Interim Site-index Curves for Longleaf Pine Plantations

1980 ◽  
Author(s):  
William D. Boyer
Keyword(s):  
Longleaf Pine ◽  
Site Index ◽  
Pine Plantations

Modelling the susceptibility of pine stands to bark stripping by Chacma baboons (Papio ursinus) in the Mpumalanga Province of South Africa

2017 ◽  
Vol 44 (4) ◽  
pp. 298 ◽  
Author(s):  
Ilaria Germishuizen ◽  
Kabir Peerbhay ◽  
Riyad Ismail
Keyword(s):  
South Africa ◽  
Random Forests ◽  
Risk Evaluation ◽  
Site Index ◽  
Pine Plantations ◽  
Bark Stripping ◽  
Papio Ursinus ◽  
Mpumalanga Province ◽  
Chacma Baboons ◽  
Pinus Spp

Context Commercial pine (Pinus spp.) plantations in southern Africa have been subjected to bark stripping by Chacma baboons (Papio ursinus) for many decades, resulting in severe financial losses to producers. The drivers of this behaviour are not fully understood and have been partially attributed to resource distribution and availability. Aims The study sought to develop a spatially explicit ecological-risk model for bark stripping by baboons to understand the environmental factors associated with the presence of damage in the pine plantations of the Mpumalanga province of South Africa. Methods The model was developed in Random Forests, a machine learning algorithm. Baboon damage information was collected through systematic surveys of forest plantations conducted annually. Environmental predictors included aspects of climate, topography and compartment-specific attributes. The model was applied to the pine plantations of the study area for risk evaluation. Key results The Random Forests classifier was successful in predicting damage occurrence (F1 score=0.84, area under curve (AUC)=0.96). Variable predictors that contributed most to the model classification accuracy were related to pine-stand characteristics, with the age of trees being the most important predictor, followed by species, site index and altitude. Variables pertaining to the environment surrounding a pine stand did not contribute substantially to the model performance. Key conclusions (1) The study suggests that bark stripping is influenced by compartment attributes; (2) predicted risk of bark stripping is higher in stands above the age of 5 years planted on high-productivity forestry sites, where site index (SI) is above 25; (3) presence of damage is not related to the proximity to natural areas; (4) further studies are required to investigate ecological and behavioural patterns associated with bark stripping. Implications The model provides a tool for understanding the potential extent of the risk of bark stripping by baboons within this region and it can be applied to other forestry areas in South Africa for risk evaluation. It contributes towards the assessment of natural hazards potentially affecting pine plantations and supports the development of risk-management strategies by forest managers. The model highlights opportunities for cultural interventions that may be tested for damage control.

scholarly journals Dynamic Site Index Equation for Thinned Stands of Even-Aged Natural Longleaf Pine

2010 ◽  
Vol 34 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Dwight K. Lauer ◽  
John S. Kush
Keyword(s):  
Longleaf Pine ◽  
Pinus Palustris ◽  
Site Index ◽  
The United States ◽  
Permanent Plots ◽  
Gulf Region ◽  
Dummy Variable ◽  
Variable Approach ◽  
One Step ◽  
Generalized Algebraic Difference Approach

Abstract A dynamic site equation derived using the generalized algebraic difference approach was developed for thinned stands of natural longleaf pine (Pinus palustris Mill.) in the East Gulf region of the United States using 40 years of measurements on 285 permanent plots. The base model predicts height growth of trees once they reach 4.5 ft and was fit using a varying parameter for each tree and global parameters that are constant for all 3,267 trees. Parameters were estimated in one step using the dummy variable approach and a first-order autoregressive error term to account for serial correlation. The final base-age invariant equation allows the user to specify the number of years required for trees to reach 4.5 ft in height.

Site Index Curves for Loblolly Pine Plantations on Cutover Site-Prepared Lands

1985 ◽  
Vol 9 (3) ◽  
pp. 166-169 ◽  
Author(s):  
Ralph L. Amateis ◽  
Harold E. Burkhart
Keyword(s):  
Differential Equation ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Pine Plantations ◽  
The South ◽  
Stem Analysis ◽  
Natural Range

Abstract Stem analysis data collected from dominant and codominant loblolly pine (Pinus taeda) trees in cutover, site-prepared plantations were used to develop site index curves. The data were collected over much of the natural range of loblolly pine. A separable differential equation which expresses height growth as a function of both height and age was used to develop the site index curves. These site index curves should be applicable to loblolly pine plantations on cutover, site-prepared lands through much of the South.1

Postthinning growth and yield of row-thinned and selectively thinned loblolly and slash pine plantations

1989 ◽  
Vol 19 (2) ◽  
pp. 247-256 ◽  
Author(s):  
V. C. Baldwin Jr. ◽  
D. P. Feduccia ◽  
J. D. Haywood
Keyword(s):  
Loblolly Pine ◽  
Unit Area ◽  
Basal Area ◽  
Site Index ◽  
Slash Pine ◽  
Pine Plantations ◽  
Growth And Yield ◽  
Growth Responses ◽  
Diameter Increment ◽  
Study Results

This study compared growth responses in planted loblolly pine (Pinustaeda L.) and slash pine (P. elliottii Engelm.) stands thinned by using three row-felling methods and at the same density levels, three selective felling methods. The study plots were in six plantations, aged 15–22 years, located in central Louisiana. Growth was measured 5 and 10 years after plot installation. Site index varied from 19.5 to 31.7 m (base age 50) and initial planting densities ranged from 1993 to 2989 trees/ha. Study results show there will likely be less diameter increment and less net basal area and cubic-metre volume per unit area growth and yield, and the growth will be in smaller-sized trees, if row thinning is used rather than selective thinning from below. These differences will probably be greater in slash pine plantations than in loblolly pine plantations.

Impact of cogongrass management strategies on generalist predators in cogongrass-infested longleaf pine plantations

2015 ◽  
Vol 71 (3) ◽  
pp. 478-484 ◽  
Author(s):  
Sallie M Sells ◽  
David W Held ◽  
Stephen F Enloe ◽  
Nancy J Loewenstein ◽  
Lori G Eckhardt
Keyword(s):  
Longleaf Pine ◽  
Management Strategies ◽  
Pine Plantations ◽  
Generalist Predators

Color Aerial Photography for Assessing the Need for Fertilizers in Loblolly Pine Plantations

1988 ◽  
Vol 12 (4) ◽  
pp. 270-273 ◽  
Author(s):  
Charles R. Blinn ◽  
Al Lyons ◽  
Edward R. Buckner
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Aerial Photography ◽  
Basal Area ◽  
Site Index ◽  
Pine Plantations ◽  
Color Coding ◽  
Foliar N ◽  
Significant Relationships ◽  
Pinus Taeda L

Abstract Color aerial photography was used to assess crown color classes in loblolly pine (Pinus taeda L.) plantations. Three distinct Munsell color classes were delineated on the resulting photographs. Foliar N levels and, to a lesser degree, foliar K levels were directly related to color. Significant relationships between color and site index and color and basal area were shown. Application of color aerial photography, combined with Munsell color coding, could expedite land classification and also make possible more efficient use of fertilizers. South J. Appl. For. 12(4):270-273.

Assessing multiple estimates of plantation productivity

1989 ◽  
Vol 19 (8) ◽  
pp. 948-954 ◽  
Author(s):  
David D. Reed ◽  
Elizabeth A. Jones
Keyword(s):  
Site Index ◽  
Classification Systems ◽  
Pine Plantations ◽  
Annual Increment ◽  
Habitat Classification ◽  
Soil Site ◽  
Plantation Productivity ◽  
Mean Annual Increment ◽  
True Values ◽  
Forest Managers

Forest managers are often faced with several estimates of plantation productivity. Not only are there different measures of productivity, such as site index or mean annual increment at some fixed age, but estimates of each may be obtained from several sources, including habitat classification systems, soil site equations, and growth measures from young stands. Site index cannot be truly observed until the stand reaches index age, and mean annual increment cannot be truly observed without measuring standing volume at the age of interest. Without observations of these "true" values, common measures of accuracy have only generally evaluated performance compared to a standard method that accurately predicts these values. In this paper, a technique of assessing alternative estimates of site index and mean annual increment in the absence of observations of the true values is presented and is illustrated through a quantitative evaluation of the alternative productivity estimates for young red pine plantations.

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