scholarly journals Using Tree Detection Algorithms to Predict Stand Sapwood Area, Basal Area and Stocking Density in Eucalyptus regnans Forest

2015 ◽  
Vol 7 (6) ◽  
pp. 7298-7323 ◽  
Author(s):  
Dominik Jaskierniak ◽  
George Kuczera ◽  
Richard Benyon ◽  
Luke Wallace
Keyword(s):  
Stocking Density ◽  
Basal Area ◽  
Sapwood Area ◽  
Eucalyptus Regnans ◽  
Detection Algorithms ◽  
Tree Detection

The effect of local stand structure on growth and growth efficiency in heterogeneous stands of ponderosa pine and lodgepole pine in central Oregon

2004 ◽  
Vol 34 (11) ◽  
pp. 2217-2229 ◽  
Author(s):  
Douglas B Mainwaring ◽  
Douglas A Maguire
Keyword(s):  
Leaf Area ◽  
Ponderosa Pine ◽  
Lodgepole Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Growth Efficiency ◽  
Projection Area ◽  
Sapwood Area ◽  
Negative Effect ◽  
Crown Projection Area

Basal area and height growth were analyzed for individual trees in uneven-aged ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and lodgepole pine (Pinus contorta Dougl. ex. Loud.) stands in central Oregon. Basal area growth was modeled as a function of other stand and tree variables to address three general objectives: (1) to compare the predictive ability of distance-dependent versus distance-independent stand density variables; (2) to determine the degree to which small trees negatively affect the growth of overstory trees; and (3) to test for differences in growth efficiency between species and between indices of spatial occupancy used to define efficiency (area potentially available, crown projection area, and a surrogate for total tree leaf area). Distance-dependent variables were found to improve growth predictions when added to models with only distance-independent variables, and small trees were found to have a quantifiably negative effect on the growth of larger trees. While volume growth efficiency declined with increasing levels of spatial occupancy for lodgepole pine, ponderosa pine volume growth efficiency was greatest at the highest levels of crown base sapwood area and crown projection area. The behavior in ponderosa pine resulted from the previously recognized correlation between tree height and total leaf area or crown size. The final statistical models distinguished between the positive effect of relative height and the negative effect of increasing tree size.

Intertree competition in uneven-aged ponderosa pine stands

2003 ◽  
Vol 33 (9) ◽  
pp. 1719-1726 ◽  
Author(s):  
C W Woodall ◽  
C E Fiedler ◽  
K S Milner
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Basal Area ◽  
Growth Efficiency ◽  
Tree Size ◽  
Basal Area Increment ◽  
Diameter Class ◽  
Individual Tree ◽  
Sapwood Area ◽  
Competition Indices

Intertree competition indices and effects were examined in 14 uneven-aged ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) stands in eastern Montana. Location, height, diameter at breast height (DBH), basal area increment, crown ratio, and sapwood area were determined for each tree (DBH >3.8 cm) on one stem-mapped plot (0.2-0.4 ha) in each sample stand. Based on tree locations, various competition indices were derived for each sample tree and correlated with its growth efficiency by diameter class. In addition, trends in individual tree attributes by diameter class and level of surrounding competition were determined. For trees with a DBH <10 cm, growth efficiency was most strongly correlated with the sum of surrounding tree heights within 10.6 m. The index most highly correlated for larger trees was the sum of surrounding basal area within 6.1 m. Regardless of tree size, individual tree growth efficiency, basal area increment, and crown ratio all decreased under increasing levels of competition, with the effect more pronounced in smaller trees. These results suggest that individual trees in uneven-aged stands experience competition from differing sources at varying scales based on their size, with response to competition diminishing as tree size increases.

scholarly journals Savanna burning and the assessment of long-term fire experiments with particular reference to Zimbabwe

2008 ◽  
Vol 32 (6) ◽  
pp. 611-634 ◽  
Author(s):  
Peter A. Furley ◽  
Robert M. Rees ◽  
Casey M. Ryan ◽  
Gustavo Saiz
Keyword(s):  
Stocking Density ◽  
Basal Area ◽  
Research Station ◽  
Herbaceous Plant ◽  
Burned Areas ◽  
Vegetation Surveys ◽  
Savanna Burning ◽  
The Impact ◽  
Fire Experiments

Long-term fire experiments in savannnas are rare, given the difficulties and demands of operation. Controlled fire experiments date from colonial times in West Africa, although the largest and best-known is located in the Kruger National Park, South Africa. The achievements of these experiments are assessed from examples in Africa, South America and Australia. A less well-known experiment in Zimbabwe was sited at the Marondera Grassland Research Station and ran from 1953 to 1991. Some of the preliminary results on the impact of fire on vegetation are analysed and compared with further vegetation surveys in 2007. Studies on tree growth in this miombo savanna woodland indicate that the plots burned at three- and four-year intervals recovered to greater mean heights than the unburned control plots. There was no significant variation between treatments, suggesting that the few trees that did survive in the frequently burned plots were large specimens. Brachystegia and Julbernadia dominated the plots throughout and after the experiment. Basal area and stocking density were highest in the four-yearly burned plots but there was a high variability throughout the experiment, suggesting that many trees may have attained heights and bark thicknesses sufficient to protect from fire damage. Fire also affected the composition of the herbaceous plant community, but not the number of species. By the end of the experiment some grass and sedge species had flourished while others revealed greater susceptibility to fire, and fire-tolerant species predominated in the most frequently burned areas. The experimental design appeared to cope well with the variability between plots and indicated the soundness of the initial design and its implementation.

Tree vigor and stand growth of Douglas-fir as influenced by laminated root rot

1985 ◽  
Vol 15 (5) ◽  
pp. 985-988 ◽  
Author(s):  
Ram Oren ◽  
Walter G. Thies ◽  
Richard H. Waring
Keyword(s):  
Leaf Area ◽  
Root Rot ◽  
Basal Area ◽  
Douglas Fir ◽  
Basal Area Increment ◽  
Sapwood Area ◽  
Stand Growth ◽  
Area Growth ◽  
The Impact ◽  
Stand Basal Area

Total stand sapwood basal area, a measure of competing canopy leaf area, was reduced 30% by laminated root rot induced by Phellinusweirii (Murr.) Gilb. in a heavily infected 40-year-old coastal stand of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) compared with that of a similar uninfected stand. Annual basal area increment per unit of sapwood area, an index of tree vigor, was expected to increase in uninfected trees in the infected stand as surrounding trees died from root rot; vigor of the uninfected trees did increase by an average of 30%, offsetting the reduction in canopy leaf area. This increase, although less than might be expected in an evenly spaced thinned stand, was sufficient to maintain stand basal area growth at levels similar to those of unthinned forests. These findings indicate that increased growth by residual trees must be taken into account when the impact of disease-induced mortality on stand production is assessed.

Calibrating jack pine allometric relationships with simultaneous regressions

2008 ◽  
Vol 38 (10) ◽  
pp. 2566-2578 ◽  
Author(s):  
Robert Schneider ◽  
Frank Berninger ◽  
Chhun-Huor Ung ◽  
Pierre Y. Bernier ◽  
D. Edwin Swift ◽  
...  
Keyword(s):  
Pinus Banksiana ◽  
Basal Area ◽  
Stand Density ◽  
Jack Pine ◽  
Seemingly Unrelated Regression ◽  
Tree Level ◽  
Model Parameters ◽  
Eastern Canada ◽  
Sapwood Area ◽  
Pipe Model

Allometric equations for estimating foliage biomass, sapwood area, and branch basal area from tree diameters and crown lengths for jack pine ( Pinus banksiana Lamb.) in eastern Canada were calibrated using mixed models. A first model is presented that relates branch foliage biomass to branch diameter and relative position within the crown. These results show that a branch’s foliage biomass is inversely proportional to its depth within the crown. At the tree level, foliage biomass was found to be proportional to crown length and to vary with stem age and slenderness. Pipe model parameters (sapwood area and branch basal area to foliage biomass) were also calculated. The sapwood area to foliage biomass parameter is proportional to stand density, whereas branch basal area to foliage biomass is constant. The tree-level allometeric models were calibrated using a mixed-effects seemingly unrelated regression to account for between-model correlations.

Comparing individual tree detection and the area-based statistical approach for the retrieval of forest stand characteristics using airborne laser scanning in Scots pine stands

2011 ◽  
Vol 41 (3) ◽  
pp. 583-598 ◽  
Author(s):  
Jussi Peuhkurinen ◽  
Lauri Mehtätalo ◽  
Matti Maltamo
Keyword(s):  
Laser Scanning ◽  
Statistical Approach ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Tree Size ◽  
Size Distributions ◽  
Individual Tree ◽  
Tree Detection ◽  
Airborne Laser ◽  
Number Of Stems

Airborne laser scanning based forest inventories employ two major methods: individual tree detection (ITD) and the area-based statistical approach (ABSA). ITD is based on the assumption that trees are of a certain form and can be delineated using airborne laser scanning techniques, whereas ABSA is an empirical method based on the relations between area-level forest attributes and laser echo height distributions. These two methods are compared here within the same test area in terms of their usefulness for estimating mean forest stand characteristics and tree size distributions. All evaluations were performed using leave-one-out cross validation. The average errors in volume and basal area did not differ significantly between the methods. ABSA resulted in overall better accuracies when estimating the diameter and height of the basal area median tree and the number of stems, whereas ITD produced significantly biased estimates for the number of stems and the mean tree size. Tree size distributions were estimated with slightly better accuracy using ABSA. More comprehensive investigations revealed that both methods were not able to estimate forest structure (tree size distribution and spatial distribution of tree locations), which in turn, affected the estimation accuracies.

Estimation of foliage area in dense Montana lodgepole pine stands

1987 ◽  
Vol 17 (4) ◽  
pp. 320-324 ◽  
Author(s):  
Roger D. Hungerford
Keyword(s):  
Lodgepole Pine ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Area Ratio ◽  
Density Range ◽  
Sapwood Area ◽  
Crown Length ◽  
Pine Stands

Six stands of lodgepole pine, Pinuscontorta ssp. latifolia (Engelm.) Critchfield, in Montana were sampled to evaluate sapwood area (at 1.37 m and the crown base), basal area (at 1.37 m), tree height, and crown length as predictors of foliage area. Densities of the six stands ranged from 2900 to 17 800 stems/ha. This density range was picked to determine how stand density affects the ratio of foliage area to basal sapwood area. Regression estimates of foliage area using basal area and sapwood area at 1.37 m and the crown base were equally good. Within the sampled range of stand densities, differences in the foliage area to sapwood area ratio were not significant. The amount of foliage area served per unit of sapwood area (at 1.37 m) averaged 0.25 m2/cm2 for all 54 trees sampled. This value of foliage area per unit of sapwood area in dense stands was smaller than most other published values.

Conducting sapwood area, foliage area, and permeability in mature trees of Piceasitchensis and Pinuscontorta

1984 ◽  
Vol 14 (6) ◽  
pp. 940-947 ◽  
Author(s):  
D. Whitehead ◽  
W. R. N. Edwards ◽  
P. G. Jarvis
Keyword(s):  
Vapour Pressure Deficit ◽  
Basal Area ◽  
Water Vapour Pressure ◽  
Mature Trees ◽  
Area Index ◽  
Sapwood Area ◽  
Local Climate ◽  
Significant Difference ◽  
Physiological Analysis ◽  
The Relationship

The relationships between foliage area and sapwood area between trees and within the crowns of 20 Piceasitchensis (Bong.) Carr., provenance Queen Charlotte Island, British Columbia (10 in a control plot and 10 in a plot fertilized with potassium and phosphorus 8 years before harvest) and 10 Pinuscontorta Dougl., provenance Ladysmith trees were examined using a physiological analysis based on Darcy's law. Foliage area index on the fertilized P. sitchensis plot was higher than on the control. The variation of foliage area density with depth in the canopies followed a normal distribution. Relationships between foliage area and sapwood basal area were linear but the slopes were different for the two species. There was no significant difference between the control and fertilized P. sitchensis trees. The relationship between foliage area and the product of sapwood area and permeability was linear and data from the three plots fell on the same line. Sapwood area, permeability, and their product decreased with depth through the crowns of the trees. Within the crowns, relationships between cumulative foliage area and sapwood area, and between cumulative foliage area and the product of sapwood area × permeability were different with species and treatment. A single linear relationship resulted when the product of cumulative foliage area above an internode × the internode length was plotted against sapwood area × permeability for the internode. This suggests that it is the drop in potential across a node and internode rather than the gradient of potential across the internode that is related to the flux of water through tree crowns. The data support the hypothesis that the relationship between foliage area and sapwood area depends on permeability of the sapwood and the local climate through its influence on transpiration rate, particularly via average water vapour pressure deficit of the air and stomatal conductance.

Biomass and leaf area in contrasting lodgepole pine forests

1984 ◽  
Vol 14 (2) ◽  
pp. 259-265 ◽  
Author(s):  
John A. Pearson ◽  
Timothy J. Fahey ◽  
Dennis H. Knight
Keyword(s):  
Leaf Area ◽  
Fine Roots ◽  
Lateral Root ◽  
Root Biomass ◽  
Basal Area ◽  
Pine Forests ◽  
Total Biomass ◽  
Area Index ◽  
Sapwood Area ◽  
Dimension Analysis

Bole, branch, foliage, root crown, and lateral root biomass of Pinuscontorta ssp. latifolia (Engelm. ex Wats.) Critchfield forests in southeastern Wyoming were estimated by a combination of aboveground dimension analysis, belowground planar intersect sampling, and soil coring. Total biomass of six stands ≥75 years old ranged from 123 to 180 Mg/ha, and roof:shoot ratios were much higher in two very dense stands than in four more open stands. Average proportions of biomass in boles, branches, foliage, woody roots, and fine roots were 61, 7, 6, 20, and 6%, respectively. Leaf area index ranged from 4.5 to 9.9. Leaf area per unit sapwood area ranged from 0.20 to 0.57 m2/cm2in stands of different densities, ages, and sites. Sapwood area was a more precise predictor of foliage biomass than was basal area for the low to moderate density stands, but was marginally inferior to basal area for two high density stands (>9000 trees/ha).

Factors affecting the relationship between sapwood area and leaf area of balsam fir

1992 ◽  
Vol 22 (11) ◽  
pp. 1684-1693 ◽  
Author(s):  
Marie R. Coyea ◽  
Hank A. Margolis
Keyword(s):  
Leaf Area ◽  
Basal Area ◽  
Tree Height ◽  
Balsam Fir ◽  
Tree Age ◽  
Cross Sectional ◽  
Sapwood Area ◽  
Crown Length ◽  
Basal Area Growth ◽  
Area Growth

The ratio between projected leaf area (LA) and cross-sectional sapwood area (SA) of dominant and codominant balsam fir trees (Abiesbalsamea (L.) Mill.) was determined in 24 forest stands across the province of Quebec. Various physical factors proposed in the Whitehead hydraulic model, and some of the easily measured surrogates of these factors, were tested for their influence on LA:SA ratios. Average growing season vapor pressure deficit, temperature, precipitation, and stand drainage class did not significantly influence LA:SA ratios. On the other hand, LA:SA ratios were positively influenced by sapwood permeability (k), tree height, and crown length. As suggested by the model, there was a positive correlation between sapwood permeability and LA:SA ratio and a negative correlation between tree height or crown length and LA/(SA k). Increases in sapwood permeability with tree age were associated with longer tracheids having larger lumen diameters. Of the various empirical factors tested, only site quality, 5-year basal area growth, and age had a significant influence on LA:SA ratios. Sapwood cross-sectional area at breast height by itself was a reasonable linear predictor of LA for all stands (LA = −0.158 + 0.709 SABH, R2 = 0.75). Using the variables that were previously determined to influence LA:SA ratios, stepwise regressions revealed that only crown length and 5-year basal area growth significantly improved linear predictions of LA based on sapwood area. However, the increase in R2 was relatively modest, i.e., 0.83 for all three independent variables versus 0.75 for SA alone. The results from this study will be useful in integrating physiologically based measurements, such as growth efficiency, into standard forest inventory practices for balsam fir and thus could be beneficial in developing new silvicultural strategies for protecting Quebec's forest resource.

Sign in / Sign up

Export Citation Format

Share Document