Long-Term Response of Planted Ponderosa Pine to Thinning in Oregon's Blue Mountains

1993 ◽  
Vol 8 (4) ◽  
pp. 126-132 ◽  
Author(s):  
P. H. Cochran ◽  
James W. Barrett
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Mountain Pine Beetle ◽  
Volume Growth ◽  
Basal Area ◽  
Stand Density ◽  
Growth Potential ◽  
Average Height ◽  
Stand Density Index ◽  
John Day

Abstract A spacing study in ponderosa pine (Pinus ponderosa) was established in 1959 by thinning plots in a 33-yr-old plantation near John Day, Oregon. The influence of 4 spacings (17.2, 12.5, 10.1, and 8.7 ft) on stand and tree growth for a 31-yr period was examined. Study plots were remeasured five times after establishment. Periodic annual increments (PAI) of gross basal area, gross volume, and average height differed with period but not with spacing (P ≤ 0.10). The PAIs of mean diameter differed with period and decreased with increasing density. Annual height growth and annual gross and net growth of basal area and volume did not differ with spacing. Annual diameter growth was much greater for trees at the widest spacing. Annual volume growth of the largest 90 trees/ac was greatest at the widest spacing. Thirty-one years after thinning, the largest 90 trees/ac on the widest spacing had 73% of the volume of all the trees on the narrowest spacing. Mortality due to mountain pine beetle (Dendroctonus ponderosae) increased markedly when values for stand density index exceeded 200. Wide spacings increased average tree volumes, increased mean diameters, and reduced the probability of mortality without sacrificing gross cubic volume growth potential. West. J. Appl. For. 8(4):126-132.

Thinning ponderosa pine (Pinus ponderosa) stands reduces mortality while maintaining stand productivity

2013 ◽  
Vol 43 (4) ◽  
pp. 311-320 ◽  
Author(s):  
Jianwei Zhang ◽  
Martin W. Ritchie ◽  
Douglas A. Maguire ◽  
William W. Oliver
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Bark Beetles ◽  
Basal Area ◽  
Stand Density ◽  
Growth Efficiency ◽  
Stand Age ◽  
Annual Increment ◽  
Stand Productivity ◽  
Residual Variation

We analyzed 45 years of data collected from three ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) levels-of-growing-stock installations in Oregon (OR) and northern California (CA), USA, to determine the effect of stand density regimes on stand productivity and mortality. We found that periodic annual increment (PAI) of diameter, basal area (BA), volume, and aboveground dry mass were significantly related to stand density index (SDI) and stand age at start of the period; the quadratic trends varied among sites. Precipitation departure from the normal for each period explained a significant amount of residual variation in all PAI variables except diameter. BA production did not change significantly as SDI exceeded 270 trees·ha−1 at the OR sites and 320 trees·ha−1 at the CA site. Stand productivity was the highest at Elliot Ranch (CA) and the least at Blue Mountains (OR). A similar trend held in growth efficiency under lower stand densities (SDI < 600). Most of the mortality was caused by Dendroctonus bark beetles in stands that exceeded SDI of 500 trees·ha−1. Limiting SDI was about 900 trees·ha−1, although plots at Elliot Ranch reached much higher than that. The results demonstrate that silvicultural control of stand density can be a powerful tool for reducing bark beetle caused mortality without sacrificing stand productivity.

Short-Term Impacts of Thinning Ponderosa Pine on Pandora Moth Densities, Pupal Weights, and Phenology

1995 ◽  
Vol 10 (3) ◽  
pp. 91-94
Author(s):  
Darrell W. Ross
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Basal Area ◽  
Stand Density ◽  
Adult Emergence ◽  
Adult Density ◽  
Egg Hatch ◽  
Second Growth ◽  
Insect Phenology ◽  
Foliage Weight

Abstract Second-growth ponderosa pine (Pinus ponderosa) stands with outbreak populations of the pandora moth (Coloradia pandora) were thinned from below removing about half of the basal area. Thinning had no effect on pandora moth pupal density or weight, or emerging adult density in the following generation. However, adult emergence and egg hatch occurred 7-10 days earlier in thinned plots compared with unthinned plots. Egg and larval densities on a foliage weight basis were not significantly different between thinned and unthinned plots. Thinning stands infested with pandora moth will not significantly affect the course of an outbreak for at least one generation. Timing of direct controls for the pandora moth should consider the effect of stand density on insect phenology. West. J. Appl. For. 10(3):91-94.

Double Sampling Increases the Efficiency of Forest Floor Inventories for Arizona Ponderosa Pine Forests

1994 ◽  
Vol 4 (1) ◽  
pp. 3 ◽  
Author(s):  
PZ Fule ◽  
WW Covington
Keyword(s):  
Ponderosa Pine ◽  
Basal Area ◽  
Stand Density ◽  
Cost Effective ◽  
Pine Forests ◽  
Double Sampling ◽  
Fuel Loading ◽  
Size Classes ◽  
Ponderosa Pine Forests ◽  
Stand Density Index

Stand and natural fuel conditions were sampled in ponderosa pine forests in northern and central Arizona to develop predictive fuel depth and loading equations. Litter and duff depths can be estimated from measurements of stand density (basal area, stand density index). Although woody fuel loading did not correlate well with stand variables, correlations were found among loadings of different woody fuel size classes, so that results from a planar intersect tally of certain single woody fuel size classes may be used to predict the loadings in certain other size classes. The relatively low precision of estimates from these predictive equations can be substantially increased by applying them in a double sampling scheme. Making use of these predictive relationships, managers can devise simple, rapid, arid cost-effective fuel inventories that focus on the fuel category of interest. Fuel loads can be estimated at a desired precision with reduced investment of time and funds compared to a more comprehensive direct fuel inventory.

scholarly journals Thinning Ponderosa Pine Affected by Armillaria Root Disease: 40 Years of Growth and Mortality on an Infected Site in Central Oregon

2009 ◽  
Vol 24 (2) ◽  
pp. 88-94 ◽  
Author(s):  
Gregory M. Filip ◽  
Stephen A. Fitzgerald ◽  
Kristen L. Chadwick ◽  
Timothy A. Max
Keyword(s):  
Ponderosa Pine ◽  
Tree Mortality ◽  
Basal Area ◽  
Stand Density ◽  
Root Disease ◽  
Precommercial Thinning ◽  
Fungal Host ◽  
Commercial Thinning ◽  
Armillaria Root Disease ◽  
Stand Density Index

Abstract Portions of a 30-year-old stand of ponderosa pine were precommercially thinned in 1966 and commercially thinned in 2000 at age 64 years to determine the effects of thinning from below on tree growth and mortality caused by Armillaria root disease in central Oregon. Thirty years after precommercial thinning, leave-tree mortality was significantly less in thinned plots than in unthinned plots, but leave-treeߝdiameter growth was not significantly increased by thinning. Leave-tree basal area (BA) per acre growth, however, was significantly greater in thinned plots.In 2007 at age 71 years, 7 years after commercial thinning of the same plots that were precommercially thinned in 1966, leave-tree mortality was less in thinned plots than in unthinned plots, but more time probably is necessary to adequately assess Armillaria-caused mortality after commercial thinning. Both tree diameter and BA growth were significantly increased by commercial thinning. Hypotheses on fungal-host dynamics are discussed, and recommendations for multiple thinning based on stand density index are given.

scholarly journals Twenty-Five-Year Growth and Mortality of Planted Ponderosa Pine Repeatedly Thinned to Different Stand Densities in Northern California

1997 ◽  
Vol 12 (4) ◽  
pp. 122-130 ◽  
Author(s):  
William W. Oliver
Keyword(s):  
Sierra Nevada ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Bark Beetles ◽  
Basal Area ◽  
Stand Density ◽  
Northern California ◽  
Winter Storms ◽  
Randomized Design ◽  
Lower Site

Abstract A 20 yr old ponderosa pine (Pinus ponderosa var. ponderosa) plantation on a productive site on the west slope of the Sierra Nevada in northern California was thinned four times over a 25 yr period. Stand densities tested were Stand Density Indexes (SDI) of 73, 128, 183, 238, and 293 (equivalent to 40,70,100,130, and 160 ft2/ac of basal area), replicated three times in a randomized design. Growth was analyzed for each of five 5 yr periods. Periodic annual increments (PAI) of diameter, net basal area, and net total volume differed significantly among periods and, in the earlier periods, among stocking levels. Mortality from winter storms and bark beetles was largely confined to the higher stand densities and in periods 3 and 4 caused PAIs of net basal area and net total volume to decline below that of lower densities. The sensitivity of mortality to stand density suggests a thinning target of SDI 183 (about 100 ft²/ac of basal area) for similar stands—no higher than that recommended for eastside stands of much lower site productivity. This sensitivity coupled with rapid growth suggests that multiple thinnings will be necessary in similar stands to maintain healthy, vigorous trees. West. J. Appl. For. 12(4):122-130.

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.

Vegetation responses to stand structure and prescribed fire in an interior ponderosa pine ecosystemThis article is one of a selection of papers from the Special Forum on Ecological Studies in Interior Ponderosa Pine — First Findings from Blacks Mountain Interdisciplinary Research.

2008 ◽  
Vol 38 (5) ◽  
pp. 909-918 ◽  
Author(s):  
Jianwei Zhang ◽  
Martin W. Ritchie ◽  
William W. Oliver
Keyword(s):  
Pinus Ponderosa ◽  
Prescribed Fire ◽  
Ponderosa Pine ◽  
Large Scale ◽  
Stand Structure ◽  
Basal Area ◽  
Stand Density ◽  
Structural Diversity ◽  
Ponderosa Pine Forest ◽  
Selection Of

A large-scale interior ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) study was conducted at the Blacks Mountain Experimental Forest in northeastern California. The primary purpose of the study was to determine the influence of structural diversity on the dynamics of interior pine forests at the landscape scale. High structural diversity (HiD) and low structural diversity (LoD) treatments were created with mechanical thinning on 12 main plots. Each plot was then split in half with one-half treated with prescribed fire. During the 5 year period after the treatments, the LoD treatments showed slightly higher periodic annual increments for basal area (BA) and significantly higher diameter increments than did the HiD treatments, although HiD carried twice as much BA as LoD did immediately after the treatments. Prescribed fire did not affect growth, but killed and (or) weakened some trees. No interaction between treatments was found for any variable. Stand density was reduced from the stands before treatments, but species composition did not change. Old dominant trees still grew and large snags were stable during the 5 year period. Treatments had minor impacts on shrub cover and numbers. These results suggest that ponderosa pine forest can be silviculturally treated to improve stand growth and health without sacrificing understory shrub diversity.

Density-dependent population dynamics of mountain pine beetle in thinned and unthinned stands

2011 ◽  
Vol 41 (5) ◽  
pp. 1031-1046 ◽  
Author(s):  
Chris J.K. MacQuarrie ◽  
Barry J. Cooke
Keyword(s):  
Population Dynamics ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Bark Beetles ◽  
Mountain Pine Beetle ◽  
Basal Area ◽  
Mortality Data ◽  
Density Dependent ◽  
Mountain Pine ◽  
Pine Beetle

Thinning, the selective removal of some trees from a forest, is one way forest managers can reduce the probability that a forest will be susceptible to attack by bark beetles. Although this method has been shown to be effective, it is not clear whether the effect arises when pre-outbreak populations are small or during the epidemic phase when outbreaks are growing. We adopted a population dynamics approach to determine if the effect of limit or basal area thinning could be observed in the form of differential beetle recruitment using lodgepole pine ( Pinus contorta Dougl. ex Loud.) and ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) mortality data from previously published studies as a proxy measure of mountain pine beetle ( Dendroctonus ponderosae Hopkins) population size. We found that mountain pine beetle populations exhibit density-dependent population dynamics that are influenced by the silvicultural history of their host’s stand. Thinning did not change the epidemic equilibrium but instead caused a shift in dynamics from linear to nonlinear. In a validation test, the models developed for thinned and unthinned stands predicted reproductive rates in independent locations. These data also suggest the epidemic dynamics of mountain pine beetle may be sensitive to perturbations and to systematic trends associated with climate variability and climate change.

Patterns of size variation over time in ponderosa pine stands established at different initial densities

2016 ◽  
Vol 46 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Kathryn I. McGown ◽  
Kevin L. O’Hara ◽  
Andrew Youngblood
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Size Variation ◽  
Basal Area ◽  
Stand Density ◽  
Absolute Size ◽  
Time Period ◽  
Symmetric Competition ◽  
Skewness Coefficient ◽  
Initial Spacing

We used six metrics of size and growth variation (standard deviation (SD), coefficient of variation (CV), skewness coefficient (S), Gini coefficient (G), Lorenz asymmetry coefficient (LAC), and growth dominance coefficient (GD)) to describe changes in two long-term ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) initial spacing trials in Oregon and Washington, USA. Trends were examined over a 35-year time period and across a range of initial stand densities (from 154 to 2470 trees·ha−1) for four measures of tree size: diameter at breast height (dbh, 1.37 m), basal area (BA), height, and volume. Unlike many previous studies of size variation in monospecific stands, our results suggest that variation declined or remained relatively stable for all treatments at both study areas. This suggests that these stands are experiencing size symmetric competition for belowground resources. We found that a combination of metrics is necessary to provide a complete picture of size variability and differentiation in developing stands. We recommend using the CV or G, as there were clear trends with increasing density for all size variables. If the objective of the assessment was to track changes in absolute size within an individual stand, we would recommend using the SD, as there were consistent trends with time for all size variables. S, LAC, and GD may be less suited for comparing differentiation during the early stages of stand development because of a lack of clear trends with stand density and time.

The effect of local stand structure on growth and growth efficiency in heterogeneous stands of ponderosa pine and lodgepole pine in central Oregon

2004 ◽  
Vol 34 (11) ◽  
pp. 2217-2229 ◽  
Author(s):  
Douglas B Mainwaring ◽  
Douglas A Maguire
Keyword(s):  
Leaf Area ◽  
Ponderosa Pine ◽  
Lodgepole Pine ◽  
Volume Growth ◽  
Basal Area ◽  
Growth Efficiency ◽  
Projection Area ◽  
Sapwood Area ◽  
Negative Effect ◽  
Crown Projection Area

Basal area and height growth were analyzed for individual trees in uneven-aged ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and lodgepole pine (Pinus contorta Dougl. ex. Loud.) stands in central Oregon. Basal area growth was modeled as a function of other stand and tree variables to address three general objectives: (1) to compare the predictive ability of distance-dependent versus distance-independent stand density variables; (2) to determine the degree to which small trees negatively affect the growth of overstory trees; and (3) to test for differences in growth efficiency between species and between indices of spatial occupancy used to define efficiency (area potentially available, crown projection area, and a surrogate for total tree leaf area). Distance-dependent variables were found to improve growth predictions when added to models with only distance-independent variables, and small trees were found to have a quantifiably negative effect on the growth of larger trees. While volume growth efficiency declined with increasing levels of spatial occupancy for lodgepole pine, ponderosa pine volume growth efficiency was greatest at the highest levels of crown base sapwood area and crown projection area. The behavior in ponderosa pine resulted from the previously recognized correlation between tree height and total leaf area or crown size. The final statistical models distinguished between the positive effect of relative height and the negative effect of increasing tree size.

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