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DocumentEffects of drought stress and nitrogen fertilization on growth and physiological characteristics of Pinus densiflora seedlings under elevated temperature and CO2 concentrations
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Pinus densiflora is the most widely distributed tree species in South Korea. Its ecological and socio-cultural attributes makes it one of the most important tree species in S. Korea. In recent times however, the distribution of P. densiflora has been affected by dieback. This phenomena has largely been attributed to climate change. This study was conducted to investigate the responses of growth and physiology of P. densiflora to drought and nitrogen fertilization according to the RCP 8.5 scenario. A Temperature Gradient Chamber (TGC) and CO2- Temperature Gradient Chamber (CTGC) were used to simulate climate change conditions. The treatments were established with temperature (control versus +3 and +5°C; aCeT) and CO2 (control: aCaT versus x1.6 and x2.2; eCeT), watering (control versus drought), fertilization (control versus fertilized). Net photosynthesis (Pn), stomatal conductance (gs), biomass and soil water content (SWC) were measured to examine physiological responses and growth. Relative SWC in aCeT significantly decreased after the onset of drought. Pn and gs in both aCeT and eCeT with fertilization were high before drought yet decreased rapidly after 13 days under drought. The fastest mortality showed in aCeT but the longest survival was observed in eCeT. Total and partial biomass (leaf, stem and root) in both aCeT and eCeT with fertilization were significantly high, but significantly low in aCeT. The results of the study are helpful in addressing P. densiflora vulnerability to climate change by highlighting physiological responses related to carbon allocation under differing simlulated environmental stressors. Keywords: Climate change ID: 3621653 -
DocumentPatula pine (Pinus patula) cones opening under different treatments for rapid seed extraction in Londiani, Kenya
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Seed extraction from pines is challenging to the forestry sector globally. This is usually contributed by the pine cone anatomy that opens through a function of temperature and humidity which varies widely in the pine growing regions of the world and the Pinus species as observed in previous works done on Pinus roxburghii, Pinus halepensis, Pinus wallichiana, Pinus pinaster, Pinus radiata, and Pinus sylvestris. This study sought to reduce the extraction time and improve the extraction efficiency of Pinus patula seed in Kenya. The experimental design used was two factorial design with replicates of twenty cones randomly picked per treatment. Data analysis was analyzed through ANOVA with a Pvalue of 0.05. We present evidence that soaking does not influence the opening of cones and seed yield for the optimum temperature which the study determined to be 65°C. We also present evidence that, for rapid seed extraction, the temperature 65°C with an exposure period of between 4 and 24 h is significantly effective. This study presents a new understanding of rapid seed extraction, which contributes to one of the Kenya Forestry Research Institute’s strategic objectives of generating technologies for enhanced production of superior germplasm for priority tree species. Keyword: Research ID: 3469689 -
ArticleImpact of Leptoglossus occidentalis on Pinus pinea cone to pine nut yield in Chile
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Stone pine nuts are highly appreciated and increasingly in demand. However, pine nut yield expressed as percentage of nut weight over cone weight, has decreased (from 4% to 2% or even less) in the European producer countries, due to the attack of the insect Leptoglossus occidentalis, which produces an increase in the presence of empty (up to 50%) and damaged seeds. The species shows a good adaptation in Chile, with over 2,000 hectares of new plantations. L. occidentalis here was first detected in 2017, with increasing captures in the last years. The objective of this study was to assess fruit traits and pine nut yield before and after the arrival of the insect, and to quantify its damages (types I (endosperm/embryo damage), II (endosperm elimination) and III (empty seeds)). Seven plantations were monitored in 2018 and 2019 and compared to data from previous years (2010/15). Cone size, seed number per cone, seed and pine nut size (length and diameter) and weight were measured at each plantation and year and pine nut yield was determined. Results showed average pine nut yield of 4% without decreases along time. In a hotspot site for the insect, a significant decrease in cone weight, seed weight and pine nuts per cone was quantified. A significant increase in damages type I and II was found in all sites after 2017. Consequently, the need of monitoring the advance of the insect in the country and its effects on stone pine cropping is relevant. Biological or chemical control will be required for adequate orchard management. Keywords: kernel yield, cone health, stone pine, insect attack ID: 3483547
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