Influences of Forest Type, Stand Age, and Weather on Deer Weights and Antler Size in the Southern Appalachians

Abstract We analyzed correlations of forest type, age structure, and site index data with weights and antler characteristics of yearling white-tailed deer (Odocoileus virginianus) bucks from specific localities in the Chattahoochee, Cherokee, Nantahala, and Pisgah national forests in Georgia, Tennessee, and North Carolina. Areas in the northern part of the study region produced larger deer with larger antlers than those in the southern portion of the region. These northern areas differed from those to the south in having more diverse ownership and land use and in origins of deer stock. Weights and antler characteristics were significantly correlated (P < 0.05) with percent area in the cove hardwood type, but otherwise were poorly correlated with forest stand type and site index. Percent area in young (0-8 yr old) cove hardwood and in mid-successional (9-20 and 21-40) cove hardwood, pine (Pinus spp.), and upland oak (Quercus spp.) were significantly correlated (P < 0.05) with deer variables, particularly in years following a poor mast crop. Much of the quantifiable habitat influences on deer in the Southern Appalachians probably is masked by low deer densities and the small site quality differences among areas examined. Because much of the forest consists of mature mast-producing oaks and abundant forage is produced in both mature and younger aged stands, deer numbers seem to be below any threshold of quantifiable effects due to forest stand age structure. South. J. Appl. For. 21(1):11-18.

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Generalized Nonlinear Mixed-Effects Individual Tree Diameter Increment Models for Beech Forests in Slovakia

Forests ◽

10.3390/f10050451 ◽

2019 ◽

Vol 10 (5) ◽

pp. 451 ◽

Cited By ~ 1

Author(s):

Ram P. Sharma ◽

Igor Štefančík ◽

Zdeněk Vacek ◽

Stanislav Vacek

Keyword(s):

Basal Area ◽

European Beech ◽

Site Index ◽

Development Stage ◽

Mixed Effects ◽

Site Quality ◽

Stand Age ◽

Sample Plot ◽

Individual Tree ◽

Diameter Increment

Individual tree growth and yield models precisely describe tree growth irrespective of stand complexity and are capable of simulating various silvicultural alternatives in the stands with diverse structure, species composition, and management history. We developed both age dependent and age independent diameter increment models using long-term research sample plot data collected from both monospecific and mixed stands of European beech (Fagus sylvatica L.) in the Slovak Republic. We used diameter at breast height (DBH) as a main predictor and other characteristics describing site quality (site index), stand development stage (dominant height and stand age), stand density or competition (ratio of individual tree DBH to quadratic mean diameter), species mixture (basal area proportion of a species of interest), and dummy variable describing stand management regimes as covariate predictors to develop the models. We evaluated eight versatile growth functions in the first stage using DBH as a single predictor and selected the most suitable one, i.e., Chapman-Richards function for further analysis through the inclusion of covariate predictors. We introduced the random components describing sample plot-level random effects and stochastic variations on the diameter increment, into the models through the mixed-effects modelling. The autocorrelation caused by hierarchical data-structure, which is assumed to be partially reduced by mixed-effects modelling, was removed through the inclusion of the parameter accounting for the autoregressive error-structures. The models described about two-third parts of a total variation in the diameter increment without significant trends in the residuals. Compared to the age independent mixed-effects model (conditional coefficient of determination, R c 2 = 0.6566; root mean square error, RMSE = 0.1196), the age dependent model described a significantly larger proportion of the variations in diameter increment ( R c 2 = 0.6796, RMSE = 0.1141). Diameter increment was significantly influenced differently by covariate predictors included into the models. Diameter increment decreased with the advancement of stand development stage (increased dominant height and stand age), increasing intraspecific competition (increased basal area proportion of European beech per sample plot), and diameter increment increased with increasing site quality (increased site index) and decreased competition (increased ratio of DBH to quadratic mean diameter). Our mixed-effects models, which can be easily localized with the random effects estimated from prior measurement of diameter increments of four randomly selected trees per sample plot, will provide high prediction accuracies. Our models may be used for simulating growth of European beech irrespective of its stand structural complexity, as these models have included various covariate variables describing both tree-and stand-level characteristics, thinning regimes, except the climate characteristics. Together with other forest models, our models will be used as inputs to the growth simulator to be developed in the future, which is important for decision-making in forestry.

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Assessing site form as an indicator of site quality in even-aged Pinus radiata D. Don stands in north-western Spain

Annals of Forest Science ◽

10.1007/s13595-019-0904-1 ◽

2019 ◽

Vol 76 (4) ◽

Cited By ~ 1

Author(s):

Juan Alberto Molina-Valero ◽

Ulises Diéguez-Aranda ◽

Juan Gabriel Álvarez-González ◽

Fernando Castedo-Dorado ◽

César Pérez-Cruzado

Keyword(s):

Pinus Radiata ◽

Goodness Of Fit ◽

Model Fitting ◽

Site Index ◽

Site Quality ◽

Stand Age ◽

Fit Statistics ◽

Dominant Height ◽

Western Spain ◽

North Western

Abstract Key message Site form and site index have shown similar precision for estimating site quality in even-agedPinus radiataD. Don stands in north-western Spain. Additionally, SF presents the advantage that it does not require stand age information and can therefore be used in a wider set of situations in the forestry practice. Context Estimation of site quality is essential for characterizing, monitoring and predicting forest resources. Site index (i.e. the dominant height of the stand at a reference age) is ordinarily used to estimate site quality; however, this index is only useful for even-aged stands of known age. By contrast, SF is age-independent as it uses the dominant height of the stand at a reference dominant diameter. Aims The aim of this study was to compare the performance of SF and SI for site quality estimation in even-aged P. radiata stands. Methods Dynamic equations derived with the Generalized Algebraic Difference Approach (GADA) from the Hossfeld IV base model were fitted to predict site quality with both SI and SF. SF predictions were compared with SI regarding variability within the same plot and consistency in site quality predictions, using the observed maximum mean annual volume increment (MAI) as a direct measure of site quality. Results Both approaches showed good performance in model fitting and provided similar goodness-of-fit statistics and variability in the predictions. However, SI performed slightly stronger when related to MAI. Conclusion SF performed adequately in estimating site quality for even-aged P. radiata stands, with results comparable to those obtained using traditional SI.

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Building a dynamic growth model for trembling aspen in western Canada without age data

Canadian Journal of Forest Research ◽

10.1139/cjfr-2012-0366 ◽

2013 ◽

Vol 43 (3) ◽

pp. 256-265 ◽

Cited By ~ 13

Author(s):

Oscar García

Keyword(s):

Populus Tremuloides ◽

Site Occupancy ◽

Basal Area ◽

Site Index ◽

Growth And Yield ◽

Site Quality ◽

Diameter Distribution ◽

Stand Age ◽

Parameter Estimates ◽

Trembling Aspen

A biologically inspired whole-stand growth and yield model was developed for even-aged thinned or unthinned stands dominated by trembling aspen (Populus tremuloides Michx.). The estimation used permanent sample plot data from British Columbia, Alberta, Saskatchewan, and Manitoba, supplemented by published site index and young stand information. An ingrowth imputation procedure was devised to facilitate the use of plot measurements where small trees are not measured. Two published site index models were closely approximated by a simple age-base invariant equation. Good parameter estimates for mortality and basal area growth were obtained without using age observations, which were unreliable or missing. Four differential equations describe the dynamics of top height, trees per hectare, basal area, and a site occupancy factor. Current values of these variables are used to estimate total and merchantable volumes up to any diameter limit and diameter distribution parameters. When an independent source of site quality estimates is available, the final model does not require stand age knowledge for making growth and yield predictions.

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The main drivers for the occurrence of six red-listed epiphytic bryophytes and lichens in the boreo-nemoral forest landscape, Latvia

Folia Cryptogamica Estonica ◽

10.12697/fce.2021.58.22 ◽

2021 ◽

Vol 58 ◽

Author(s):

Anna Mežaka ◽

Rolands Moisejevs ◽

Māris Nitcis

Keyword(s):

Forest Type ◽

Forest Stand ◽

Data Management System ◽

Tree Bark ◽

Stand Age ◽

Forest Landscape ◽

Environmental Predictors ◽

Natural Data ◽

National Information ◽

Occurrence Of Species

Forest landscape plays a significant role in rare cryptogam distribution. However, data about the environmental demands of rare epiphytic bryophytes and lichens in boreo-nemoral forest landscapes are not complete. In this study, we focused on finding the main environmental predictors influencing the occurrence of three red-listed epiphytic bryophytes and three red-listed epiphytic lichens in the Latvian boreo-nemoral forest landscape. We obtained the records of species from the Natural Data Management System OZOLS database, which is a national information system on all rare taxa. We analyzed the occurrence of species in relation to forest stand age and area, forest type, heterogeneity and tree bark pH class. We found that selected red-listed bryophyte and lichen occurrence was mainly influenced by forest stand age and area. However, each of the red-listed epiphytic bryophyte and lichen has their own ecological demands in the boreo-nemoral landscape.

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Foliar chemical concentrations, growth, and site productivity relations in western red cedar

Canadian Journal of Forest Research ◽

10.1139/x86-185 ◽

1986 ◽

Vol 16 (5) ◽

pp. 1069-1075 ◽

Cited By ~ 17

Author(s):

M. A. Radwan ◽

Constance A. Harrington

Keyword(s):

Soil Ph ◽

Nutrient Management ◽

Site Index ◽

Essential Elements ◽

Site Quality ◽

Stand Age ◽

Base Line ◽

Red Cedar ◽

Foliar Concentrations ◽

Western Red Cedar

Important site and tree characteristics of western red cedar (Thujaplicata Donn ex D. Don) were examined in 19 natural stands in the coastal and interior zones of western Washington and Oregon, U.S.A., and in western Vancouver Island, British Columbia, Canada. The stands occurred at various elevations and on different soil types and differed in age, soil pH, and associated plant species. Current-year foliage was collected during the winter and concentrations of N, P, K, S, Ca, Mg, Fe, Mn, B, Zn, Cu, Mo, Al, and the chlorophylls were determined. Mean terminal growth during the previous 3 years and site index at 50-year breast-height age were calculated for each stand. Site index ranged from 18 to 26 m. Terminal growth and foliar concentrations of the macronutrients, micronutrients, Al, and the chlorophylls varied among the 19 sites and between the two zones. Compared with known values for the most common associated conifers, foliar concentrations of red cedar were especially low in Mn and Al and high in Ca and Mo. Site index was correlated positively with N, the chlorophylls, S, Cu, and B, and negatively with Fe and Al. Also, N was positively correlated with the chlorophylls and with some of the other nutrients; there were many correlations among the nutrients and between some nutrients and soil pH or stand age. The data obtained provide base-line information for future analytical work with red cedar foliage. In addition, results suggest that (i) nutrient management strategies in western red cedar stands may differ from those for other conifers and different strategies may be necessary for the coastal and interior zones, (ii) productivity of red cedar may be improved by cultural treatments, including fertilization, which would enhance levels of chlorophyll as well as some essential elements (N, S, P, B, and Mo) in the foliage, (iii) levels of some chemicals in the foliage, such as N, chlorophyll, S, and B, may be useful as indicators to assess site quality for red cedar production, and (iv) chlorophyll may be used as a simple means to estimate N status of red cedar.

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An Interim Economic Comparison of Thinning Treatments in a High Site Quality Red Pine Plantation

Northern Journal of Applied Forestry ◽

10.1093/njaf/5.3.211 ◽

1988 ◽

Vol 5 (3) ◽

pp. 211-215 ◽

Cited By ~ 1

Author(s):

Hal O. Liechty ◽

David D. Reed ◽

Glenn D. Mroz

Keyword(s):

Loblolly Pine ◽

Economic Value ◽

Site Index ◽

Red Pine ◽

Site Quality ◽

Stand Age ◽

Economic Returns ◽

Machine Productivity ◽

Current Product ◽

Harvesting Costs

Abstract Harvesting costs for seven thinning treatments applied to a highly productive (site index 81 at base age 50) red pine stand (age 22) were calculated using machine productivity rates developed for loblolly pine. The economic value of each treatment 10 years after the initial thinning was determined using the calculated harvesting costs and current product prices. Plots thinned to 60 ft2 ba/ac, 30% height, and 120 ft2 ba/ac treatments had the highest returns regardless of whether pulpwood or pulpwood and sawtimber markets were used to determine returns. The superior economic returns from the 30% and 120 ft2 treatments reflected the higher overall product yields from these thinning strategies. However, the 60 ft2 treatment, which had the second lowest merchantable cubic-foot yields in the study, had returns similar to the higher yielding treatments. This was due to: (1) larger early returns from the initial heavy thinnings in the 60 ft2 treatment, and (2) the decreased harvesting costs related to increased stand diameter growth of the heavier thinned treatment. North. J. Appl. For. 5:211-215, Sept. 1988.

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Yellow-Poplar Site Quality Related to Slope Type in Mountainous Terrain

Northern Journal of Applied Forestry ◽

10.1093/njaf/4.4.189 ◽

1987 ◽

Vol 4 (4) ◽

pp. 189-192 ◽

Cited By ~ 2

Author(s):

W. Henry McNab

Keyword(s):

Land Surface ◽

Appalachian Mountains ◽

Site Index ◽

Important Variable ◽

Surface Shape ◽

Site Quality ◽

Stand Age ◽

Mountainous Terrain ◽

Yellow Poplar ◽

Southern Appalachian

Abstract Site index and topographic variables were measured on 112, ¼-ac sample plots with yellow-poplar overstory in the Blue Ridge Province of the Southern Appalachian Mountains. The plots were grouped by slope type—nose, side, or head—and multiple regression analysis was used to develop equations for predicting height at 50 years. Estimated site index was significantly less on side slopes than on head slopes. Stand age was the most important variable in both equations, followed by aspect and land surface shape. The equations accounted for 79% of the variation of yellow-poplar height on head slopes and 84% on side slopes. North. J. Appl. For. 4:189-192, Dec. 1987.

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Modelling the susceptibility of pine stands to bark stripping by Chacma baboons (Papio ursinus) in the Mpumalanga Province of South Africa

Wildlife Research ◽

10.1071/wr16170 ◽

2017 ◽

Vol 44 (4) ◽

pp. 298 ◽

Cited By ~ 4

Author(s):

Ilaria Germishuizen ◽

Kabir Peerbhay ◽

Riyad Ismail

Keyword(s):

South Africa ◽

Random Forests ◽

Risk Evaluation ◽

Site Index ◽

Pine Plantations ◽

Bark Stripping ◽

Papio Ursinus ◽

Mpumalanga Province ◽

Chacma Baboons ◽

Pinus Spp

Context Commercial pine (Pinus spp.) plantations in southern Africa have been subjected to bark stripping by Chacma baboons (Papio ursinus) for many decades, resulting in severe financial losses to producers. The drivers of this behaviour are not fully understood and have been partially attributed to resource distribution and availability. Aims The study sought to develop a spatially explicit ecological-risk model for bark stripping by baboons to understand the environmental factors associated with the presence of damage in the pine plantations of the Mpumalanga province of South Africa. Methods The model was developed in Random Forests, a machine learning algorithm. Baboon damage information was collected through systematic surveys of forest plantations conducted annually. Environmental predictors included aspects of climate, topography and compartment-specific attributes. The model was applied to the pine plantations of the study area for risk evaluation. Key results The Random Forests classifier was successful in predicting damage occurrence (F1 score=0.84, area under curve (AUC)=0.96). Variable predictors that contributed most to the model classification accuracy were related to pine-stand characteristics, with the age of trees being the most important predictor, followed by species, site index and altitude. Variables pertaining to the environment surrounding a pine stand did not contribute substantially to the model performance. Key conclusions (1) The study suggests that bark stripping is influenced by compartment attributes; (2) predicted risk of bark stripping is higher in stands above the age of 5 years planted on high-productivity forestry sites, where site index (SI) is above 25; (3) presence of damage is not related to the proximity to natural areas; (4) further studies are required to investigate ecological and behavioural patterns associated with bark stripping. Implications The model provides a tool for understanding the potential extent of the risk of bark stripping by baboons within this region and it can be applied to other forestry areas in South Africa for risk evaluation. It contributes towards the assessment of natural hazards potentially affecting pine plantations and supports the development of risk-management strategies by forest managers. The model highlights opportunities for cultural interventions that may be tested for damage control.

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Soil Organic Carbon Stocks in Afforested Agricultural Land in Lithuanian Hemiboreal Forest Zone

Forests ◽

10.3390/f12111562 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1562

Author(s):

Iveta Varnagirytė-Kabašinskienė ◽

Povilas Žemaitis ◽

Kęstutis Armolaitis ◽

Vidas Stakėnas ◽

Gintautas Urbaitis

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Forest Floor ◽

Agricultural Land ◽

Forest Stand ◽

Stand Age ◽

Soc Stock ◽

The Mean ◽

Soc Stocks ◽

Topsoil Layer

In the context of the specificity of soil organic carbon (SOC) storage in afforested land, nutrient-poor Arenosols and nutrient-rich Luvisols after afforestation with coniferous and deciduous tree species were studied in comparison to the same soils of croplands and grasslands. This study analysed the changes in SOC stock up to 30 years after afforestation of agricultural land in Lithuania, representing the cool temperate moist climate region of Europe. The SOC stocks were evaluated by applying the paired-site design. The mean mass and SOC stocks of the forest floor in afforested Arenosols increased more than in Luvisols. Almost twice as much forest floor mass was observed in coniferous than in deciduous stands 2–3 decades after afforestation. The mean bulk density of fine (<2 mm) soil in the 0–30 cm mineral topsoil layer of croplands was higher than in afforested sites and grasslands. The clear decreasing trend in mean bulk density due to forest stand age with the lowest values in the 21–30-year-old stands was found in afforested Luvisols. In contrast, the SOC concentrations in the 0–30 cm mineral topsoil layer, especially in Luvisols afforested with coniferous species, showed an increasing trend due to the influence of stand age. The mean SOC values in the 0–30 cm mineral topsoil layer of Arenosols and Luvisols during the 30 years after afforestation did not significantly differ from the adjacent croplands or grasslands. The mean SOC stock slightly increased with the forest stand age in Luvisols; however, the highest mean SOC stock was detected in the grasslands. In the Arenosols, there was higher SOC accumulation in the forest floor with increasing stand age than in the Luvisols, while the proportion of SOC stocks in mineral topsoil layers was similar and more comparable to grasslands. These findings suggest encouragement of afforestation of former agricultural land under the current climate and soil characteristics in the region, but the conversion of perennial grasslands to forest land should be done with caution.

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A Novel Approach to Modelling Stand-Level Growth of an Even-Aged Forest Using a Volume Productivity Index with Application to New Zealand-Grown Coast Redwood

Forests ◽

10.3390/f12091155 ◽

2021 ◽

Vol 12 (9) ◽

pp. 1155 ◽

Cited By ~ 1

Author(s):

Mark O. Kimberley ◽

Michael S. Watt

Keyword(s):

New Zealand ◽

Growth Model ◽

Growth Models ◽

Stand Density ◽

Site Index ◽

Growth And Yield ◽

Productivity Index ◽

Site Quality ◽

Spatial And Temporal Variation ◽

Coast Redwood

Empirical growth models are widely used to predict the growth and yield of plantation tree species, and the precise estimation of site quality is an important component of these models. The most commonly used proxy for site quality in growth models is Site Index (SI), which describes the mean height of dominant trees at a specified base age. Although SI is widely used, considerable research shows significant site-dependent variation in height for a given volume, with this latter variable more closely reflecting actual site productivity. Using a national dataset, this study develops and describes a stand-level growth and yield model for even-aged New Zealand-grown coast redwood (Sequoia sempervirens). We used a novel modelling approach that quantifies site quality using SI and a volume-based index termed the 300 Index, defined as the volume mean annual increment at age 30 years for a reference regime of 300 stems ha−1. The growth model includes a number of interrelated components. Mean top height is modelled from age and SI using a polymorphic Korf function. A modified anamorphic Korf function is used to describe tree quadratic mean diameter (Dq) as a function of age, stand density, SI and a diameter site index. As the Dq model includes stand density in its formulation, it can predict tree growth for different stand densities and thinning regimes. The mortality model is based on a simple attritional equation improved through incorporation of the Reineke stand density index to account for competition-induced mortality. Using these components, the model precisely estimates stand-level volume. The developed model will be of considerable value to growers for yield projection and regime evaluation. By more robustly describing the site effect, the growth model provides researchers with an improved framework for quantifying and understanding the causes of spatial and temporal variation in plantation productivity.

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