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DocumentA preliminary study on ecological features of two natural enemies against two vectors of pine wilt disease for mass rearing in Korea
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Two species of the genus Monochamus (Coleoptera: Cerambycidae), M. alternatus and M. saltuarius are well-known as vectors of the pine wilt disease and they causes economically damages in South Korea. Among various control methods to reduce the density of vectors, a method by biological control agents (natural enemies) is eco-friendly indispensable. Since 2017, we have carried out the studies on the parasitic natural enemies againt for the vector species and found two parasitoids, Spathius verustus Chao, 1977 (Braconidae) and Cyanopterus flavator (Fabricius, 1793) (Bracondiae), would be a useful agents for biological controls. For accumulation of biological data, we conducted a preliminary study on life span and parasitic rate of two parasitic wasps against for two vector species. As results, we found that S. verustus has the longest adult life span of 33.4±19.2 days (avg.) in M. alternatus (T=30°C, H=60%) and C. flavator has the longest adult life span of 25.1±10.6 days (avg.) in M. alternatus (T=25°C, H=60%). The average parasitic rate (62.5%) of S. verustus was highest in M. alternatus (T=30°C, H=60%). In addition, it is confirmed that the offsprings of S. verustus can be made by parthenogenetic reproducton. Keywords: Research ID: 3622037 -
DocumentModelling pine and spruce wood mechanical properties in different initial stand density plantations in Lithuania
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Two main parameters of wood quality in constructions are wood modulus of elasticity (MOE) and bending strength (MOR). To understand what kind of quality wood we are growing in our forests and how environment and forest management could affect wood quality parameters, we need to model these parameters by stand, tree, and sample results. This would help to predict MOE and MOR for the future stands.
To determine the influence of stand density and thinning intensity on wood mechanical and physical properties of Scots pine and Norway spruce, the data was obtained from experimental trials plots, which were established in 1990 by Institute of Forestry. The experimental object was divided to a smaller trial plots with different initial stand density: 2 plots with 3000-4400 trees per hectare, 2 plots with 2000-2400 trees per hectare, 2 plots with 1000-1200 trees per hectare. In these trial plots different thinning programs were used 3; 2; 1 time. From each trial plot 6 model trees were chosen (38 Spruce and 76 Pine trees).
Models were created by SAS statistical package. General linear regression models were chosen to create 4 models for prediction of: dynamic modulus of elasticity for log (MOElog); dynamic modulus of elasticity for samples (MOEdyn); global static modulus of elasticity (MOE) and bending strength (MOR) All parameters for creating models were chosen as random effects. Stand parameter was stand density (SD). Tree parameters were diameter at breast high (DBH), competition index (CI), average ring width (RD), average ring density (RD) and log high (LH). Sample parameters were knot at fracture point (K) and sample wood density (WD).
Best result for MOE models was in pine stand R2=0,82 spruce stand R2=0,85. R2=0,57 was in pine stand for MOR and R2=0,65 in spruce stand. Keywords: Sustainable forest management, Research ID: 3484790 -
DocumentExperimental analysis of the effect of pine needle ash on water movement of forest soil
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.The effect of the ash layer on the infiltration capacity of the wildfire-affected area depends on the type of ash, the thickness of the ash layer, and the rainfall characteristics. In this study, the sealing and clogging of the soil were quantitatively analyzed according to the thickness of the ash layer and the intensity of rainfall, and the effects of these phenomena on the infiltration capacity of the soil were comparatively analyzed.
As a result of analyzing the porosity according to the soil depth using the resin impregnation method, the average porosity at a depth of 0 – 5 mm was reduced by up to 29% and at least 9% compared to the soil without ash layer (control), and the average porosity at a depth of 0–10 mm decreased up to 54 %, at least 10%. At a soil depth of 5–10 mm, the degree of pore reduction decreased with increasing ash thickness at the same rainfall intensity. At the ash thickness of 20 mm, the porosity at a soil depth of 10–15 mm decreased for more than 10-year rainfall. The porosity index according to the average porosity of soil depth 0-15 mm and the infiltration rate of clogged soil had a positive correlation, and when the porosity index decreased by 1%, the soil infiltration rate decreased by 0.0003812 cm/s. Keywords: Deforestation and forest degradation, Monitoring and data collection ID: 3623004
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