• Journal of Forest and Environmental Science
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• 제28권3호
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• pp.179-184
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• 2012

Dipterocarps (Dipterocarpaceae) is a dominant tree family of tropical rainforest in Southeast Asia. Dipterocarps have been exploited for its timber and disappearing fast in East Kalimantan. In this study, we predicted the distribution of dipterocarpus, one of the main dipterocarps genera, by evaluating its habitat suitability using logistic regression analysis with specimen collection points and environmental factors from GIS data. Current distribution of dipterocarpus was generated by combining the habitat suitability classes with an updated forest cover map. Rainfall, soil type, followed by elevation was the main factors that influence the distribution of dipterocarpus in East Kalimantan. Dipterocarpus can be found in a quarter of the current forest cover, which is highly suitable as habitat of Dipterocarpus.

• 한국가구학회지
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• 제20권1호
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• pp.52-60
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• 2009

Joyangru, which is located in Woodo mountain in Chuncheon, Korea, was a gate tower of Monsogak. There are little historical records about Joyangru except of the 20th-century records. To study about Joyangru history, a dendrochronological analysis was conducted. We identified also the species of woods, We took 87 samples of wood elements for the species analysis and 13 samples for the dendrochronological analysis. We found 78 hard pines(Diploxylon), 4 Douglass-fir, 3 exotic hard pines(Pinus ponderosa type) and 1 Shorea sp.(Dipterocarpaceae). In the dendrochronological analysis, 2 floor flames were dated in 1887 (with complete sapwood) and 2 beams in 1884. We concluded that Joyangru was reconstructed just after 1888, most likely in 1890 together with Monsogak.

• Mass Spectrometry Letters
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• 제6권4호
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• pp.99-104
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• 2015

A liquid chromatography mass spectrometry (LC-MS) system was used to identify and distinguish oligostilbene diastereoisomers. A polyphenolic extract from Neobalanocarpus heimii known to be rich in oligostilbenes of various degrees of condensation was used as test material. Fourteen oligostilbenes were isolated from this extract on a fully automated semi-preparative HPLC system. Out of these, two pairs of dimers, one pair of trimers, two pairs of tetramers and a group of four tetramers with similar skeleton were identified as diastereoisomers. Their structures and configurations were established by spectroscopic methods. All isolated compounds were subjected to an LC-MS/MS to study their fragmentation patterns. The experiments were performed on a liquid chromatography-mass spectrometry (LC-MS) with electrospray-ionization (ESI) interface in positive mode. MS/MS spectra of each pure compound were recorded by direct infusion in identical conditions and their product ion spectra were analysed. Some subtle yet significant differences were observed between the spectra of oligostilbenes from the various diastereoisomeric series.

• Journal of Forest and Environmental Science
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• 제28권3호
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• pp.170-178
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• 2012

Dipterocarps or Dipterocarpaceae is a commercially important timber producing and dominant keystone tree family in the rain forests of Borneo. Borneo's landscape is changing at an unprecedented rate in recent years which affects this important biodiversity. This paper attempts to model the natural occurrence (distribution including those areas with natural forests before being converted to other land uses as opposed to current distribution) of dipterocarp species in Sarawak which is important for forest biodiversity conservation and management. Local modeling method of Inverse Distance Weighting was compared with commonly used statistical method (Binary Logistic Regression) to build the best natural distribution models for three genera (12 species) of dipterocarps. Database of species occurrence data and pseudoabsence data were constructed and divided into two halves for model building and validation. For logistic regression modeling, climatic, topographical and edaphic parameters were used. Proxy variables were used to represent the parameters which were highly (p>0.75) correlated to avoid over-fitting. The results show that Inverse Distance Weighting produced the best and consistent prediction with an average accuracy of over 80%. This study demonstrates that local interpolation method can be used for the modeling of natural distribution of dipterocarp species. The Inverse Distance Weighted was proven a better method and the possible reasons are discussed.

• Journal of Forest and Environmental Science
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• 제28권3호
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• pp.158-169
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• 2012

Sabah has experienced a rapid decline in the extent of forest cover. The precise impact of habitat loss on the conservation status of the plants of Sabah is uncertain. In this study we use the niche modelling algorithm MAXENT to construct preliminary, revised and final ecological niche models for Dipterocarpus lamellatus and Dipterocarpus ochraceus and combined these models with data on current land-use to derive conservation assessments for each species. Preliminary models were based on herbarium data alone. Ground surveys were conducted to evaluate the performance of these preliminary models, and a revised niche model was generated from the combined herbarium and ground survey data. The final model was obtained by constraining the predictions of the revised models by filters. The range overlap between the preliminary and revised models was 0.47 for D. lamellatus and 0.39 for D. ochraceus, suggesting poor agreement between them. There was substantial variation in estimates of habitat loss for D. ochraceus, among the preliminary, revised and constrained models, and this has the potential to lead to incorrect threat assessments. From these estimates of habitat loss, the historic distribution and estimates of population size we determine that both species should be classified as Critically Endangered under IUCN Red List guidelines. Our results suggest that ground-truthing of ecological niche models is essential, especially if the models are being used for conservation decision making.

• 보존과학회지
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• 제35권3호
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• pp.245-251
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• 2019

본 논문은 대통령기록관에서 소장하고 있는 목가구의 보존처리 과정을 정리한 것으로, 최근 증가하고 있는 근 현대목제문화재에 대한 보존처리 방법과 기존의 보존처리 방법의 적용 가능성을 확인하고자 하였다. 재질분석 결과, 대통령기록관 소장 의자(이136-2)와 책상(윤37)은 이우시과의 수종으로 제작되었으며, 두 가구 모두 2개의 도료층이 확인되었다. FT-IR을 이용한 분석 결과 의자는 니트로셀룰로오스계 도료, 책상은 탑코트의 스펙트럼과 유사하여 합성재료를 사용한 것으로 확인되었다. 보존처리 전 목가구의 표면에는 이물질이 고착되어 있었고 도료와 목재의 갈라짐과 손상으로 인해 불안정한 상태이었다. 따라서 과학적 조사를 통해 얻은 자료를 바탕으로 유사한 재료를 이용하여 손상된 부분을 원형의 형태로 보존처리 하고자 하였다.