scholarly journals Estimation of Tree Stem Attributes Using Terrestrial Photogrammetry with a Camera Rig

Forests ◽  
2016 ◽  
Vol 7 (12) ◽  
pp. 61 ◽  
Author(s):  
Mona Forsman ◽  
Niclas Börlin ◽  
Johan Holmgren
Keyword(s):  
Terrestrial Photogrammetry ◽  
Tree Stem

scholarly journals Accuracy of common stem volume formulae using terrestrial photogrammetric point clouds: a case study with savanna trees in Benin

2021 ◽  
Author(s):  
Hospice A. Akpo ◽  
Gilbert Atindogbé ◽  
Maxwell C. Obiakara ◽  
Arios B. Adjinanoukon ◽  
Madaï Gbedolo ◽  
...  
Keyword(s):  
Point Clouds ◽  
Stem Volume ◽  
Individual Tree ◽  
Volume Calculation ◽  
Tropical Regions ◽  
Solid Of Revolution ◽  
Taper Function ◽  
Geometric Solids ◽  
Traditional Approaches ◽  
Tree Stem

AbstractRecent applications of digital photogrammetry in forestry have highlighted its utility as a viable mensuration technique. However, in tropical regions little research has been done on the accuracy of this approach for stem volume calculation. In this study, the performance of Structure from Motion photogrammetry for estimating individual tree stem volume in relation to traditional approaches was evaluated. We selected 30 trees from five savanna species growing at the periphery of the W National Park in northern Benin and measured their circumferences at different heights using traditional tape and clinometer. Stem volumes of sample trees were estimated from the measured circumferences using nine volumetric formulae for solids of revolution, including cylinder, cone, paraboloid, neiloid and their respective fustrums. Each tree was photographed and stem volume determined using a taper function derived from tri-dimensional stem models. This reference volume was compared with the results of formulaic estimations. Tree stem profiles were further decomposed into different portions, approximately corresponding to the stump, butt logs and logs, and the suitability of each solid of revolution was assessed for simulating the resulting shapes. Stem volumes calculated using the fustrums of paraboloid and neiloid formulae were the closest to reference volumes with a bias and root mean square error of 8.0% and 24.4%, respectively. Stems closely resembled fustrums of a paraboloid and a neiloid. Individual stem portions assumed different solids as follows: fustrums of paraboloid and neiloid were more prevalent from the stump to breast height, while a paraboloid closely matched stem shapes beyond this point. Therefore, a more accurate stem volumetric estimate was attained when stems were considered as a composite of at least three geometric solids.

Evaluation of mutagenic activity in an extract of pepper tree stem bark (Schinus terebinthifolius Raddi)

2003 ◽  
Vol 42 (3) ◽  
pp. 185-191 ◽  
Author(s):  
Maria Cleide Ribeiro Dantas de Carvalho ◽  
Francisco Napole�o T�lio Varela Barca ◽  
Lucymara Fassarella Agnez-Lima ◽  
S�lvia Regina Batistuzzo de Medeiros
Keyword(s):  
Mutagenic Activity ◽  
Stem Bark ◽  
Schinus Terebinthifolius ◽  
Pepper Tree ◽  
Tree Stem

MEASURING AND MAPPING OF GLACIER VARIATIONS

1966 ◽  
Vol 3 (6) ◽  
pp. 775-781 ◽  
Author(s):  
W. Kick
Keyword(s):  
Velocity Profiles ◽  
Height Variation ◽  
Field Methods ◽  
Surface Level ◽  
Mountain Glaciers ◽  
Important Index ◽  
Nanga Parbat ◽  
The Himalaya ◽  
Terrestrial Photogrammetry ◽  
Glacier Mapping

One of the main purposes of glacier mapping is to determine the temporary state of glaciers and to investigate glacier variations by successive mappings. The author illustrates this work with particular reference to terrestrial photogrammetric surveys of mountain glaciers in the Nanga Parbat region of the Himalaya and of the Tunsbergdalsbre in southwest Norway, in both cases 24 years after R. Finsterwalder's original surveys. The author shows that the most important index of variation is the height variation of the surface level in the region of the firn line. The accuracy necessary for measuring the height variation and the scale of map plotting are discussed. Field methods are also discussed, and information is given on the measurement of volumetric changes from contourline shifts and on the measurement of velocity profiles by terrestrial photogrammetry.

FURTHER DEVELOPMENTS IN THE PHOTO-RADIATION METHOD OF TERRESTRIAL PHOTOGRAMMETRY

1993 ◽  
Vol 14 (82) ◽  
pp. 627-634
Author(s):  
B. J. Collins ◽  
B. Madge ◽  
C. M. Beckett
Keyword(s):  
Radiation Method ◽  
Terrestrial Photogrammetry

scholarly journals Low-cost chamber design for simultaneous CO2 and O2 flux measurements between tree stems and the atmosphere

2021 ◽  
Author(s):  
Juliane Helm ◽  
Henrik Hartmann ◽  
Martin Göbel ◽  
Boaz Hilman ◽  
David Herrera ◽  
...  
Keyword(s):  
Low Cost ◽  
Co2 Flux ◽  
Co2 Efflux ◽  
Stem Respiration ◽  
Ecosystem Carbon ◽  
O2 Concentration ◽  
Flux Measurements ◽  
Stem Co2 Efflux ◽  
Tree Stem

Abstract Tree stem CO2 efflux is an important component of ecosystem carbon fluxes and has been the focus of many studies. While CO2 efflux can easily be measured, a growing number of studies have shown that it is not identical with actual in situ respiration. Complementing measurements of CO2 flux with simultaneous measurements of O2 flux provides an additional proxy for respiration, and the combination of both fluxes can potentially help getting closer to actual measures of respiratory fluxes. To date, however, the technical challenge to measure relatively small changes in O2 concentration against its high atmospheric background has prevented routine O2 measurements in field applications. Here we present a new and low-cost field-tested device for autonomous real-time and quasi-continuous long-term measurements of stem respiration by combining CO2 (NDIR based) and O2 (quenching based) sensors in a tree stem chamber. Our device operates as a cyclic closed system and measures changes in both CO2 and O2 concentration within the chamber over time. The device is battery-powered with a > 1 week power independence and data acquisition is conveniently achieved by an internal logger. Results from both field and laboratory tests document that our sensors provide reproducible measurements of CO2 and O2 exchange fluxes under varying environmental conditions.

Hepatic Progenitor Cells and Biliary Tree Stem Cells

2020 ◽  
pp. 29-35 ◽  
Author(s):  
Guido Carpino ◽  
Sergio Morini ◽  
Simone Carotti ◽  
Eugenio Gaudio
Keyword(s):  
Stem Cells ◽  
Progenitor Cells ◽  
Biliary Tree ◽  
Hepatic Progenitor Cells ◽  
Tree Stem

scholarly journals Error predictions for average end diameter sectional formula in tree stem volume measurement

2016 ◽  
Vol 37 (1) ◽  
pp. 211-215
Author(s):  
Gildardo Cruz de León ◽  
Isaac Alfaro-Trujillo ◽  
Margarita Bañuelos-Jiménez
Keyword(s):  
Volume Measurement ◽  
Stem Volume ◽  
Tree Stem
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