Impacts of lodgepole pine dwarf mistletoe (Arceuthobium americanum) infestation on stand structure and fuel load in lodgepole pine dominated forests in central Colorado

Botany ◽  
2017 ◽  
Vol 95 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Scott M. Ritter ◽  
Chad M. Hoffman ◽  
Seth A. Ex ◽  
Jane E. Stewart
Keyword(s):  
Stand Structure ◽  
Temporal Dynamics ◽  
Lodgepole Pine ◽  
Fire Behavior ◽  
Basal Area ◽  
Fuel Load ◽  
Fuel Loading ◽  
Dwarf Mistletoe ◽  
Individual Host ◽  
Live Tree

Parasitic plants are capable of causing substantial alterations to plant communities through impacts on individual host plants. Lodgepole pine dwarf mistletoe is an important parasite in forests of the western USA that causes reductions to productivity and is thought to alter wildland fuel complexes. These impacts are hypothesized to vary with infestation severity. To test this, we used a linear mixed modeling approach to evaluate the relationship between dwarf mistletoe infestation severity and parameters representing stand structure and surface and canopy fuels in infested lodgepole pine stands in central Colorado. Infestation severity was negatively related to live basal area, average tree size, canopy base height, canopy fuel load, and canopy bulk density, and was positively related to the loading of woody surfaces fuels greater than 0.64 cm in diameter. No relationship was detected between infestation severity and live tree density, or live crown ratio. These results confirm the long-held assumption that dwarf mistletoe increases surface fuel loading in lodgepole pine communities, but also suggest that infested stands have reduced amounts of available canopy fuel. These findings have implications for potential fire behavior and highlight the importance of dwarf mistletoe in predicting the spatial and temporal dynamics of wildland fuels.

scholarly journals The Difficulty of Predicting Eastern Spruce Dwarf Mistletoe in Lowland Black Spruce: Model Benchmarking in Northern Minnesota, USA

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Ella R. Gray ◽  
Matthew B. Russell ◽  
Marcella A. Windmuller-Campione
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Forest Health ◽  
Basal Area ◽  
Predictive Performance ◽  
Stand Age ◽  
Management Decisions ◽  
Dwarf Mistletoe ◽  
Growing Seasons ◽  
Model Interpretation

Insects, fungi, and diseases play an important role in forest stand development and subsequently, forest management decisions and treatments. As these disturbance agents commonly occur within and across landscapes, modeling has often been used to inform forest planning and management decisions. However, models are rarely benchmarked, leaving questions about their utility. Here, we assessed the predictive performance of a Bayesian hierarchical model through on–the-ground sampling to explore what features of stand structure or composition may be important factors related to eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck) presence in lowland black spruce (Picea mariana (Mill.) B. S. P.). Twenty-five state-owned stands included in the predictive model were sampled during the 2019 and 2020 growing seasons. Within each stand, data related to the presence of eastern spruce dwarf mistletoe, stand structure, and species composition were collected. The model accurately predicted eastern spruce dwarf mistletoe occurrence for 13 of the 25 stands. The amount of living and dead black spruce basal area differed significantly based on model prediction and observed infestation, but trees per hectare, total living basal area, diameter at breast height, stand age, and species richness were not significantly different. Our results highlight the benefits of model benchmarking to improve model interpretation as well as to inform our understanding of forest health problems across diverse stand conditions.

scholarly journals Effects of Lodgepole Pine Dwarf Mistletoe, Arceuthobium americanum, on Jack Pine, Pinus banksiana, Growth in Manitoba

2004 ◽  
Vol 118 (4) ◽  
pp. 595 ◽  
Author(s):  
Brock Epp ◽  
Jacques C. Tardif
Keyword(s):  
Pinus Banksiana ◽  
Growth Models ◽  
Lodgepole Pine ◽  
Wood Quality ◽  
Basal Area ◽  
Jack Pine ◽  
Dwarf Mistletoe ◽  
Tree Form ◽  
Arceuthobium Americanum ◽  
Pine Trees

The Lodgepole Pine Dwarf Mistletoe (Arceuthobium americanum Nutt. ex Engelm.) is an important pathogen of Jack Pine (Pinus banksiana Lamb.). Dwarf Mistletoe alters tree form, suppresses growth, and reduces volume and overall wood quality of its host. Stem analysis and a 3-parameter logistic regression model were used to compare the growth of heavily and lightly to non infected Jack Pine trees. At the time of sampling, no significant reduction in diameter at breast height and basal area were observed in heavily infected trees. However, a significant reduction in height and volume and an increase in taper were observed in heavily infected trees. Growth models predicted a 21.1% lower basal area, 23.4% lower height and 42.1% lower volume by age 60 for the high infection group.

Dwarf mistletoe effects on fuel loadings in ponderosa pine forests in northern Arizona

2007 ◽  
Vol 37 (3) ◽  
pp. 662-670 ◽  
Author(s):  
Chad Hoffman ◽  
Robert Mathiasen ◽  
Carolyn Hull Sieg
Keyword(s):  
Ponderosa Pine ◽  
Fire Behavior ◽  
Fuel Loading ◽  
Dwarf Mistletoe ◽  
Forest Fuels ◽  
Ponderosa Pine Forests ◽  
Northern Arizona ◽  
Basaltic Soils ◽  
Four Levels ◽  
Fuels Treatments

Southwestern dwarf mistletoe ( Arceuthobium vaginatum (Willd.) J. Presl ssp. cryptopodum ) infests about 0.9 million ha in the southwestern United States. Several studies suggest that dwarf mistletoes affect forest fuels and fire behavior; however, few studies have quantified these effects. We compared surface fuel loadings and predicted fire behavior among four levels of dwarf mistletoe infestation (none, light, moderate, and severe) in a total of 239 plots on 11 sites on basaltic soils in northern Arizona. In each plot we measured tree attributes, dwarf mistletoe rating and surface fuel loading. Stands severely infested by dwarf mistletoe had lower (P < 0.05) tree density and higher snag density, but higher (P < 0.05) total surface fuel loadings and total fuel loadings >7.62 cm and <7.62 cm, than non-infested stands. However, there were no statistical differences in any canopy fuel variables among infestation classes. Predicted fire behavior indicated that the wind speed required to promote the spread of a surface fire into the canopy was lower in severely infested stands than in non-infested stands. These results suggest that stands in northern Arizona that are severely infested with dwarf mistletoe should be priority areas for fuels treatments.

scholarly journals Paths of Recovery: Landscape Variability in Forest Structure and Function 25 Years after the 1988 Yellowstone Fires

2013 ◽  
Vol 36 ◽  
pp. 99-101
Author(s):  
Monica Turner ◽  
Winslow Hansen ◽  
Timothy Whitby ◽  
William Romme ◽  
Daniel Tinker
Keyword(s):  
Forest Structure ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Fire Severity ◽  
Fire Behavior ◽  
Structure And Function ◽  
Sampling Effort ◽  
Quarter Century ◽  
And Function

Understanding succession following severe wildfire is increasingly important for forest managers in western North America and critical for anticipating the resilience of forested landscapes to changing environmental conditions. Successional trajectories set the stage for future carbon storage, abundance and distribution of fuels, and habitat for many species. Early successional forests are increasing throughout the West in response to greater fire activity, but few long-term studies have considered succession following stand-replacing wildfires over large areas. The size and heterogeneity of the 1988 Yellowstone fires created novel opportunities to study succession at an unprecedented scale following severe fire, and we have studied the consequences of these fires for >20 years. In 2012, we began a re-sampling effort in long-term vegetation plots within the area burned by the 1988 fires to answer three overarching questions: (1) Are stand structure and function beginning to converge twenty-five years after the Yellowstone Fires, and what mechanisms may contribute to convergence or divergence? Heterogeneity in forest structure was the rule after the 1988 fires, and postfire lodgepole pine (Pinus contorta var. latifolia) densities ranged from zero to >500,000 trees/ha. The post-1988 cohort of lodgepole pine is reaching a time of critical transitions in structure and function. (2) Are plant community composition and species richness converging or diverging across gradients in local fire severity, post-fire lodgepole pine density, elevation and soil type a quarter-century after the 1988 fires? A central objective in our research has been to understand the relative influence of contingent factors (e.g., local fire severity) vs. deterministic factors (e.g., elevation, soils) on postfire ecosystem development, and how these influences may change through time. (3) How do canopy and surface fuels vary across the postfire landscape, and how will the variation in fuels influence potential fire behavior a quarter century post-fire? Field sampling was conducted for this third question during summer 2012, and data analyses and interpretation are in progress. Overall, results from the proposed study will enhance understanding of succession after one of the most notorious fires of the 20th century. Yellowstone’s postfire forests may serve as benchmarks for forests throughout the region and effective sentinels of change for the Rockies.

Fuel dynamics during oak woodland and savanna restoration in the Mid-South USA

2019 ◽  
Vol 28 (1) ◽  
pp. 70 ◽  
Author(s):  
Andrew L. Vander Yacht ◽  
Patrick D. Keyser ◽  
Charles Kwit ◽  
Michael C. Stambaugh ◽  
Wayne K. Clatterbuck ◽  
...  
Keyword(s):  
Basal Area ◽  
Fuel Load ◽  
Fuel Loading ◽  
Oak Woodlands ◽  
Thinning Intensity ◽  
The Usa ◽  
Closed Canopy ◽  
Fuel Dynamics ◽  
Restoration Strategies ◽  
Fine Fuels

Thinning and burning can restore imperilled oak woodlands and savannas in the Southern Appalachian and Central Hardwood regions of the USA, but concomitant effects on fuels are less understood. We monitored (2008 to 2016) fuel load response to replicated combinations of thinning (none, 7, and 14m2ha−1 residual basal area) and seasonal fire (none, March, and October) at three sites. All treatments except burn-only increased total fuel loading. Thinning doubled (+16Mgha−1) 1000-h fuels relative to controls, and three fires in 6 years did not eliminate this difference. Increasing thinning intensity did not consistently enhance the combustion of larger fuels. October fires reduced 100- and 10-h fuels more than March fires. Burning alone reduced leaf litter and 1-h twigs by 30%. Burning after thinning doubled this reduction but increased herbaceous fuels 19-fold. Herbaceous fuels increased at a rate that suggests compensation for losses in woody fine fuels with continued burning. Where fuel reduction is a goal, restoration strategies could be more intentionally designed; however, oak woodlands and savannas are inherently more flammable than closed-canopy forests. Management decisions will ultimately involve weighing the risks associated with increased fuel loads against the benefits of restoring open oak communities.

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 Long-Term Effects of Fuel Reduction Treatments on Surface Fuel Loading in the Blue Mountains of Oregon

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1306
Author(s):  
Kat E. Morici ◽  
John D. Bailey
Keyword(s):  
Fire Behavior ◽  
Fuel Load ◽  
Fire Season ◽  
Fuel Reduction ◽  
Prescribed Burn ◽  
Long Term Effects ◽  
Fuel Loading ◽  
Fuel Treatments ◽  
Blue Mountains ◽  
Pre Treatment

Fire exclusion and a lengthening fire season has resulted in an era of megafires. Fuel reduction treatments in forested ecosystems are designed to guard against future extreme wildfire behavior. Treatments create a heterogenous landscape and facilitate ecosystem function and resilience in fire-adapted forests of the western United States. Despite widespread recognition that repeated fuel treatments are needed to maintain desired stand characteristics over time, few field studies have evaluated treatment longevity. The Blue Mountains Fire and Fire Surrogate site in northeastern Oregon presented an opportunity to investigate woody fuel loading 15–17 years after four treatments: mechanical thin, prescribed burn, both thin and burn, and no treatment control. The principal findings were: (1) fine fuel load 15 years post-burn remained slightly below pre-treatment values; (2) rotten coarse fuel load was reduced post-burn, but sound coarse fuel was not altered by any active treatment; and (3) total woody fuel load 15–17 years post-treatment was similar to pre-treatment values. Understanding surface fuel loading is essential for predicting fire behavior. Overall, the effects of fuel reduction treatments on woody surface fuels were transitory in dry mixed conifer forests. Frequent maintenance treatments are recommended to protect values at risk in areas with high fire hazards. Quantifying the persistence of changes in forest conditions aids in the planning and analysis of future fuel treatments, along with scheduling maintenance of existing treated areas.

Alteration to Woodland Structure through Midstory Mastication Increased Fuel Loading and Cover of Understory Species in Two Upland Hardwood Stands

2019 ◽  
Vol 65 (3) ◽  
pp. 344-354 ◽  
Author(s):  
Devin E Black ◽  
Mary A Arthur ◽  
Wendy Leuenberger ◽  
David D Taylor ◽  
Jeffrey F Lewis
Keyword(s):  
United States ◽  
Stand Structure ◽  
Landscape Heterogeneity ◽  
Time Lag ◽  
Basal Area ◽  
Ground Cover ◽  
Habitat Diversity ◽  
Stem Density ◽  
Eastern United States ◽  
Fuel Loading

Abstract The contemporary decline of open woodlands in the eastern United States has prompted land managers to implement management prescriptions that encourage landscape and habitat diversity, often using mechanical thinning and prescribed fire as tools to alter stand structure. To increase habitat diversity and restore natural processes, a long-term oak woodland restoration project was planned for two upland hardwood stands in the Daniel Boone National Forest, Kentucky, United States. As an initial phase of restoration, we examined the effects of midstory mastication on stand structure, understory vegetation response, and fuels. The mastication treatment reduced stem density and basal area of trees ≤7.9 in. (20.1 cm) dbh by 69 percent and 47 percent, respectively, encouraged vigorous stump/root sprouting, and increased ground cover of forbs (204 percent) and native graminoids (253 percent) the first year on treated plots. Additionally, mastication created a variable cover of woody mulch on the forest floor and increased 1-h and 100-h time-lag fuels compared with controls. In year 2, Microstegium vimineum (invasive grass) cover increased by 700 percent on treated plots. This study imparts novel information on the mastication of upland hardwoods to benefit land managers in directing future treatments to shape desired stand structures and compositions, and increase landscape heterogeneity.

scholarly journals Effects of Stand Structure, Browsing, and Biophysical Conditions on Regeneration Following Mountain Pine Beetle in Mixed Lodgepole Pine and Aspen Forests of the Southern Rockies

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 525
Author(s):  
Kristen Pelz ◽  
Frederick Smith
Keyword(s):  
Populus Tremuloides ◽  
Pinus Contorta ◽  
Mountain Pine Beetle ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Animal Damage ◽  
Mountain Pine ◽  
Pine Regeneration ◽  
Pine Beetle

Aspen (Populus tremuloides) and lodgepole pine (Pinus contorta var. latifolia) co-occur in the southern Rocky Mountains (USA), where mountain pine beetle (MPB, Dendroctonus ponderosae) has caused extensive lodgepole pine mortality since the late 1990s. Both species excel in post-disturbance high-light environments, but lodgepole pine has generally been thought to establish poorly on undisturbed seedbeds, and aspen suckering may be inhibited by intact aspen overstory. We ask whether lodgepole pine and aspen will regenerate in sufficient quantities to revegetate these forests. We visited a random sample of aspen and lodgepole pine stands across the affected landscape in northern Colorado and southern Wyoming to measure regeneration and overstory mortality. Lodgepole pine regeneration is occurring in 85% of stands, and most stands have >550 stems ha−1. The median aspen sucker density was 6175 stems ha−1. Surprisingly, neither lodgepole pine nor aspen regeneration density was related to overstory mortality level. Animal damage is currently affecting aspen in these forests. Over 50% of stands had damage to 60% or more of their suckers, but 30% of stands had <20% of their stems damaged. Browsed stems were significantly shorter for their ages and were shorter than the 2.5-m height threshold for possible elk browsing. However, the results suggest that sufficient quantities of down lodgepole pine may protect aspen from damage and allow aspen to successfully recruit to the overstory. Multiple regression analysis showed that down lodgepole pine basal area, followed by browsing pressure, were the most important predictors of sucker height and the proportion of suckers browsed. Although 15% of stands had no lodgepole pine regeneration, aspen and lodgepole pine forests are generally regenerating despite animal browsing on aspen. This study is the first to present a regional perspective on regeneration in MPB-affected lodgepole pine and aspen forests, and overall, intervention does not seem necessary to ensure a mix of both species in the future.

scholarly journals MODELAGEM DE MATERIAL COMBUSTÍVEL EM PLANTAÇÕES DE Pinus taeda NO NORTE DE SANTA CATARINA

FLORESTA ◽  
2003 ◽  
Vol 33 (2) ◽  
Author(s):  
Luiz Joaquim Bacelar De Souza ◽  
Ronaldo Viana Soares ◽  
Antonio Carlos Batista
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Correlation Coefficients ◽  
Basal Area ◽  
Dry Weight ◽  
Fuel Load ◽  
Fuel Loading ◽  
Santa Catarina ◽  
Independent Variables ◽  
Dominant Height

Um inventário foi conduzido em Três Barras, Santa Catarina, para quantificar e modelar material combustível superficial vivo e morto em plantações de Pinus taeda. De forma sistemática foram estabelecidas 20 parcelas para cada povoamento de 3, 5, 7, 9, 11, 13, 15, e 17 anos de idade, nas quais foram medidos a carga de combustível, o DAP, a altura e o diâmetro dominantes, a área basal e a espessura da liteira. Nove modelos foram ajustados através dos métodos Stepwise e “todas as regressões possíveis”. O melhor modelo para estimar a carga de acículas foi (R2 = 0,9563), ajustado com base na espessura (S) da camada de acículas. Para a carga de combustível morto de até 2,5 cm de espessura o melhor modelo foi (R2 = 0,8577). O modelo considerado mais adequado para determinação da carga total de combustível foi (R2 = 0,7034). Três gráficos para estimativa indireta do combustível e um calibrador para estimar a carga de acículas são também apresentados. FUEL MODELING IN Pinus taeda PLANTATIONS IN THE STATE OF SANTA CATARINA, BRAZIL Abstract A fuel inventory was conducted in Três Barras county, state of Santa Catarina, Brazil (26o15’ S latitude and 50o48’W longitude), in order to develop predicting models for fuel loading in loblolly pine (Pinus taeda) plantations. Sampling was done in 03, 05, 07, 09, 11, 13, 15, and 17-year-old stands, covering the whole rotation of the plantations. Twenty (20) plots of 1.0m2 (1.0x1.0m) were randomly located in each stand, totalizing 160 plots. The independent variables measured in the stands were age (in years), mean DBH (cm), dominant DBH (cm), dominant height of the trees (m), basal area (m2), and fuel bed depth (cm). The dependent variables were live surface fuel, dead foliage (needles), dead woody fuel (separated by size classes), and total fuel load, all measured in ton.ha-1 (oven dry weight). Results showed good correlation between fuel bed depth and age and most of the dependent (fuel related) variables. Live surface fuel only presented significant correlation with mean DBH and basal area. However, live surface fuel was only significant in the 3-year-old plantation, and practically disappeared when the pines canopy intercepted most of the sun light, usually after the 5th year. Models were developed to estimate the following variables: dead foliage (Wa) dead fuel up to 10-hour (Æ £ 2.5cm) timelag (W10), and total fuel load (WT). Independent variables were chosen not only by the correlation coefficients, but also for the measuring facility, and based on these principles, fuel bed depth (S), age (I), dominant height (hdom), and dominant DBH (Ddom) were selected. The models were built through the Stepwise method, using the Statistic 5.0 software. Fuel bed depth was the variable that provided best fits for all predicting models, and the inclusion of other independent variables did not improve the models precision. The best model to estimate the needles load was (R2 = 0,9563); to estimate dead fine fuel load was (R2 = 0,8577); and to estimate the total fuel load was (R2 = 0,7034). Total fuel load in the loblolly pine plantations in the studied site ranged from approximately 6.0 to 21.0 ton.ha-1.

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