bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth in Relation to Canopy Light Interception in a Red Pine (Pinus resinosa) Thinning Study
Authors: Law Beverly E. , Riitters Kurt H. , Ohmann Lewis F.
Published: April 2024

Growth data from the most recent 5 years of a 40-year thinning study in an even-aged red pine (Pinus resinosa) forest in Cutfoot Sioux Experimental Forest, Minnesota, were used with intercepted photosynthetically active radiation (IPAR) data to determine the relationship between light interception and growth for a range of stand densities. Stand basal area (BA) growth was proportional to the amount of light intercepted within the stand (P = 0.06, r² = 0.73), and individual tree growth was inversely related to the amount of light intercepted by the canopy (P = 0.08, r² = 0.69). Stand growth efficiency (SGE = ratio of 5-year plot BA growth to plot median %IPAR) was only weakly correlated with stand density (P » 0.10, r = 0.31). The rate of change in stand growth efficiency may be a good indicator of change in forest condition over a range of stand densities. For. Sci. 38(1):199-202.
Leaf Area Estimation of Mature Foliage of Juniperus
Authors: Cregg Bert M.
Published: April 2024

The ratio of total surface area to projected leaf area was determined for mature foliage samples collected at three canopy heights from Juniperus virginiana and J. scopulorum from four seed sources grown in southeastern Nebraska. The relation of projected leaf area to leaf dry weight and volume was also determined. Total surface area was estimated to be 3.2 times the projected surface area. This relationship was independent of seed source or crown position. Projected leaf area can be satisfactorily estimated from weight or volume. However, these relationships differed by crown position or seed source. These results indicate that leaf area of mature juniper foliage may be rapidly estimated through measurement of projected surface area. Further, the leaf area of large samples may be estimated by determining the appropriate specific leaf area or surface-to-volume ratios. For. Sci. 38(1):61-67.
A Comparison of Hierarchical Bayes and Empirical Bayes Methods with a Forestry Application
Authors: Green Edwin J. , Strawderman William E.
Published: April 2024

Gibbs sampling for generating marginal posterior distributions in Bayesian analysis is introduced to the forestry literature. Hierarchical Bayes and (parametric) empirical Bayes methods are compared theoretically and with a practical example. It is shown that in the latter procedures, the error due to estimating the hyperparameters from the marginal distribution of the data is ignored. This results in underestimating the scale of the marginal posterior distributions. For. Sci. 38(2):350-366.
The Efficiency of Half-Sib, Half-Diallel and Circular Mating Designs in the Estimation of Genetic Parameters in Forestry: A Simulation
Authors: Huber Dudley A. , White Timothy L. , Hodge Gary R.
Published: April 2024

A technique based on MIVQUE (minimum variance quadratic unbiased estimation) and the first approximation of the variance of a ratio was used to compare efficiency per unit observation in lowering the variance of estimation of three genetic ratios (single tree heritability, Type B correlation, and dominance-to-additive variance ratio). The efficiency comparisons were made over eight levels of genetic control for three mating designs (half-sib, half-diallel, and circular with four crosses per parent) with variable numbers of parents at two or five locations. The field design was held constant within a location as four randomized complete blocks with a six-tree row-plot per cross (full-sib designs) or per half-sib family (half-sib design). For heritability estimation the half-sib mating design is the most efficient over numbers of location and parents in seven of the eight levels of genetic control, and the circular design is more efficient over all levels examined than the half-diallel design. For estimation of Type B correlation the circular design is superior under five of the eight genetic control levels and superior for every case examined to the half-diallel design. In the remaining 3 Type B correlation estimation cases, the half-sib design is superior. For dominance-to-additive variance ratio estimation, the half-diallel design offers little, if any, advantages over the circular design. Optimal numbers of parents (highest efficiency) for a mating design exist only for the half-diallel design and optima are extant for all three genetic ratios. Optimal numbers of locations exist for all three mating designs and vary with mating design and level of genetic control. For. Sci. 38(4):757-776.
Population Differentiation in Seedling Root Size Between Adjacent Stands of Jack Pine
Authors: Wright Robert A. , Wein Ross W. , Dancik Bruce P.
Published: April 2024

Seeds from adjacent wet-site and dry-site jack pine stands were planted in a common growth chamber, and seedlings were grown with and without drought. Population differentiation in root and shoot growth traits was assessed 14 and 35 days after seedling emergence. Seedlings originating from the wet site had significantly more tertiary roots than those originating from the dry site. Differences between wet- and dry-site populations in secondary root length and shoot biomass disappeared when adjusted for the effects of higher mean seed weight in the dry-site population. The strength of correlations between seedling size parameters and seed weight varied with seedling age and exposure to drought. Droughty conditions inhibited secondary and tertiary but not primary root growth. For. Sci: 38(4):777-785.
Modeling Rubber Tree Root Disease Epidemics with a Markov Spatial Process
Authors: Chadoeuf J. , Pierrat J. C. , Nandris D. , Geiger J. P. , Nicole M.
Published: April 2024

Root diseases of the rubber tree (Hevea Brasiliensis) due to Rigidoporus lignosus (Klotzsch) Imaz. and Phellinus noxius (Corner) G.H. Cunn spread along planting lines and cause serious damage. Various control methods exist. A mathematical model was developed which allows the influence of their various parameters on the dynamics of an epidemic to be evaluated. The health status of the trees on a planting line was considered as a Markov process. The model parameters were given a biological interpretation and estimated using the results of an epidemiological survey carried out in Côte d'Ivoire from 1977 to 1984. Hypotheses of influence of dead trees before the survey, stationarity of secondary infection, and development of initial infection were tested. By simulation of the main model, the parameters were linked to percentages of infected trees on each inspection and of healthy trees at the end of the epidemic, thereby allowing the effects of the control methods to be evaluated according to their nature, efficiency, and mode of application. FOR. SCI. 39(1):41-54.
Control Variate Estimators of Survivor Growth from Point Samples
Authors: Roesch F. A. , Van Deusen P. C.
Published: April 2024

Two estimators of the control variate type for survivor growth from remeasured point samples are proposed and compared with more familiar estimators. The large reductions in variance, observed in many cases for estimators constructed with control variates, are also realized in this application. A simulation study yielded consistent reductions in variance which were often 50% and occasionally over 70%. FOR. SCI. 39(1):66-77.
Douglas-fir Nutrients and Terpenes: Potential Resistance Factors to Western Spruce Budworm Defoliation
Authors: Clancy Karen M. , Itami Joanne K. , Huebner Daniel P.
Published: April 2024

Differences in the nutritional quality of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) foliage may explain why some individual trees are more resistant or susceptiable than others to damage from the western spruce budworm, Choristoneura occidentalis Freeman. We compared levels of foliar nutrients (nitrogen, sugars, phosphorus, potassium, calcium, magnesium, copper, manganese, zinc, iron, sodium, and sulfur) and allelochemicals (mono- and sesquiterpenes) between "resistant" (light defoliation history) and "susceptible" (history of heavy defoliation) Douglas-fir trees in 1989 and 1990. Phenology of bud burst and the radial growth rate of the trees were also examined. Susceptible trees had lower levels of N and sugars than resistant trees. These results agreed with published predictions from artificial diet bioassays. Moreover, susceptible trees had mineral/N ratios (for P, K, Ca, Mg, Cu, and Zn) which were closer to the optimum levels previously established in diet bioassays. There were no detectable differences in foliar concentrations of terpenes. However, susceptible trees had a greater proportion of total terpenes that were monoterpenes, whereas resistant trees had a greater percentage of oxygenated monoterpenes. Resistant trees also had delayed bud burst and shoot expansion compared to susceptible trees, and they had accumulated more radial growth over the past 25 yr, implying they were more vigorous than susceptible trees. FOR. SCI. 39(1):78-94.
The Maximum Density Concept Applied to Uneven-Aged Mixed-Species Stands
Authors: Sterba Hubert , Monserud Robert A.
Published: April 2024

In even-aged pure stands, the relationship between density and quadratic mean diameter of different stands can be described by a hyperbola, the coefficients of which depend allometrically on dominant height (Sterba's modified Competition Density Rule). From the equations describing these relationships the slope of Reineke's maximum density line can be calculated and (for a given data set) tested against the hypothesis that this slope is - 1.605. Data from 134 even- and uneven-aged mixed species stands in northern Idaho and northwestern Montana showed that this slope depended on the skewness of the dbh1.5 distribution, which in turn was correlated with structural stand characteristics like "unevenagedness" and species mixture. The parameters of the extended Competition Density Rule were simultaneously estimated by nonlinear regression under an assumption relating asymptotic dominant height and maximum basal area by habitat type. Results demonstrated that both the maximum basal area at a given dominant height are higher in even-aged pure stands (with smaller skewness of the dbh1.5 distribution) than in uneven-aged mixed stands. Furthermore, the differences in maximum stem number and maximum basal area resulting from differing skewness decrease with increasing dominant height. Large differences in maximum basal area can be shown between different habitat types and any given site index, thus demonstrating that habitat types can be used to distinguish yield levels sensu Assmann. For. Sci. 39(3):432-452.
Use of TREGRO to Simulate the Effects of Ozone on the Growth of Red Spruce Seedlings
Authors: Laurence J. A. , Kohut R. J. , Amundson R. G.
Published: April 2024

TREGRO, a model developed to simulate the growth of sapling red spruce (Picea rubens Sarg.), was parameterized to grow 2- to 3-yr-old seedlings. Results of the simulation compared favorably to actual growth of seedlings used in a field study of the effects of ozone and acidic precipitation on tree physiology and development. Furthermore, a 10-yr simulation produced a modeled tree that corresponded to saplings used in another field experiment. Additional simulations were conducted to compare predicted effects of ozone on seedling growth to those measured in controlled experiments. Based on the performance of the model, we believe TREGRO can be used effectively to simulate both seedling and sapling red spruce growth, and the potential effects of ozone on the development of the trees. For. Sci. 39(3):453-464.
Fitting Discrete-Time Dynamic Models Having Any Time Interval
Authors: McDill Marc E. , Amateis Ralph L.
Published: April 2024

When the desired time interval of a difference equation is not the same as the interval at which the data used to fit the equation were collected (the measurement interval), some kind of interpolation method is necessary before fitting. Linear growth assumptions, which are often used for such interpolations, are almost always inconsistent with the growth function that is estimated and can lead to biased growth projections. A more logical approach is to use the hypothesized functional form of the difference equation as the basis for interpolation. Two interpolation methods based on this approach are presented. With one method, both the interpolation and the parameter estimation steps are implemented simultaneously. The second method implements the interpolation and parameter estimation steps separately and requires repeated model fittings until consistency is obtained between both steps. The procedures are demonstrated using a tree height growth example. Results are compared with an integrated, continuous-time version of the growth model that can be fitted without interpolation. Growth projections obtained with the proposed interpolation methods are closer to the projections obtained with the integrated, continuous-time model than projections obtained with other commonly used interpolation methods. A simple Monte Carlo analysis showed that two common interpolation methods based on linear assumptions produce biased parameter estimates but failed to show any bias in the parameter estimates obtained with the proposed methods. Parameter estimates obtained with the new interpolation methods converge to limiting values as the time interval of the difference equation is shortened. These limiting values can be used as estimates of the parameters of continuous-time versions of the growth model. For. Sci. 39(3):499-519.
Early Successional Pathways Following Wildfire and Subsequent Silvicultural Treatment in Douglas-Fir/Hardwood Forests, NW California
Authors: Stuart John D. , Grifantini Michael C. , Fox III Lawrence
Published: April 2024

Early successional sites were contrasted with old-growth Douglas-fir/hardwood forests to detect community-level, life form, and species diversity differences due to postwildfire silvicultural treatments. Treatments included: (1) salvage logged after wildfire; (2) not salvage logged after wildfire; and (3) previously established plantations. These silvicultural treatments were compared 2 yr after a 1987 wildfire and 12 yr after a 1977 wildfire. There was more forb and shrub cover on 1987 unsalvaged sites than on salvaged. Sites salvaged following the 1977 fire had more hardwood cover but less shrub cover than unsalvaged sites. Old-growth sites had more conifer and hardwood cover than the early successional sites. There was no difference in species diversity among the successional treatments; old-growth sites, however, were less diverse than all treatment sites combined. Based on these and results from other studies, tanoak and other hardwoods inhibited the establishment and growth of Douglas-fir on salvaged sites, while deerbrush and other shrubs inhibited Douglas-fir on unsalvaged sites. For. Sci. 39(3):561-572.
Fuel Loading, Bulk Density, and Depth of Forest Floor in Coast Redwood Stands
Authors: Finney Mark A. , Martin Robert E.
Published: April 2024

The relationship between forest floor depth and bulk density was examined for purposes of estimating fuel loading and consumption in forests dominated by the coast redwood (Sequoia sempervirens [D. Don] Endl.). Data were obtained from 47 samples at 2 sites. Samples of forest floor varied from 2 to 10 cm deep. For each sample, organic material was excavated in 1 cm strata within a 20 x 20 cm frame. Multiple regression analysis indicated that bulk density increased with strata depth, although a given stratum had lower bulk density in deeper profiles (P = 0.05). In practical terms, these variations have a small effect on the accuracy of estimates of forest floor consumption derived using the constant mean bulk density. For. Sci. 39(3): 617-622.
Adaptive Cluster Sampling for Forest Inventories
Authors: Roesch Francis A.
Published: April 2024

Adaptive cluster sampling is shown to be a viable alternative for sampling forests when there are rare characteristics of the forest trees which are of interest and occur on clustered trees. The ideas of recent work in Thompson (1990) have been extended to the case in which the initial sample is selected with unequal probabilities. An example is given in which the initial sample of trees is selected with probability proportional to tree basal area. If a characteristic of interest is observed on a sample tree, additional trees within a fixed distance of the sample tree are also included in the sample. For. Sci. 39(4):655-669.
Calibrating a Model of Stochastic Effects on Diameter Increment for Individual-Tree Simulations of Stand Dynamics
Authors: Stage Albert R. , Wykoff William R.
Published: April 2024

Stand dynamics is the expression of variation in tree and site attributes within the stand operating through the physiologic processes of establishment, accretion, and mortality. Because stand dynamics is the consequence of deviation-amplifying processes, models of stand dynamics should include both variation in processes attributable to known causes as well as to causes that can only be included by stochastic representation of the unexplainable residuum. When the magnitude and serial correlation of unexplained sources of variation in diameter increment are modeled by addition of a random variable, simulated development of both stand volume and spread of diameters are affected. In this report, we develop a model of the tree-to-tree component of unexplained variation that affects stand dynamics. This model is intended for use in individual-tree models of stand development in which time advances in intervals of unequal length. Our model combines results from published time-series analyses with original analyses of residuals from increment models and of measurement variation for diameter increment within individual trees. This eclectic approach is required because extensive data sets do not exist that include adequate samples of the factors known to affect increment and also include information required to model the error structure as well. For. Sci. 39(4):692-705.
The Relationship Between Timber Production, Local Historical Events, and Community Social Change: A Quantitative Case Study
Authors: Force Jo Ellen , Machlis Gary E. , Zhang Lianjun , Kearney Anne
Published: April 2024

This paper reports on a case study examining the relationship between timber production, local history, and community social change in a timber-dependent community over a 60-yr period. We hypothesize that community social change is associated with changes in the production level of the local resource system and/or local historical events. Regression models were developed for four community social change variables: size (number of employees), structure (number of churches), cohesion (number of marriages), and anomie (number of arrests). Indicators of timber production and local historical events were treated as independent variables influencing community social change. Local history events were divided into four categories: (1) nontimber related economic development, (2) timber-related development, (3) natural disasters, and (4) social unrest. The arrests model has a coefficient of determination (R²) of 0.86. This model included four independent variables: (1) mill production, (2) natural disasters, (3) national forest harvest, and (4) nontimber development. The model for the number of employees in timber-related jobs, with an R² of 0.58, includes both timber production and local history independent variables. The paper concludes with a discussion of the implications of these findings for the development of theory concerning timber-dependent communities. For. Sci. 39(4): 722-742.
Family Differences in Equations for Predicting Biomass and Leaf Area in Douglas-Fir (Pseudotsuga menziesii var. menziesii)
Authors: St. Clair J. B.
Published: April 2024

Logarithmic regression equations were developed to predict component biomass and leaf area for an 18-yr-old genetic test of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) based on stem diameter or cross-sectional sapwood area. Equations did not differ among open-pollinated families in slope, but intercepts assuming equal slopes did differ for equations predicting leaf, branch, or bark biomass, or leaf area. These results may be explained by family differences in partitioning between stemwood and bark and between stem and crown. Predictions of biomass and leaf area based on equations developed in this study differed from predictions based on equations from other studies by as much as a factor of two, suggesting that discretion is needed when applying equations to other sites at other stages of stand development and with other ranges of tree sizes. For. Sci. 39(4): 743-755.
Characterizing Spatial Patterns of Trees Using Stem-Mapped Data
Authors: Moeur Melinda
Published: April 2024

Procedures for stem-mapping trees on fixed area plots are described. Two statistical procedures for analyzing spatial patterns of the completely mapped tree data are presented. These procedures, known as nearest neighbor analysis and Ripley's K(d) function, consider the cumulative distributions of distances between trees, compared to a distance distribution for a point pattern generated by a random process. Nearest neighbor uses tree-to-nearest-tree distances, and Ripley's K(d) considers distances between all pairs of trees. Both procedures include edge correction schemes for trees near plot boundaries. The two analyses were applied to stem-mapped data from several old-growth study plots to investigate spatial interactions within and between groups of canopy trees. Patterns for trees in different mortality, size, and competitive classes were analyzed separately. Results showed that between-tree competitive interactions drive forest patterns from clustering toward regularity. There was also evidence that canopy gaps are an important mechanism in the regeneration process. The examples illustrate how spatial pattern analysis can be useful in describing and interpreting complicated development processes that result from competitive interactions between individual trees. For. Sci. 39(4):756-775.
Estimating the Historic Probability of Stand-Replacement Fire Using the Age-Class Distribution of Undisturbed Forest
Authors: Reed William J.
Published: April 2024

A simple probabilistic model for the destruction of forest stands by fire is used to determine a likelihood function for the problem of estimating the per annum probability of stand-replacement fire using data in the form of areas in various age classes of undisturbed old-growth forest. This enables the estimation of either an age-independent fire probability or of the parameters of a parametrically defined age-dependent probability. The model includes contagion effects (the probability of a stand burning being increased by other stands burning). Maximum likelihood is used to obtain estimates of the age-independent per annum probability of stand-replacement fire (or the parameters of an age-dependent model), along with a contagion parameter. Confidence intervals for the fire probability are also obtained. For. Sci. 40(1):104-119.
Tree Size Diversity and Economic Returns in Uneven-Aged Forest Stands
Authors: Buongiorno Joseph , Dahir Sally , Lu Hsien-Chih , Lin Ching-Rong
Published: April 2024

Methods are presented to predict some of the effects of management on the tree size diversity of forest stands, measured with the Shannon-Wiener index applied to diameters. The diameter distribution is an indicator of stand structure and a determinant of biological diversity. The methods, which involve linear and nonlinear programming models of managed stands, were applied to northern hardwood forests. The attendant stand growth model was calibrated and validated with remeasured plots. The results suggest that, in this specific case, a natural, undisturbed stand would reach the highest possible sustainable diversity of tree size. Any intervention would decrease that diversity. In particular, economic harvesting policies would reduce tree size diversity by 10 to 20%, depending on the length of the cutting cycle. However, economics and diversity did not necessarily conflict. With the data and model used here, lengthening the cutting cycle up to 30 yr led to higher tree size diversity, while it also increased the soil rent of a stand by decreasing the present value of the cost of re-entry. Similarly, for a given cutting cycle, the soil rent increased with tree size diversity up to about 90% of the sustainable maximum, but decreased sharply thereafter. Real internal rates of return of 2 to 4% could be earned with stands that had either mediocre or very good levels of diversity. Likewise, starting from the same initial stand state, proper choice of a cutting guide could lead to much higher levels of tree size diversity, without decreasing forest value. For. Sci. 40(1):83-103.
Spatial Autocorrelation in Growth of Undisturbed Natural Pine Stands Across Georgia
Authors: Czaplewski Raymond L. , Reich Robin M. , Bechtold William A.
Published: April 2024

Moran's I statistic measures the spatial autocorrelation in a random variable measured at discrete locations in space. Permutation procedures test the null hypothesis that the observed Moran's I value is no greater than that expected by chance. The spatial autocorrelation of gross basal area increment is analyzed for undisturbed, naturally regenerated stands in three Georgia forest types: loblolly, shortleaf, and slash pine. The analysis uses 0.4-ha permanent sample plots from a forest inventory that included two remeasurement intervals (1961-1972 and 1972-1982). We present a new statistic for exploratory spatial analyses, and this statistic revealed an anomalous cluster of unusually slow-growing shortleaf pine plots occurred in the mountains 100 km north of Atlanta. A regression model was used to predict gross basal area increment as a function of variables that describe local stand conditions, and no significant spatial autocorrelations existed in the regression residuals. This result suggests that the anomalous cluster of slow-growing plots can be explained by the spatial distribution of local stand conditions rather than spatial patterns of other possible causes such as air pollution, although alternative interpretations are possible. For. Sci. 40(2):314-328.
Land Attributes and Land Allocation: Nonindustrial Forest Use in the Pacific Northwest
Authors: Parks Peter J. , Murray Brian C.
Published: April 2024

A land allocation model quantifies the influence of timber benefits, agricultural benefits, population, and land attributes on nonindustrial forestland allocation in the Pacific Northwest. The proportion of land in forest use only gradually changes and may be unresponsive to markets for land products or market-based policy instruments such as reforestation cost subsidies. Consequently, economic responses to policies may take place within forest rotations, which could change the mix of timber and nontimber benefits from private forests in favor of timber. If joint production of timber and nontimber benefits on private lands is to be considered a policy goal, new policy instruments may be needed. For. Sci. 40(3):558-575.
The Law of One Price for U.S. Softwood Lumber: A Multivariate Cointegration Test
Authors: Jung Chulho , Doroodian Khosrow
Published: April 2024

The multivariate cointegration testing procedures are used to determine if there exists a single long-run equilibrium price for four softwood lumber regional markets in the United States during the period 1950-1985. The Dickey-Fuller tests reveal strong evidence for the presence of a unit root in levels of the univariate price series, but the absence of a unit root in the first-differenced series for all four U.S. regional markets. The Johansen test results support the hypothesis commonly known as the "law of one price." For. Sci. 40(4):595-600.
Causes and Remedies for Errors in International Forest Products Trade Data: Examples from the Hardwood Trade Statistics
Authors: Luppold William G.
Published: April 2024

The quality of data concerning international hardwood products trade declined in the 1980s because of several problems associated with the collection and processing of individual export transaction records. This note examines the source, impact, and remedies for data problems caused by data screening procedures, nonreporting, recording errors, and alternative accounting systems. Although this study focuses on the hardwood products, many of the problems discussed affect trade data for other forest products. For. Sci. 41(2):278-283.
Estimating Gopher Populations and Their Abatement in Forest Plantations
Authors: Smallwood K. Shawn , Erickson William A.
Published: April 2024

Indirect sampling methods for pocket gophers (Family: Geomyidae) lack adequate assessment for accuracy and efficiency. During gopher abatement trials in forest clearcuts, our new "burrow index" accounted for 95% of the gophers, while the widely used 24 hr open-hole test accounted for only 68%. Using published data, we found that mound counts and plot occupancy provided precise estimates (R² = 0.76 - 0.99) of gopher density in clearcuts. We recommend the more efficient "burrow index" for sampling gophers, and "effective depopulation" for estimating population change due to abatement, after accounting for natural population dynamics in "control" plots. A modified burrow index on strip transects can be used for measuring association of gophers with ecological variables. For. Sci. 41(2):284-296.
Most Similar Neighbor: An Improved Sampling Inference Procedure for Natural Resource Planning
Authors: Moeur Melinda , Stage Albert R.
Published: April 2024

To model ecosystem functioning for landscape design, analysts would like detailed data about each parcel of land in the landscape. Usually, only information of low resolution is available for the entire area, supplemented by detailed information for a sample of the parcels. These sample data, usually obtained through two-phase sampling, provide initial values of important design elements for dynamic, often nonlinear, models of ecosystem functioning. However, to represent the contribution of the nonsampled portions of the landscape to ecosystem functioning, it would be convenient to be able to operate as if the detailed design information were available for each and every parcel in the analysis. Inference procedures to complete the design information for the unsampled parcels have usually followed the techniques of stratified or regression sampling. These procedures have been developed with regard to their efficiency for estimating population means and totals rather than for their utility to model ecosystem functioning and response to intervention. Stratified sampling or regression estimates therefore do not retain the complex relationships between multivariate design attributes. We present a new multivariate inference procedure for use in such circumstances. In place of estimating design attributes element-by-element in a traditional sense for each first-phase observation, the procedure simply chooses the most similar parcel from the set of parcels with detailed examinations to act as its stand-in. The stand-in is chosen on the basis of a similarity measure that summarizes the multivariate relationships between the set of low resolution indicator attributes and the set of detailed design attributes derived from the second-phase sample. Canonical correlation analysis is used to derive a similarity function for this procedure, which we call "Most Similar Neighbor Inference." We compared most similar neighbor estimates for a multivariate forest inventory to estimates from regression, stratified sampling, and a Swedish National Forest Survey method. The indicator attributes were recorded from stand records, maps, and aerial photographs, while the design attributes were stand yield characteristics derived from on-the-ground inventories. The most similar neighbor estimates have prediction errors that are comparable in magnitude to the traditional estimates for easy-to-predict design attributes. Thus, most similar neighbor inference should be expected to perform almost as well as regression in sampling contexts requiring estimates of population means or totals. More importantly, the most similar neighbor procedure more closely reproduces the covariance structure of the design attributes. Preserving the relationships among design attributes is a vital feature when the purpose of the modeling is to evaluate management options. Furthermore, because most similar neighbor is an exact interpolator, estimates derived from it are consistent in a finite population sense. For. Sci. 41(2):337-359.
An Assessment of Factors Associated with Damage to Tree Crowns from the 1987 Wildfires in Northern California
Authors: Weatherspoon C. Phillip , Skinner Carl N.
Published: April 2024

Relationships between (1) degree of damage caused by the 1987 fires in northern California and (2) prior management activities, fuelbed characteristics, and site/stand factors were studied on the Hayfork Ranger District of the Shasta-Trinity National Forests. Postfire aerial photography was used to assess scorch and consumption of tree crowns (the selected measure of fire damage), and other data were obtained from existing records. Data were collected and analyzed separately for (1) plantations and (2) uncut and partial-cut stands. Ordinal logistic regression was the primary analytical technique used. Factors significantly related to degree of fire damage in plantations were cover of grasses, cover of forbs, elevation, site preparation method, and level of damage in the adjacent stand. Damage to uncut and partial-cut stands depended on stand treatment, primary tree species, and aspect. The variables that most strongly influenced fire damage tended to be those most directly related to management activities--site preparation method and damage in adjacent stand for plantations, and stand treatment for uncut and partial-cut stands. For. Sci. 41(3):430-451.
A Sampling Strategy to Estimate the Area and Perimeter of Irregularly Shaped Planar Regions
Authors: Gregoire Timothy G. , Valentine Harry T.
Published: April 2024

The length of a randomly oriented ray emanating from an interior point of a planar region can be used to unbiasedly estimate the region's area and perimeter. Estimators and corresponding variance estimators under various selection strategies are presented. For. Sci. 41(3):470-476.
Establishment, Resource Acquisition, and Early Productivity as Determined by Biomass Allocation Patterns of Three Tropical Tree Species
Authors: Haggar Jeremy P. , Ewel John J.
Published: April 2024

Speed of stand establishment and rate of stem biomass production after canopy closure are two important criteria in the selection of species in the expanding field of tropical reforestation. How biomass allocation patterns determine establishment and stem production was studied in 0 to 2-yr-old plantations of Cedrela odorata, Cordia alliodora, and Hyeronima alchorneoides on fertile soil in the humid Atlantic lowlands of Costa Rica. The species were evaluated by: (1) their allocation of biomass to leaves and fine roots; (2) the resource-capturing capacity of the stands as expressed in leaf area, cover, fine-root length, and root distribution; and (3) biomass accrual and aboveground productivity. All species grew very fast: average stand heights at 2 yr ranged from 4 to 6 m, and some individuals were >12 m tall. Canopy closure and root-system overlap were fastest in Cordia, occurring within a year after planting. Cordia's rapid stand closure was achieved by its higher specific leaf area and specific root length, plus an architecture that distributed leaves and fine roots more widely. Maximum aboveground net primary productivities after canopy closure were 7.3, 4.9, and 3.3 g m-2d-1 for Hyeronima, Cordia, and Cedrela stands, respectively. High productivity of Hyeronima correlated with development of a high LAI coupled with a low leaf turnover rate. Cordia and Cedrela, on the other hand, had higher rates of leaf turnover, so a higher rate of leaf production was required to maintain a given leaf area; this, in turn, limited biomass allocation to production of stem biomass. Cedrela productivity was severely reduced by attacks of the stem-borer Hypsipyla grandella. Biomass allocation patterns that promoted rapid establishment of a tree stand, such as broad crowns, high specific leaf area, and high specific root length, did not lead to the highest levels of stem biomass production after canopy closure. Once stand closure is achieved, species having low rates of leaf turnover, high leaf area indices, and high density of fine roots are likely to be most productive. Fast-growing tropical tree species should be evaluated not just on initial growth but also on the stem production attained after stand closure. For. Sci. 41(4):689-708.
Hydrologic and Erosional Responses of a Granitic Watershed to Helicopter Logging and Broadcast Burning
Authors: Megahan Walter F. , King John G. , Seyedbagheri Kathleen A.
Published: April 2024

Forest land managers are concerned about the effects of logging and site preparation on erosion, site productivity, streamflow, and water quality. Effects of helicopter logging and prescribed burning on streamflow and sediment yields from headwater drainages in the Idaho Batholith were evaluated, using paired watersheds monitored from 1966 to 1986. In the fall of 1976, 23% of a 162 ha watershed was clearcut. All the cutting units were located on south-facing slopes. Helicopter logging was followed by broadcast burning on the cutting units. Streamflow parameters showed little change in response to the logging and burning. However, total annual sediment yields on the treated watershed increased an average of 97% in the 10 yr following logging, with the largest increases occurring in the years of highest sediment yields. Increased sediment yields did not appear to result from accelerated channel erosion; rather, about 94% was attributed to accelerated surface erosion on the cutting units, and 6% was contributed by a single mass erosion site. Accelerated erosion persisted on the cutting units throughout the study period. The accelerated surface erosion occurred primarily as a result of the prescribed burning (rather than the helicopter logging); surface erosion rates on the burned areas were about 66 times greater than those on undisturbed slopes. The accelerated rates of erosion and sedimentation have potentially serious implications for on-site productivity and downstream resources. For. Sci. 41(4):777-795.
An Economic Analysis of the Differences Between Bid Prices on Forest Service and Private Timber Sales
Authors: Munn Ian A. , Rucker Randal R.
Published: April 2024

Data on 220 private and 99 Forest Service sealed bid timber sales in North Carolina indicate that per acre prices are about $675 higher on the private sales. Hedonic timber price equations for Forest Service and private sales are used to decompose this price difference into (1) differences due to characteristics of the sales and (2) differences due to the valuation of those characteristics. Both components of this decomposition are found to explain a portion of the price difference. The valuation of particular tract characteristics is found to be higher on private sales. In particular, our results suggest that pine sawtimber, pine pulpwood, and hardwood pulpwood have higher market valuations on private sales. For Sci. 41(4):823-840.
The Effects of Aboveground and Belowground Competition on Understory Species Composition in a Pinus densiflora Forest
Authors: Riegel Gregg M. , Miller Richard F. , Krueger William C.
Published: April 2024

The objective of this research was to test the hypothesis that water and nutrients, and not light, control understory plant species composition in a Pinus ponderosa forest in northeastern Oregon. The experiment was conducted as a split-plot experimental design with a 2 x 2 factorial analysis. To assess the effects of root competition of overstory trees on understory species composition, 20 plots (4 x 4 m) were trenched approximately 1.0 m in depth, and compared to 24 nontrenched plots. To increase light levels to understory vegetation, trees were thinned from 345 to 148 trees ha-1 in half of each block (2.5 ha) during the winter and early spring of 1986. Canonical discriminant analysis indicated that light accounted for the greatest environmental resource response among the treatments. The number of species (8) that increased in cover and density was 60% greater when tree root competition was reduced in the root-reduction treatment, versus 5 when tree canopy influences were reduced in the canopy-reduction treatment. Simple correlation showed that changes in species composition were significantly (P ≤ 0.05) related to both changes in aboveground attributes (light, midday air temperature, and soil temperature) and belowground attributes (soil water potential, pH, and nitrogen). Competition for limited resources, light, water, and nutrients, does affect understory species composition as evidenced by the response of individual species to increasing availability of these resources. For. Sci. 41(4):864-889.
Inbreeding Depression in Conifers: Implications for Breeding Strategy
Authors: Williams Claire G. , Savolainen Outi
Published: April 2024

Use of selfing as a breeding tool for conifers is controversial; this topic is addressed with a review of genetic models, theory, and experimental results based on a wide range of plants and animals. Some supporting evidence is available from conifer studies. For most conifers, selfing will not be the best method for reducing inbreeding depression in small subpopulations or elite lines of deleterious alleles; sib- or random-mating is a better option in the early generations of conifer domestication. Possible exceptions are conifer species that have few lethal alleles. Few organisms have been studied which have more lethal equivalents than conifers, so slower rates of inbreeding than selfing are needed initially to prevent large losses to low offspring survival and adult fecundity. Inbred breeding populations will also require large numbers of replicate lines and progeny per replicate because the probability of extinction for each line is expected to be high. Like maize, few valuable lines will result from selfing in the initial generations. If inbreeding depression is based on deleterious mutations then it is hypothesized to decline with stringent selection against deleterious alleles (purging). After the initial purging phase, selfingwould be efficient. Advantages of selfing include perfect assortative mating, increased selection efficacy among lines and increased uniformity within lines. Theoretical predictions for inbreeding depression in conifers have outpaced experimentation. Operational breeding programs will not provide needed data on changes in inbreeding depression, but the inbreeding assumptions for breeding strategies must be tested experimentally. We advocate using experimental inbred populations to study direct use of inbreeding depression as a breeding method. It provides first-hand results and lends confidence to long-term population management decisions. The greatest value will be to reveal unforeseen problems, preventing irreversible mistakes. As an example, we outline a plan for a rapidly cycled experimental inbred population for Pinus taeda L. which combines early selection, rapid screening for adult fecundity, and traditional genetic testing. Inbreeding depression research is central to the success of long-term population management. It has become more powerful with integrated classical genetics-molecular approaches, accelerated breeding techniques, and computer simulation models. For. Sci. 42(1):102-117.
The Grid Packing Problem: Selecting a Harvesting Pattern in an Area with Forbidden Regions
Authors: Synder Stephanie , ReVelle Charles
Published: April 2024

The problem of determining the maximum value or maximum volume cutting pattern in a forested area which is divided into a regular grid is approached as a 0-1 integer programming model. Constraints are included to preclude harvests in blocks which are adjacent to one another in an effort to reduce large forest openings which can have negative environmental impacts. One form of adjacency constraints can be used to exclude the cutting of blocks which share a common edge. Other forms can prevent harvesting blocks which share an edge or point. The challenge is to write these constraints in a form that favors 0-1 solutions. The integer-friendly forms that are chosen are applied to large tracts of land in which significant areas are excluded from cutting because of habitat preservation requirements or other prohibitions. More than 100 experimental runs with hypothetical data were conducted. For. Sci. 42(1):27-34.
Pluralism by Default: Community Power in a Paper Mill Town
Authors: Beckley Thomas M.
Published: April 2024

Forest-dependent communities are often isolated geographically and culturally but linked politically and economically to industrial core areas. Theories of underdevelopment and resource-dependence, and theories of community power are used to explain the implications of forest-dependence for the structure of local politics in one Maine paper mill town. Three models of power, as outlined by sociologists and political scientists, suggest three possible configurations of community power structures. Historical, documentary analysis and contemporary field research demonstrate the fluidity of the power structure for the community in question. As the needs and interests of the dominant local economic force have changed over time, the community has experienced elitist, hegemonic, and pluralist regimes of power. The contemporary power structure is a pluralism by default. The withdrawal from local politics of the major economic player has created a political vacuum and the historic dependency relationship between paper mill managers and the community has created an apathetic and nonparticipative citizenry. For. Sci. 42(1):35-45.
Growth Phenology and Crown Structure of Selected Loblolly Pine Families Planted at Two Spacings
Authors: McCrady R.L. , Jokela E.J.
Published: April 2024

Growth phenology and crown structure of five open-pollinated loblolly pine (Pinus taeda L.) families, planted at two spacings (0.92 and 1.83 m) and grown in pure plots near Summerville, SC, were investigated using a split-plot (main plots = spacing, subplots = genotype) field design. Shoot, branch, and foliage characteristics were quantified during the fourth growing season and related to standing volume. Genotype variation in shoot and branch characteristics was generally small and nonsignificant except for differences in annual height increment (from 135 to 152 cm) and current-year branch production (from 11.1 to 14.0). Significant genotype variation in foliage amount, distribution, and longevity was associated with contrasting growth performances and stage of stand development. Foliage biomass differed by as much as 60% among genotypes (from 4.8 to 7.7 Mg ha-1), with 38% of the variation related to family differences in total height. The large range in foliage biomass was the major contributor to leaf area index differences (LAI; from 7.9 to 13.6 m² m-2), although significant genotype differences in weighted specific needle area (SNA; from 175 to 199 cm² g-1) were also a factor. Genotype variation in foliage biomass and LAI was related to the vertical distribution of foliage, and both were significantly correlated with standing volume at age 3 yr (r = 0.64 and 0.59). The best performing families (3, 7, and 49 based on progeny testing) held > 60% of their total foliage biomass in the middle crown third (nonuniform distribution), whereas the poorest families (37 and 138), had < 50% in the same region (more uniform distribution). Compared to the other genotypes, family 37 exhibited reduced foliage longevity, which may have contributed to its low LAI and poor growth performance. Results of this study suggest that foliage display, amount, and duration are the crown characteristics important in conferring differential family performance for loblolly pine. For. Sci. 42(1):46-57.