Growth basal area: a field method for appraising forest site potential for stockability

1983 ◽  
Vol 13 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Frederick C. Hall
Keyword(s):  
Growth Rate ◽  
Basal Area ◽  
Site Index ◽  
Field Method ◽  
Stand Age ◽  
Diameter Growth ◽  
Forest Site ◽  
A Site

Growth basal area (GBA) is a field method for determining site potential limitations on stockability. It is defined as the basal area (BA) at which dominant trees grow 1 in. (25 mm) diameter per decade at age 100. Diameter growth is a constant used to compare sites; basal area is a variable used to express different site potentials for stockability. For example, a site with GBA = 220 ft2/acre (50 m2/ha) means dominants will grow 1 in. per decade (25 mm) in diameter at 220 ft2 BA. This is twice the stockability potential of a site with GBA = 110 ft2 (25 m2/ha). GBA is determined by relating current stand diameter growth rate and BA to a curve which permits adjustment of current BA to that for 1 in. per decade diameter growth. GBA is based on two assumptions: (i) rate of diameter growth decreases with increasing basal area and is an index of intertree competition. (ii) Change in GBA with age is related to stand age. GBA can be combined with site index (SI), shown as SI-GBA, to connote different productivities within an SI class. GBA is discussed in regard to concept of GBA curve development, assumptions made, applications, and constraints.

AN EVALUATION OF SEVERAL METHODS OF ESTIMATING SITE INDEX OF IMMATURE STANDS

1952 ◽  
Vol 28 (3) ◽  
pp. 63-74 ◽  
Author(s):  
John W. Ker
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Site Quality ◽  
Average Height ◽  
Office Procedure ◽  
Minimum Sample ◽  
A Site ◽  
The University ◽  
Site Classes

The use of dominant heights for the estimation of site index is compared with the use of the average of dominant and codominant heights. Data collected on the University Research Forest are presented to illustrate the variability in tree heights and diameters within the two upper crown classes in well-stocked stands of immature Douglas fir.HeightIt is shown that the use of dominant heights reduces considerably the number of measurements required for a site index determination of given accuracy. Minimum sample sizes are given for three limits of accuracy for use in different site qualities. A general field and office procedure is outlined for the determination of minimum sample size in stands other than those described.DiameterThe use of diameter in site determination is discussed. Site indices based on the height of the tree of mean diameter, the height of the tree of mean basal area, and mean height are compared.ConclusionsQuick estimates of site quality can best be obtained by the measurement of total height of sample dominant trees, selected at random. For this purpose, tables are presented which list the average height of dominant trees by age and site classes for use in stands of Douglas fir, and western hemlock, respectively.

Eight-Year Performance of Loblolly Pine with Pisolithus Ectomycorrhizae on a Good-Quality Forest Site

1988 ◽  
Vol 12 (4) ◽  
pp. 275-280 ◽  
Author(s):  
Donald H. Marx ◽  
Charles E. Cordell ◽  
Alexander Clark
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Site Index ◽  
Forest Site ◽  
Water Deficits ◽  
Growing Seasons ◽  
Area Growth ◽  
Pinus Taeda L ◽  
Crown Closure

Abstract Loblolly pine (Pinus taeda L) seedlings with different initial amounts of Pisolithus tinctorius (Pt) ectomycorrhizae (Pt index 0, 27, 46, 68, or 88) were planted on a good-quality site (site index 90 ft at age 50) in southwest Georgia. After 8 years and crown closure, trees with Pt indices of 88 and 68 had significantly better survival and greater heights, diameters, volumes, and green weights per tree and per ac than nursery-run, control seedlings (Pt index 0). Volume and weight yields per ac were over 50% greater and volume and weight yields per tree were over 20% greater for trees in the Pt index 88 treatment than they were for control trees. A special statistical analysis indicated that average per ac volume was positively correlated with initial Pt index values larger than 58. Tree-ring analyses showed that trees with a Pt index of 88 had significantly greater annual basal area growth than controls during growing seasons with water deficits of 8 to 13 in. Annual growth did not differ when water deficits were greater or less than these amounts. After 8 years, Pt basidiocarps were present throughout the study site. Mycorrhizal treatment integrity may have been lost after 3 or 4 years. South. J. Appl. For. 12(4):275-280

scholarly journals Creating Landscape-Scale Site Index Maps for the Southeastern US Is Possible with Airborne LiDAR and Landsat Imagery

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 234 ◽  
Author(s):  
Ranjith Gopalakrishnan ◽  
Jobriath Kauffman ◽  
Matthew Fagan ◽  
John Coulston ◽  
Valerie Thomas ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Laser Scanning ◽  
Landsat Imagery ◽  
Site Index ◽  
Airborne Lidar ◽  
Stand Age ◽  
Forest Site ◽  
Large Area ◽  
Southeastern Us ◽  
Index Maps

Sustainable forest management is hugely dependent on high-quality estimates of forest site productivity, but it is challenging to generate productivity maps over large areas. We present a method for generating site index (a measure of such forest productivity) maps for plantation loblolly pine (Pinus taeda L.) forests over large areas in the southeastern United States by combining airborne laser scanning (ALS) data from disparate acquisitions and Landsat-based estimates of forest age. For predicting canopy heights, a linear regression model was developed using ALS data and field measurements from the Forest Inventory and Analysis (FIA) program of the US Forest Service (n = 211 plots). The model was strong (R2 = 0.84, RMSE = 1.85 m), and applicable over a large area (~208,000 sq. km). To estimate the site index, we combined the ALS estimated heights with Landsat-derived maps of stand age and planted pine area. The estimated bias was low (−0.28 m) and the RMSE (3.8 m, relative RMSE: 19.7%, base age 25 years) was consistent with other similar approaches. Due to Landsat-related constraints, our methodology is valid only for relatively young pine plantations established after 1984. We generated 30 m resolution site index maps over a large area (~832 sq. km). The site index distribution had a median value of 19.4 m, the 5th percentile value of 13.0 m and the 95th percentile value of 23.3 m. Further, using a watershed level analysis, we ranked these regions by their estimated productivity. These results demonstrate the potential and value of remote sensing based large-area site index maps.

scholarly journals Incidence of ash dieback in the Left-Bank Forest-Steppe depending on stand characteristics

2020 ◽  
pp. 157-164
Author(s):  
V. L. Meshkova ◽  
V. L. Borysova
Keyword(s):  
Stocking Density ◽  
Site Index ◽  
Stand Age ◽  
Forest Steppe ◽  
Forest Site ◽  
Left Bank ◽  
Site Conditions ◽  
Ash Dieback ◽  
European Ash ◽  
Stand Characteristics

The incidence of ash dieback in the forest-steppe part of Sumy and Kharkiv Regions was analysed taking into account the type of forest site conditions, the stand age, relative stocking density, site index class and the proportion of European ash in the stand composition. Ash dieback is quite widespread in inspected stands of the Left-Bank Forest-Steppe of Sumy and Kharkiv Regions. The disease spreads similarly in natural and artificial stands. It was more often revealed in the fresh fertile forest site conditions, however, such forest site conditions are the most spread and the most favourable for European ash. It was found that ash dieback incidence tends to grow with a stand aging and lasts up to the stand’s age of 80. It can be explained by the development of stem and collar rots which occur later. Ash dieback incidence is the highest in the stands with 40–70 % of ash in their composition, at a relative density of stocking over 0.5 in the stands of different site index classes.

Growth of 20-Year-Old Virginia Pine Planted at Three Spacings in Tennessee

1985 ◽  
Vol 9 (1) ◽  
pp. 32-37
Author(s):  
Glendon W. Smalley
Keyword(s):  
Basal Area ◽  
Site Index ◽  
The Other ◽  
Average Height ◽  
Cumberland Plateau ◽  
Plantation Age ◽  
A Site ◽  
Pinus Virginiana Mill

Abstract Average height of dominant and codominant Virginia pines (Pinus virginiana Mill). on a Mid-Cumberland Plateau site was 46 feet at plantation age 20, equivalent to a site index (base age 50) of 75. Trees planted at a spacing of 8 x 8 feet had a merchantable yield (outside bark to a 4.0 inch top for all trees with a dbh of 4.6 inches and larger) of 1,987 ft³ per acre with a basal area of 114 ft² per acre. Comparative statistics on the other spacings tested were: 6 x 6 feet—2,067 ft³ and 123 ft² and 4 x 4 feet—2,155 ft³ and 141 ft². Survival on the plots was: 4 x 4 feet—38%; 6 x 6 feet—58%; and 8 x 8 feet—75%. Height to base of live crown averaged 25 feet, and dead branches remained nearly to the ground on most trees at all spacings.

scholarly journals RELATIONSHIP BETWEEN CLIMATE VARIABLES, TRUNK GROWTH RATE AND WOOD DENSITY OF Eucalyptus grandis W. Mill ex Maiden TREES

2016 ◽  
Vol 40 (2) ◽  
pp. 337-346 ◽  
Author(s):  
Carlos Roberto Sette Jr ◽  
Mario Tomazello F ◽  
José Luis Lousada ◽  
Domingos Lopes ◽  
Jean Paul Laclau
Keyword(s):  
Growth Rate ◽  
Wood Density ◽  
Eucalyptus Grandis ◽  
Basal Area ◽  
High Sensitivity ◽  
Cambial Activity ◽  
Climatic Conditions ◽  
Diameter Growth ◽  
Climate Variables ◽  
Trunk Diameter

ABSTRACT Climatic conditions stimulates the cambial activity of plants, and cause significant changes in trunk diameter growth and wood characteristics. The objective of this study was to evaluate the influence of climate variables in the diameter growth rate of the stem and the wood density of Eucalyptus grandis trees in different classes of the basal area. A total of 25 Eucalyptus trees at 22 months of age were selected according to the basal area distribution. Dendrometer bands were installed at the height of 1.30 meters (DBH) to monitor the diameter growth every 14 days, for 26 months. After measuring growth, the trees were felled and wood discs were removed at the DBH level to determine the radial density profile through x-ray microdensitometry and then re-scale the average values every 14 days. Climatic variables for the monitoring period were obtained and grouped every 14 days. The effect of the climate variables was determined by maximum and minimum growth periods in assessing trunk growth. These growth periods were related with precipitation, average temperature and relative air humidity. The re-scaled wood density values, calculated using the radial growth of the tree trunks measured accurately with steel dendrometers, enabled the determination of the relationship of small changes in wood density and the effect of the climatic variations and growth rate of eucalyptus tree trunks. A high sensitivity of the wood density to variation in precipitation levels was found.

Modelling survival probability of individual trees in Norway spruce stands under different thinning regimes

2005 ◽  
Vol 35 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Kjell Karlsson ◽  
Lennart Norell
Keyword(s):  
Norway Spruce ◽  
Goodness Of Fit ◽  
Basal Area ◽  
Site Index ◽  
Stand Age ◽  
Goodness Of Fit Test ◽  
Individual Tree ◽  
Thinning Intensity ◽  
Diameter At Breast Height ◽  
Breast Height

The probability that an individual tree will remain in even-aged Norway spruce (Picea abies (L.) Karst.) stands subjected to different thinning programmes was modelled, using data from a thinning experiment established in 25 localities in southern Sweden. A logistic regression approach was used to predict the probability and the Hosmer–Lemeshow goodness-of-fit test to evaluate the fit. Diameter at breast height (DBH), quadratic mean DBH, thinning intensity, thinning quotient, basal area, number of stems per hectare, stand age, number of thinnings, and site index were used as explanatory variables. Separate analyses for stands thinned from below, stands thinned from above, and unthinned stands were performed. The modelled probability graphs for trees not being removed, plotted against their diameter at breast height, had clear S-shapes for both unthinned stands and stands thinned from below. The graph for stands thinned from above was bell-shaped.

Improving estimates of tree mortality probability using potential growth rate

2015 ◽  
Vol 45 (7) ◽  
pp. 920-928 ◽  
Author(s):  
Adrian J. Das ◽  
Nathan L. Stephenson
Keyword(s):  
Growth Rate ◽  
Sierra Nevada ◽  
Tree Mortality ◽  
Basal Area ◽  
Growth Index ◽  
Diameter Growth ◽  
Potential Growth ◽  
Mortality Probability ◽  
Growth Metrics ◽  
Tree Survival

Tree growth rate is frequently used to estimate mortality probability. Yet, growth metrics can vary in form, and the justification for using one over another is rarely clear. We tested whether a growth index (GI) that scales the realized diameter growth rate against the potential diameter growth rate (PDGR) would give better estimates of mortality probability than other measures. We also tested whether PDGR, being a function of tree size, might better correlate with the baseline mortality probability than direct measurements of size such as diameter or basal area. Using a long-term dataset from the Sierra Nevada, California, U.S.A., as well as existing species-specific estimates of PDGR, we developed growth–mortality models for four common species. For three of the four species, models that included GI, PDGR, or a combination of GI and PDGR were substantially better than models without them. For the fourth species, the models including GI and PDGR performed roughly as well as a model that included only the diameter growth rate. Our results suggest that using PDGR can improve our ability to estimate tree survival probability. However, in the absence of PDGR estimates, the diameter growth rate was the best empirical predictor of mortality, in contrast to assumptions often made in the literature.

RPGrow$: A Red Pine Analysis Spreadsheet for the Lake States

1994 ◽  
Vol 11 (4) ◽  
pp. 141-145
Author(s):  
Carol A. Hyldahl ◽  
Gerald H. Grossman
Keyword(s):  
Financial Analysis ◽  
Basal Area ◽  
Site Index ◽  
Red Pine ◽  
Growth And Yield ◽  
Stand Age ◽  
Management Scenarios ◽  
Stand Management ◽  
Lake States ◽  
Final Harvest

Abstract RPGrow$ is a spreadsheet that interactively projects standlevel growth and yield with financial analysis of red pine plantations in the Lake States. Three types of commonly found conditions related to red pine management can be analyzed: (1) an entire rotation from initial planting to final harvest; (2) an existing stand from any point in time until final harvest; and (3) conversion of an existing stand to red pine (marginal analysis). Stand growth projections are for 70 yr. User input includes site index, stand age, initial basal area, trees per acre, thinning regime, costs associated with establishment and culture, tax rates, inflation rate, and discount rate. RPGrow$ calculates and values pulpwood and sawtimber volumes from user-defined stumpage prices. The financial analysis uses discounted cash flow methods to calculate results both with and without tax effects. Different stand management scenarios and economic factors can be compared easily through sensitivity analysis. North. J. Appl. For. 11(4):141-145.

Whole Stand Yield and Density Equations for Fourteen Forest Types in Minnesota

1993 ◽  
Vol 10 (2) ◽  
pp. 75-85 ◽  
Author(s):  
David K. Walters ◽  
Alan R. Ek
Keyword(s):  
Goodness Of Fit ◽  
Basal Area ◽  
Nonlinear Least Squares ◽  
Analysis Data ◽  
Site Index ◽  
Stand Age ◽  
Parameter Estimates ◽  
Forest Types ◽  
Fit Statistics ◽  
Number Of Stems

Abstract Models that estimate per acre basal area, number of stems, quadratic mean diameter, volumes to specified top diameters, and biomass per acre by stand age and site index were developed and fitted to data for 14 forest types in Minnesota. The resulting equations were developed from linear and nonlinear least squares analyses using USDA Forest Service Forest Inventory and Analysis data. These equations are intended for projecting future forest characteristics including yield on a statewide basis assuming the continuation of the level of management inherent in the data. Parameter estimates and goodness-of-fit statistics are provided for each model. Also discussed are the implementation procedures, assumptions, consistency of estimates, estimates for mixed species stands, and other considerations in applications. North. J. Appl. For. 10(2): 75-85.

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