the layout of a single cable road requires considering the standards of structural design, aiming to (1) guarantee structural safety, and (2) provide the required serviceability. Currently applied analysis methods, such as the Pestal method are unprecise. Alternatively, methods based on the catenary, such as Zweifel or Irvine are better suited to analyze and predict load path and occurring forces for skylines anchored fix on both ends. However, studies that validate those catenary analyses (concurrently load path and forces) are rare and were not carried out under realistic heavy load conditions. Therefore, the aim of the project was to validate the catenary analyses under realistic, heavy load conditions for cable roads with multiple spans. In two case studies in Switzerland the deflection in every span as well as the skyline tensile force at the anchor were measured for different load configurations and compared with theoretical computations of Zweifel and Pestal.

The approach of Zweifel maps the mechanical properties realistic. However, as proven by our measurements, he slightly overestimated the deflection and the skyline tensile forces because the friction on the supports was neglected (between skyline and saddle). The deflections calculated with the Pestal formulas were significantly larger than the measured values, in particular with heavy load and in large spans. Our measurement studies confirmed that the mechanical properties of a cable road can be described adequately with the algorithm by Zweifel. However, it should be further developed with inclusion of effects like the friction to improve the efficiency, safety and cost-performance ratio in cable road planning.

  • Open access
  • 43 Reads
Comparison of microsatellites and SNP markers in genetic diversity level of two Scots pine stands

Scots pine (Pinus silvestris), is one of the dominant species in Poland and one of the main forest tree species in northern and central Europe. This species is of great economic importance. The Scots pine is highly adaptable to changing environmental conditions. A number of ecotypes have been characterized and formation of these ecotypes are related with development of different phenotypic characteristics: morphological, physiological and ecological. Molecular studies, based on DNA polymorphism, have been used for more than 20 years to analyzed genetic diversity of Scots pine population. The most popular are microsatellite markers due to the fact of wide availability and high polymorphism. However, the use of these markers is also associated with certain limitations: due to complex mutation models or high incidence of homoplasia. These features are prompting scientists to look for alternative types of markers such as for example SNP. In our study we conducted a comparison of the basic parameters of genetic variability of two Scots pine stands (25 and 24 trees in each) for 20 SNP markers and 4 microsatellite markers. For the 20 SNP loci the observed heterozygosity (Ho) was equal 0,34 for both stands and the expected heterozygosity (He) for the first stand was equal 0,34 and for the second 0,37. No statistical significant genetic distance was observed between them. For the microsatellite markers observed heterozygosity (Ho) was 0,81 and 0,74 and the expected heterozygosity (He) was equal 0,85 and 0,85 respectively for stands and similarly no statistical significant genetic distance was observed.

Literature data of different genetic markers showed higher informativeness of random chosen microsatellite than SNP markers for study population differentiation. But some analyzes confirm that the appropriate number of SNP markers can be more informative for population structure inference.

  • Open access
  • 15 Reads
INFLUENCE OF SELECTED MATERIAL AND PROCESS PARAMETERS ON THE DURABILITY OF BRIQUETTES FROM SHREDDED LOGGING RESIDUES

The principles of rational management of residues from forest production recommend the use of logging residues, including for energy purposes. The shredded material can undergo compaction to increase the energy value and improve its physical properties This idea is a manifestation of innovation in the world of technology and efforts to protect the natural environment.

It should be remembered that inhomogeneous physical properties of the raw material, and its structure and composition can cause serious problems in its further use. As a result of the research, it was found that the elemental composition of logging residues (low nitrogen and ash content) is suitable for energy raw materials. The correlation between the physical properties of the produced briquettes and the parameters of the raw material subjected to the briquetting process was also determined. The biomass was compacted in a closed chamber at unit pressures of about 60 MPa. The material to be compacted was forest chips with a moisture content of 10, 15, 20%, the process temperature was22 and 73°C. For both temperatures, the best results were obtained for a material with a moisture content of 10%. It was found that the temperature of the chips during agglomeration influences the degree of compaction and durability of the obtained briquettes, and that agglomeration carried out at a higher temperature gives better results. The study also determined the impact of the fractional composition of the briquetted mixture, its humidity and the temperature of the agglomeration process on the durability of the product. The raw material under examination were divided into four independent groups with dimensions: 0 – 1, 1 – 4, 4 – 8 and 8 – 16 mm. The most favorable fractional composition of the briquetted mixture, its moisture and the temperature of the compaction process were determined. The mixture, from which the most durable briquettes were made, contained 50% of fraction 0 – 1; 15% of fraction 1 – 4 and 25% of fraction 4 – 8. Its humidity was 15% and the process temperature was 73°C.

  • Open access
  • 16 Reads
Effect of genotypes on micropropagation of Terminalia arjuna – an important medicinal tree

Terminalia arjuna is an important tree of medicinal and sericulture industry, commonly known as Arjun. It’s bark rich in secondary metabolites makes this plant highly valuable in medicine industry to treat cardiovascular disease. It is also used as feeder plant for tasar silkworm (Antheraea mylitta). Over exploitation due to high demand in medicine, low seed germination, limitations of conventional method of propagation push this plant towards being endangered. To conserve germplasm of such tree species and meet the requirement in medicinal industry, some non-conventional propagation method like micropropagation have been developed. The present work highlighted the effect of genotypes on tissue culture of T. arjuna. For this objective, nodal explants were collected from three genotypes (G-1, G-2 and G-3) of T. arjuna situated at Jodhpur, Rajasthan, India. In vitro shoot proliferation was achieved on modified MS medium enriched with BAP + additives. Genotype -1 showed maximum bud break response (100%) followed by G-3 (93.33 %) and G-2 (86.66%). Further multiplication of these shoots on modified MS medium containing BAP + NAA + additives gave 11.38±0.26 (G-1), 9.44±0.21 (G-2) and 10.22±0.32 (G-3) shoots. In vitro rooting was done by pulse treatment with IBA for 10 min prior to transfer on hormone free half strength MS medium containing 0.1% activated charcoal. Maximum in vitro rooting was obtained in G-1 (80%) followed by G-3 (71.11%) and G-2 (68.88%). In present study it was observed that optimum growth in all three genotypes require different dose of Plant Growth Regulator. Thus, by identifying and multiplying the best performing genotypes the gap between demand and supply of such medicinal plant can be fulfilled.

  • Open access
  • 27 Reads
Assessment of leaf litter decomposition in a pine and beech mixed forest: case study in northern Spain

The promotion of mixed forests represents an adaptation strategy in forest management to cope with climate change. The mixing of tree species with complementary ecological traits may modify forest functioning regarding productivity, stability, or resilience against disturbances. Litter decomposition is an important process for global carbon and nutrient cycles in terrestrial ecosystems, also affecting the functionality and sustainability of forests. Decomposition of mixed leaf litters has become an active research area because it mimics the natural state of leaf litters in most forests. Thus, it is important to understand the factors controlling decomposition rates and nutrient cycles in mixed stands. In this study, we conducted a litter decomposition experiment in a Scots pine and European beech mixed forest in the province of Navarre (north of Spain). The effects of forest management (i.e. different thinning intensities), leaf litter types and tree canopy on mass loss and chemical composition in such decomposing litter were analysed over a period of three years. Higher decomposition rates were observed in leaf litter mixtures, suggesting the existence of positive synergies between both pine and beech litter types. Moreover, decomposition process was favoured under mixed tree canopy patches. Regarding thinning treatments significant differences on decomposition rates disappeared at the end of the study period. Time influenced the nutrient concentration after the leaf litter incubation, with significant differences in the chemical composition between the different types of leaf litter. Higher Ca and Mg concentrations were found in beech litter types than in pine ones. It was observed an increase of certain nutrients throughout the decomposition process, due to immobilization by microorganisms (e.g. Mg in all leaf litter types, K only in beech leaves, P in thinned plots and under mixed canopy). Evaluating the overall response in mixed leaf litters and the contribution of single species is necessary for understanding the litter decomposition and nutrient processes in mixed forest ecosystems.

  • Open access
  • 55 Reads
Analysis on operational efficiencies and costs for extracting thinned woods in small-scale forestry, Nasunogahara area, Tochigi Prefecture, Japan

In this study, two operation methodologies to extract thinned woods were investigated on Nasunogahara area, Tochigi prefecture, Japan. Methodology 1 included manual extraction and light truck transportation. Methodology 2 included mini-forwarder forwarding and 4-ton truck transportation. Furthermore, a newly introduced chipper was investigated. As a result, costs of manual extractions within 10 m and 20 m were JPY942/m3 and JPY1,040/m3, respectively. On the other hand, forwarding cost of mini-forwarder was JPY499/m3 which was significantly lower than those of manual extractions. Transportation costs with light truck and 4-ton truck were JPY7,224/m3 and JPY1,298/m3 with 28-km transportation distances. Chipping operation costs were JPY1,036/m3 and JPY1,160/m3 with 3 and 2 persons, respectively. Lastly, total costs of methodologies 1 and 2 from extraction within 20 m to chipping were estimated as JPY9,300/m3 and JPY2,833/m3 with 28-km transportation distances and 3-men chipping operations (EUR1 = JPY124).

  • Open access
  • 55 Reads
Transport work for the supply of pine sawlogs to the sawmill

The aim of the presented research is to characterize the scale of transport work performed on the supply of large-size pine wood to the sawmill, with indication of factors influencing its structure and parameters. Appropriate analyzes were carried out for deliveries to a sawmill in northern Poland, which supplies pine as a sawlogs and long wood assortments. The distance of deliveries on public and forest roads was determined, as well as transport work for each type of road and the total value. The transport work was defined as a multiplication of driven kilometers with the load and the weight of the load in ton kilometers. Data on the distance traveled was obtained on the basis of information from the driver, and the parameters of the transported pine sawlogs on the basis of the delivery note. Based on the collected data over a period of 12 months, the transport work was determined for selected courses.

The total transport work for the 1,509 analyzed deliveries was 3,447,486 tonne-kilometers (tkm). The average transport work for one course amounted to 2,286 tkm and was characterized by a high variability SD = 1 207. The minimum value of the transport work was recorded at the level of 83 tkm, and the maximum as much as 7,803 tkm. The median of the analyzed deliveries was 2,220 tkm, while the first quartile Q1 = 1,358, and the third quartile Q3 = 2,997. The transport work for a single course is at a comparable level in all months, but the analysis using the Kruskal-Wallis test showed statistically significant differences (p = 0.0000). Comparison of the transport work for deliveries carried out in each months by using the Dunn's test shows statistically significant differences only when comparing the results between XI and I; III; IV, VI and X and III from I, IV and X and the last pair differing from IV is from VIII. The deliveries in July and December were not included in the statistical analyzes due to the insufficient sample size due to plant maintenance breaks.

Top