scholarly journals Numerical-Analytical Study Of The Tree Growth Model Under Light Competition

Author(s):  
А.Н. Колобов ◽  
A.N. Kolobov
2004 ◽  
Vol 34 (10) ◽  
pp. 1985-1992 ◽  
Author(s):  
Michael S Watt ◽  
Mark O Kimberley ◽  
Brian Richardson ◽  
David Whitehead ◽  
Euan G Mason

A juvenile tree growth model sensitive to competition from weeds was developed and tested. Tree growth is predicted by reducing potential growth from an empirically determined optimum rate for the site (weed-free) using a seasonally estimated competition modifier, which accounts for the degree of weed competition for both water and light availability. The model was tested against data from a field trial at a dryland site, where juvenile Pinus radiata D. Don trees were grown with and without competition from the woody weed broom (Cytisus scoparius (L.) Link). For trees in plots without broom, seasonal fluctuations in growth were adequately modelled by a single-term Fourier series, which showed that maximum rates of diameter growth occurred during early summer. Diameter growth of trees in plots with broom was initially predicted by including a light-competition modifier into the model developed for weed-free plots on sites not subject to growth-limiting seasonal water deficit. Although the light modifier reduced growth from the weed-free state by 12% over the first year and 25% over the second year, modelled values still significantly exceeded measured diameter growth. To account for this overprediction a competition modifier based on modelled root-zone water storage was added into the model. Predictions of diameter growth using this modified model corresponded closely to measured diameter growth in both treatments.


2012 ◽  
Vol 6-7 ◽  
pp. 175-179
Author(s):  
Li Ying Duan ◽  
Jun Ling Li ◽  
Qian Dong ◽  
Qing Yong Jin ◽  
Xu Ning Liu

With the application of growth model and computer techniques in tree growth management, in order to grasp growth pattern of tree, further improve the level of tree growth management, and make the research on the tree growth model gradually develop towards the intelligent and science. The paper carried out simulation research technology for management model of the tree growth, meanwhile the database technology and modeling technology are used in the tree growth model, so the management model of tree growth is established, then visually display the states which are at different stages of tree growth management, which can contribute to predict the development states of tree growth. The research on tree growth model has important theory and practical significance in understanding the yield of the various parts of the tree and in taking the reasonable management measures.


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