The effects of dwarf mistletoe, witches' brooms, stand structure, and site characteristics on the crown architecture of lodgepole pine in Oregon

2002 ◽  
Vol 32 (8) ◽  
pp. 1360-1371 ◽  
Author(s):  
R C Godfree ◽  
R O Tinnin ◽  
R B Forbes
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Soil Type ◽  
Pinus Contorta ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Stand Density ◽  
Dwarf Mistletoe ◽  
Site Characteristics ◽  
Crown Dimensions

We investigated the importance of lodgepole pine dwarf mistletoe (Arceuthobium americanum Nutt.) in determining the height to crown top (HCT), height to crown base (HCB), and live crown ratio (LCR) of 2025 lodgepole pine (Pinus contorta var. murrayana (Grev. & Balf.) Engelm.) growing over a 24-km2 study site in central Oregon. We compared the effects of infection and associated witches' brooms with those of site topography, soil type, shrub cover, stand density, and the abundance of mature ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws). using multiple regression and path analysis. The density of dominant-size P. contorta was consistently the most important factor influencing HCT, HCB, and LCR across the study site. In dense stands, trees tended to have elevated crown bases due to self-pruning and, hence, lower values of LCR. Dwarf mistletoe and related witches' brooms uniquely explained 6.9% of the variance in LCR, which was close to that of dominant P. contorta (7.1%) and more than that of soil type (3.0%), but explained only 2.6% of the variance in HCB, which was less than that of dominant P. contorta (6.5%) and soil type (4.6%). Regression models suggest that heavily infected trees should be 18% shorter and have crown bases 37% lower than uninfected trees, while moderately infected trees should have an LCR over 20% larger than that of uninfected and heavily infected trees. We also found that the largest 25 heavily infected trees sampled were approximately 19% shorter and 11–13% smaller in diameter than the largest 25 uninfected trees. The results suggest that dwarf mistletoe can be an important factor in determining the crown dimensions of P. contorta but that these effects may be interpreted only in the context of site characteristics and stand structure.

scholarly journals Stand structure governs the crown collisions of lodgepole pine

2003 ◽  
Vol 33 (7) ◽  
pp. 1238-1244 ◽  
Author(s):  
Mark Rudnicki ◽  
Victor J Lieffers ◽  
Uldis Silins
Keyword(s):  
Wind Speed ◽  
High Frequency ◽  
Pinus Contorta ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Stand Density ◽  
Empty Space ◽  
Tree Sway ◽  
Individual Trees ◽  
Crown Dimensions

We investigated tree sway and crown collision behavior of even-aged lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands of different structure in Alberta, Canada, to examine how these factors might affect loss of leaf area as stands mature. The Two Creeks stand (TC) had high density and slender trees, while the Chickadee stand (CH) had stout trees. The TC stand was then thinned (TCT) to reduce the stand density. For each stand, simultaneous tree sways of a group of 10 trees were monitored with biaxial clinometers during wind speed of 5 m/s (canopy top). Crown collisions were reconstructed by combining sway displacement of individual trees with their respective crown dimensions. Comparing the sway statistics between stands with contrasting mean bole slenderness (TC and CH) indicated that more slender trees have greater sway displacements, faster sway speeds, and a greater depth of collision. Disturbance by thinning increased sway displacements, sway speeds, and depth of collisions at TCT. Tree sway patterns were circular in shape and not aligned with wind direction, but patterns were elongated after thinning. This demonstrates the high frequency of crown collision experienced by stands with slender trees and supports the notion that crown collisions result in empty space between crowns of trees.

scholarly journals Ponderosa Pine and Lodgepole Pine Growth Response to One-Time Application of Herbicide During Seedling Establishment in Western Montana

2003 ◽  
Vol 18 (3) ◽  
pp. 149-154 ◽  
Author(s):  
Chad E. Keyser ◽  
Kelsey S. Milner
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Seedling Establishment ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Tree Height ◽  
Height Growth ◽  
Western Montana ◽  
Growth Effect ◽  
Percent Cover

Abstract This study examined long-term diameter and height response of ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta var. latifolia) to a one-time application of herbicide during seedling establishment in western Montana. Two herbicide trials initiated in 1981 and 1983 by Champion International Corporation were resurrected during the summer of 1997. Analysis of variance (ANOVA) F-tests along with Duncan's Multiple Range tests (DMR) were performed on mean tree dbh, tree height, and competing vegetation percent cover estimates. In addition, a graphical analysis of mean annual height growth over time was performed. Significant increases (alpha = 0.05) in ponderosa pine dbh (25 to 44%) and height (11 to 28%) were found after 16 yr of growth on Velpar L. (hexazinone) treated plots, while lodgepole pine had significant increases in dbh (70 to 118%) and height (41 to 82%) after 15 yr of growth on Velpar L. treated plots. Graphical analyses indicated a positive height growth effect for a period of 11 to 13 yr following treatment for ponderosa pine; however, total height gains had decreased in recent years. Positive increases in height growth for lodgepole pine were continuing after 15 yr of growth. These results indicate that a one-time application of herbicide applied during seedling establishment will promote faster tree growth in western Montana. We also note that proper density management will be necessary early in the life of the stand to maintain height gains. West. J. Appl. For. 18(3):149–154.

Mixed-severity fire in lodgepole pine dominated forests: are historical regimes sustainable on Oregon’s Pumice Plateau, USA?

2014 ◽  
Vol 44 (6) ◽  
pp. 593-603 ◽  
Author(s):  
Emily K. Heyerdahl ◽  
Rachel A. Loehman ◽  
Donald A. Falk
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Pinus Contorta ◽  
Fire Regime ◽  
Forest Type ◽  
Lodgepole Pine ◽  
Fire Behavior ◽  
Forest Composition ◽  
Crown Fire ◽  
Fire Exclusion

In parts of central Oregon, coarse-textured pumice substrates limit forest composition to low-density lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson) with scattered ponderosa pine (Pinus ponderosa Lawson & C. Lawson) and a shrub understory dominated by antelope bitterbrush (Purshia tridentata (Pursh) DC.). We reconstructed the historical fire regime from tree rings and simulated fire behavior over 783 ha of this forest type. For centuries (1650–1900), extensive mixed-severity fires occurred every 26 to 82 years, creating a multi-aged forest and shrub mosaic. Simulation modeling suggests that the historical mix of surface and passive crown fire were primarily driven by shrub biomass and wind speed. However, a century of fire exclusion has reduced the potential for the high-severity patches of fire that were common historically, likely by reducing bitterbrush cover, the primary ladder fuel. This reduced shrub cover is likely to persist until fire or insects create new canopy gaps. Crown fire potential may increase even with current fuel loadings if the climate predicted for midcentury lowers fuel moistures, but only under rare extreme winds. This study expands our emerging understanding of complexity in the disturbance dynamics of lodgepole pine across its broad North American range.

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.

Snag dynamics in a chronosequence of 26 wildfires on the east slope of the Cascade Range in Washington State, USA

1999 ◽  
Vol 9 (4) ◽  
pp. 223 ◽  
Author(s):  
Richard Everett ◽  
John Lehmkuhl ◽  
Richard Schellhaas ◽  
Pete Ohlson ◽  
David Keenum ◽  
...  
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Douglas Fir ◽  
Cascade Range ◽  
Abies Lasiocarpa ◽  
Engelmann Spruce ◽  
Standards And Guidelines ◽  
Topographic Positions

Snag numbers and decay class were measured on a chronosequence of 26 wildfires (ages 1-81 years) on the east slope of the Cascade Range in Washington. Snag longevity and resultant snag densities varied spatially across burns in relation to micro-topographic position. Longevity of snags < 41cm dbh was greater for thin-barked Engelmann spruce (Picea engelmannii), subalpine fir (Abies lasiocarpa) and lodgepole pine (Pinus contorta) than thick-barked Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa). With larger diameter snags, however, Douglas-fir persisted longer than Engelmann spruce. The time period required for recruitment of soft snags > 23 cm dbh was estimated to exceed snag longevity for ponderosa pine, Englemann spruce, lodgepole pine, and subapline fir, causing an “on-site gap” in soft snags for these species. Snags of Douglas-fir ≥ 41 cm dbh stood for a sufficient time (40% standing after 80 years) to potentially overlap the recruitment of soft snags ≥ 23 cm dbh from the replacement stand. Providing continuity in soft snags following stand-replacement events would require a landscape-scale perspective, incorporating adjacents stands of different ages or disturbance histories. Results suggest that standards and guidelines for snags on public forest lands need to be sufficiently flexible to accomodate both disturbance and stand development phases and differences in snag longevity among species and topographic positions.

Carbon pools of managed and unmanaged stands of ponderosa and lodgepole pine forests in Wyoming

2009 ◽  
Vol 39 (10) ◽  
pp. 1893-1900 ◽  
Author(s):  
A. Chatterjee ◽  
G. F. Vance ◽  
D. B. Tinker
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Pinus Contorta ◽  
Management Practices ◽  
Lodgepole Pine ◽  
Timber Harvesting ◽  
Major Influence ◽  
Forest Types ◽  
Soil C ◽  
C Pools

Forest management practices can have a significant effect on above- and below-ground carbon (C) pools. To better understand the distribution of forest C pools, we evaluated representative forest stands within two dominant Wyoming forest types to assess differences resulting from management practices that have occurred over several decades. Study sites included four ponderosa pine ( Pinus ponderosa Douglas ex Lawson & C.Lawson) treatments (100-year-old unmanaged, 46-year-old even-aged, 110-year-old uneven-aged, and 90-year-old intensively harvested) and two lodgepole pine ( Pinus contorta Engelm. var. latifolia (Engelm. ex Wats.) Critchfield) treatments (145-year-old unmanaged and 45-year-old even-aged). Comparisons of aboveground C pools revealed that distributions of live and dead biomass C pools were different between unmanaged and managed stands; however, belowground soil C pools were similar among stands within the two forest types. Overall, unmanaged stands of both forest types had higher total ecosystem C pools (249 and 247 Mg C·ha–1 for ponderosa and lodgepole pine, respectively) compared with managed stands (ponderosa pine: even-aged, 164 Mg C·ha–1; uneven-aged, 170 Mg C·ha–1; intensively harvested, 200 Mg C·ha–1; and lodgepole pine even-aged, 117 Mg C·ha–1). Our results indicate timber harvesting has a major influence on total ecosystem C pools by reducing live tree biomass.

Forest structure altered by mountain pine beetle outbreaks affects subsequent attack in a Wyoming lodgepole pine forest, USA

2011 ◽  
Vol 41 (12) ◽  
pp. 2403-2412 ◽  
Author(s):  
Daniel M. Kashian ◽  
Rebecca M. Jackson ◽  
Heather D. Lyons
Keyword(s):  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Climate Change Scenarios ◽  
Cone Production ◽  
Mountain Pine ◽  
Large Trees ◽  
Pine Beetle ◽  
The 1960S

Extensive outbreaks of the mountain pine beetle ( Dendroctonus ponderosae Hopkins) will alter the structure of many stands that will likely be attacked again before experiencing a stand-replacing fire. We examined a stand of lodgepole pine ( Pinus contorta var. latifolia Engelm. ex S. Watson) in Grand Teton National Park currently experiencing a moderate-level outbreak and previously attacked by mountain pine beetle in the 1960s. Consistent with published studies, tree diameter was the main predictor of beetle attack on a given tree, large trees were preferentially attacked, and tree vigor, age, and cone production were unimportant variables for beetle attack at epidemic levels. Small trees killed in the stand were killed based mainly on their proximity to large trees and were likely spatially aggregated with large trees as a result of the previous outbreak. We concluded that the driving factors of beetle attack and their spatial patterns are consistent across outbreak severities but that stand structure altered by the previous outbreak had implications for the current outbreaks in the same location. This study should catalyze additional research that examines how beetle-altered stand structure affects future outbreaks — an important priority for predicting their impacts under climate change scenarios that project increases in outbreak frequency and extent.

scholarly journals Long-term influence of stand thinning and repeated fertilization on forage production in young lodgepole pine forests

2017 ◽  
Vol 47 (8) ◽  
pp. 1123-1130 ◽  
Author(s):  
Pontus M.F. Lindgren ◽  
Thomas P. Sullivan ◽  
Douglas B. Ransome ◽  
Druscilla S. Sullivan ◽  
Lisa Zabek
Keyword(s):  
Pinus Contorta ◽  
Large Scale ◽  
Bos Taurus ◽  
Lodgepole Pine ◽  
Stand Density ◽  
Stand Age ◽  
Forage Production ◽  
South Central ◽  
Stand Thinning

Integration of trees with forage and livestock production as silvopastoralism is another potential component of intensive forest management. Stand thinning and fertilization may enhance growth of crop trees and understory forage for livestock. We tested the hypothesis that large-scale precommercial thinning (PCT) (particularly heavy thinning to ≤1000 stems·ha−1) and repeated fertilization, up to 20 years after the onset of treatments, would enhance production of graminoids, forbs, and shrubs as cattle (Bos taurus L.) forage. Results are from two long-term studies: (1) PCT (1988–2013) and (2) PCT with fertilization (PCT–FERT) (1993–2013) of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) stands in south-central British Columbia, Canada. Mean biomass estimates of graminoids, forbs, total herbs, and shrubs were not affected by stand density. However, fertilization enhanced mean biomass estimates of graminoids, forbs, and total herbs, but not shrubs. Thus, the density part of our hypothesis was not supported, but the nutrient addition part was supported at least for the herbaceous components. Biomass of the herbaceous understory was maintained as a silvopasture component for up to 20 years (stand age 13 to 33 years) in fertilized heavily thinned stands prior to canopy closure.

Stand density, drought, and herbivory constrain ponderosa pine regeneration pulse

2020 ◽  
Vol 50 (9) ◽  
pp. 862-871 ◽  
Author(s):  
Thomas E. Kolb ◽  
Kelsey Flathers ◽  
John B. Bradford ◽  
Caitlin Andrews ◽  
Lance A. Asherin ◽  
...  
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Seedling Survival ◽  
Stand Density ◽  
Survival Duration ◽  
Northern Arizona ◽  
Growing Seasons ◽  
Pine Regeneration ◽  
Stand Thinning ◽  
Survival And Growth

Trees in dry forests often regenerate in episodic pulses when wet periods coincide with ample seed production. Factors leading to success or failure of regeneration pulses are poorly understood. We investigated the impacts of stand thinning on survival and growth of the 2013 cohort of ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) seedlings in northern Arizona, United States. We measured seedling survival and growth over the first five growing seasons after germination in six stand basal areas (BAs; 0, 7, 14, 23, 34, and 66 (unthinned) m2·ha−1) produced by long-term experimental thinnings. Five-year survival averaged 2.5% and varied among BAs. Mean survival duration was longer in intermediate BAs (11 to 16 months) than in clearings and high BAs (5 months). The BAs of 7, 14, and 23 m2·ha−1 had >2600 5-year-old seedlings·ha−1. In contrast, regeneration was lower in the clearing (666 seedlings·ha−1) and failed completely in the 34 m2·ha−1 and unthinned treatments. Seedling survival was highest during wet years and lowest during drought years. Many surviving seedlings had no net height growth between years 4 and 5 because of stem browsing. Results indicate that natural regeneration of ponderosa pine is influenced by stand BA, drought, herbivory, and interactions between extreme climatic events.

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