scholarly journals Analytical approaches for modeling tree crown volume in black wattle (Acacia mearnsii De Wild.) stands

2016 ◽  
Vol 11 (49) ◽  
pp. 4979-4989
Author(s):  
C. Cadori Guilherme ◽  
R. Sanquetta Carlos ◽  
Pellico Netto Sylvio ◽  
Behling Alexandre ◽  
Costa Junior Sergio ◽  
...  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tijana Narandžić ◽  
Mirjana Ljubojević ◽  
Jovana Ostojić ◽  
Goran Barać ◽  
Vladislav Ognjanov

Abstract Severe climate alterations that seriously challenge fruit production, combined with the demand for healthy, pesticide-free fruits, continuously direct rootstock/cultivar selection towards high adaptable varieties breeding. This study aimed to investigate the rootstocks’ influence on the performance of grafted ‘Summit’ cherry trees, including potentially dwarfing Prunus cerasus, Prunus fruticosa and Prunus mahaleb rootstock candidates. Anatomical properties of rootstock and scion stems were investigated to determine variation among different rootstocks and scion-rootstock combinations and to establish the link between trunk hydraulic conductivity, effective tree crown volume and yielding potential. Cross-section anatomical characteristics varied significantly both in rootstock and scion stems, indicating a clear influence of rootstock genotype on grafted sweet cherry trees. It was observed that all investigated cherry rootstock candidates belong to the low-vigorous rootstocks, based on the estimated effective crown volume of grafted trees compared to ‘Gisela 5’, with values ranging from 0.86 to 2.97 m3 in the fifth year after planting. Results showed a statistically significant positive correlation between trunk hydraulic conductivity, effective tree crown volume and yielding potential, with correlation coefficients up to 0.96. Significantly higher effective crown volume and trunk hydraulic conductance of trees grafted on P. cerasus compared to the trees on control, as well as highest yielding potential, showed better adaptation of these rootstock candidates in the trial without irrigation implemented. It was found that PC_05_04 rootstock candidate could be considered as the most appropriate choice when raising the high-density sweet cherry plantations, due to assessed parameters of vegetative and generative growth.


Holzforschung ◽  
2003 ◽  
Vol 57 (5) ◽  
pp. 527-532 ◽  
Author(s):  
L. R. Schimleck ◽  
Y. Yazaki

Summary The analysis of two sets of Acacia mearnsii De Wild (Black Wattle) samples by near infrared (NIR) spectroscopy is reported. Set 1 samples were characterised in terms of hot water extractives, Stiasny value and polyflavanoid content. Set 2 samples were characterised by nine different parameters, including tannin content. NIR spectra were obtained from the milled bark of all samples and calibrations developed for each parameter. Calibrations developed for hot water extractives and polyflavanoid content (set 1) gave very good coefficients of determination (R2) and performed well in prediction. Set 2 calibrations were generally good with total and soluble solids, tannin content, Stiasny value-2 and UV-2, all having R2 greater than 0.8. Owing to the small number of set 2 samples, no predictions were made using the calibrations. The strong relationships obtained for many parameters in this study indicates that NIR spectroscopy has considerable potential for the rapid assessment of the quality of extractives in A. mearnsii bark.


2015 ◽  
Vol 73 (5) ◽  
Author(s):  
Muhammad Zulkarnain Abdul Rahman ◽  
Zulkepli Majid ◽  
Md Afif Abu Bakar ◽  
Abd Wahid Rasib ◽  
Wan Hazli Wan Kadir

Detailed forest inventory and mensuration of individual trees have drawn attention of research society mainly to support sustainable forest management. This study aims at estimating individual tree attributes from high density point cloud obtained by terrestrial laser scanner (TLS). The point clouds were obtained over single reference tree and group of trees in forest area. The reference tree is treated as benchmark since detailed measurements of branch diameter were made on selected branches with different sizes and locations. Diameter at breast height (DBH) was measured for trees in forest. Furthermore tree height, height to crown base, crown volume and tree branch volume were also estimated for each tree. Branch diameter is estimated directly from the point clouds based on semi-automatic approach of model fitting i.e. sphere, ellipse and cylinder. Tree branch volume is estimated based on the volume of the fitted models. Tree height and height to crown base are computed using histogram analysis of the point clouds elevation. Tree crown volume is estimated by fitting a convex-hull on the tree crown. The results show that the Root Mean Squared Error (RMSE) of the estimated tree branch diameter does not have a specific trend with branch sizes and number of points used for fitting process. This explains complicated distribution of point clouds over the branches. Overall cylinder model produces good results with most branch sizes and number of point clouds for fitting. The cylinder fitting approach shows significantly better estimation results compared to sphere and ellipse fitting models.   


2020 ◽  
Vol 12 (11) ◽  
pp. 1841 ◽  
Author(s):  
Zihui Zhu ◽  
Christoph Kleinn ◽  
Nils Nölke

Crown volume is a tree attribute relevant in a number of contexts, including photosynthesis and matter production, storm resistance, shadowing of lower layers, habitat for various taxa. While commonly the total crown volume is being determined, for example by wrapping a convex hull around the crown, we present here a methodological approach towards assessing the tree green crown volume (TGCVol), the crown volume with a high density of foliage, which we derive by terrestrial laser scanning in a case study of solitary urban trees. Using the RGB information, we removed the hits on stem and branches within the tree crown and used the remaining leaf hits to determine TGCVol from k-means clustering and convex hulls for the resulting green 3D clusters. We derived a tree green crown volume index (TGCVI) relating the green crown volume to the total crown volume. This TGCVI is a measure of how much a crown is “filled with green” and scale-dependent (a function of specifications of the k-means clustering). Our study is a step towards a standardized assessment of tree green crown volume. We do also address a number of remaining methodological challenges.


2004 ◽  
Vol 34 (3) ◽  
pp. 686-694 ◽  
Author(s):  
Jürgen Bauhus ◽  
Aaron P van Winden ◽  
Adrienne B Nicotra

This study compared productivity in mixed-species plantations of Eucalyptus globulus ssp. pseudoglobulus (Naudin ex Maiden) Kirkpatr. and Acacia mearnsii de Wild with pure stands of each species and investigated how this might be explained by canopy stratification between species and changes in leaf characteristics of eucalypts. Investigations were carried out at a trial using the replacement series design, which consisted of the following combinations: 100% eucalypts (100%E), 75% eucalypts + 25% acacia (75%E:25%A), 50% eucalypts + 50% acacia (50%E:50%A), 25% eucalypts + 75% acacia (25%E:75%A), and 100% acacia (100%A). At 9.5 years, stem volume and biomass were highest in 50%E:50%A treatments. Canopy stratification occurred in all mixtures, with acacias in the lower and eucalypts in the upper canopy stratum. This and the increasing canopy light interception with increasing proportion of acacia in the mixture indicated that A. mearnsii is substantially more shade tolerant than E. globulus. Midcanopy foliage of E. globulus in the 50%E:50%A mixture had higher foliage nitrogen (N) but lower phosphorus (P) concentrations and lower light-saturated net photosynthesis rates (Amax) than those in the 100%E treatment. In addition, similar relationships between eucalypt crown volume and stem biomass across treatments indicated that eucalypt crowns were not more efficient in mixture. Our study indicates that the productivity gains in these mixtures may be partially attributable to aboveground niche separation between species.


2020 ◽  
Vol 42 ◽  
pp. e44
Author(s):  
Ricardo Alberti ◽  
Fernanda Lais Novello ◽  
Eduardo Alexandre Albarello ◽  
Ewerton Jose de Medeiros Torres ◽  
Fernando De Jesus Moreira Junior

The objective of this work was to analyze the efficacy of different methods of dormancy break in seeds of Acacia mearnsii De Wild. The work was performed at the UFSM Botany Lab and Forest Nursery, in Frederico Westphalen, RS. The treatments were: (T1) control; (T2) immersion in hot water (90 °C) for 5 minutes, followed by rest; (T3) immersion in hot water (90 °C) for 10 minutes, followed by rest; (T4) chemical scarification with concentrated sulfuric acid for 3 minutes, followed by washing under running water; (T5) chiseling with concentrated sulfuric acid for 5 minutes, followed by washing under running water. The seeds were sown in plastic trays with Oxisol and vermiculite. The results were submitted to analysis of variance and data were differentiated by Test t with 5% of probability. The most efficient treatment to overcome dormancy was T2, presenting 81.29% of germinated seeds and IVG of 18.23 days for germination. This treatment was also the best for the variables of physical vigor and best performing root length and aerial part, and did not differ from improved treatments for diameter and green mass weight.


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