• Journal of Korean Society of Forest Science
• /
• v.106 no.2
• /
• pp.249-257
• /
• 2017

This study was conducted to analyze the relationship between tree-ring growth of Pinus densiflora and climate factors based on national forest inventory(NFI) data. Annual tree-ring growth data of P. densiflora collected by the $5^{th}$ NFI were first organized to analyze yearly growth patterns of the species. Yearly growing degree days and standard precipitation index based on daily mean temperature and precipitation data from 1951 to 2010 were calculated. Using the information, yearly temperature effect index(TEI) and precipitation effect index(PEI) were estimated to analyze the effect of climate conditions on the tree-ring growth of the species. A tree-ring growth estimation equation appropriate for P. densiflora was then developed by using the TEI and PEI as independent variables. The tree-ring growth estimation equation was finally applied to the climate change scenarios of RCP 4.5 and RCP 8.5 for predicting the changes in tree-ring growth of P. densiflora from 2011 to 2100. The results indicate that tree-ring growth of P. densiflora is predicted to be decreased over time when the tree-ring growth estimation equation is applied to the climate change scenarios of RCP 4.5 and RCP 8.5. It is predicted that the decrease of tree-ring growth over time is relatively small when RCP 4.5 is applied. On the other hand, the steep decrease of tree-ring growth was found in the application of RCP 8.5, especially after the year of 2050. The results of this study are expected to provide valuable information necessary for estimating local growth characteristics of P. densiflora and for predicting changes in tree-ring growth patterns caused by climates change.

• Membrane Journal
• /
• v.32 no.6
• /
• pp.486-495
• /
• 2022

This study presents the improved recovery efficiency of rare metal ions through the modified separation membrane wettability and hydrogen ion permeation in the anion exchange membrane (AEM) under the recovery process of combined electrodialysis and solvent extraction. Specifically, the wettability of the separator was enhanced by hydrophilic modification on one separator surface through polydopamine (PDA) and lipophilic modification on the other surface through SiO₂ or graphene oxide (GO). In addition, the modified surface of AEM with polyethyleneimine (PEI), PDA, poly(vinylidene fluoride) (PVDF), etc. reduces the water uptake and modify the pore structure for proton ions generation. The suppressed transport resulted in the reduced hydrogen ion permeation. In the characterization, the surface morphology, chemical properties and composition of membrane or AEM were analyzed with Scanning Electron Microscopy (SEM) and Fourier Transform-Infrared Spectroscopy (FT-IR). Based on the analyses, improved extraction and stripping and hydrogen ion transport inhibition were demonstrated for the copper ion recovery system.