Estimating ovendry mass of trembling aspen and white birch using measurements from aerial photographs

1986 ◽  
Vol 16 (1) ◽  
pp. 163-165 ◽  
Author(s):  
I. S. Alemdag

A pilot study tested the estimation of stem, crown, and whole-tree biomass of single trees from measurements of total tree height and crown area taken from large-scale aerial photographs. The results indicated the feasibility of this method, provided that time of photography is optimal. More extensive testing is required to confirm these encouraging preliminary results.

1971 ◽  
Vol 1 (3) ◽  
pp. 193-194
Author(s):  
A. D. Kiil

Sixty-three lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) trees were measured on the ground, felled, and their crowns and stems were weighed. The combined independent variables of tree height and crown width gave the most precise estimate of fuel components. No significant differences were found between ground and air photo measurements of total tree height and crown width. Hence, the weight of all branchwood, entire crown, and entire tree can be estimated by the use of large-scale aerial photographs.


1981 ◽  
Vol 57 (4) ◽  
pp. 169-173 ◽  
Author(s):  
I. S. Alemdag ◽  
K. W. Horton

Ovendry mass of single trees of trembling aspen, largetooth aspen, and white birch in the Great Lakes — St. Lawrence and Boreal forest regions in Ontario was studied in relation to stem dimensions. Mass equations for tree components based on diameter at breast height outside bark and tree height were developed. Results were found more dependable for stem wood and the whole tree than for stem bark, live branches, and twigs plus leaves. Ovendry mass values were slightly higher than those reported for New York and northern Minnesota.


1989 ◽  
Vol 65 (2) ◽  
pp. 114-120 ◽  
Author(s):  
R. J. Hall ◽  
R. T. Morton ◽  
R. N. Nesby

The performance of 12 diameter prediction models suggested in the literature was studied in a controlled operational test. These models were linear and logarithmic transformations of tree height and/or crown area and were analyzed for white spruce, lodgepole pine, and trembling aspen and balsam poplar combined. Overall, all models were statistically significant, with differences due to variations in species and model form. Although simpler models may be adequate depending on operational objectives, two models emerged as deserving further investigation. It was unclear whether both tree height and crown area were needed as predictors of tree dbh for all species. Tree height was more highly correlated with dbh than crown area for all species except lodgepole pine. Measuring both tree height and crown area in comparison with tree height alone, however, increases measurement cost substantially from $10.29 to $17.50 per plot (1987 dollars).


1993 ◽  
Vol 23 (9) ◽  
pp. 1781-1785 ◽  
Author(s):  
P.A. Gagnon ◽  
J.P. Agnard ◽  
C. Nolette

This article describes and evaluates the application of a soft-copy photogrammetry system to large-scale forest inventories. A specially designed software, developed by the authors, has been investigated in terms of accuracy and general operability. Tests based on 1:1100 color aerial photographs, taken with a 10-m cross-boom system and digitized at resolutions of 300, 450, and 600 dots per inch, confirmed the expected tree-height accuracies of 48, 32, and 24 cm, respectively. This indicates that a photographic scale of 1:800 and a scanning resolution of 800 dots per inch could produce a tree-height precision of the order of 10 cm. The tests have shown that model orientation takes about 15 min; for a tree plot of 24 trees, measurements (height and crown diameter) and observations (species and condition) also take about 15 min. As the important problem of positioning a helicopter over a tree plot has now been solved using global positioning system receivers, the results and information presented in this paper indicate that the existing technology can provide a rigorous and operational photogrammetric system for large-scale forest inventories and regeneration monitoring.


2001 ◽  
Vol 18 (4) ◽  
pp. 110-118 ◽  
Author(s):  
R.J. Hall ◽  
Y. Wang ◽  
D.J. Morgan

Abstract Large-scale photo (LSP) mensurational procedures were developed, in part, to reduce field costs by replacing much of the ground sampling with less expensive photo measurements. The conventional LSP approach uses photo measurements of tree height and crown area, which serve as independent variables in models, to predict tree diameter or volume. This study compared 18 linear and nonlinear model forms for estimating tree diameters and assessed the use of a provincial taper model to estimate total tree volume from LSP data. On average, linear models produce R2, root mean square error, and mean bias values that were at least equivalent to, if not statistically better than, nonlinear models for the range of data evaluated. For lodgepole pine, white spruce and a composite of two deciduous species (trembling aspen and balsam poplar), total volume estimates were not statistically different from those estimated from field measurements. A comparative analysis of LSP and field sampling costs suggests the use of taper models in LSP mensuration could save considerable cost and effort in data collection and model development. This finding may result in an increased use of LSP in operational forest inventory work. North J. Appl. For. 18(4):110–118.


1993 ◽  
Vol 23 (10) ◽  
pp. 2159-2169 ◽  
Author(s):  
D.G. Pitt ◽  
G.R. Glover

Two 35-mm cameras were mounted on a boom and suspended from a tethered helium-filled blimp to obtain nominally vertical aerial photographs (1:828 and 1:414 contact scale) of vegetation-management research plots. Photo and ground estimates of woody plant crown area (m2/ha) and rootstock density (number/ha) were compared for several experimental vegetation-control treatments. Horizontal point-sampling estimates of total crown area made directly on 1:93 scale prints (enlarged from 1:414) correlated strongly with equivalent estimates made on the ground (n = 62, r2 = 0.97). An estimated 20 ground-truth plots were required to adequately quantify photo bias and correct subsequent prediction of actual total crown area on the plots studied. Much of the observed photo bias could be attributed to the undersampling of small rootstocks. Exclusion of individual rootstocks less than 0.10 m2 in crown area (or, equivalently, <56 cm in height) resulted in a 1:1 relation between the two sampling methods for estimates of both total crown area (r2 = 0.98) and rootstock density (r2 = 0.97). If data for rootstocks in smaller size classes are not needed, uncorrected photo estimates may be appropriate for evaluation of treatment response. Ground-sampling costs averaged $200 (Canadian) per plot, compared with photo costs of $104 per plot (without ground truth) or $150 per plot (with 20 ground-truth plots). Smaller scale photos (1:828 contact) cost 11% less than the larger scale tested, but resulted in significant undersampling of individual rootstocks less than 0.2 m2 in crown area (or, equivalently, <80 cm in height).


2011 ◽  
Vol 59 (7) ◽  
pp. 640 ◽  
Author(s):  
J. H. Jonson ◽  
D. Freudenberger

In the south-western region of Australia, allometric relationships between tree dimensional measurements and total tree biomass were developed for estimating carbon sequestered in native eucalypt woodlands. A total of 71 trees representing eight local native species from three genera were destructively sampled. Within this sample set, below ground measurements were included for 51 trees, enabling the development of allometric equations for total biomass applicable to small, medium, and large native trees. A diversity of tree dimensions were recorded and regressed against biomass, including stem diameter at 130 cm (DBH), stem diameter at ground level, stem diameter at 10 cm, stem diameter at 30 cm, total tree height, height of canopy break and mean canopy diameter. DBH was consistently highly correlated with above ground, below ground and total biomass. However, measurements of stem diameters at 0, 10 and 30 cm, and mean canopy diameter often displayed equivalent and at times greater correlation with tree biomass. Multi-species allometric equations were also developed, including ‘Mallee growth form’ and ‘all-eucalypt’ regressions. These equations were then applied to field inventory data collected from three locally dominant woodland types and eucalypt dominated environmental plantings to create robust relationships between biomass and stand basal area. This study contributes the predictive equations required to accurately quantify the carbon sequestered in native woodland ecosystems in the low rainfall region of south-western Australia.


2001 ◽  
Vol 31 (6) ◽  
pp. 960-970 ◽  
Author(s):  
W A Retzlaff ◽  
J A Handest ◽  
D M O'Malley ◽  
S E McKeand ◽  
M A Topa

To assess the contribution of belowground biomass allocation towards total carbon (C) allocation of two provenances of loblolly pine (Pinus taeda L.), we examined the total biomass allocation of a fast- and slow-growing family from each provenance. Since planting on a xeric, infertile site in Scotland County, N.C., U.S.A., trees in this study have been subjected to one of two nutrient treatments: optimal nutrition or control (no fertilization). Total biomass of 24 (1 tree/family plot × 2 families × 2 provenances × 2 treatments × 3 blocks) 5-year-old (juvenile) trees was harvested in January 1998. Fertilization increased total root, total shoot, and total tree biomass in all families as compared with harvested trees in control plots. Fertilization also increased biomass of coarse-root, woody-root, taproot, stem, branch, and foliar components of families as compared with trees in control plots. Although there were treatment and family differences in standing-crop biomass of the total root, total shoot, total tree, and various individual root and shoot components, the percent biomass (whole-tree) allocation to these tissues remained similar across treatments. Total nonstructural carbohydrate (TNC) analysis indicated some treatment, family, and provenance differences in TNC concentrations and partitioning to starch and soluble sugars. At the time of harvest, TNC concentrations of belowground tissues were much higher than those of aboveground tissues, and enhanced partitioning towards starch in root tissues indicates an important C storage role for belowground tissues at this time. Indeed, more than 90% of the trees starch content was present in root tissue in January. Although constrained by a sample size of three harvested trees per family, this study suggests that biomass allocation on a whole-tree level was similar between fast- and slow-growing families of different provenances of juvenile loblolly pine and was not affected by fertilizer treatment.


2006 ◽  
Vol 36 (10) ◽  
pp. 2585-2594 ◽  
Author(s):  
Avi Bar Massada ◽  
Yohay Carmel ◽  
Gilad Even Tzur ◽  
José M Grünzweig ◽  
Dan Yakir

Studies of forest biomass dynamics typically use long-term forest inventory data, available in only a few places around the world. We present a method that uses photogrammetric measurements from aerial photographs as an alternative to time-series field measurements. We used photogrammetric methods to measure tree height and crown diameter, using four aerial photographs of Yatir Forest, a semi-arid forest in southern Israel, taken between 1978 and 2003. Height and crown-diameter measurements were transformed to biomass using an allometric equation generated from 28 harvested Aleppo pine (Pinus halepensis Mill.) trees. Mean tree biomass increased from 6.37 kg in 1978 to 97.01 kg in 2003. Mean plot biomass in 2003 was 2.48 kg/m2 and aboveground primary productivity over the study period ranged between 0.14 and 0.21 kg/m2 per year. There was systematic overestimation of tree height and systematic underestimation of crown diameter, which was corrected for at all time points between 1978 and 2003. The estimated biomass was significantly related to field-measured biomass, with an R2 value of 0.78. This method may serve as an alternative to field sampling for studies of forest biomass dynamics, assuming that there is sufficient spatial and temporal coverage of the investigated area using high-quality aerial photography, and that the tree tops are distinguishable in the photographs.


1989 ◽  
Vol 19 (4) ◽  
pp. 527-530 ◽  
Author(s):  
Allen F. Johnson ◽  
Paul M. Woodard ◽  
Stephen J. Titus

Equations were developed to predict the ovendry weight of the total crown, live crown, foliage, and the roundwood diameter classes of <0.5, 0.5–1.0, 1.0–3.0, 3.0–5.0, 5.0–7.0, 7.0–10.0 cm for lodgepole pine (n = 27) and white spruce (n = 23) occurring in Alberta, Canada. The nonlinear allometric model using total tree height and a measure of crown width provided high R2 and low SEE values. This precision could not be duplicated when total tree height was used as the only independent variable. Our results suggest the possibility of using tree height and crown width measured from aerial photographs to estimate standing live and dead fuel loadings in undisturbed forest stands.


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