Carbon stocks and its variations with topography in an intact lowland mixed dipterocarp forest in Brunei

이소혜,이동호,윤태경,Kamariah Abu Salim,한새롬,윤현민,윤미해,김은지,이우견,Stuart James Davies,손요환 한국생태학회 2015 Journal of Ecology and Environment Vol.38 No.1

Tropical forests play a critical role in mitigating climate change, and therefore, an accurate and precise estimation of trop¬ical forest carbon (C) is needed. However, there are many uncertainties associated with C stock estimation in a tropical forest, mainly due to its large variations in biomass. Hence, we quantified C stocks in an intact lowland mixed dipterocarp forest (MDF) in Brunei, and investigated variations in biomass and topography. Tree, deadwood, and soil C stocks were estimated by using the allometric equation method, the line intersect method, and the sampling method, respectively. Understory vegetation and litter were also sampled. We then analyzed spatial variations in tree and deadwood biomass in relation to topography. The total C stock was 321.4 Mg C ha-1, and living biomass, dead organic matter, and soil C stocks accounted for 67%, 11%, and 23%, respectively, of the total. The results reveal that there was a relatively high C stock, even compared to other tropical forests, and that there was no significant relationship between biomass and topography. Our results provide useful reference data and a greater understanding of biomass variations in lowland MDFs, which could be used for greenhouse gas emission-reduction projects.

Carbon stocks and its variations with topography in an intact lowland mixed dipterocarp forest in Brunei

Lee, Sohye,Lee, Dongho,Yoon, Tae Kyung,Salim, Kamariah Abu,Han, Saerom,Yun, Hyeon Min,Yoon, Mihae,Kim, Eunji,Lee, Woo-Kyun,Davies, Stuart James,Son, Yowhan The Ecological Society of Korea 2015 Journal of Ecology and Environment Vol.38 No.1

Tropical forests play a critical role in mitigating climate change, and therefore, an accurate and precise estimation of tropical forest carbon (C) is needed. However, there are many uncertainties associated with C stock estimation in a tropical forest, mainly due to its large variations in biomass. Hence, we quantified C stocks in an intact lowland mixed dipterocarp forest (MDF) in Brunei, and investigated variations in biomass and topography. Tree, deadwood, and soil C stocks were estimated by using the allometric equation method, the line intersect method, and the sampling method, respectively. Understory vegetation and litter were also sampled. We then analyzed spatial variations in tree and deadwood biomass in relation to topography. The total C stock was 321.4 Mg C $ha^{-1}$, and living biomass, dead organic matter, and soil C stocks accounted for 67%, 11%, and 23%, respectively, of the total. The results reveal that there was a relatively high C stock, even compared to other tropical forests, and that there was no significant relationship between biomass and topography. Our results provide useful reference data and a greater understanding of biomass variations in lowland MDFs, which could be used for greenhouse gas emission-reduction projects.

Forest structure and carbon dynamics of an intact lowland mixed dipterocarp forest in Brunei Darussalam

Lee, Sohye,Lee, Jongyeol,Kim, Seongjun,Roh, Yujin,Salim, Kamariah Abu,Lee, Woo-Kyun,Son, Yowhan Springer-Verlag 2018 JOURNAL OF FORESTRY RESEARCH Vol.29 No.1

<P>Tropical forests play a critical role in mitigating climate change because they account for large amount of terrestrial carbon storage and productivity. However, there are many uncertainties associated with the estimation of carbon dynamics. We estimated forest structure and carbon dynamics along a slope (17.3A degrees-42.8A degrees) and to assess the relations between forest structures, carbon dynamics, and slopes in an intact lowland mixed dipterocarp forest, in Kuala Belalong, Brunei Darussalam. Living biomass, basal area, stand density, crown properties, and tree family composition were measured for forest structure. Growth rate, litter production, and litter decomposition rates were also measured for carbon dynamics. The crown form index and the crown position index were used to assess crown properties, which we categorized into five stages, from very poor to perfect. The living biomass, basal area and stand density were 261.5-940.7 Mg ha(-1), 43.6-63.6 m(2) ha(-1) and 6,675-8400 tree ha(-1), respectively. The average crown form and position index were 4, which means that the crown are mostly symmetrical and sufficiently exposed for photosynthesis. The mean biomass growth rate, litter production, litter decomposition rate were estimated as 11.9, 11.6 Mg ha(-1) a(-1), and 7.2 g a(-1), respectively. Biomass growth rate was significantly correlated with living biomass, basal area, and crown form. Crown form appeared to strongly influence living biomass, basal area and biomass growth rate in terms of light acquisition. However, basal area, stand density, crown properties, and biomass growth rate did not vary by slope or tree family composition. The results indicate that carbon accumulation by tree growth in an intact lowland mixed dipterocarp forest depends on crown properties. Absence of any effect of tree family composition on carbon accumulation suggests that the main driver of biomass accumulation in old-growth forests of Borneo is not species-specific characteristics of tree species.</P>

브루나이 열대 원시 dipterocarp 혼효림의 탄소 저장량 추정 및 불확도 평가

이동호 ( Dong Ho Lee ),한새롬 ( Sae Rom Han ),이소혜 ( So Hye Lee ),( Kamariah Abu Salim ),이우균 ( Woo Kyun Lee ),손요환 ( Yow Han Son ) 한국임학회 2014 산림과학 공동학술대회 논문집 Vol.2014 No.-

본 연구는 브루나이 열대 원시 dipterocarp 혼효림에서 탄소 저장량을 추정하고, 추정치의 불확도를 평가하기 위해 수행되었다. 이를 위하여 쿠알라벨라롱 지역에 연구 대상림을 설정하고 이 안에 6개의 60 m × 60 m의 조사구를 설치한 다음 임목, 고사목, 낙엽층 및 토양 내 탄소 저장량을 추정하였으며, 탄소 저장고별 불확도는 t-분포를 가정하여 95% 신뢰구간에서 추정하였다. 탄소 저장량(Mg C ha-1; mean±SD)은 임목의 지상부에서 183.2±34.0(비율, 53.7%; 불확도, 19.5%), 지하부에서 33.0±6.1(9.7%; 19.5%), 고사목에서 25.5±30.2(7.5%; 124.1%), 낙엽층에서 2.8±1.2(0.8%; 46.3%), 토양에서 96.4±16.9(28.3%; 18.4%) 등으로 총 340.9±49.2(100%; 15.2%)이었다. 연구 대상림의 총 탄소 저장량 추정치는 유사한 기후대인 말레이시아 사바 지역의 택벌된 diptercarp 혼효림의 2배 정도에 해당되며, 전 세계 산림의 탄소 저장량을 추정한 선행 연구와 비교하여 임목에 저장된 비율은 높고 고사목, 낙엽층, 그리고 토양에 저장된 비율은 낮은 것으로 나타났다. 한편 탄소 저장고별 불확도는 선행 연구에 비하여 높아 조사구의 크기를 크게 할 필요가 있는 것으로 사료된다. This research aimed to estimate carbon (C) stocks of tropical intact mixed dipterocarp forests (MDF) in Brunei and to analyze uncertainties of the estimates. We established 6 plots (60 m × 60 m) in Kuala Belalong and estimated C stocks in tree, dead wood, litter, and soil. Uncertainties of the estimates were evaluated at the 95% confidence interval assuming t-distribution. We found that the C stocks (Mg C ha-1; mean±SD) in aboveground tree, belowground tree, dead wood, litter, soil, and total C pool were 183.2±34.0 (proportion, 53.7%; uncertainty, 19.5%), 33.0±6.1 (9.7%; 19.5%), 25.5±30.2 (7.5%; 124.1%), 2.8±1.2 (0.8%; 46.3%), 96.4±16.9 (28.3%; 18.4%), and 340.9±49.2 (100%; 15.2%), respectively. Total C stock in the research area was about two times higher than that of the selective logged MDF in the same climate zone in Sabah, Malaysia. The results showed that the proportion of tree C was higher while that of the dead wood, litter, and soil were lower than the literature values of the world`s forests C stock. Uncertainties were higher than those of the previous related studies, therefore, it seemed that larger plots are required to estimate forest C stocks in the area.

항공 LiDAR 자료를 이용한 브루나이 열대우림의 임분단위 지상부 생체량 추정

윤미해 ( Mi Hae Yoon ),김은지 ( Eun Ji Kim ),곽두안 ( Doo Ahn Kwak ),이우균 ( Woo Kyun Lee ),이종열 ( Jong Yeol Lee ),김문일 ( Moon Il Kim ),이소혜 ( So Hye Lee ),손요환 ( Yo Whan Son ),( Kamariah Abu Salim ) 대한원격탐사학회 2015 大韓遠隔探査學會誌 Vol.31 No.2

본 연구는 항공 LiDAR 자료를 이용하여 열대원시림인 브루나이 지역의 지상부 생체량을 정량화하기 위하여 수행되었다. 25ha 크기의 연구대상지에 0.09ha (30m×30m) 크기의 24개의 표본구 내에서 조사된 각 표본점 내 개체목의 흉고직경 및 위치자료를 활용하였다. 또한, 항공 LiDAR 자료를 이용하여 수치표면모델(Digital Surface Model), 수치지형모델(Digital Terrain Model), 수고모델(Canopy Height Model)을 구축하였다. 수고모델을 표본구단위로 분할하고 총 12개의 LiDAR 높이변수를 구축하였다. 표본구별로 상대생장식을 이용하여 계산된 생체량과 LiDAR 자료로부터 추출된 변수간의 다중회귀분석을 통해 LiDAR자료로부터 생체량을 추정할 수 있는 식을 도출하였다. 표본구의 생체량은 평균 366.48 Mg/ha였으며, 155.81 Mg/ha부터 597.21 Mg/ha까지 분포하였다. LiDAR로부터 생체량을 추정하는 식의 검증 결과, 결정계수 값은 0.84로 나타났다. This study aims to quantify the stand-level above ground biomass in intact tropical rain forest of Brunei using airborne LiDAR data. Twenty four sub-plots with the size of 0.09ha (30 m×30 m) were located in the 25ha study area along the altitudinal gradients. Field investigated data (Diameter at Breast Height (DBH) and individual tree position data) in sub-plots were used. Digital Surface Model (DSM), Digital Terrain Model (DTM) and Canopy Height Model (CHM) were constructed using airborne LiDAR data. CHM was divided into 24 sub-plots and 12 LiDAR height metrics were built. Multiple regression equation between the variables extracted from the LiDAR data and biomass calculated by using a allometric equation was derived. Stand-level biomass estimated from LiDAR data were distributed from 155.81 Mg/ha to 597.21 Mg/ha with the mean value of 366.48 Mg/ha. R-square value of the verification analysis was 0.84.