bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long-Term Effects of Site Preparation Treatments, Complete Competition Control, and Repeated Fertilization on Growth of Slash Pine Plantations in the Flatwoods of the Southeastern United States
Authors: Zhao Dehai , Kane Michael , Borders Bruce , Harrison Mike 
Published: April 2024

Abstract
Data through age 26 from a well-designed study established in 1979 were analyzed with a repeated-measures analysis of variance approach to evaluate effects of site preparation treatments, complete competition control, and repeated fertilization on growth of slash pine (Pinus elliottii Engelm.) plantations on Spodosols and non-Spodosols in the flatwoods region of southern Georgia and northern Florida. Complete and sustained vegetation control and repeated fertilization consistently and significantly increased slash pine productivity, with greater responses occurring on Spodosols than on non-Spodosols; their combination had less than additive effects on Spodosols and additive effects on non-Spodosols. Complete and sustained vegetation control resulted in greater cumulative responses than repeated fertilization over more than 20 years, and then the gains from repeated fertilization had caught or surpassed the gains from complete vegetation control. Bedding resulted in significant responses in the early ages. Burning improved stand basal area and volume growth rather than average tree height and dbh on non-Spodosols and had little effect on Spodosols. Chopping had no significant effect on either soil group. Results of this study emphasize the need for site-specific silvicultural prescriptions.
Estimating Forest Attributes Using Observations of Canopy Height: A Model-Based Approach
Authors: Mehtätalo Lauri , Nyblom Jukka 
Published: April 2024

Abstract
An airborne laser scanner can be used to make observations of canopy height at given locations within a forest stand. In recent years, foresters have developed methods to extract information on forest attributes, such as stand density and size distribution of the trees, from laser data for forest inventory purposes. These methods are based on empirical relationships rather than on theory about how observations are generated by tree canopies. We recover the relationship between canopy height and forest attributes, based on assumptions about the shape of a single tree crown, the distribution of tree height, and the spatial distribution of tree locations. This work improves our understanding of how stand characteristics are related to observations collected by airborne laser scanners and links the problem to the theory of germ-grain models and random closet sets in spatial statistics. Furthermore, we use the derived relationship to develop a model-based approach for estimating stand density and distribution of tree heights using observations of canopy height. A simulation study showed that the method is capable of producing fairly accurate estimates for the number of stems and mean tree height, yielding only slight biases in mean tree height and stand density.
Motivations and Land-Use Intentions of Nonindustrial Private Forest Landowners: Comparing Inheritors to Noninheritors
Authors: Majumdar Indrajit , Laband David , Teeter Lawrence , Butler Brett 
Published: April 2024

Abstract
The documented importance of intergenerational human capital transfers in agriculture generally gives us reason to suspect that such transfers may be important in a forestry context and that there may be important implied differences between first-generation woodland owners and multigeneration woodland owners with respect to their motivations and future intentions. In turn, knowledge of the motivations and intentions of nonindustrial private landowners may be extremely important because such knowledge may be vital in terms of our ability to predict future timber supply and the availability of nontimber amenities. Also, the effectiveness of public policies targeting nonindustrial private forest landowners may depend critically on their motivations and intentions. In this article, we analyzed 8,373 responses to the National Woodland Owner Survey to compare characteristics, motivations, and intentions of multigeneration forest landowners against those of single-generation forest landowners. In brief, we found there were significant differences in their motivations and management behavior; inheritors are more active forest managers and manage for both timber and nontimber forest products more aggressively than noninheritors who typically value esthetics, privacy, protection of biodiversity, and nonhunting recreation.
Terrain Trafficability Prediction with GIS Analysis
Authors: Suvinen Antti , Tokola Timo , Saarilahti Martti 
Published: April 2024

Abstract
The aim of this article is to test a GIS-based model for predicting terrain trafficability. The resistance forces restricting the movement of a forest tractor are estimated using a digital soil map, a 25 × 25-m digital elevation model (DEM) and an improved elevation model. Virtual total resistances along the 1,150-m test track were measured using the controller area network (CAN) bus-based technique. Rolling resistance prediction based on the soil type map was quite successful on frictional soils, but the predictions were clear underestimations on cohesive soils because the characteristics of Finnish soil types as substrates for vehicle motion are not well known. The 25 × 25-m DEM seems to be too inaccurate to predict the slope resistance and total resistance, whereas the results obtained with the improved DEM support the null hypothesis that the prediction is adequate enough from a terramechanical point of view and that the method could be used as a tool for predicting terrain trafficability.
Fertilization and Seeding Effects on Vegetative Cover After Wildfire in North-Central Washington State
Authors: Peterson David W. , Dodson Erich K. , Harrod Richy J. 
Published: April 2024

Abstract
Land surface treatments are often applied after severe wildfires to mitigate runoff and erosion threats. However, questions remain about treatment effectiveness, even as treatment costs continue to rise. We experimentally evaluated the effects of seeding and fertilization treatments on vegetative and total soil cover for two growing seasons after the Pot Peak wildfire in the eastern Cascade Mountains. Without treatments, vegetative cover averaged 15% the first year and 27% the second year after wildfire. Fertilization significantly increased vascular plant cover and reduced bare soil area in both years, but differences between low and high fertilization levels were not significant. Fertilization also increased cryptogam cover. Seeding alone was generally ineffective; however, the combination of fertilization with a seed mixture containing the native forb, yarrow (Achillea millefolium L.), produced the highest vascular plant cover and lowest bare soil area. Our results suggest that fertilization may be more effective than seeding, probably providing a degree of protection from erosion, especially the second year after fire. However, treatment effectiveness must be evaluated in context against costs and potential ecosystem impacts.
An Evaluation of Spatial Autocorrelation and Heterogeneity in the Residuals of Six Regression Models
Authors: Zhang Lianjun , Ma Zhihai , Guo Luo 
Published: April 2024

Abstract
Spatial effects include spatial autocorrelation and heterogeneity. Ignoring spatial effects in a modeling process causes misleading significance tests and suboptimal model prediction. In this study, we used three forest plots with different spatial patterns of tree locations (i.e., clustered, random, and regular patterns) to investigate the spatial distributions and heterogeneity in the model residuals from six regression models with the ordinary least squares (OLS) as the benchmark. Our results revealed that when significant spatial autocorrelations and variations existed in the relationship between tree height and diameter, as in the softwood plot (clustered) and hardwood plot (random), OLS was not appropriate for modeling the relationship between tree variables. Spatial regression models (i.e., spatial lag and spatial error models) were effective for accounting for spatial autocorrelation in the model residuals, but they were insufficient to deal with the problem of spatial heterogeneity. It was evident that the model residuals in both spatial lag and spatial error models had a similar pattern and magnitudes of spatial heterogeneity at spatial scales different from those of the OLS model. In contrast, the linear mixed model and geographically weighted regression incorporated the spatial dependence and variation into modeling processes, and consequently, fitted the data better and predicted the response variable more accurately. The model residuals from both the linear mixed model and geographically weighted regression had desirable spatial distributions, meaning fewer clusters of similar or dissimilar model residuals over space.
Microhabitat Selection of Bark-Foraging Birds in Response to Fire and Fire Surrogate Treatments
Authors: Farris Kerry L. , Zack Steve , Amacher Andrew J. , Pierson Jennifer C. 
Published: April 2024

Abstract
We examined the short-term response of the bark-foraging bird community to mechanical thinning, prescribed fire, and thinning/prescribed fire combination treatments designed to reduce fuel loads at study sites throughout the continental United States as part of the national Fire and Fire Surrogate (FFS) project. We modeled the effects of study site, treatment, treatment category, and time since treatment on the foraging encounter rate of four individual species (red-breasted nuthatch [Sitta canadensis], mountain chickadee [Poecile gambeli], hairy woodpecker [Picoides villosus], and brown creeper [Certhia americana]) and assessed the relative importance of several tree and snag characteristics in the selection of foraging trees by these same species. The foraging encounter rate of all four species responded inconsistently across both treatment categories and study sites. Substrate diameter was the strongest and most consistent characteristic positively influencing the selection of foraging habitat structures for all species across all treatment categories. Other influential variables included the presence of bark beetles for red-breasted nuthatches, hairy woodpeckers, and brown creepers in control and burn-only treatment areas and tree species for brown creepers in burn-only and thin-only treatment areas. Although this study did not detect any major negative treatment response by any species, our results suggest that there is substantial variability in the reaction of this particular bird community to fuel reduction treatments and that managers may need to evaluate the effects of these treatments on a site-by-site and species-by-species basis.
Short-Term Response of Ground-Dwelling Arthropods to Prescribed Fire and Mechanical Fuel Reduction in a Southern Appalachian Upland Hardwood Forest
Authors: Greenberg Cathryn H. , Forrest T. G. , Waldrop Thomas 
Published: April 2024

Abstract
As part of the multidisciplinary National Fire and Fire Surrogate Study, we used drift fences with pitfall traps to determine how three fuel reduction treatments affected ground-dwelling macroarthropods in the southern Appalachian Mountains of North Carolina. Four experimental units, each &gt;14 ha, were contained within each of three replicate blocks. Treatments were (1) prescribed burning, (2) mechanical felling of shrubs and small trees, (3) mechanical felling + burning, and (4) untreated controls. Mechanical understory felling was conducted in winter 2001–2002, and prescribed burning was conducted in March 2003. Mechanical felling + burning resulted in greater canopy openness compared with the other treatments as a result of hotter fires and elevated levels of subsequent tree mortality. Burning reduced leaf litter depth in both burned treatments by &gt;80%. We captured 6,776 individual macroarthropods (460 g of dry biomass) within 22 identified orders and 59 identified families. Coleoptera and Hymenoptera were numerically dominant (27.3 and 25.9%, respectively); Lepidoptera larvae also were a dominant component of dry biomass (37%). We found no differences among treatments in the relative abundance or dry biomass of total ground-dwelling macroarthropods or within most orders; Hymenoptera (predominantly Formicidae) dry biomass was greater with mechanical felling + burning than with mechanical felling. Total relative abundance and dry biomass were low in spring and higher in late summer. Our results indicate that prescribed burning and mechanical fuel reduction treatments conducted in winter or early spring have little impact on the community composition, relative abundance, or biomass of total arthropods or most arthropod orders and families, at least in the short term. However, because we did not use a killing agent, our trapping method probably undersampled macroarthropods that could climb or fly from traps, and results for those groups should be interpreted cautiously. Our study suggests that the fuel reduction methods studied may be used as a land management tool in upland hardwood forest with little effect on macroarthropod communities or the ground-dwelling arthropod prey base for vertebrates.
On Conducting a Multisite, Multidisciplinary Forestry Research Project: Lessons from the National Fire and Fire Surrogate Study
Authors: McIver James Duncan , Weatherspoon Charles Phillip 
Published: April 2024

Abstract
The National Fire and Fire Surrogate (FFS) study is described, from its conceptual stage in early 1996 to the completion of its short-term phase in May 2006. Comprising 12 sites, the FFS study is a comprehensive multidisciplinary experiment designed to evaluate the economics and ecological consequences of alternative fuel reduction treatments in seasonally dry forests of the United States. The FFS study uses a common experimental design across the 12-site network, with each site consisting of a fully replicated experiment that compares four treatments: an unmanipulated control, prescribed fire, mechanical treatments, and mechanical + fire. We measured operational costs and variables within several components of the ecosystem, including vegetation, the fuel bed, soils, bark beetles, tree diseases, and wildlife in the same 10-ha experimental units. This design allowed us to assemble a fairly complete picture of ecosystem response to treatment at the site scale, and to compare treatment response across sites representing a wide variety of conditions. We offer the FFS study as a model for conducting a complex multidisciplinary management experiment focused on natural resource issues. We then discuss why we believe it was successful and how it could be improved. We discuss seven key features that we believe must be considered to conduct a successful multidisciplinary experiment: funding, design, partnerships, organization, standardization, data management, and outreach. Although experiments such as the FFS study are difficult to execute, they may be our best hope for answering some of our more pressing questions in the field of natural resource management.
Thinning and Burning in Dry Coniferous Forests of the Western United States: Effectiveness in Altering Diameter Distributions
Authors: Youngblood Andrew 
Published: April 2024

Abstract
Western United States land managers are conducting fuel reduction and forest restoration treatments in forests with altered structural conditions. As part of the National Fire and Fire Surrogate (FFS) study, thinning and burning treatments were evaluated for changing forest structure. Shifts between pretreatment and posttreatment diameter distributions at seven western FFS study sites were determined by assessing live tree diameter frequency distributions and the 10th and 90th percentile and mean diameter. Diameter distributions were based on 31,517 live trees within 76 pretreatment units and 25,061 live trees within 85 posttreatment units. Cross-site comparisons were made using meta-analysis. Values for 10th percentile diameter increased at two sites, values for 90th percentile diameter increased at six sites, and values for mean diameter increased at five sites (P &lt; 0.05) after active treatments (thin, burn, or thin + burn) compared with control sites. Across the seven western FFS study sites, the overall effect size of the thin treatment increased for 90th percentile and mean diameter, the overall effect size of the burn treatment increased for 10th percentile, 90th percentile, and mean diameter, and the overall effect size of the thin + burn treatment increased for 10th percentile, 90th percentile, and mean diameter. This work indicates that although each of the active treatments was effective in shifting diameter distributions toward larger trees, no single treatment or entry will probably mitigate nearly a century of fire exclusion and fuel accumulation in dry coniferous forests of the western United States.
Effects of Fire and Fire Surrogate Treatments on Bark Beetle-Caused Tree Mortality in the Southern Cascades, California
Authors: Fettig Christopher , Borys Robert , Dabney Christopher 
Published: April 2024

Abstract
We examined bark beetle responses to fire and fire surrogate treatments 2 and 4 years after the application of prescribed fire in a mixed-conifer forest in northern California. Treatments included an untreated control (C), thinning from below (T), and applications of prescribed fire (B) and T + B replicated three times in 10-ha experimental units. A total of 1,822 pine and fir trees (5.1% of all trees) were killed by bark beetles. Mountain pine beetle (Dendroctonus ponderosae Hopkins) was found infesting ponderosa pine (Pinus ponderosa Dougl. ex Laws.), sugar pine (Pinus lambertiana Dougl.), and lodgepole pine (Pinus contorta Dougl. ex Loud.); western pine beetle (Dendroctonus brevicomis LeConte) was found infesting ponderosa pine; and fir engraver (Scolytus ventralis LeConte) was found infesting white fir (Abies concolor [Gord. & Glend.] Lindl. ex Hildebr.). Significantly higher rates of bark beetle-caused tree mortality occurred on B (9.2%) than on C (3.2%), T (&lt;1%), or T + B (3.3%) cumulatively during the 4-year period. A total of 723 pines (4.4% of all pines) were killed by bark beetles, primarily mountain pine beetle. Attacks resulted in significantly more pine mortality on B (5%) than on C, T, or T + B (all &lt;1%) 2 years after the application of prescribed fire. No significant treatment effects were found during the second sample period or cumulatively during the 4-year period. A total of 1,098 white fir trees (5.8% of all white fir) were killed by the fir engraver. Attacks resulted in significantly higher rates of fir mortality on T + B than on T during both sample periods but not cumulatively during the 4-year period. Overall, bark beetle-caused tree mortality was concentrated in the smaller diameter classes. The implications of these and other results to forest management are discussed.
Effectiveness of Litter Removal to Prevent Cambial Kill-Caused Mortality in Northern Arizona Ponderosa Pine
Authors: Fowler James F. , Sieg Carolyn Hull , Wadleigh Linda L. 
Published: April 2024

Abstract
Removal of deep litter and duff from the base of mature southwestern ponderosa pine (Pinus ponderosa Laws.) is commonly recommended to reduce mortality after prescribed burns, but experimental studies that quantify the effectiveness of such practices in reducing mortality are lacking. After a pilot study on each of four sites in northern Arizona, we monitored 15–16 sets of 8 matched trees on areas designated to be burned and adjacent not-burned sites and randomly assigned one of four litter and duff removal (to mineral soil) treatments: (1) rake to a distance of 23 cm from the bole, (2) leaf blow to a distance of 23 cm, (3) rake to a distance of 1 m, and (4) no litter or duff disturbance or removal. By 3 years postburn, no trees had died because of any of the treatments, but litter and duff removal prevented most cambial kill. However, 17% of the burned, no removal trees had some cambial kill. Litter and duff removal to 23 cm was as effective in preventing cambial kill and bole char as removal to 1 m, and there was no difference between removal by raking versus leaf blower removal. These results suggest that litter and duff removal is not needed to prevent ponderosa pine mortality after fall prescribed burns, but removal to 23 cm is adequate to prevent spots of cambial kill or moderate bark char.
Conservation Contracts for Forest Biodiversity: Theory and Experience from Finland
Authors: Juutinen Artti , Ollikainen Markku 
Published: April 2024

Abstract
We examined the Finnish biodiversity conservation pilot project, called Trading in Natural Values (TNV), using a simulated biodiversity auction model. We found, first, that the share of the most valuable old stands in the key ecological forest habitats was higher in the actual TNV program than in a simulated auction. Second, the actual bids in the TNV program were on average €400–1,200 lower per ha than the bids generated by the auction model. These findings indicate the presence of strong conservation motives among the Finnish landowners. Third, because the number of stands with high biodiversity values is limited in the study area and conservation costs are high for these stands, increasing the size of the conservation budget enrolls more stands in the program but with lower biodiversity values.
Age–Age Correlations and Early Selection for Height in a Clonal Genetic Test of Norway Spruce
Authors: Isik Kani , Kleinschmit Jochen , Steiner Wilfried 
Published: April 2024

Abstract
Heights of rooted cuttings from 40 clones of Norway spruce (Picea abies [L.] Karst) were measured at ages 3, 5, 8, 10, 13, and 17 from rooting at seven test environments in northern Germany. To determine the optimal age for juvenile selection for height, age-related changes in variance components, clone-mean heritability, and age–age correlations were estimated. Partitions of variance components were essentially constant after age 8. Clone-mean heritabilities were highest at age 3 (0.94) and were essentially stable after age 5. Age–age correlations were generally high between similar ages but declined as the difference between pairs of measurement ages increased. Genetic correlations were greater than corresponding phenotypic correlations but were similar in value. Trait–trait correlations between height and diameter (rG = 0.83) and height and volume (rG = 0.90) at age 17 were also high. Simple linear regressions of genetic and phenotypic age–age correlations on LAR (natural log of the ratio of younger age to older age) were significant (R2 ≥ 0.76). Predicted efficiencies of selection suggested that for a rotation age of 60 years, the optimum selection age would be as early as 13 years. Furthermore, gains per year would be increased by about 1½ times if selections were made at about age 15 rather than age 60.
The Bivariate Gompertz Diffusion Model for Tree Diameter and Height Distribution
Authors: Rupšys Petras , Petrauskas Edmundas 
Published: April 2024

Abstract
With this research we present a new method for describing the bivariate diameter and height distribution of trees growing in a pure, uneven-aged forest. We use a stochastic differential equation framework to derive a bivariate age-dependent probability density function of tree diameter and height when the tree diameter and height follow a bivariate stochastic Gompertz shape growth process. We also adopt the two-dimensional transition probability function methodology for growth modeling of forest stands. The bivariate stochastic Gompertz model is fit to diameter and height observations for 1,575 pine trees in the Dubrava district of Lithuania. A considerable advantage of the bivariate stochastic Gompertz growth model is that the model parameters are easily interpretable. All results are implemented in the symbolic algebra system MAPLE.