IOP Conference Series: Earth and Environmental Science
Wood density (WD) is a critical determinant of estimating forest above-ground biomass (AGB) and c... more Wood density (WD) is a critical determinant of estimating forest above-ground biomass (AGB) and carbon stock. Thus, heterogeneity in WD on individuals within species trees needs to be scrutinized, and acquisition of fixed WD value is essential to estimate carbon stock with confidence. This study investigated intraspecific variation in WD of Syzgium sp., also known as “Jambu” or “Kelat”. It is the most occurring species in study areas, and is regarded as an economically important species. Firstly, one half-diameter drilling from bark-to-pith measurement was taken per tree using Rinntech Resistograph R650-ED at breast height. Meanwhile, 5.15 mm-diameter core was sampled at 1.30 m above-ground, with DeWalt DCF899HP2 20V impact wrench 950 Nm and Haglöf increment borer. WD was estimated for each core sample using a dimensional method. Drilling resistance (DR) profiles were processed using DECOM 2.38m1 Scientific (c), and several independent variables were extracted from the resistogram. ...
Bola sepak adalah sejenis sukan di luar rumah (outdoor) yang dimainkan di padang bola sepak atau ... more Bola sepak adalah sejenis sukan di luar rumah (outdoor) yang dimainkan di padang bola sepak atau kawasan lapang yang berumput turf biasanya jenis 'Cowgrass'. Objektif kajian adalah memperoleh data berkenaan padang bola sepak di sekitar Bandaraya Kota Kinabalu seperti jenis rumput, saiz, pemilik/pentdbir padang, jenis aktiviti yang dijalankan, kadar sewa, kecerunan dan kualiti penjagaan padang. Ini bertujuan untuk mengujudkan databes GIS padang-padang bola sepak di sekitar kawasan Zon Pantai Barat Sabah. Kaedah yang yang digunakan ialah pemeriksaan lapangan selepas pengenalpastian padang bola sepak melalui GIS. Sebanyak 45 padang telah diperiksa pada Ogos dan September 2009. Hasil kajian menunjukkan bahawa dari segi jenis rumput, semua padang yang ditinjau adalah berumput campuran (mixed grass). Dari segi saiz pula, majoriti padang memenuhi piawai saiz padang biasa. Kebanyakan padang yang ada dimiliki Lembaga Sukan Sabah atau organisasi berkaitan pendidikan (sekolah/kolej/uni...
Accurate estimation of aboveground biomass (AGB) has increasingly important especially dealing wi... more Accurate estimation of aboveground biomass (AGB) has increasingly important especially dealing with various levels of forest degradation. Exploration of forest texture and forest structure helps to define forest type which shaping a distribution of AGB. In this study, high resolution satellite imagery of IKONOS-2 was used to assess the AGB of tropical Borneo rainforest at specific degradation level. Study site consists of degraded lowland Dipterocarp forest located at Tangkulap forest reserves in Sabah. The satellite image was segmented using eCognition and classified into three specific levels of forest cluster that are early, mid and late-successional forest. Field plots were assigned to the cluster by AGB to reflect the degradation levels. Multiple stepwise regression analyses were performed between AGB and independent variables of spectral and textural properties. The resulted estimation models of AGB within each forest cluster level had R2 ranging from 0.65 to 0.70 (Pearson coe...
The information on biophysical parameters—such as height, crown area, and vegetation indices such... more The information on biophysical parameters—such as height, crown area, and vegetation indices such as the normalized difference vegetation index (NDVI) and normalized difference red edge index (NDRE)—are useful to monitor health conditions and the growth of oil palm trees in precision agriculture practices. The use of multispectral sensors mounted on unmanned aerial vehicles (UAV) provides high spatio-temporal resolution data to study plant health. However, the influence of UAV altitude when extracting biophysical parameters of oil palm from a multispectral sensor has not yet been well explored. Therefore, this study utilized the MicaSense RedEdge sensor mounted on a DJI Phantom–4 UAV platform for aerial photogrammetry. Three different close-range multispectral aerial images were acquired at a flight altitude of 20 m, 60 m, and 80 m above ground level (AGL) over the young oil palm plantation area in Malaysia. The images were processed using the structure from motion (SfM) technique i...
Oil palms (OP) in Sabah, Malaysia were studied to explore the relationship between canopy size an... more Oil palms (OP) in Sabah, Malaysia were studied to explore the relationship between canopy size and aboveground biomass (AGB). Four available allometric equations were used to calculate the dry AGB. Pearson's correlation analysis was performed between crown diameter (CD) and crown area (CA) towards the variables of AGB, height and dbh. In this analysis, the transformation to natural log of variable resulted in better coefficient compared to the original one. The mean of various variables such as height (stem, total and height difference), biomass (crown, trunk and total), dbh (inner and outer) and number of petiole leaf were calculated based on 32 independent sample plots (N = 222 palms) across various age stages from 2 to 24 years. These variables were regressed against CD and age. AGB versus CD was a nonlinear with R2 ranging from 0.950 to 0.975. Random modelling and cross validation between AGB and CD was applied at the ratio of 70:30. Upon checking, the best estimation was ac...
Climage Change Office, Forestry and Forest Products Research Institute, Tsukuba, Japan, e-mail: h... more Climage Change Office, Forestry and Forest Products Research Institute, Tsukuba, Japan, e-mail: hirat09@affrc.go.jp School of International Tropical Forestry, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Nalaysia, e-mail: pmh@ums.edu.my, w.wilson@ums.edu.my Kyusyu Research Center, Forestry and Forest Products Research Institute, Kumamoto, Japan, e-mail: rslsaito@ffpri.affrc.go.jp Department of Forest Management, Forestry and Forest Products Research Institute, Tsukuba, Japan, e-mail: matsuu50@affrc.go.jp Universiti Teknologi MARA Sabah Branch, Kota Kinabalu, Sabah, Malaysia Graduate School of Agriculture, University of Kyoto, Kyoto, Japan
Assessing forest degradation is increasingly important to support a transparent and reliable repo... more Assessing forest degradation is increasingly important to support a transparent and reliable reporting system for Reduced Emission from Deforestation and Forest Degradation-plus (REDD+) in combating the climate change. Exploration of forest degradation is still insufficient in the tropical region. In this paper, the logged-over Tangkulap and Deramakot Forest Reserves in Sabah, Malaysia-Borneo were thoroughly studied. Using the IKONOS-2 image, forest was segmented based on multi-resolution algorithm in eCognition and classified into forest degradation types. AGB was used to guide the classification into three levels of forest degradation i.e. very-degraded (VDF), degraded (DF) and intact forests (IF). The accuracy was assessed at 0.65 of Kappa coefficient (79% of overall accuracy). Under each forest degradation class, the distribution patterns of tree densities and AGBs at the respective strata of understory, canopy and emergent were examined. Statistical mean and standard deviation were used to describe the variation patterns. Tree density of understory strata is saturating at DF and IFs. Tree density of emergent strata at IF is about twice higher than at DF. AGB at IF is 3.6 and 1.8 times higher than at VDF and DF, respectively. Standard deviation of AGB tends to increase nonlinearly from VDF to IF. This study has examined the patterns of tree density and AGB in order to understand the recovery processes of the degraded forest.
Estimation of AGB and carbon of tropical forests has been a crucial factor to 'Reduction of c... more Estimation of AGB and carbon of tropical forests has been a crucial factor to 'Reduction of carbon emissions from deforestation and forest degradation-plus', a monetary mechanism for combating global warming. We examined the use of IKONOS 2 data for estimating aboveground biomass of a tropical forest in Long Mio, Sabah, Malaysia. The IKONOS 2 data was corrected for path radiance and topographic effect before segmentation using the watershed method in ArcGIS. Correlation analyses between the segment variables and forest variables revealed that crown area extracted from the IKONOS 2 data (CA s) had the strongest correlation with the field-measured diameter at breast height (DBH f). Linear regression analysis produced a model to estimate DBH f using CA s with R 2 of 0.71. Cross-validation using the remaining half of the data set also showed very consistent result. The CA s only represented upper canopy trees but estimated about 80% of the aboveground biomass.
Assessing forest degradation is increasingly important to support a transparent and reliable repo... more Assessing forest degradation is increasingly important to support a transparent and reliable reporting system for Reduced Emission from Deforestation and Forest Degradation-plus (REDD+) in combating the climate change. Exploration of forest degradation is still insufficient in the tropical region. In this paper, the logged-over Tangkulap and Deramakot Forest Reserves in Sabah, Malaysia-Borneo were thoroughly studied. Using the IKONOS-2 image, forest was segmented based on multi-resolution algorithm in eCognition and classified into forest degradation types. AGB was used to guide the classification into three levels of forest degradation i.e. very-degraded (VDF), degraded (DF) and intact forests (IF). The accuracy was assessed at 0.65 of Kappa coefficient (79% of overall accuracy). Under each forest degradation class, the distribution patterns of tree densities and AGBs at the respective strata of understory, canopy and emergent were examined. Statistical mean and standard deviation were used to describe the variation patterns. Tree density of understory strata is saturating at DF and IFs. Tree density of emergent strata at IF is about twice higher than at DF. AGB at IF is 3.6 and 1.8 times higher than at VDF and DF, respectively. Standard deviation of AGB tends to increase nonlinearly from VDF to IF. This study has examined the patterns of tree density and AGB in order to understand the recovery processes of the degraded forest.
IOP Conference Series: Earth and Environmental Science
Wood density (WD) is a critical determinant of estimating forest above-ground biomass (AGB) and c... more Wood density (WD) is a critical determinant of estimating forest above-ground biomass (AGB) and carbon stock. Thus, heterogeneity in WD on individuals within species trees needs to be scrutinized, and acquisition of fixed WD value is essential to estimate carbon stock with confidence. This study investigated intraspecific variation in WD of Syzgium sp., also known as “Jambu” or “Kelat”. It is the most occurring species in study areas, and is regarded as an economically important species. Firstly, one half-diameter drilling from bark-to-pith measurement was taken per tree using Rinntech Resistograph R650-ED at breast height. Meanwhile, 5.15 mm-diameter core was sampled at 1.30 m above-ground, with DeWalt DCF899HP2 20V impact wrench 950 Nm and Haglöf increment borer. WD was estimated for each core sample using a dimensional method. Drilling resistance (DR) profiles were processed using DECOM 2.38m1 Scientific (c), and several independent variables were extracted from the resistogram. ...
Bola sepak adalah sejenis sukan di luar rumah (outdoor) yang dimainkan di padang bola sepak atau ... more Bola sepak adalah sejenis sukan di luar rumah (outdoor) yang dimainkan di padang bola sepak atau kawasan lapang yang berumput turf biasanya jenis 'Cowgrass'. Objektif kajian adalah memperoleh data berkenaan padang bola sepak di sekitar Bandaraya Kota Kinabalu seperti jenis rumput, saiz, pemilik/pentdbir padang, jenis aktiviti yang dijalankan, kadar sewa, kecerunan dan kualiti penjagaan padang. Ini bertujuan untuk mengujudkan databes GIS padang-padang bola sepak di sekitar kawasan Zon Pantai Barat Sabah. Kaedah yang yang digunakan ialah pemeriksaan lapangan selepas pengenalpastian padang bola sepak melalui GIS. Sebanyak 45 padang telah diperiksa pada Ogos dan September 2009. Hasil kajian menunjukkan bahawa dari segi jenis rumput, semua padang yang ditinjau adalah berumput campuran (mixed grass). Dari segi saiz pula, majoriti padang memenuhi piawai saiz padang biasa. Kebanyakan padang yang ada dimiliki Lembaga Sukan Sabah atau organisasi berkaitan pendidikan (sekolah/kolej/uni...
Accurate estimation of aboveground biomass (AGB) has increasingly important especially dealing wi... more Accurate estimation of aboveground biomass (AGB) has increasingly important especially dealing with various levels of forest degradation. Exploration of forest texture and forest structure helps to define forest type which shaping a distribution of AGB. In this study, high resolution satellite imagery of IKONOS-2 was used to assess the AGB of tropical Borneo rainforest at specific degradation level. Study site consists of degraded lowland Dipterocarp forest located at Tangkulap forest reserves in Sabah. The satellite image was segmented using eCognition and classified into three specific levels of forest cluster that are early, mid and late-successional forest. Field plots were assigned to the cluster by AGB to reflect the degradation levels. Multiple stepwise regression analyses were performed between AGB and independent variables of spectral and textural properties. The resulted estimation models of AGB within each forest cluster level had R2 ranging from 0.65 to 0.70 (Pearson coe...
The information on biophysical parameters—such as height, crown area, and vegetation indices such... more The information on biophysical parameters—such as height, crown area, and vegetation indices such as the normalized difference vegetation index (NDVI) and normalized difference red edge index (NDRE)—are useful to monitor health conditions and the growth of oil palm trees in precision agriculture practices. The use of multispectral sensors mounted on unmanned aerial vehicles (UAV) provides high spatio-temporal resolution data to study plant health. However, the influence of UAV altitude when extracting biophysical parameters of oil palm from a multispectral sensor has not yet been well explored. Therefore, this study utilized the MicaSense RedEdge sensor mounted on a DJI Phantom–4 UAV platform for aerial photogrammetry. Three different close-range multispectral aerial images were acquired at a flight altitude of 20 m, 60 m, and 80 m above ground level (AGL) over the young oil palm plantation area in Malaysia. The images were processed using the structure from motion (SfM) technique i...
Oil palms (OP) in Sabah, Malaysia were studied to explore the relationship between canopy size an... more Oil palms (OP) in Sabah, Malaysia were studied to explore the relationship between canopy size and aboveground biomass (AGB). Four available allometric equations were used to calculate the dry AGB. Pearson's correlation analysis was performed between crown diameter (CD) and crown area (CA) towards the variables of AGB, height and dbh. In this analysis, the transformation to natural log of variable resulted in better coefficient compared to the original one. The mean of various variables such as height (stem, total and height difference), biomass (crown, trunk and total), dbh (inner and outer) and number of petiole leaf were calculated based on 32 independent sample plots (N = 222 palms) across various age stages from 2 to 24 years. These variables were regressed against CD and age. AGB versus CD was a nonlinear with R2 ranging from 0.950 to 0.975. Random modelling and cross validation between AGB and CD was applied at the ratio of 70:30. Upon checking, the best estimation was ac...
Climage Change Office, Forestry and Forest Products Research Institute, Tsukuba, Japan, e-mail: h... more Climage Change Office, Forestry and Forest Products Research Institute, Tsukuba, Japan, e-mail: hirat09@affrc.go.jp School of International Tropical Forestry, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Nalaysia, e-mail: pmh@ums.edu.my, w.wilson@ums.edu.my Kyusyu Research Center, Forestry and Forest Products Research Institute, Kumamoto, Japan, e-mail: rslsaito@ffpri.affrc.go.jp Department of Forest Management, Forestry and Forest Products Research Institute, Tsukuba, Japan, e-mail: matsuu50@affrc.go.jp Universiti Teknologi MARA Sabah Branch, Kota Kinabalu, Sabah, Malaysia Graduate School of Agriculture, University of Kyoto, Kyoto, Japan
Assessing forest degradation is increasingly important to support a transparent and reliable repo... more Assessing forest degradation is increasingly important to support a transparent and reliable reporting system for Reduced Emission from Deforestation and Forest Degradation-plus (REDD+) in combating the climate change. Exploration of forest degradation is still insufficient in the tropical region. In this paper, the logged-over Tangkulap and Deramakot Forest Reserves in Sabah, Malaysia-Borneo were thoroughly studied. Using the IKONOS-2 image, forest was segmented based on multi-resolution algorithm in eCognition and classified into forest degradation types. AGB was used to guide the classification into three levels of forest degradation i.e. very-degraded (VDF), degraded (DF) and intact forests (IF). The accuracy was assessed at 0.65 of Kappa coefficient (79% of overall accuracy). Under each forest degradation class, the distribution patterns of tree densities and AGBs at the respective strata of understory, canopy and emergent were examined. Statistical mean and standard deviation were used to describe the variation patterns. Tree density of understory strata is saturating at DF and IFs. Tree density of emergent strata at IF is about twice higher than at DF. AGB at IF is 3.6 and 1.8 times higher than at VDF and DF, respectively. Standard deviation of AGB tends to increase nonlinearly from VDF to IF. This study has examined the patterns of tree density and AGB in order to understand the recovery processes of the degraded forest.
Estimation of AGB and carbon of tropical forests has been a crucial factor to 'Reduction of c... more Estimation of AGB and carbon of tropical forests has been a crucial factor to 'Reduction of carbon emissions from deforestation and forest degradation-plus', a monetary mechanism for combating global warming. We examined the use of IKONOS 2 data for estimating aboveground biomass of a tropical forest in Long Mio, Sabah, Malaysia. The IKONOS 2 data was corrected for path radiance and topographic effect before segmentation using the watershed method in ArcGIS. Correlation analyses between the segment variables and forest variables revealed that crown area extracted from the IKONOS 2 data (CA s) had the strongest correlation with the field-measured diameter at breast height (DBH f). Linear regression analysis produced a model to estimate DBH f using CA s with R 2 of 0.71. Cross-validation using the remaining half of the data set also showed very consistent result. The CA s only represented upper canopy trees but estimated about 80% of the aboveground biomass.
Assessing forest degradation is increasingly important to support a transparent and reliable repo... more Assessing forest degradation is increasingly important to support a transparent and reliable reporting system for Reduced Emission from Deforestation and Forest Degradation-plus (REDD+) in combating the climate change. Exploration of forest degradation is still insufficient in the tropical region. In this paper, the logged-over Tangkulap and Deramakot Forest Reserves in Sabah, Malaysia-Borneo were thoroughly studied. Using the IKONOS-2 image, forest was segmented based on multi-resolution algorithm in eCognition and classified into forest degradation types. AGB was used to guide the classification into three levels of forest degradation i.e. very-degraded (VDF), degraded (DF) and intact forests (IF). The accuracy was assessed at 0.65 of Kappa coefficient (79% of overall accuracy). Under each forest degradation class, the distribution patterns of tree densities and AGBs at the respective strata of understory, canopy and emergent were examined. Statistical mean and standard deviation were used to describe the variation patterns. Tree density of understory strata is saturating at DF and IFs. Tree density of emergent strata at IF is about twice higher than at DF. AGB at IF is 3.6 and 1.8 times higher than at VDF and DF, respectively. Standard deviation of AGB tends to increase nonlinearly from VDF to IF. This study has examined the patterns of tree density and AGB in order to understand the recovery processes of the degraded forest.
Uploads
Papers by Alexius Korom