Population density influences assessment and application of site index

2000 ◽  
Vol 30 (9) ◽  
pp. 1472-1475 ◽  
Author(s):  
David W MacFarlane ◽  
Edwin J Green ◽  
Harold E Burkhart
Keyword(s):  
Loblolly Pine ◽  
Geographic Location ◽  
Stand Density ◽  
Tree Height ◽  
Significant Negative Correlation ◽  
Site Index ◽  
Height Growth ◽  
Planting Density ◽  
Site Quality ◽  
Pinus Taeda L

The height growth of dominant trees in plantations is often assumed to be independent of initial planting density. This assumption allows for the use of dominant tree height as an index of site quality. We found that this assumption was false for the seven tallest trees in 184 even-aged loblolly pine (Pinus taeda L.) stands, planted at nine initial planting densities, at four different geographic locations. A strong, highly significant negative correlation was found between dominant height and initial planting density for stands 14 and 16 years of age. This leads to large differences in predicted site index for stands with different initial planting densities planted at the same geographic location. Use of these site indices to predict yield produced large differences in predicted yield (m3/ha) at age 25. These results provide strong evidence for density-dependent height growth, even for dominant trees in the stand, and suggest that site index, used as a measurement of site quality, is confounded with stand density.

Site-Index Comparisons for Naturally Seeded Loblolly Pine and Shortleaf Pine

1987 ◽  
Vol 11 (2) ◽  
pp. 86-91
Author(s):  
Constance A. Harrington
Keyword(s):  
Loblolly Pine ◽  
Mississippi River ◽  
Correlation Coefficients ◽  
Site Index ◽  
Site Quality ◽  
Regression Equations ◽  
Shortleaf Pine ◽  
Southern States ◽  
Pinus Taeda L ◽  
Simple Regression

Abstract Site-index comparisons were made between loblolly pine (Pinus taeda L.) and shortleaf pine (P. echinata Mill.) based on 190 plots in 9 southern states. The relationship between site-index values for the two species appeared to be linear, with the mean difference in site index greateston poor sites and decreasing as site quality increased. Site-index prediction equations were developed for each species using site index of the other species or using site index plus one to three additional independent variables. The simple correlation between the site indexes of the two specieswas 0.855 (r² = 0.73). Somewhat higher correlation coefficients were obtained when elevation or slope was included as a second independent variable. Simple regression equations developed separately for plots east and west of the Mississippi River did not differ statistically. Separationof the plots into two groups, however, resulted in several multiple regression equations for each geographic division; these had slightly higher correlation coefficients than the simple regression equations. South. J. Appl. For. 11(2):86-91.

scholarly journals Modeling Early Responses of Loblolly Pine Growth to Thinning in the Western Gulf Coastal Plain Region

2020 ◽  
Vol 66 (5) ◽  
pp. 623-633
Author(s):  
Y H Weng ◽  
J Grogan ◽  
D W Coble
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Tree Height ◽  
Height Growth ◽  
Growth Responses ◽  
Individual Tree ◽  
Large Trees ◽  
The Difference ◽  
Pinus Taeda L ◽  
Stand Basal Area

Abstract Growth response to thinning has long been a research topic of interest in forest science. This study presents the first 3–4 years of response of loblolly pine (Pinus taeda L.) growth to thinning at different intensities. Data were collected from the East Texas Pine Research Project’s region-wide loblolly pine thinning study, which covers a wide variety of stand conditions. Four treatments, light, moderate, and heavy thinning, respectively having 370, 555, and 740 residual trees per hectare after thinning, and an unthinned control, were included. Individual tree diameter at breast height (dbh) and total height were recorded annually for the first 3–4 years after thinning. Results indicate significant differences between treatments in dbh growth in each year after thinning, as well as for all years combined. Each thinning treatment had significantly greater dbh growth than the control in the first growing season with this positive response being more evident in the case of the heavier thinning or at the later years post-thinning. Conversely, the thinning effect on tree height growth was initially negligibly negative, then becoming positive after 2–4 years, with the heavier thinning becoming positive sooner. Tree size class, assigned based on prethinning dbh, had a significant effect on both dbh and height growth responses. Compared to the control, small trees had a greater response both in dbh and in height growth than the medium and large trees over the measurement period. At the stand level, the heavier thinning had significantly less stand basal area per hectare, but the difference in stand basal area per hectare between the thinned and the unthinned plots decreased with years post-thinning. Results from this study can improve our understanding in thinning effects and help forest managers make accurate decisions on silvicultural regimes.

Fusiform Rust Prediction Models for Site-Prepared Slash and Loblolly Pine Plantations in the Southeast

1986 ◽  
Vol 10 (3) ◽  
pp. 145-151 ◽  
Author(s):  
B. E. Borders ◽  
R. L. Bailey
Keyword(s):  
Loblolly Pine ◽  
Regression Models ◽  
Prediction Models ◽  
Geographic Location ◽  
Stand Density ◽  
Site Index ◽  
Cultural Factors ◽  
Pine Plantations ◽  
Permanent Plots ◽  
Fusiform Rust

Abstract Several workers have reported relationships between the incidence of fusiform rust in pine plantations and climatic, edaphic, biotic, and cultural factors. These relationships were investigated quantitatively with a regionwide databank compiled from several replicated unthinned stand density studies. Data from over 2,000 remeasured permanent plots were used to develop regression models that predict the proportion of trees per acre with one or more fusiform rust stem galls. Predictor variables are geographic location, age of the plantation, and site index. Use of the models is illustrated with an example. South. J. Appl. For. 10:145-51, Aug. 1986.

Dominant Height Growth and Site Index Curves for Loblolly Pine Plantations in the Carolina Flatwoods

1980 ◽  
Vol 4 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Leon V. Pienaar ◽  
Barry D. Shiver
Keyword(s):  
Loblolly Pine ◽  
Site Index ◽  
Height Growth ◽  
Site Preparation ◽  
Preparation Methods ◽  
Mechanical Site Preparation ◽  
Drainage Class ◽  
Separate Site ◽  
Pinus Taeda L ◽  
Dominant Height Growth

Abstract Stem analysis was used to reconstruct the past height growth of sample trees taken from the upper canopy in loblolly pine (Pinus taeda L.) plantations in the Carolina flat-woods. From a soil profile description a Soil Conservation Service drainage class was determined for each sampled location. The effects of soil drainage class and method of site preparation on the height growth trends were examined, and resulted in the construction of two sets of site index curves: one for very poorly drained (almost exclusively North Carolina pocosin) soils, and another for soils ranging from poorly to well drained. Within drainage classes the different categories of mechanical site preparation methods considered did not require the construction of separate site index curves.

scholarly journals Effects of Stand Density on Top Height Estimation for Ponderosa Pine

2012 ◽  
Vol 27 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Martin Ritchie ◽  
Jianwei Zhang ◽  
Todd Hamilton
Keyword(s):  
Ponderosa Pine ◽  
Stand Density ◽  
Tree Height ◽  
Site Index ◽  
Fixed Number ◽  
Site Quality ◽  
Height Estimation ◽  
Growing Stock ◽  
Dominant Height ◽  
Definition Of

Abstract Site index, estimated as a function of dominant-tree height and age, is often used as an expression of site quality. This expression is assumed to be effectively independent of stand density. Observation of dominant height at two different ponderosa pine levels-of-growing-stock studies revealed that top height stability with respect to stand density depends on the definition of the dominant height. Dominant height estimates calculated from a fixed number of trees per acre (ranging from 10 to 60 of the tallest trees per acre) were less affected by density than those calculated from a proportion (with the cutoff ranging from 95th to the 70th percentile) of the largest trees in the stand.

The relationship of tree height and crown class to the induced plant defenses of loblolly pine

1987 ◽  
Vol 65 (10) ◽  
pp. 2090-2092 ◽  
Author(s):  
T. D. Paine ◽  
F. M. Stephen
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Tree Height ◽  
Dendroctonus Frontalis ◽  
Site Quality ◽  
Pine Beetle ◽  
Loblolly Pines ◽  
Pinus Taeda L ◽  
Relationship Of ◽  
The Relationship

Loblolly pines, Pinus taeda L., were inoculated with a fungus associated with the southern pine beetle, Dendroctonus frontalis Zimm., at three heights to determine whether the trees responded to infection differently at each height. Loblolly pines responded to inoculation of this fungus by producing lesions of various dimensions. These were dissected and weighed. Lesions had the same weight at all three heights up the stem. However, the extent (or intensity) of reaction to fungal infection and wounding varied as a function of crown class of the tree. The influence of site quality on induced defenses may be assessed using this technique.

Long-term effects of stand density management and genotype on wood properties of loblolly pine (Pinus taeda L.) in the mid-South USA

2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Stand Density ◽  
Wood Properties ◽  
Long Term Effects ◽  
Stand Density Management ◽  
Pinus Taeda L

scholarly journals Four Site-Preparation Techniques for Regenerating Pine-Hardwood Mixtures in the Piedmont

1997 ◽  
Vol 21 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Thomas A. Waldrop
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Height Growth ◽  
Site Preparation ◽  
Site Conditions ◽  
Growing Seasons ◽  
Southern Appalachian ◽  
Medium Quality ◽  
Pinus Taeda L ◽  
Preparation Techniques

Abstract Four variations of the fell-and-burn technique, a system developed to produce mixed pine-hardwood stands in the Southern Appalachian Mountains, were compared in the Piedmont region. All variations of this technique successfully improved the commercial value of low-quality hardwood stands by introducing a pine component. After six growing seasons, loblolly pine (Pinus taeda L.) occupied the dominant crown position and oaks the codominant position in fell-and-burn treated stands on poor to medium quality sites. The precise timing of felling residual stems, as prescribed by the fell-and-burn technique, may be flexible because winter and spring felling produced similar results. Although summer site preparation burns reduced hardwood height growth by reducing the length of the first growing season, they did not improve pine survival or growth. Pines were as tall as hardwoods within four growing seasons in burned plots and within six growing seasons in unburned plots. Additional research is needed to determine the level or intensity of site preparation needed to establish pine-hardwood mixtures over a range of site conditions. South. J. Appl. For. 21(3):116-122.

scholarly journals A Novel Approach to Modelling Stand-Level Growth of an Even-Aged Forest Using a Volume Productivity Index with Application to New Zealand-Grown Coast Redwood

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1155 ◽  
Author(s):  
Mark O. Kimberley ◽  
Michael S. Watt
Keyword(s):  
New Zealand ◽  
Growth Model ◽  
Growth Models ◽  
Stand Density ◽  
Site Index ◽  
Growth And Yield ◽  
Productivity Index ◽  
Site Quality ◽  
Spatial And Temporal Variation ◽  
Coast Redwood

Empirical growth models are widely used to predict the growth and yield of plantation tree species, and the precise estimation of site quality is an important component of these models. The most commonly used proxy for site quality in growth models is Site Index (SI), which describes the mean height of dominant trees at a specified base age. Although SI is widely used, considerable research shows significant site-dependent variation in height for a given volume, with this latter variable more closely reflecting actual site productivity. Using a national dataset, this study develops and describes a stand-level growth and yield model for even-aged New Zealand-grown coast redwood (Sequoia sempervirens). We used a novel modelling approach that quantifies site quality using SI and a volume-based index termed the 300 Index, defined as the volume mean annual increment at age 30 years for a reference regime of 300 stems ha−1. The growth model includes a number of interrelated components. Mean top height is modelled from age and SI using a polymorphic Korf function. A modified anamorphic Korf function is used to describe tree quadratic mean diameter (Dq) as a function of age, stand density, SI and a diameter site index. As the Dq model includes stand density in its formulation, it can predict tree growth for different stand densities and thinning regimes. The mortality model is based on a simple attritional equation improved through incorporation of the Reineke stand density index to account for competition-induced mortality. Using these components, the model precisely estimates stand-level volume. The developed model will be of considerable value to growers for yield projection and regime evaluation. By more robustly describing the site effect, the growth model provides researchers with an improved framework for quantifying and understanding the causes of spatial and temporal variation in plantation productivity.

Yields of Southwestern Pinyon-Juniper Woodlands

1988 ◽  
Vol 3 (3) ◽  
pp. 70-74 ◽  
Author(s):  
Frederick W. Smith ◽  
Thomas Schuler
Keyword(s):  
Maximum Yield ◽  
Stand Density ◽  
Site Index ◽  
Average Density ◽  
Pinus Edulis ◽  
Site Quality ◽  
Mixed Species ◽  
Growing Stock ◽  
Highly Correlated ◽  
Utah Juniper

Abstract Site quality and growth-growing stock relations were developed for southwestern woodlands of pinyon (Pinus edulis) and one-seed juniper (Juniperus monosperma) or Utah juniper (J. osteosperma). Anamorphic height-age site index curves for pinyon were developed from a regional sample of 60 woodlands. Site index was unaffected by variation in stocking and was correlated with woodland yield when used in conjunction with density. Pinyon and juniper PAI, when taken separately, were highly correlated with stand density and pinyon site index. Pinyon was twice as productive as juniper at similar stand densities. Pinyon and juniper yields in woodlands of average density and site index were estimated at 0.29 and 0.15 m3ha-1y-1. At high densities pinyon and juniper yields increased to 0.61 and 0.31 m3ha-1y-1 Pinyon and juniper yields appeared independent of the density of the other species in an individual woodland. Maximum yield of dense mixed species woodlands on average sites was 0.78 m3ha-1y-1, and occurred when pinyon constituted 65% of woodland density. West. J. Appl. For. 3(3):70-74, July 1988.

Sign in / Sign up

Export Citation Format

Share Document