Comparing biomass regressions by site and stand age for red maple

1983 ◽  
Vol 13 (2) ◽  
pp. 283-288 ◽  
Author(s):  
T. R. Crow
Keyword(s):  
Predictive Model ◽  
Error Variance ◽  
Site Index ◽  
Stand Age ◽  
Site Conditions ◽  
Red Maple ◽  
Wide Range ◽  
Regional Estimates ◽  
Predictive Relations ◽  
Sampling Procedures

Allometric regressions for estimating red maple (Acerrubrum L.) biomass did not differ by stand age and site index. Significant differences were found only in terms of error variance, not in terms of regression slope or intercept. These trends suggest a single predictive model is valid for regional estimates. More attention should be given to regional sampling procedures and predictive relations that are valid for a wide range of stand and site conditions in developing weight tables and conducting biomass inventories.

scholarly journals Incidence of ash dieback in the Left-Bank Forest-Steppe depending on stand characteristics

2020 ◽  
pp. 157-164
Author(s):  
V. L. Meshkova ◽  
V. L. Borysova
Keyword(s):  
Stocking Density ◽  
Site Index ◽  
Stand Age ◽  
Forest Steppe ◽  
Forest Site ◽  
Left Bank ◽  
Site Conditions ◽  
Ash Dieback ◽  
European Ash ◽  
Stand Characteristics

The incidence of ash dieback in the forest-steppe part of Sumy and Kharkiv Regions was analysed taking into account the type of forest site conditions, the stand age, relative stocking density, site index class and the proportion of European ash in the stand composition. Ash dieback is quite widespread in inspected stands of the Left-Bank Forest-Steppe of Sumy and Kharkiv Regions. The disease spreads similarly in natural and artificial stands. It was more often revealed in the fresh fertile forest site conditions, however, such forest site conditions are the most spread and the most favourable for European ash. It was found that ash dieback incidence tends to grow with a stand aging and lasts up to the stand’s age of 80. It can be explained by the development of stem and collar rots which occur later. Ash dieback incidence is the highest in the stands with 40–70 % of ash in their composition, at a relative density of stocking over 0.5 in the stands of different site index classes.

Analysis of stand basal area development of thinned and unthinned Acer rubrum forests in the upper Great Lakes region, USA

2016 ◽  
Vol 46 (5) ◽  
pp. 645-655 ◽  
Author(s):  
Justin L. Pszwaro ◽  
Anthony W. D’Amato ◽  
Thomas E. Burk ◽  
Matthew B. Russell ◽  
Brian J. Palik ◽  
...  
Keyword(s):  
Mean Squared Error ◽  
Acer Rubrum ◽  
Basal Area ◽  
Climatic Conditions ◽  
Growth And Yield ◽  
Site Quality ◽  
Stand Age ◽  
Red Maple ◽  
Growth Responses ◽  
Wide Range

Red maple (Acer rubrum L.), historically a common but not abundant tree species in North America, has increased in abundance throughout its range over the last several decades; however, it has received little attention in growth and yield studies. The objectives of this study were to (i) evaluate the effects of stocking level and stand density on overall patterns of red maple stand productivity and (ii) quantify these relationships across a wide range of stand age, site quality, geographic location, and climatic conditions. We used long-term measurements from 52 sites in Wisconsin and Michigan to examine growth responses of even-aged red maple stands to various levels of thinning. Using linear, mixed-effects modeling, future stand-level red maple basal area was modeled as a function of stand and plot characteristics and climatic variables. Growing season precipitation and its interaction with initial red maple basal area were significant predictors; however, they only collectively reduced the mean squared error by 2.1% relative to a base model containing solely stand and plot factors. Model projections indicated there was little difference in predicted future basal area for the range of climate conditions experienced by these stands highlighting red maple’s wide tolerance of environmental conditions across the region.

Assessment of natural regeneration of longleaf pine (Pinus palustris) 15 years post-regeneration control

2021 ◽  
Author(s):  
Zhaofei Fan ◽  
W. Keith Moser ◽  
Cameron Poyner ◽  
Shaoyang Yang ◽  
Sunil Nepal ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Longleaf Pine ◽  
Basal Area ◽  
Pinus Palustris ◽  
Site Index ◽  
Stand Age ◽  
Quadratic Mean ◽  
Wide Range ◽  
Grass Stage ◽  
Quadratic Mean Diameter

We assessed natural regeneration of longleaf pine (Pinus palustris Mill.) using the data col-lected from the Escambia Experimental Forest in southern Alabama. Fifteen years following the regeneration control, natural regeneration of longleaf remained patchy across a wide range of site/stand conditions, with slightly more than half of all plots containing regeneration, but the den-sity of seedlings and saplings varied significantly. The abundance of seedlings ≤ 1-year-old was positively related to stand age and time since last fire, but negatively related to overstory basal area. The abundance of seedlings and saplings was positively related to stand age, but negatively related to time since last fire and overstory basal area. The probability of achieving ≥ 15,000 seedlings > 1-year-old but ≤ 1-m-tall ha-1 and ≥ 1,250 saplings > 1-m-tall ha-1 was, respectively, positively related to the ratio of time since last fire to overstory basal area and the ratio of quadratic mean diameter to site index. A longer fire interval (> two to three years) should be adopted to naturally regenerate longleaf. We did not find clear zones of exclusion present in natural regeneration even though over-story trees, seedlings and saplings tended to be repulsive spatially and > 80% grass stage seedlings and saplings occurred outside tree crowns.

Validation of forest height–age models

1996 ◽  
Vol 26 (5) ◽  
pp. 810-818 ◽  
Author(s):  
Gordon D. Nigh ◽  
Vera Sit
Keyword(s):  
Forest Management ◽  
Confidence Intervals ◽  
Error Variance ◽  
Site Index ◽  
Random Coefficients ◽  
Multivariate Technique ◽  
Forest Height ◽  
Preliminary Validation ◽  
Age Model ◽  
Validation Procedure

Forest height–age models are used in forest management to estimate height and (or) site index. It is useful to know the bias and precision of these models in order to evaluate their applicability. Methods are available for validating the models; however, many problems exist with the methods because of a lack of independence in the data and nonconstant error variance across a range of ages. A validation procedure is presented that overcomes these problems by using a multivariate technique (random coefficients) to model the structure of the errors associated with the models. Confidence intervals for bias and precision can then be constructed based on the error structure. This method of validation was demonstrated on the white spruce (Piceaglauca (Moench) Voss) height–age model for British Columbia, Canada. The preliminary validation showed the model to be unbiased for estimating both height and site index; however, its precision was poor.

Vegetation variation among mesic successional forest stands in northern lower Michigan

1988 ◽  
Vol 66 (6) ◽  
pp. 1080-1090 ◽  
Author(s):  
Mark R. Roberts ◽  
Norman L. Christensen
Keyword(s):  
Quercus Rubra ◽  
Abies Balsamea ◽  
Acer Rubrum ◽  
Pinus Strobus ◽  
Pinus Resinosa ◽  
Fagus Grandifolia ◽  
Prunus Serotina ◽  
Stand Age ◽  
Site Conditions ◽  
Soil Variables

Vegetation composition of the shrub–tree and herb layers was sampled in 70 successional aspen (Populus tremuloides and Populus grandidentata) stands of different ages (1–90 years) on a variety of sites in northern lower Michigan. Physical and chemical characteristics of soil profiles were also measured at each site. Three stand groupings were identified based on site conditions and detrended correspondence analysis (DCA) ordination of the vegetation. Sandy dry-mesic soils support forests of Acer rubrum, Quercus rubra, Pinus resinosa, and Pinus strobus. On lowland sandy soils with a fluctuating water table, Pinus strobus, Abies balsamea, Viburnum lentago, and Viburnum cassinoides are important. Mesic soils with stratified calcareous layers or clay till substrates support Acer saccharum, Fagus grandifolia, Tilia americana, Fraxinus americana, Ostrya virginiana, and Acer pensylvanicum. Canonical correlation analysis (CCA) was used to compare DCA scores with soil variables; first-axis DCA scores were correlated with a suite of soil variables and stand age was correlated with second or third DCA axis scores. Separate DCA ordinations of the dry-mesic and mesic groups revealed successional relations on these sites. On dry-mesic sites, Pinus resinosa and Pinus strobus increase in importance with stand age, while Prunus serotina, Prunus virginiana, Prunus pensylvanica, and the aspens decrease. On mesic sites, early successional species include the aspens, Corylus cornuta, Prunus serotina, and Prunus pensylvanica. Fagus grandifolia, Acer pensylvanicum, Quercus rubra, Viburnum acerifolium, Betula papyrifera, Acer rubrum, and Tilia americana are more abundant in mature mesic-site stands. Ordinations of the herb data were remarkably similar to those for trees and shrubs except on dry-mesic sites. Much of the residual variability in vegetation not accounted for by site conditions and stand age is probably related to historical factors such as the nature of disturbance and variations in seed rain.

scholarly journals Enhanced Surveillance of Foodborne Mycotoxins by Immunochemical Assay

1988 ◽  
Vol 71 (6) ◽  
pp. 1075-1081 ◽  
Author(s):  
James J Pestka
Keyword(s):  
Quality Control ◽  
Solid Phase ◽  
Protein Conjugates ◽  
Sample Extract ◽  
Large Numbers ◽  
Wide Range ◽  
Enzyme Conjugate ◽  
Aflatoxin B ◽  
Sampling Procedures ◽  
Instrumental Methods

Abstract Mycotoxins are a chemically diverse group of fungal secondary metabolites with a wide range of toxic effects. Conventional thin-layer and instrumental methods of mycotoxin analysis are time-consuming and make routine safety and quality control screening of these compounds in agricultural commodities difficult. As an alternative, specific polyclonal and monoclonal antibodies have been raised against mycotoxin-protein conjugates and used in sensitive radioimmunoassays (RIAs) and enzyme-linked immunosorbent assays (ELISAs). One of the simplest ELISA approaches involves competition for a solid-phase antibody between a mycotoxin-enzyme conjugate and an unconjugated mycotoxin in the sample extract. ELISAs have been developed for aflatoxins B, and M„ zearalenone, T-2 toxin, and deoxynivalenol, which are highly specific, rapid (10 min), easily adaptable for analyzing large numbers of samples, and directly applicable to assaying methanol-water extracts of a wide range of foods. Several commercial mycotoxin ELISAs using this approach (most typically for aflatoxin B,) are currently being marketed. Since ELISAs will be used in large part by personnel with limited technical expertise, individual kits must be critically evaluated by analytical chemists for suggested sampling procedures, efficiency of extraction, crossreactivity, mycotoxin recovery, assay reproducibility, and product shelf-life prior to routine use in food safety and quality control screening

scholarly journals Stand Characteristics and Productivity Potential of Indiana Surface Mines Reclaimed Under SMCRA

2006 ◽  
Vol 23 (2) ◽  
pp. 94-99 ◽  
Author(s):  
John W. Groninger ◽  
Stephen D. Fillmore ◽  
Ron A. Rathfon
Keyword(s):  
Forest Cover ◽  
Robinia Pseudoacacia ◽  
Surface Mining ◽  
Forest Productivity ◽  
Site Index ◽  
Green Ash ◽  
Surface Mines ◽  
Wide Range ◽  
Study Sites ◽  
Productivity Potential

Abstract The Surface Mining Control and Reclamation Act of 1977 (SMCRA) addresses a wide range of environmental concerns. However, its impacts on forest stand development and productive potential have only recently been investigated. We surveyed the vegetation and forest productivity on 22 surfacemine sites throughout the coal-bearing region of Indiana that were reclaimed to forest cover under the provisions of SMCRA 7–14 years prior to sampling. Black locust (Robinia pseudoacacia) and green ash (Fraxinus pennsylvanica) were the most widely occurring tree species.Tall fescue and goldenrod were the most widely occurring nonarborescent species. Median site index (base age 50 for black oak) was 30 ft. Although satisfying forest cover stocking requirements for bond release, these reclaimed surface mines almost always displayed a level of productivity farbelow those of native forests typical of this region. Reclamation techniques differing from those used on these study sites are needed to restore forest productivity to surface-mined lands while still complying with SMCRA.

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

1997 ◽  
Vol 21 (1) ◽  
pp. 11-18 ◽  
Author(s):  
William M. Ford ◽  
A. Sydney Johnson ◽  
Philip E. Hale ◽  
James M. Wentworth
Keyword(s):  
Age Structure ◽  
Forest Type ◽  
Site Index ◽  
Forest Stand ◽  
Site Quality ◽  
Stand Age ◽  
Southern Appalachians ◽  
Study Region ◽  
Pinus Spp ◽  
Percent Area

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.

scholarly journals Results of Czech ash provenance experiment

2017 ◽  
Vol 63 (No. 6) ◽  
pp. 263-274
Author(s):  
Buriánek Václav ◽  
Novotný Petr ◽  
Dostál Jaroslav
Keyword(s):  
Czech Republic ◽  
Growth Parameters ◽  
Stand Age ◽  
Diameter Growth ◽  
Site Conditions ◽  
Provenance Trial ◽  
The Czech Republic ◽  
Forest Regions

This study is focused on testing progenies of common and narrow-leaved ash based on the measurement of provenance trial plots established in various forest regions under different site conditions within the Czech Republic in the spring of 1999. Height and diameter growth of 35 provenances was measured and evaluated at the stand age of 10–14 years. The main goal of this research is to analyse and compare differences in growth between progenies originating from alluvial versus scree habitats as well as between the two evaluated ash species. Moreover, the influence of localities on growth was tested using standard provenances planted on all plots. The results of the last measurement were compared with those from the first survey in 2000 at the age of 4–5 years (1 year after planting). With the exception of DBH on the Koněprusy plot, statistically significant differences in height and diameter growth between provenances were verified. The results confirmed a very strong site influence on growth. The main conclusions indicate significant differences in growth parameters between provenances, faster growth of alluvial versus scree provenances on most lowland plots, and generally faster growth of narrow-leaved ash as compared to common ash.

scholarly journals Creating Landscape-Scale Site Index Maps for the Southeastern US Is Possible with Airborne LiDAR and Landsat Imagery

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 234 ◽  
Author(s):  
Ranjith Gopalakrishnan ◽  
Jobriath Kauffman ◽  
Matthew Fagan ◽  
John Coulston ◽  
Valerie Thomas ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Laser Scanning ◽  
Landsat Imagery ◽  
Site Index ◽  
Airborne Lidar ◽  
Stand Age ◽  
Forest Site ◽  
Large Area ◽  
Southeastern Us ◽  
Index Maps

Sustainable forest management is hugely dependent on high-quality estimates of forest site productivity, but it is challenging to generate productivity maps over large areas. We present a method for generating site index (a measure of such forest productivity) maps for plantation loblolly pine (Pinus taeda L.) forests over large areas in the southeastern United States by combining airborne laser scanning (ALS) data from disparate acquisitions and Landsat-based estimates of forest age. For predicting canopy heights, a linear regression model was developed using ALS data and field measurements from the Forest Inventory and Analysis (FIA) program of the US Forest Service (n = 211 plots). The model was strong (R2 = 0.84, RMSE = 1.85 m), and applicable over a large area (~208,000 sq. km). To estimate the site index, we combined the ALS estimated heights with Landsat-derived maps of stand age and planted pine area. The estimated bias was low (−0.28 m) and the RMSE (3.8 m, relative RMSE: 19.7%, base age 25 years) was consistent with other similar approaches. Due to Landsat-related constraints, our methodology is valid only for relatively young pine plantations established after 1984. We generated 30 m resolution site index maps over a large area (~832 sq. km). The site index distribution had a median value of 19.4 m, the 5th percentile value of 13.0 m and the 95th percentile value of 23.3 m. Further, using a watershed level analysis, we ranked these regions by their estimated productivity. These results demonstrate the potential and value of remote sensing based large-area site index maps.

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