Species-specific forest variable estimation using non-parametric modeling of multi-spectral photogrammetric point cloud data

The recent development in software for automatic photogrammetric processing of multispectral aerial imagery, and the growing nation-wide availability of Digital Elevation Model (DEM) data, are about to revolutionize data capture for forest management planning in Scandinavia. Using only already available aerial imagery and ALS-assessed DEM data, raster estimates of the forest variables mean tree height, basal area, total stem volume, and species-specific stem volumes were produced and evaluated. The study was conducted at a coniferous hemi-boreal test site in southern Sweden (lat. 58° N, long. 13° E). Digital aerial images from the Zeiss/Intergraph Digital Mapping Camera system were used to produce 3D point-cloud data with spectral information. Metrics were calculated for 696 field plots (10 m radius) from point-cloud data and used in k-MSN to estimate forest variables. For these stands, the tree height ranged from 1.4 to 33.0 m (18.1 m mean), stem volume from 0 to 829 m3 ha-1 (249 m3 ha-1 mean) and basal area from 0 to 62.2 m2 ha-1 (26.1 m2 ha-1 mean), with mean stand size of 2.8 ha. Estimates made using digital aerial images corresponding to the standard acquisition of the Swedish National Land Survey (Lantmäteriet) showed RMSEs (in percent of the surveyed stand mean) of 7.5% for tree height, 11.4% for basal area, 13.2% for total stem volume, 90.6% for pine stem volume, 26.4 for spruce stem volume, and 72.6% for deciduous stem volume. The results imply that photogrammetric matching of digital aerial images has significant potential for operational use in forestry

Retrieval of forest stem volume using VHF SAR

The ability to retrieve forest stem volume using CARABAS (coherent all radio band sensing) SAR images (28–60 MHz) has been investigated. The test site is a deciduous mixed forest on the island of Öland in southern Sweden. The images have been radiometrically calibrated using an array of horizontal dipoles. The images exhibit a clear discrimination between the forest and open fields. The results show that the dynamic range of the backscattering coefficient among the forest stands is higher than what has been found with conventional SAR using microwave frequencies. The backscatter increases with increasing radar frequency. This work shows an advantage compared to higher frequencies for stem volume estimation in dense forests

Effects of potassium/sodium fertilization and water availability on wood properties of Eucalyptus grandis trees

In Brazil. most Eucalyptus plantations are located in regions experiencing periods of water shortage where fertilizers such as potassium (K) are intensively used to achieve high productivity. Recently. sodium(, a) has also been considered a potential nutrient. As well as tree growth, wood properties are also an important factor to consider in order to measure the impacts of silvicultural practices and water deficit on forest productivity, since they are determinants for quality and yield of pulp and paper. In a split-plot experimental design with 4-year-old Eucalyptus grandis trees, located in Sao Paulo State, Brazil, we evaluate the effects or K and Na supply compared with a control treatment under two water supply regimes (37% throughfall reduction versus no throughfall reduction) on stem volume, heartwood proportion. basic density, fiber, and vessel properties. K and Na fertilization increased stem volume 2. 7 and 1.9 fold. respectively, with a nonsignificant effect of 37% throughfall reduction. Na fertilization was more detrimental to wood properties that K fertilization, affecting heartwood proportion, basic density, and fiber wall thickness. K fertilization affected only heartwood proportion and basic density. The 37% throughfall reduction only affected wood basic density. increasing it. Effects of fertilization treatments did not change regardless changes in water supply.Despite the detrimental effects of fertilizers (stronger with Na supply) in wood properties there is a large beneficial effect on stem volume (stronger with K supply), even under a water availability reduction, that would be compensates the loss of wood quality for pulp and paper production

Evaluasi Uji Keturunan Pulai Darat (Alstonia Angustiloba Miq.) Umur Tiga Tahun Di Wonogiri, Jawa Tengah

Evaluation were observed at three years old of Alstonia angustiloba Miq. progeny trial at Wonogiri, Central Java. The experimental design of the trial was laid out in Randomized Complete Block Design consisting of 43 families, 6 replications, 4 tree-plot and spacing of 3 x 3 meters. This study was aimed to observe the adaptability, the growth variation (height, stem diameter and stem volume) and the estimates of heritability, genetic correlation and phenotipic correlation among the three growth traits.The results of study showed that the adaptability was not significantly different between populations and families with survival rate at 80.04 ± 25.34%. Analysis of variance showed that population and families were significantly different for height, stem diameter and stem volume. Pendopo, Carita, and Lubuk Linggau were the best populations in height growth (3.12 – 3.4 m) and stem diameter (4.07 – 4.65 cm). Pendopo population was the best population in stem volume (0.0047 m3). The estimates of individual heritabilities were around 0.32; 0.20, and 0.13 for height, stem diameter and stem volume, respectively. While the family heritabilities were around 0.59; 0.49, and 0.42 for height, stem diameter and stem volume, respectively. Genetic and phenotipic correlation among the three traits were positive and strong at 0.96 and 0.86 for height and diameter, 0.92 and 0.80 for height and stem volume then 0.89 and 0.95 for diameter and stem volume

Functional imaging of plants: A nuclear magnetic resonance study of a cucumber plant

Functional magnetic resonance imaging was used to study transients of biophysical parameters in a cucumber plant in response to environmental changes. Detailed flow imaging experiments showed the location of xylem and phloem in the stem and the response of the following flow characteristics to the imposed environmental changes: the total amount of water, the amount of stationary and flowing water, the linear velocity of the flowing water, and the volume flow. The total measured volume flow through the plant stem was in good agreement with the independently measured water uptake by the roots. A separate analysis of the flow characteristics for two vascular bundles revealed that changes in volume flow of the xylem sap were accounted for by a change in linear-flow velocities in the xylem vessels. Multiple-spin echo experiments revealed two water fractions for different tissues in the plant stem; the spin-spin relaxation time of the larger fraction of parenchyma tissue in the center of the stem and the vascular tissue was down by 17% in the period after cooling the roots of the plant. This could point to an increased water permeability of the tonoplast membrane of the observed cells in this period of quick recovery from severe water los

Asymptotic and numerical analysis of a porous medium model for transpiration-driven sap flow in trees

We develop a 3D porous medium model for sap flow within a tree stem, which consists of a nonlinear parabolic partial differential equation with a suitable transpiration source term. Using an asymptotic analysis, we derive approximate series solutions for the liquid saturation and sap velocity for a general class of coefficient functions. Several important non-dimensional parameters are identified that can be used to characterize various flow regimes. We investigate the relative importance of stem aspect ratio versus anisotropy in the sapwood hydraulic conductivity, and how these two effects impact the radial and vertical components of sap velocity. The analytical results are validated by means of a second-order finite volume discretization of the governing equations, and comparisons are drawn to experimental results on Norway spruce trees.Comment: 24 pages, 9 figure

Pengaruh Seleksi Terhadap Perolehan Genetik Pada Uji Keturunan Generasi Pertama (F-1) Jabon Merah (Anthocephalus Macrophyllus (Roxb.) Havil) Di Wonogiri

Selection is a fundamental process in the establishment of a progeny trial that will be converted into a seedling seed orchard. In present study, selection practiced in first-generation progeny trial of jabon merah (Anthocephalus macrophyllus Roxb. Havil.) was observed. The study was aimed to find out a criteria selection accompanied with the effective coefficient weight for predicting genetic gain in the first-generation progeny trial of jabon merah. The trial was established in Wonogiri which was laid out in randomized complete block design (RCBD) using 55 families, 4 replications, 4 tree-plot with a spacing of 4 x 2 meter. Measurement was conducted at 40 months after planting covering tree height, diameter at breast height, stem straightness, stem volume. First within-plot selection by culling 2 poorer trees within each plot was practiced at 46 months age. Selection differential from within-plot selection was used to derive coefficient weight which was then applied to predict genetic gain. Results of study showed that selection differential from first within-plot selection were positive for all measured traits. Stem volume was observed as highest priority trait with coefficient weight for each trait were -0.0863 (height), 0.1426 (diameter), 0.2195 (stem straightness), 2.3025 (stem volume). Prediction of genetic gain from within-plot selection were 3,50% (height), 3.58% (diamater), 3.41% (stem straightness), 7.40% (stem volume). While the gain from family selection were 2.80%, 3.75%, 3.54%, 7.10% for height, diamater, stem straightness, stem volume, respectively

Developing Allometric Equations for Teak Plantations Located in the Coastal Region of Ecuador from Terrestrial Laser Scanning Data

Traditional studies aimed at developing allometric models to estimate dry above-ground biomass (AGB) and other tree-level variables, such as tree stem commercial volume (TSCV) or tree stem volume (TSV), usually involves cutting down the trees. Although this method has low uncertainty, it is quite costly and inefficient since it requires a very time-consuming field work. In order to assist in data collection and processing, remote sensing is allowing the application of non-destructive sampling methods such as that based on terrestrial laser scanning (TLS). In this work, TLS-derived point clouds were used to digitally reconstruct the tree stem of a set of teak trees (Tectona grandis Linn. F.) from 58 circular reference plots of 18 m radius belonging to three different plantations located in the Coastal Region of Ecuador. After manually selecting the appropriate trees from the entire sample, semi-automatic data processing was performed to provide measurements of TSCV and TSV, together with estimates of AGB values at tree level. These observed values were used to develop allometric models, based on diameter at breast height (DBH), total tree height (h), or the metric DBH2 × h, by applying a robust regression method to remove likely outliers. Results showed that the developed allometric models performed reasonably well, especially those based on the metric DBH2 × h, providing low bias estimates and relative RMSE values of 21.60% and 16.41% for TSCV and TSV, respectively. Allometric models only based on tree height were derived from replacing DBH by h in the expression DBH2 x h, according to adjusted expressions depending on DBH classes (ranges of DBH). This finding can facilitate the obtaining of variables such as AGB (carbon stock) and commercial volume of wood over teak plantations in the Coastal Region of Ecuador from only knowing the tree height, constituting a promising method to address large-scale teak plantations monitoring from the canopy height models derived from digital aerial stereophotogrammetry

Change in hematologic indices over time in pediatric inflammatory bowel disease treated with azathioprine

Azathioprine leads to changes in mean corpuscular volume (MCV) and white blood cell (WBC) indices reflecting efficacy or toxicity. Understanding the interactions between bone marrow stem cells and azathioprine could highlight abnormal response patterns as forerunners for hematologic malig-nancies. This study gives a statistical description of factors influencing the relationship between MCV and WBC in children with inflammatory bowel disease treated with azathioprine. We found that leukopenia preceded macro¬cytosis. Macrocytosis is therefore not a good predictor of leukopenia. Further studies will be necessary to determine the subgroup of patients at increased risk of malignancies based on bone marrow response