Drone-Image-Based Method of Estimating Forest-Fire Fuel Loads

A method of estimating forest-fire fuel loads was developed using drones to collect information about the height and diameter-at-breast-height (DBH) of individual trees. It was conducted for forest fire prevention monitoring (Control, 20% thinned, and 40% thinned area) located in Goseong-gun, Gangwon-do. Object-based images and 3D-model red/green/blue band characteristics were superimposed to select and extract individual trees. A digital crown height model was developed based on the difference between the heights of digital surface and terrain models. In addition, the DBH was estimated based on the crown area. The 40%-thinned area exhibited the highest accuracy (95%) for extracting individual trees, and the difference between the field-survey and drone-image heights was in the range of 0.64-2.02 m. The goodness-of-fit of the DBH-crown area model was 0.61. The difference between the imageand field-survey-based forest-fire fuel loads ranged from -1.20 to 0.40 ton/ha.

Relationship of Oil Palm Crown Features Extracted Using Terrestrial Laser Scanning for Basal Stem Rot Disease Classification

The oil palm is the largest plantation industry in Malaysia. It has been one of the major contributors to the country’s economy and the main pillar of the commodity sectors. For over 40 years, the oil palm industry has faced a lethal and incurable disease, Basal Stem Rot (BSR), which is caused by a type of bracket fungus, Ganoderma boninense. The oil palm physical symptoms infected by BSR disease are appearance of many unopened spears, flattening of crown and smaller crown size. Terrestrial Laser Scanning (TLS, also known as ground-based LiDAR) can be used to provide accurate and precise information on tree morphology with high resolution. This study proposed an image processing technique using the ground input data taken from a TLS. Five parameters were used in the study are number of laser hits in strata 200 cm and 850 cm from the top, namely as C200 and C850, respectively, crown area, frond number and frond angle. The objectives of this study are to analyse the relationship between the parameters and to study the relationship of the parameters with the levels of BSR disease. Results have shown that all parameters were significant in all levels of healthiness with p-values less than 5%. Frond number and frond angle showed the highest correlation value, which is equal to -0.94. Frond angle is increasing, while frond number and crown area are decreasing concurrently with the severity levels of BSR infection.

Space Planting, Competition, and Productivity of a Seven-Year-Old Clonal Teak Plantation in the East Java Monsoon Forest Area

Tree breeding of teak results in selected clones with high growth. Intensive silviculture is required to support a large-scale clonal teak plantation. Appropriate spacing is one of the methods to increase forest plantation productivity. Research of teak clone spacing was conducted on a seven-year-old clonal teak plantation with randomized completely block design. The treatments tested in this study were four plant spacing distances, namely, 3 m × 3 m, 6 m × 2 m, 8 m × 2 m, and 10 m × 2 m. Results show that spacing had significantly different effects on diameter, height, bole height, branch angle, crown area, crown projections, volume, and competition index. However, the height growth did not exhibit any significant differences. The 10 m × 2 m spacing produced the best diameter growth, crown area, and competition index, but has a low volume per hectare and the lowest height of free branch and branch angle. Meanwhile, the 3 m × 3 m spacing will increase bole height and stand volume per hectare. This result suggests that spacing could improve the growth of teak clone but must be followed by intensification of proper maintenance to reduce branch angle and increase bole height.

POTENSI TEGAKAN DAN PRODUKSI BUAH PENAGE (Calophyllum inophyllum) DI PESISIR PANTAI PULAU DATOK KECAMATAN SUKADANA

Abstrak Tanaman penage (Calophyllum inophyllum) tumbuh secara alami di pantai Pulau Datok Kecamatan Sukadana Kabupaten Kayong Utara diameter yang sudah besar dengan diameter lebih dari 30 cm). Tujuan penelitian untuk mengkaji potensi tegakan dan produksi buah penage (C. inophyllum) di pesisir pantai Pulau Datok Kabupaten Kayong Utara dan mengetahui korelasi antara diameter dan luas tajuk terhadap produksi buah. Penelitian ini dilakukan di pantai Pulau Datok Kecamatan Sukadana Kabupaten Kayong Utara Provinsi Kalimantan Barat, menggunakan metode survei dengan teknik pengambilan data dilakukan secara sensus. Data yang dikumpulkan berupa tinggi total (m), tinggi bebas cabang (m), diameter setinggi dada dari permukaan tanah, tinggi tajuk (m), diameter tajuk (m), luas tajuk (m2). Hasil penelitian menunjukan pohon penage yang terdapat di pantai Pulau Datok Desa Sutera Kecamatan Sukadana, ditemukan sebanyak 70 dengan ukuran tinggi 8,1 -14 m, dan volume sebesar 47,72 m3.Produksi buah pohon penage yang terdapat di pantai Pulau Datok sebanyak ± 31,14 kg/pohon. Luas tajuk pohon penage di pesisir pantai Pulau Datok sebesar 647,26 m2 atau rata-rata luas 9,25 m2/pohon. Ukuran luas tajuk dan diameter pohon berkorelasi dengan produksi buah dimana semakin besar ukuran tajuk dan diameter pohon, maka produksi buah semakin besar. Kata kunci : penage, jumlah pohon, luas tajuk dan produksi buah. AbstractPenage (Calophyllum inophyllum) plants grow naturally on the coast of Pulau Datok, Sukadana District, Kayong Utara Regency, which has a large diameter of more than 30 cm. The research objective was to assess the stand potential and production of penage fruit (C. inophyllum) on the coast of Pulau Datok, Kayong Utara Regency and to determine the correlation between diameter and crown area on fruit production. This research was conducted on the coast of Pulau Datok, Sukadana District, Kayong Utara Regency, using a survey method with the data collection technique carried out by census. Data collected in the form of total height (m), branch-free height (m), diameter at breast height from ground level, crown height (m), crown diameter (m), crown area (m2). The results showed that there were 70 penage trees found on the coast of Pulau Datok, Sutera Village, Sukadana District, with a height of 8,1-14 m, and volume is 47,72 m³. The fruit production of penage trees on Datok Island is ± 31,14 kg / tree. Penage tree crown area on the coast of Datok Island is 647,26 m2 or an average area of 9,25 m2/tree. The size of crown area and tree diameter correlated with fruit production where greater the crown size and tree diameter, Fruit production is getting biger. Keywords: penage, number of trees, crown area and fruit production

Refining tree size and dose-response functions for control of invasive Pinus contorta

Exotic conifers are rapidly spreading in many regions of New Zealand, as well as in many other countries, with detrimental impacts on both natural ecosystems and some productive sector environments. Herbicides, in particular the active ingredient (a.i.) triclopyr, are an important tool to manage invasive conifers, yet there is a paucity of information that quantifies the amount of herbicide required to kill trees of different sizes when applied as a basal bark treatment. Two sequential experiments were conducted to define the amount of triclopyr required to kill individual invasive Pinus contorta trees of different sizes when applied in a methylated seed oil to bark (either the whole stem or base of the tree) and to determine which tree size variates (height (HT), diameter at breast height (DBH), crown diameter (CD)), or derived attributes (crown area, crown volume index) best characterised this dose-response relationship. The outcomes of the dose-response research were compared to field operations where triclopyr was applied to the bark of trees from an aerial platform. Applying the herbicide to the whole stem, as opposed to the base of the tree only, significantly increased treatment efficacy. The tree size variates DBH, CD, crown area and crown volume index all provided good fits to the tree mortality data, with >91% prediction accuracy. Of these variates, crown diameter provided the most practical measure of tree size for ease of in-field calculation of dose by an operator. Herbicide rates used in field operations were 7 to 8 times higher than lethal doses calculated from experimental data. Our results highlight the potential for substantial reductions in herbicide rates for exotic conifer control, especially if dose-response data are combined with remotely sensed quantitative measurements of canopy area or volume using new precision technologies such as unmanned aerial vehicles.

Effects of Differences in Structure from Motion Software on Image Processing of Unmanned Aerial Vehicle Photography and Estimation of Crown Area and Tree Height in Forests

This study examines the effects of differences in structure from motion (SfM) software on image processing of aerial images by unmanned aerial vehicles (UAV) and the resulting estimations of tree height and tree crown area. There were 20 flight conditions for the UAV aerial images, which were a combination of five conditions for flight altitude, two conditions for overlap, and two conditions for side overlap. Images were then processed using three SfM programs (Terra Mapper, PhotoScan, and Pix4Dmapper). The tree height and tree crown area were determined, and the SfM programs were compared based on the estimations. The number of densified point clouds for PhotoScan (160 × 105 to 50 × 105) was large compared to the two other two SfM programs. The estimated values of crown area and tree height by each SfM were compared via Bonferroni multiple comparisons (statistical significance level set at p < 0.05). The estimated values of canopy area showed statistically significant differences (p < 0.05) in 14 flight conditions for Terra Mapper and PhotoScan, 16 flight conditions for Terra Mapper and Pix4Dmapper, and 11 flight conditions for PhotoScan and Pix4Dmappers. In addition, the estimated values of tree height showed statistically significant differences (p < 0.05) in 15 flight conditions for Terra Mapper and PhotoScan, 19 flight conditions for Terra Mapper and Pix4Dmapper, and 20 flight conditions for PhotoScan and Pix4Dmapper. The statistically significant difference (p < 0.05) between the estimated value and measured value of each SfM was confirmed under 18 conditions for Terra Mapper, 20 conditions for PhotoScan, and 13 conditions for Pix4D. Moreover, the RMSE and rRMSE values of the estimated tree height were 5–6 m and 20–28%, respectively. Although the estimation accuracy of any SfM was low, the estimated tree height by Pix4D in many flight conditions had smaller RMSE values than the other software. As statistically significant differences were found between the SfMs in many flight conditions, we conclude that there were differences in the estimates of crown area and tree height depending on the SfM used. In addition, Pix4Dmapper is suitable for estimating forest information, such as tree height, and PhotoScan is suitable for detailed monitoring of disaster areas.

Classification of Basal Stem Rot Disease in Oil Palm Plantations Using Terrestrial Laser Scanning Data and Machine Learning

The oil palm industry is vital for the Malaysian economy. However, it is threatened by the Ganoderma boninense fungus, which causes basal stem rot (BSR) disease. Foliar symptoms of the disease include the appearance of several unopened spears, flat crowns, and small crown size. The effect of this disease depends on the severity of the infection. Currently, the disease can be detected manually by analyzing the oil palm tree’s physical structure. Terrestrial laser scanning (TLS) is an active ranging method that uses laser light, which can directly represent the tree’s external structure. This study aimed to classify the healthiness levels of the BSR disease using a machine learning (ML) approach. A total of 80 oil palm trees with four different healthiness levels were pre-determined by the experts during data collection with 40 each for training and testing. The four healthiness levels are T0 (healthy), T1 (mildly infected), T2 (moderately infected), and T3 (severely infected), with 10 trees in each level. A terrestrial scanner was mounted at a height of 1 m, and each oil palm was scanned at four positions at a distance of 1.5 m around the tree. Five tree features were extracted from the TLS data: C200 (crown slice at 200 cm from the top), C850 (crown slice at 850 cm from the top), crown area (number of pixels inside the crown), frond angle, and frond number. C200 and C850 were obtained using the crown stratification method, while the other three features were obtained from the top-down image. The obtained features were then analyzed by principal component analysis (PCA) to reduce the dimensionality of the dataset and increase its interpretability while at the same time minimizing information loss. The results showed that the kernel naïve Bayes (KNB) model developed using the input parameters of the principal components (PCs) 1 and 2 had the best performance among 90 other models with a multiple level accuracy of 85% and a Kappa coefficient of 0.80. Furthermore, the combination of the two highest PC variance with the most weighted to frond number, frond angle, crown area, and C200 significantly contributed to the classification success. The model also could classify healthy and mildly infected trees with 100% accuracy. Therefore, it can be concluded that the ML approach using TLS data can be used to predict early BSR infection with high accuracy.

Biomass equations for 24 understory species in a temperate forest in Northeastern China

Background: Understory plants are important components of forest ecosystem productivity and diversity. Compared to biomass models of overstory canopy trees, few are available for understory saplings and shrubs and therefore their contributions to forest carbon pools are often ignored.Methods: We harvested 24 understory species including 4 saplings, 9 tree-like shrubs and 11 typical shrubs in coniferous and broadleaved mixed forest in north-eastern China. We developed the species-specific or multispecies best fit allometric equations of total, above- and below-ground biomass using morphological measurements of basal diameter, height and crown area as independent variables.Results: Single basal diameter, height or crown area had good explanatory power for both species-specific and multispecies equations (p<0.001). The best-fit models included only basal diameter in sapling and tree-like shrubs, and combinations of crown area, height, and basal diameter in typical shrubs. The logarithmic model was most desired among the 4 model forms of linear, quadratic, multiple linear and logarithmic, for species-specific and multispecies equations.Conclusion: The models we developed should help the estimation of forest ecosystem carbon stocks, especially for the belowground component, and provide tools for quantification of individual species biomass of understory plants.

How to qualify the vegetation in public squares to help the management of urban ecosystem services?

We adopted procedures to analyze the floristic composition of public squares in Irati, Paraná, in order to diversify the provision of methods to generate information for public management. We found that describing the ratio of taxa may not be efficient for presenting problems regarding species diversification. Species diversity analysis should be divided into tree quantity and canopy area to determine the benefits that could be lost from removing exotic species. Using the procedure that considers crown area is more effective for estimating the cover value of the species. The diameter distribution, total height, and crown area curves can help management decisions about new plantings and prioritize risk assessment. The results of spatial indices can complement the information about data distribution.