Deriving forest canopy fuel parameters for loblolly pine forests in eastern Texas

2011 ◽  
Vol 41 (8) ◽  
pp. 1618-1625 ◽  
Author(s):  
Muge Agca ◽  
Sorin C. Popescu ◽  
Clinton W. Harper

Crown fires, the fastest spreading of all forest fires, can occur in any forest type throughout the world. The overall aim of this study was to estimate forest canopy fuel parameters including canopy bulk density and canopy base height for loblolly pines ( Pinus taeda L.) at the plot level using both allometric equations and CrownMass/FMAPlus software. Allometric equation results were compared with the CrownMass outputs for validation. According to our results, the calculated average canopy bulk density values, across all 50 plots, were 0.18 and 0.07 kg/m3 for the allometric equation and the CrownMass program, respectively. Lorey’s mean height approach was used in this study to calculate canopy base height at the plot level. The average height values of canopy base height obtained from the Lorey height approach was 10.6 m and from the CrownMass program was 9.1 m. The results obtained for the two methods are relatively close to each other, with the estimate of canopy base height being 1.16 times larger than the CrownMass value. This study provides a practical method for quantifying these parameters and making them directly available to fire managers. The accuracy of these parameters is very important for realistic predictions of wildfire initiation and growth.


1988 ◽  
Vol 12 (4) ◽  
pp. 273-274
Author(s):  
David B. South ◽  
Hans M. Williams ◽  
Alan Webb

Abstract In 1985, fall irrigation on an Alpin sand reduced seedling stress and increased production of plantable loblolly pine (Pinus taeda L.) seedlings by 6% (40,000/ac). Applying about 0.5 in. of water/week (for 10 weeks) increased average height by 1 cm, average diameter by 0.4 mm, and average dry weight by 20%. At a cost of $17/ac, the additional irrigations increased crop value by $l,000/ac. Although ceasing fall irrigation has been recommended for nurseries located on sands, biological and economic data are needed to demonstrate that gains from stressing seedlings will offset the potential decrease in production of plantable seedlings. South. J. Appl. For. 12(4):273-274.



1987 ◽  
Vol 11 (3) ◽  
pp. 128-133 ◽  
Author(s):  
Stephen C. Cade ◽  
Roy L. Hedden

Abstract Growth impact of pine tip moths (Rhyacionia spp.) in two 12-year-old Arkansas loblolly pine (Pinus taeda L.) plantations was measured, and growth loss through rotation was projected. Two tip moth control treatments (azinphos-methyl foliar spray and carbofuran granules) were appliedto trees in the protected treatments at ages 3, 4, and 5, and growth was compared to unprotected trees at 2-year intervals. Trees in protected treatments had significantly greater average height (2.0 ft), dbh (0.35 in.), and total volume (182 ft³/ac) than did trees in the unprotectedtreatment. Volume losses at age 12 were proportional to tip moth infestation levels during the period of protection. Potential long-term impact of a tip moth was estimated using the results of this study as input to growth and yield models for thinned and unthinned stands. Projected gainsfrom early tip moth control in light to moderately infested stands were: unthinned, 2 to 6 cords/ac at age 30; thinned, 300 to 700 bf/ac of sawtimber and 1 to 3 cords/ac of pulpwood on a 35-year rotation. An economic analysis comparing the present value of growth benefits to the treatmentcosts showed tip moth control to be marginally cost effective only in the thinned, sawtimber regime. South J. Appl. For. 11(2):128-133



2005 ◽  
Vol 35 (3) ◽  
pp. 724-739 ◽  
Author(s):  
Robert E Keane ◽  
Elizabeth D Reinhardt ◽  
Joe Scott ◽  
Kathy Gray ◽  
James Reardon

Canopy bulk density (CBD) is an important crown characteristic needed to predict crown fire spread, yet it is difficult to measure in the field. Presented here is a comprehensive research effort to evaluate six indirect sampling techniques for estimating CBD. As reference data, detailed crown fuel biomass measurements were taken on each tree within fixed-area plots located in five important conifers types in the western United States, using destructive sampling following a series of four sampling stages to measure the vertical and horizontal distribution of canopy biomass. The six ground-based indirect measurement techniques used these instruments: LI-COR LAI-2000, AccuPAR ceptometer, CID digital plant canopy imager, hemispherical photography, spherical densiometer, and point sampling. These techniques were compared with four aggregations of crown biomass to compute CBD: foliage only, foliage and small branchwood, foliage and all branchwood (no stems), and all canopy biomass components. Most techniques had the best performance when all canopy biomass components except stems were used. Performance dropped only slightly when the foliage and small branchwood canopy biomass aggregation (best approximates fuels available for crown fires) was employed. The LAI-2000, hemispherical photography, and CID plant canopy imager performed best. Regression equations that predict CBD from gap fraction are presented for all six techniques.



Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 321-330 ◽  
Author(s):  
Mitchell M Sewell ◽  
Bradley K Sherman ◽  
David B Neale

Abstract A consensus map for loblolly pine (Pinus taeda L.) was constructed from the integration of linkage data from two unrelated three-generation outbred pedigrees. The progeny segregation data from restriction fragment length polymorphism, random amplified polymorphic DNA, and isozyme genetic markers from each pedigree were recoded to reflect the two independent populations of parental meioses, and genetic maps were constructed to represent each parent. The rate of meiotic recombination was significantly greater for males than females, as was the average estimate of genome length for males {1983.7 cM [Kosambi mapping function (K)]} and females [1339.5 cM(K)]. The integration of individual maps allows for the synthesis of genetic information from independent sources onto a single consensus map and facilitates the consolidation of linkage groups to represent the chromosomes (n = 12) of loblolly pine. The resulting consensus map consists of 357 unique molecular markers and covers ∼1300 cM(K).



2021 ◽  
Vol 491 ◽  
pp. 119176
Author(s):  
Michael A. Blazier ◽  
Thomas Hennessey ◽  
Laurence Schimleck ◽  
Scott Abbey ◽  
Ryan Holbrook ◽  
...  


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 935
Author(s):  
Mohammad Bataineh ◽  
Ethan Childs

The need for a comprehensive and mechanistic understanding of competition has never been more important as plants adapt to a changing environment and as forest management evolves to focus on maintaining and enhancing complexity. With the recent decline in shortleaf pine (Pinus echinata Mill.) land area, it is critical to determine the effects of competition on shortleaf pine and its performance against loblolly pine (Pinus taeda L.), the preferred planted replacement. We evaluate differences in shortleaf and loblolly pine 10 year mean basal area increment (BAI) and crown dimensions across a gradient of neighborhoods. Linear mixed-effects regression models were developed using BAI and several crown metrics as responses and crowding, competitor species abundance and identity, and initial size and species identity of focal tree as predictors. Crowding of focal trees negatively impacted BAI and crown size (p < 0.001, respectively). Although loblolly pine had three times higher BAI as compared to shortleaf pine within similar neighborhoods, BAI was variable, and the crowding effect did not differ between shortleaf and loblolly pine (p ranged from 0.51–0.99). Competitive impacts on focal trees did not differ by competitor identity (p ranged from 0.07–0.70). Distance-independent competition indices better explained the variation in BAI and horizontal crown metrics, while distance-dependent size ratios were more effective at evaluating vertical crown metrics. These findings highlight shortleaf pine competitive potential in mature, natural-origin stands and provide support for the restoration of pine–hardwood and hardwood–pine stratified mixtures as well as management of shortleaf pine at long rotations.



2001 ◽  
Vol 25 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Bruce E. Borders ◽  
Robert L. Bailey

Abstract With mean annual increments up to 5.4 cords/ac/yr, six loblolly pine (Pinus taeda L.) research sites in Georgia produced yields on par with other results from intensively managed loblolly plantations around the world. Cultural treatments in the Georgia study include complete control of vegetation other than the planted pines with multiple applications of herbicide, annual fertilization, the combination of complete vegetation control and annual fertilization, and an intensive mechanical site preparation treatment. Complete vegetation control resulted in higher yield production at ages 10 to 12 yr than the intensive mechanical treatment at all locations. This regime also resulted in higher yield production than the annual fertilization treatment at four of six locations. Volume mean annual increment for 10- to 12-yr-old plantations with the combination treatment of complete vegetation control and annual fertilization ranged from 325 to 490 ft3/ac, growth rates comparable to those obtained at other high biomass production areas throughout the world. Our economic evaluation based on these results shows that 8 to 12% real rates of return are feasible from investments in intensive loblolly pine plantations in the southeastern United States. South. J. Appl. For. 25(2):69–74.



1997 ◽  
Vol 21 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Thomas A. Waldrop

Abstract Four variations of the fell-and-burn technique, a system developed to produce mixed pine-hardwood stands in the Southern Appalachian Mountains, were compared in the Piedmont region. All variations of this technique successfully improved the commercial value of low-quality hardwood stands by introducing a pine component. After six growing seasons, loblolly pine (Pinus taeda L.) occupied the dominant crown position and oaks the codominant position in fell-and-burn treated stands on poor to medium quality sites. The precise timing of felling residual stems, as prescribed by the fell-and-burn technique, may be flexible because winter and spring felling produced similar results. Although summer site preparation burns reduced hardwood height growth by reducing the length of the first growing season, they did not improve pine survival or growth. Pines were as tall as hardwoods within four growing seasons in burned plots and within six growing seasons in unburned plots. Additional research is needed to determine the level or intensity of site preparation needed to establish pine-hardwood mixtures over a range of site conditions. South. J. Appl. For. 21(3):116-122.



1997 ◽  
Vol 21 (2) ◽  
pp. 84-89 ◽  
Author(s):  
Steven E. McKeand ◽  
Robert P. Crook ◽  
H. Lee Allen

Abstract The lack of rank change in growth characteristics when open-pollinated families of loblolly pine (Pinus taeda L.) are planted on different sites in the Southeast has greatly simplified breeding for superior genotypes. Although family rank does not usually change, genotype by environment interactions (GxE) may be very important in operational deployment of families in regeneration programs. Using data from GxE trials and two site preparation-fertilization-herbicide trials, we estimated the growth that different families should achieve following application of these silvicultural practices. Better performing families tend to be most responsive to site changes (i.e. genetically unstable). Growth responses to silvicultural treatment will be overestimated if only the most responsive families are used in silvicultural research trials. Similarly, genetic gains will be overestimated if gain trials are planted on only the best sites or receive intensive culture. South. J. Appl. For. 21(2):84-89.



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