scholarly journals Overstory Longleaf Pines and Hardwoods Create Diverse Patterns of Energy Release and Fire Effects During Prescribed Fire

2021 ◽  
Vol 4 ◽  
Author(s):  
Andrew W. Whelan ◽  
Seth W. Bigelow ◽  
Joseph J. O’Brien
Keyword(s):  
Energy Release ◽  
Longleaf Pine ◽  
Fire Behavior ◽  
Fire Effects ◽  
Additive Models ◽  
Ground Layer ◽  
Neighborhood Models ◽  
Pine Regeneration ◽  
Dormant Season ◽  
Overstory Trees

Litter from pine trees in open woodlands is an important fuel for surface fires, but litter from hardwood species may quell fire behavior. Lower intensity fires favor hardwood over longleaf pine regeneration, and while overstory hardwoods are important sources of food and shelter for many wildlife species, too many could result in canopy closure and a loss of ground layer diversity. Although some researchers have found synergies in fire effects when leaves of different species are combined, field tests of effects of tree guild diversity on fire behavior are lacking from the literature. We used neighborhood modeling to understand how diverse overstory trees in longleaf pine forests affect fire radiative energy density (FRED), and to determine the effect on top-kill of shrub-form hardwood trees. We measured the effects of three guilds of overstory trees (longleaf pine, upland oaks, and mesic oaks) on FRED, and related FRED to post-fire damage in four guilds of understory hardwoods (sandhill oaks, upland oaks, mesic oaks, and fleshy-fruited hardwoods). We found that FRED increased 33–56% near overstory longleaf pine but decreased 23–37% near overstory mesic oaks. Additive models of FRED performed well and no synergies or antagonisms were present. Seventy percent of stems of understory hardwoods survived fire with energy release typical of dormant-season fires in canopy gaps and near overstory mesic oaks. We also found that among understory trees >2 m tall, upland and sandhill oaks were more likely than mesic oaks or fleshy-fruited hardwoods to avoid top-kill. We conclude that neighborhood models provide a method to predict longleaf pine forest structure and composition that allows for the ecological benefits of overstory hardwoods while maintaining ground-layer diversity. To maintain hardwood control, fire practitioners may need to select fire weather conditions to increase fire behavior especially during dormant-season burns.

Effects of overstory competition on canopy recruitment patterns of naturally regenerated longleaf pine on two site types

2020 ◽  
Vol 50 (7) ◽  
pp. 624-635
Author(s):  
Patrick J. Curtin ◽  
Benjamin O. Knapp ◽  
Steven B. Jack ◽  
Lance A. Vickers ◽  
David R. Larsen ◽  
...  
Keyword(s):  
Longleaf Pine ◽  
Pinus Palustris ◽  
Height Growth ◽  
Growth Patterns ◽  
High Density ◽  
Low Density ◽  
Individual Tree ◽  
Pine Trees ◽  
Overstory Trees

Recent interest in continuous cover forest management of longleaf pine (Pinus palustris Mill.) ecosystems raises questions of long-term sustainability because of uncertainty in rates of canopy recruitment of longleaf pine trees. We destructively sampled 130 naturally regenerated, midstory longleaf pines across an 11 300 ha, second-growth longleaf pine landscape in southwestern Georgia, United States, to reconstruct individual tree height growth patterns. We tested effects of stand density (using a competition index) and site quality (based on two site classifications: mesic and xeric) on height growth and demographics of midstory trees. We also compared height growth of paired midstory and overstory trees to infer stand regeneration and recruitment dynamics. In low-density stands, midstory trees were younger and grew at greater rates than trees within high-density stands. Midstory trees in low-density stands were mostly from a younger regeneration cohort than their paired overstory trees, whereas midstory–overstory pairs in high-density stands were mostly of the same cohort. Our results highlight the importance of releasing midstory longleaf pine trees from local competition for sustained height growth in partial-harvesting management systems. They also demonstrate patterns of long-term persistence in high-density stands, indicating flexibility in the canopy recruitment process of this shade-intolerant tree species.

scholarly journals Improvement of fire danger rating and vegetation fire behaviour prediction on protected areas

2019 ◽  
Vol 16 ◽  
pp. 00040
Author(s):  
Aleksandra Volokitina ◽  
Dina Nazimova ◽  
Tatiana Sofronova ◽  
Mikhail Korets
Keyword(s):  
Protected Areas ◽  
Biological Diversity ◽  
Fire Behavior ◽  
Fire Spread ◽  
Fire Effects ◽  
Nature Reserves ◽  
Fire Danger ◽  
Behavior Prediction ◽  
Forest Fire Danger ◽  
Economic Use

Protected areas (PAs) are established to conserve biological diversity, to maintain nature complexes and objects in their natural condition. Strict nature reserves prevail in Russia by their total area. The whole nature complex is forever extracted from economic use in nature reserves. Here it is prohibited to pursue any activity which might disturb or damage the nature complexes. Even under the existing strict protection from anthropogenic ignition sources, vegetation fires do occur on their territory. Besides, lightnings − these natural ignition sources − are impossible to exclude. Since large destructive fires are impermissible in nature reserves, the later especially need vegetation fire behavior prediction for fire management. Fire behavior prediction includes fire spread rate, development (from surface fire into crown or ground one) and fire effects. All this is necessary for taking optimal decisions on how to control each occurring fire and how to suppress it. The Sukachev Institute of Forest SB RAS has developed a method to improve forest fire danger rating and a technique of vegetation fire behavior prediction using vegetation fuel maps (VF maps).

Container-Grown Longleaf Pine Regeneration Costs in the Sandhills

1982 ◽  
Vol 6 (1) ◽  
pp. 33-39
Author(s):  
Richard W. Guldin
Keyword(s):  
Longleaf Pine ◽  
Pinus Palustris ◽  
Cost Effective ◽  
Pine Regeneration ◽  
The Cost

Abstract Planting longleaf pine (Pinus palustris Mill.) seedlings grown in containers is a biologically feasible and cost-effective regeneration method for sandhill sites. Considering the cost of replanting sites where regeneration efforts fail, using container-grown seedlings can result in a lower total regeneration cost. A method of analysis is outlined for specific sites.

scholarly journals Effects of Biomass Removal Treatments on Stand-Level Fire Characteristics in Major Forest Types of the Northern Rocky Mountains

2010 ◽  
Vol 25 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Elizabeth D. Reinhardt ◽  
Lisa Holsinger ◽  
Robert Keane
Keyword(s):  
Ponderosa Pine ◽  
Rocky Mountains ◽  
Fire Behavior ◽  
Fire Effects ◽  
Forest Types ◽  
Prescribed Burns ◽  
Northern Rocky Mountains ◽  
Biomass Removal ◽  
Fuel Dynamics ◽  
Fire Characteristics

Abstract Removal of dead and live biomass from forested stands affects subsequent fuel dynamics and fire potential. The amount of material left onsite after biomass removal operations can influence the intensity and severity of subsequent unplanned wildfires or prescribed burns. We developed a set of biomass removal treatment scenarios and simulated their effects on a number of stands that represent two major forests types of the northern Rocky Mountains: lodgepole and ponderosa pine. The Fire and Fuels Extension to the Forest Vegetation Simulator was used to simulate effects including stand development, fire behavior, and fire effects prior to the biomass removal treatment and 1, 10, 30, and 60 years after the treatment. Analysis of variance was used to determine whether these changes in fuel dynamics and fire potential differed significantly from each other. Results indicated that fire and fuel characteristics varied within and between forest types and depended on the nature of the treatment, as well as time since treatment. Biomass removal decreased fire potential in the short term, but results were mixed over the long term.

Extrapolation Problems in Modeling Fire Effects at Large Spatial Scales: a Review

1996 ◽  
Vol 6 (4) ◽  
pp. 165 ◽  
Author(s):  
D Mckenzie ◽  
DL Peterson ◽  
E Alvarado
Keyword(s):  
Vegetation Change ◽  
Spatial Scales ◽  
Fire Behavior ◽  
Fire Effects ◽  
Ecological Effects ◽  
Challenging Problem ◽  
Landscape Disturbance ◽  
Level Data ◽  
Behavior Models ◽  
Single Approach

Models of vegetation change in response to global warming need to incorporate the effects of disturbance at broad spatial scales. Process-based predictive models, whether for fire behavior or fire effects on vegetation, assume homogeneity of crucial inputs over the spatial scale to which they are applied. Landscape disturbance models predict final burning patterns, but either do not model mechanistic behavior and explicit spread rates, or require large amounts of data to initialize simulations and predict ecological effects. Empirical data on the ecological effects of fire are not generally available at these scales, and conclusions are often extrapolated upward from stand-level data. Three methods for extrapolating ecological effects of fire across spatial scales and the sources of error associated with each were identified: (1) extrapolating fire behavior models directly to larger spatial scales; (2) integrating fire behavior and fire effects models with successional models at the stand level, then extrapolating upward; and (3) aggregating model inputs to the scale of interest. Extreme fire events present a challenging problem for modelers, regardless of which extrapolation method is employed. No single approach to modeling fire effects is inherently superior; modeling objectives and the characteristics of specific systems will determine the best strategy for each situation.

Gaps in a gappy forest: plant resources, longleaf pine regeneration, and understory response to tree removal in longleaf pine savannas

2001 ◽  
Vol 31 (5) ◽  
pp. 765-778 ◽  
Author(s):  
John P McGuire ◽  
Robert J Mitchell ◽  
E Barry Moser ◽  
Stephen D Pecot ◽  
Dean H Gjerstad ◽  
...  
Keyword(s):  
Seedling Survival ◽  
Longleaf Pine ◽  
Light Availability ◽  
Pinus Palustris ◽  
Understory Vegetation ◽  
Net N Mineralization ◽  
Plant Resources ◽  
Pine Seedlings ◽  
Pine Regeneration ◽  
Tree Removal

Resource availability and planted longleaf pine (Pinus palustris Mill.) seedling and understory vegetation response within and among three sizes of experimentally created canopy gaps (0.11, 0.41, 1.63 ha) in a mature longleaf pine savanna were investigated for 2 years. Longleaf pine seedlings and understory vegetation showed increased growth in gaps created by tree removal. Longleaf pine seedling growth within gaps was maximized approximately 18 m from the uncut savanna. Increased longleaf pine seedling survival under the uncut savanna canopy observed after the first year suggests that the overstory may facilitate establishment of longleaf pine seedlings rather than reduce survival through competition. Despite the relative openness of the uncut longleaf pine forest, light quantity was increased by tree removal. Light was also the resource most strongly correlated with seedling and understory vegetation growth. Although net N mineralization was correlated to seedling response, the amount of variation explained was low relative to light. Belowground (root) gaps were not strong, in part because of non-pine understory roots increasing in biomass following tree removal. These results suggest that regeneration of longleaf pine may be maximized within gap sizes as small as approximately 0.10 ha, due largely to increases in light availability.

Silvicultural treatments for converting loblolly pine to longleaf pine dominance: effects on ground layer and midstorey vegetation

2016 ◽  
Vol 19 (2) ◽  
pp. 280-290 ◽  
Author(s):  
Huifeng Hu ◽  
Benjamin O. Knapp ◽  
G. Geoff Wang ◽  
Joan L. Walker
Keyword(s):  
Loblolly Pine ◽  
Longleaf Pine ◽  
Ground Layer ◽  
Silvicultural Treatments

The wildland fuel cell concept: an approach to characterize fine-scale variation in fuels and fire in frequently burned longleaf pine forests

2009 ◽  
Vol 18 (3) ◽  
pp. 315 ◽  
Author(s):  
J. Kevin Hiers ◽  
Joseph J. O'Brien ◽  
R. J. Mitchell ◽  
John M. Grego ◽  
E. Louise Loudermilk
Keyword(s):  
Fuel Cells ◽  
Numerical Models ◽  
Longleaf Pine ◽  
Fire Behavior ◽  
Pine Forests ◽  
Fire Intensity ◽  
Fine Scale ◽  
Understorey Vegetation ◽  
Ground Based Lidar

In ecosystems with frequent surface fire regimes, fire and fuel heterogeneity has been largely overlooked owing to the lack of unburned patches and the difficulty in measuring fire behavior at fine scales (0.1–10 m). The diverse vegetation in these ecosystems varies at these fine scales. This diversity could be driven by the influences of local interactions among patches of understorey vegetation and canopy-supplied fine fuels on fire behavior, yet no method we know of can capture fine-scale fuel and fire measurements such that these relationships could be rigorously tested. We present here an original method for inventorying of fine-scale fuels and in situ measures of fire intensity within longleaf pine forests of the south-eastern USA. Using ground-based LIDAR (Light Detection and Ranging) with traditional fuel inventory approaches, we characterized within-fuel bed variation into discrete patches, termed wildland fuel cells, which had distinct fuel composition, characteristics, and architecture that became spatially independent beyond 0.5 m2. Spatially explicit fire behavior was measured in situ through digital infrared thermography. We found that fire temperatures and residence times varied at similar scales to those observed for wildland fuel cells. The wildland fuels cell concept could seamlessly connect empirical studies with numerical models or cellular automata models of fire behavior, representing a promising means to better predict within-burn heterogeneity and fire effects.

scholarly journals Local forest structure variability increases resilience to wildfire in dry western U.S. coniferous forests

2019 ◽  
Author(s):  
Michael J Koontz ◽  
Malcolm P. North ◽  
Chhaya M. Werner ◽  
Stephen E. Fick ◽  
Andrew M. Latimer
Keyword(s):  
Sierra Nevada ◽  
Forest Structure ◽  
Tree Mortality ◽  
Forest Ecosystems ◽  
Fire Suppression ◽  
Fire Severity ◽  
Fire Behavior ◽  
Dry Forest ◽  
Structural Variability ◽  
Overstory Trees

A “resilient” forest endures disturbance and is likely to persist. Resilience to wildfire may arise from feedback between fire behavior and forest structure in dry forest systems. Frequent fire creates fine-scale variability in forest structure, which may then interrupt fuel continuity and prevent future fires from killing overstory trees. Testing the generality and scale of this phenomenon is challenging for vast, long-lived forest ecosystems. We quantify forest structural variability and fire severity across >30 years and >1,000 wildfires in California’s Sierra Nevada. We find that greater variability in forest structure increases resilience by reducing rates of fire-induced tree mortality and that the scale of this effect is local, manifesting at the smallest spatial extent of forest structure tested (90 x 90m). Resilience of these forests is likely compromised by structural homogenization from a century of fire suppression, but could be restored with management that increases forest structural variability.

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