Basal Area Growth Estimators for Survivor Component: A Quality Control Application

1990 ◽  
Vol 14 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Charles E. Thomas ◽  
Francis A. Roesch
Keyword(s):  
Quality Control ◽  
Quality Assurance ◽  
Forest Inventory ◽  
Data Use ◽  
Basal Area ◽  
Forest Inventory And Analysis ◽  
Basal Area Growth ◽  
Area Growth ◽  
Forest Experiment Station ◽  
Control Application

Abstract Several possible estimators are available for basal area growth of survivor trees, when horizontal prism (or point plots (HPP) are remeasured. This study's comparison of three estimators not only provides a check for the estimate of basal area growth but suggests that they can provide a quality control indicator for yield procedures. An example is derived from remeasurements in Alabama for the Southern Forest Experiment Station by Forest Inventory and Analysis. Remeasurements are for 1962-72 and 1972-82. It is suggested that computation of two or perhaps all three of the estimators be routinely incorporated in analysis of remeasured HPP data. Use of the two elemental estimators can provide a quality assurance check on field procedures. South. J. Appl. For. 14(1):12-18.

Variation in forest inventory field measurements

1994 ◽  
Vol 24 (9) ◽  
pp. 1766-1770 ◽  
Author(s):  
Ronald E. McRoberts ◽  
Jerold T. Hahn ◽  
Glenda J. Hefty ◽  
Jerry R. Van Cleve
Keyword(s):  
Forest Inventory ◽  
Basal Area ◽  
Field Measurements ◽  
Site Index ◽  
Upper Peninsula ◽  
The North ◽  
Basal Area Growth ◽  
Coefficients Of Variation ◽  
Area Growth ◽  
Forest Experiment Station

Field crews from the North Central Forest Experiment Station independently measured two forest inventory plots in Michigan's Upper Peninsula; one plot was measured by eight crews and the other was measured by nine different crews. For 61 trees, the variation in measurements of diameter at breast height (DBH), crown ratio, and site index is described. For DBH, the distribution of field crew mistakes and the distribution of measurements without mistakes are described separately. For crown ratio, the distribution of differences between individual estimates and the most frequently occurring estimate for corresponding trees is described. For site index, the distribution of differences between individual estimates and the mean of plot estimates is described. Coefficients of variation were less than 5% for DBH, approximately 73% for crown ratio, and 13% and 16% for site index for the two plots. The effects of variation in measurements on 20-year predictions of basal area and cumulative basal area growth were estimated for the two plots using STEMS, TWIGS, and Monte Carlo simulations. Coefficients of variation were 2% and 3% for basal area and 7% and 9% for cumulative basal area growth for the two plots. Variation in site index estimates had the greatest effect on variation in the output variables.

scholarly journals Regional Variability of the Romanian Main Tree Species Growth Using National Forest Inventory Increment Cores

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 409
Author(s):  
Gheorghe Marin ◽  
Vlad C. Strimbu ◽  
Ioan V. Abrudan ◽  
Bogdan M. Strimbu
Keyword(s):  
Mixed Models ◽  
Forest Inventory ◽  
Basal Area ◽  
National Forest Inventory ◽  
Forest Growth ◽  
National Forest ◽  
Sessile Oak ◽  
Basal Area Growth ◽  
Temporal Grouping ◽  
Area Growth

In many countries, National Forest Inventory (NFI) data is used to assess the variability of forest growth across the country. The identification of areas with similar growths provides the foundation for development of regional models. The objective of the present study is to identify areas with similar diameter and basal area growth using increment cores acquired by the NFI for the three main Romanian species: Norway spruce (Picea abies L. Karst), European beech (Fagus sylvatica L.), and Sessile oak (Quercus petraea (Matt.) Liebl.). We used 6536 increment cores with ages less than 100 years, a total of 427,635 rings. The country was divided in 21 non-overlapping ecoregions based on geomorphology, soil, geology and spatial contiguousness. Mixed models and multivariate analyses were used to assess the differences in annual dimeter at breast height and basal area growth among ecoregions. Irrespective of the species, the mixed models analysis revealed significant differences in growth between the ecoregions. However, some ecoregions were similar in terms of growth and could be aggregated. Multivariate analysis reinforced the difference between ecoregions and showed no temporal grouping for spruce and beech. Sessile oak growth was separated not only by ecoregions, but also by time, with some ecoregions being more prone to draught. Our study showed that countries of median size, such as Romania, could exhibit significant spatial differences in forest growth. Therefore, countrywide growth models incorporate too much variability to be considered operationally feasible. Furthermore, it is difficult to justify the current growth and yield models as a legal binding planning tool.

Field Notes: Predicted Vs. Actual Basal Area Growth in West Virginia

1988 ◽  
Vol 5 (3) ◽  
pp. 221-222
Author(s):  
Arlyn W. Perkey ◽  
Kenneth L. Carvell
Keyword(s):  
West Virginia ◽  
Basal Area ◽  
Basal Area Growth ◽  
Area Growth ◽  
Field Notes

A New Index Representing Individual Tree Competitive Status

1973 ◽  
Vol 3 (4) ◽  
pp. 495-500 ◽  
Author(s):  
James A. Moore ◽  
Carl A. Budelsky ◽  
Richard C. Schlesinger
Keyword(s):  
Spatial Distribution ◽  
Strong Correlation ◽  
Basal Area ◽  
Tree Size ◽  
Competition Index ◽  
Individual Tree ◽  
Silvicultural Practices ◽  
Basal Area Growth ◽  
Hardwood Species ◽  
Area Growth

A new competition index, modified Area Potentially Available (APA), was tested in a complex unevenaged stand composed of 19 different hardwood species. APA considers tree size, spatial distribution, and distance relationships in quantifying intertree competition and exhibits a strong correlation with individual tree basal area growth. The most important characteristic of APA is its potential for evaluating silvicultural practices.

scholarly journals An Individual-Tree Growth and Yield Prediction System for Uneven-Aged Shortleaf Pine Stands

2000 ◽  
Vol 24 (2) ◽  
pp. 112-120 ◽  
Author(s):  
Michael M. Huebschmann ◽  
Lawrence R. Gering ◽  
Thomas B. Lynch ◽  
Onesphore Bitoki ◽  
Paul A. Murphy
Keyword(s):  
Basal Area ◽  
Growth Patterns ◽  
Growth And Yield ◽  
Prediction System ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Area Growth ◽  
Pine Stands

Abstract A system of equations modeling the growth and development of uneven-aged shortleaf pine (Pinus echinata Mill.) stands is described. The prediction system consists of two main components: (1) a distance-independent, individual-tree simulator containing equations that forecast ingrowth, basal-area growth, probability of survival, total and merchantable heights, and total and merchantable volumes and weights of shortleaf pine trees; and (2) stand-level equations that predict hardwood ingrowth, basal-area growth, and mortality. These equations were combined into a computer simulation program that forecasts future states of uneven-aged shortleaf pine stands. Based on comparisons of observed and predicted stand conditions in shortleaf pine permanent forest inventory plots and examination of the growth patterns of hypothetical stands, the simulator makes acceptable forecasts of stand attributes. South. J. Appl. For. 24(2):112-120.

Long-term patterns of diameter and basal area growth of old-growth Douglas-fir trees in western Oregon

2002 ◽  
Vol 32 (7) ◽  
pp. 1232-1243 ◽  
Author(s):  
Nathan J Poage ◽  
John C Tappeiner, II
Keyword(s):  
Large Diameter ◽  
Basal Area ◽  
Douglas Fir ◽  
Slope Aspect ◽  
Site Factors ◽  
Old Growth ◽  
Site Class ◽  
Basal Area Growth ◽  
Area Growth ◽  
Age Range

Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that rapid early and sustained growth of old Douglas-fir trees were extremely important in terms of attaining large diameters at ages 100–300 years. The diameters of the trees at ages 100–300 years (D100–D300) were strongly, positively, and linearly related to their diameters and basal area growth rates at age 50 years. Average periodic basal area increments (PAIBA) of all trees increased for the first 30–40 years and then plateaued, remaining relatively high and constant from age 50 to 300 years. Average PAIBA of the largest trees at ages 100–300 years were significantly greater by age 20 years than were those of smaller trees at ages 100–300 years. The site factors province, site class, slope, aspect, elevation, and establishment year accounted for little of the variation observed in basal area growth at age 50 years and D100–D300. The mean age range for old-growth Douglas-fir at the sample locations was wide (174 years). The hypothesis that large-diameter old-growth Douglas-fir developed at low stand densities was supported by these observations.

Individual-tree basal area growth models for jack pine and black spruce in northern Ontario

2004 ◽  
Vol 80 (3) ◽  
pp. 366-374 ◽  
Author(s):  
Lianjun Zhang ◽  
Changhui Peng ◽  
Qinglai Dang
Keyword(s):  
Tree Growth ◽  
Black Spruce ◽  
Basal Area ◽  
Jack Pine ◽  
Mixed Stands ◽  
Northern Ontario ◽  
Individual Tree ◽  
Basal Area Growth ◽  
Wide Range ◽  
Area Growth

Individual-tree models of five-year basal area growth were developed for jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana (Mill.) BSP) in northern Ontario. Tree growth data were collected from long-term permanent plots of pure and mixed stands of the two species. The models were fitted using mixed model methods due to correlated remeasurements of tree growth over time. Since the data covered a wide range of stand ages, stand conditions and tree sizes, serious heterogeneous variances existed in the data. Therefore, the coefficients of the final models were obtained using weighted regression techniques. The models for the two species were evaluated across 4-cm diameter classes using independent data. The results indicated (1) the models of jack pine and black spruce produced similar prediction errors and biases for intermediate-sized trees (12–28 cm in tree diameter), (2) both models yielded relatively large errors and biases for larger trees (> 28 cm) than those for smaller trees, and (3) the jack pine model produced much larger errors and biases for small-sized trees (< 12 cm) than did the black spruce model. Key words: mixed models, repeated measures, model validation

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