Growth Reductions in Naturally Regenerated Southern Pine Stands in Alabama and Georgia

1991 ◽  
Vol 15 (2) ◽  
pp. 73-79 ◽  
Author(s):  
G. A. Ruark ◽  
C. E. Thomas ◽  
W. A. Bechtold ◽  
D. M. May
Keyword(s):  
Pinus Taeda ◽  
Growth Rates ◽  
Stand Structure ◽  
Basal Area ◽  
Stand Density ◽  
Site Quality ◽  
Usda Forest Service ◽  
Forest Inventory And Analysis ◽  
Pine Stands ◽  
Growth Differences

Abstract Data from Forest Inventory and Analysis (FIA) units of the USDA Forest Service were used to compare average annual stand-level basal area accretion onto survivor pines in naturally regenerated pine stands throughout Alabama and Georgia. Growth rates measured between 1972-82 were compared to growth rates during the previous 10-year survey cycle in each state. Separate analyses were conducted for loblolly (Pinus taeda), longleaf (P. palustris), shortleaf (P. echinata), and slash (P. elliottii) pine cover types. The unadjusted average stand-level growth rates for survivor pines 1.0 in. diameter and greater at breast height were notably lower for all cover types during the latter survey in Georgia, while only the average unadjusted growth of shortleaf was substantially lower during this period in Alabama. However, when growth rates were adjusted with regression models to account for differences in initial stand structure (stand size class, stand density, site quality class, hardwood competition, and mortality) between the two survey periods, reductions in average adjusted basal area growth ranged from 3% to 31% during the later cycle in both states. The reductions were statistically significant in almost every case. The agents causing the growth differences were not identified, but it is unlikely that stand dynamics are responsible. The observational nature of the FIA dataset precludes further resolution of causal relationships. South. J. Appl. For. 15(2):73-79.

scholarly journals A Density Management Diagram for Even-aged Ponderosa Pine Stands

2005 ◽  
Vol 20 (4) ◽  
pp. 205-215 ◽  
Author(s):  
James N. Long ◽  
John D. Shaw
Keyword(s):  
Ponderosa Pine ◽  
Selection Criteria ◽  
Basal Area ◽  
Stand Density ◽  
Geographic Area ◽  
Western United States ◽  
Selection System ◽  
Forest Inventory And Analysis ◽  
Pine Stands ◽  
Stand Density Index

Abstract We developed a density management diagram (DMD) for ponderosa pine using Forest Inventory and Analysis (FIA) data. Analysis plots were drawn from all FIA plots in the western United States on which ponderosa pine occurred. A total of 766 plots met the criteria for analysis. Selection criteria were for purity, defined as ponderosa pine basal area ≥80% of plot basal area, and even-agedness, as defined by a ratio between two calculations of stand density index. The DMD is relatively unbiased by geographic area and therefore should be applicable throughout the range of ponderosa pine. The DMD is intended for use in even-aged stands, but may be used for uneven-aged management where a large-group selection system is used. Examples of density management regimes are illustrated, and guidelines for use are provided. West. J. Appl. For. 20(4):205–215.

scholarly journals Loblolly and Slash Pine Growth and Yield Prediction for Regional Timber Supply Projection Algorithms

1999 ◽  
Vol 23 (4) ◽  
pp. 230-237
Author(s):  
Bruce E. Borders ◽  
Jeffrey B. Jordan
Keyword(s):  
Loblolly Pine ◽  
Analysis Data ◽  
Growth And Yield ◽  
Yield Prediction ◽  
Projection Algorithms ◽  
Timber Supply ◽  
Usda Forest Service ◽  
Forest Inventory And Analysis ◽  
Pine Stands ◽  
Growth And Yield Models

Abstract Regional and national timber supply models require standing inventory update procedures. To date, most inventory update procedures used in regional timber supply algorithms have not made use of growth and yield methodology. We present growth and yield models to update standing inventories for natural and planted slash and loblolly pine stands in Georgia. These models were fitted to USDA Forest Service Forest Inventory and Analysis data obtained from the sixth survey of Georgia and should prove useful in regional timber supply projection algorithms. South. J. Appl. For. 23(4):230-237.

Population dynamics of sugar maple through the southern portion of its range: implications for range migration

Botany ◽  
2014 ◽  
Vol 92 (8) ◽  
pp. 563-569 ◽  
Author(s):  
Justin L. Hart ◽  
Christopher M. Oswalt ◽  
Craig M. Turberville
Keyword(s):  
Forest Inventory ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Basal Area ◽  
Usda Forest Service ◽  
Forest Inventory And Analysis ◽  
Southern Boundary ◽  
Range Boundary ◽  
The Stability ◽  
Biophysical Changes

The range of sugar maple (Acer saccharum Marsh.) is expected to shift northward in accord with changing climate. However, a pattern of increased sugar maple abundance has been reported from sites throughout the eastern US. The goal of our study was to examine the stability of the sugar maple southern range boundary by analyzing its demography through the southern extent of its distribution. We analyzed changes in sugar maple basal area, relative frequency, relative density, relative importance values, diameter distributions, and the ratio of sapling biomass to total sugar maple biomass at three spatial positions near the southern boundary of the species’ range using forest inventory data from the USDA Forest Service Forest Inventory and Analysis program over a 20 year observation period (1990–2010). We contend that the southern range boundary of sugar maple neither contracted nor expanded during this period. We speculated that biophysical changes caused by succession may provide a short-lived ameliorative barrier to a rapid southern range contraction for some species. The eclipse of some greater climate change threshold may therefore be required to realize significant range movement for mesophytic tree species.

scholarly journals Site factors and stand conditions associated with Persian oak decline in Zagros mountain forests

2018 ◽  
Vol 26 (3) ◽  
pp. e014 ◽  
Author(s):  
Ahmad Hosseini ◽  
Seyed M. Hosseini ◽  
Juan C. Linares
Keyword(s):  
Climate Change ◽  
Tree Mortality ◽  
Stand Structure ◽  
Basal Area ◽  
Stand Density ◽  
Change Scenario ◽  
Climate Trends ◽  
Site Factors ◽  
Main Hypothesis ◽  
Shallow Soils

Aim of study: Drought and stand structure are major and interconnected drivers of forest dynamics. Water shortage and tree-to-tree competition may interact under the current climate change scenario, increasing tree mortality. In this study, we aimed to investigate climate trends, site and stand structure effects on tree mortality, with the main hypothesis that drought-induced mortality is higher as competition increases.Area of study: Persian oak forests from Zagros Range, western Iran.Material and Methods: We split the study area into 20 topographical units (TUs), based on aspect, slope and elevation. In each TU, three 0.1 ha plots were established to quantify site and stand characteristics, namely the diameter of all trees and shrubs, stand density and basal area, canopy dieback and mortality. In addition, soil profiles were analyzed to obtain physical and chemical soil properties. Six transects 100 m length were established per TU to measure tree-to-tree competition for alive and dead trees.Main Results: The highest mortality rates and crown dieback were found at higher elevations and southern and western aspects. Our findings confirm increasing rates of tree mortality in stands with higher tree density and shallow soils. As regard links between climate change and forest decline, our results suggest that changing forest structure may have a significant impact on dust emission.Research highlights: Despite severe dry years occurred recently the study area, they are not significantly different than those recorded in the past. Stand structure appears as a modulating factor of climate change effects, linked to competition-related tree vulnerability to drought.

scholarly journals Lowering Stand Density Enhances Resiliency of Ponderosa Pine Forests to Disturbances and Climate Change

2019 ◽  
Vol 65 (4) ◽  
pp. 496-507 ◽  
Author(s):  
Jianwei Zhang ◽  
Kaelyn A Finley ◽  
Nels G Johnson ◽  
Martin W Ritchie
Keyword(s):  
Climate Change ◽  
Tree Growth ◽  
Ponderosa Pine ◽  
Tree Mortality ◽  
Ring Width ◽  
Basal Area ◽  
Stand Density ◽  
Site Quality ◽  
Climate Trends ◽  
Ponderosa Pine Forests

AbstractStand density affects not only structure and growth, but also the health of forests and, subsequently, the functions of forest ecosystems. Here, we integrated dendrochronology and repeated inventories for ponderosa pine research plots to determine whether long-term growth and mortality responded to climate trends and how varying stand density influenced the responses. The plots were established prior to 1975 on existing stands throughout northern California. Although annual temperature increased consistently for the last 65 years, ring-width indices produced by eliminating age and thinning effects failed to detect radial trend regardless of site quality. However, interannual variation for the indices was substantial, reflecting a strong influence of climate on tree growth. Plot-level basal area increments were significantly affected by tree mortality. Stand density index explained most variation of mortality. Lowering stand density enhanced remaining tree growth, reduced mortality, and increased stand resiliency to disturbances and climate change. Besides higher climate moisture indices or lower vapor pressure deficits, any treatments that improve tree vigor and reduce stress will have a similar effect to reducing stand density. Although neither biotic disturbances nor abiotic conditions can be controlled, forest managers can manage stand density appropriately to enhance resilience to climate change and disturbances.

Stand structure, thinning prescriptions, and density indexes in a Douglas-fir thinning study, Western Washington, U.S.A.

1983 ◽  
Vol 13 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Chadwick Dearing Oliver ◽  
Marshall D. Murray
Keyword(s):  
Stand Structure ◽  
Volume Growth ◽  
Basal Area ◽  
Stand Density ◽  
Close Relation ◽  
Douglas Fir ◽  
Volume Number ◽  
Large Trees ◽  
Before And After ◽  
Number Of Stems

A Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) thinning study was established in 1959 in a stand begun after logging in 1930. Thinnings to set basal area densities were done in 1959, 1962, 1966, and 1970. On each plot both large and small trees were removed since average basal area per tree was kept constant before and after thinning. Volume growth varied greatly between plots of the same age, initial basal area, and site because of differences in stand structure. Large trees on a plot grew more per tree and per basal area than small trees. Stand basal area, stand volume, number of stems, or number of dominant and codominant trees were not closely related to volume growth per hectare, although density indexes giving weight to larger trees showed the closest relation. The lack of close relation between stand density indexes and growth found here and elsewhere probably means the indexes do not uniquely define stand structures; it does not necessarily mean that thinning will not increase volume growth per hectare. Volume growth per hectare after thinning to a given basal area density will be greater and probably more consistent if larger trees are left and enough time is allowed for the stand to recover following thinning.

Sawtimber Volume Predictions for Uneven-Aged Loblolly-Shortleaf Pine Stands on Average Sites

1983 ◽  
Vol 7 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Paul A. Murphy ◽  
Robert M. Farrar
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Site Index ◽  
Selection System ◽  
Pinus Echinata ◽  
Shortleaf Pine ◽  
Elapsed Time ◽  
Pine Stands ◽  
Pinus Taeda L

Abstract Equations are given to estimate current and projected sawtimber volumes and projected basal area of the sawtimber portion of uneven-aged loblolly-shortleaf (Pinus taeda L.-Pinus echinata Mill.) pine stands managed under the selection system. The independent variables are elapsed time, initial merchantable basal area, and the initial ratio of sawtimber basal area to merchantable basal area. The results should provide guidelines for the board-foot and cubic-foot production of sawtimber-sized trees in uneven-aged stands that occur on average sites (site index 90, loblolly pine) in the Coastal Plain.

scholarly journals Evaluating and modeling variation in site-level maximum carrying capacity of mixed-species forest stands in the Acadian Region of northeastern North America

2019 ◽  
Vol 95 (03) ◽  
pp. 171-182 ◽  
Author(s):  
Aaron R. Weiskittel ◽  
Christian Kuehne
Keyword(s):  
North America ◽  
Prediction Model ◽  
Carrying Capacity ◽  
Stand Structure ◽  
Regional Scale ◽  
Basal Area ◽  
Climatic Variables ◽  
Site Quality ◽  
Forest Stands ◽  
Mixed Species

Currently no universal approach exists to estimate regional site-level maximum carrying capacity in terms of stand densityindex (SDIMAX) of mixed species stands across contrasting forest ecosystems. Regional research efforts that account forinfluential stand-level variables and species traits are needed to reliably derive SDIMAX under varying environmental conditions and stand characteristics. This study used regionally comprehensive forest inventory data from various permanentsampling efforts to evaluate the effects of contrasting biotic and abiotic stand- and site-level factors on SDIMAX of multiple-species, structurally heterogeneous stands of the climatically diverse Acadian Forest Region of North America. Specifically,we aimed to i) quantify the stand-level maximum size-density line for an array of forest stands found across the study area,irrespective of stand structure; ii) evaluate the relationship between this stand-specific estimate of SDIMAX and various other stand-level attributes; and, iii) develop a generalized SDIMAX prediction model using SDIMAX estimates from objective i) aswell as potential regional drivers of SDIMAX from objective ii). The most influential stand-level factors on SDIMAX were proportion of total stand basal area in hardwood species, basal area weighted mean specific gravity, range in stem diameter, andspecies diversity. Direct climatic variables were not included in our SDIMAX prediction model due to the limited variationexplained, but relationships with elevation and a site quality index based on these climatic variables were. Overall, we con-clude that i) variation in SDIMAX appears to be mostly driven by the softwood to hardwood ratio of the mixed species,structurally complex stands evaluated in our study and ii) the general approach offers a viable framework for estimating sitemaximum carrying capacity at a regional-scale and effectively managing stand density accordingly.

Recovery and Development of Understocked Loblolly-Shortleaf Pine Stands

1989 ◽  
Vol 13 (3) ◽  
pp. 132-139 ◽  
Author(s):  
James B. Baker
Keyword(s):  
Pinus Taeda ◽  
Growth And Development ◽  
Basal Area ◽  
Shortleaf Pine ◽  
Stand Growth ◽  
Good Site ◽  
Rehabilitation Period ◽  
Pine Stands ◽  
Pinus Taeda L ◽  
Time Required

Abstract Plots in two uneven-aged loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands were cut back to stocking levels of approximately 10, 20, 30, 40, and 50% to simulate cutover, understocked stands. One stand was on a good site (SI = 90 ft at age 50), the other on a medium site(SI = 75 ft at age 50). As a rehabilitation treatment, all hardwoods 1-in. or larger in groundline diameter were injected with Tordon 101®. Two and 5 years later, the plots were reinventoried to determine stand growth and development. During the 5-year rehabilitation period the understockedstands changed dramatically, and because of the rapid growth of the pines left in the residual stands, stocking levels, basal areas, and tree volumes increased markedly. Average increases in stocking level, basal area, pulpwood, and sawlog volume were 40, 155, 160, and 355%, respectively,for the good site and 35, 110, 125, and 220% for the medium site. Projections of the time required for understocked stands to reach an acceptable stocking level of 60% (based on number and size of trees), or 45 ft² of basal area per acre, indicate that stands having at least 15 to 25%stocking, or 5 ft² of basal area per acre, can reach an acceptable stocking level in 15 years or less at a rehabilitation cost of $45 to $50 per acre. South. J. Appl. For. 13(3):132-139.

scholarly journals Stand Density Index for Loblolly Pine Plantations in North Louisiana

1996 ◽  
Vol 20 (2) ◽  
pp. 110-113 ◽  
Author(s):  
Roger A. Williams
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Basal Area ◽  
Stand Density ◽  
Pine Plantations ◽  
Density Index ◽  
Pinus Taeda L ◽  
Stand Density Index ◽  
North Louisiana

Abstract Stand Density Index (SDI) equations and diagrams were developed and presented for loblolly pine (Pinus taeda L.) plantations in north Louisiana. Two different SDI diagrams are presented—one that utilizes the number of trees per acre and average stand diameter, and a second that uses the number of trees per acre and the basal (ft²) per acre. Basal area is presented as a second alternative to average stand diameter since many practicing foresters commonly use basal area for density management. South. J. Appl. For. 20(2):110-113.

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