Generalized functions of biomass expansion factors for conifers and broadleaved by stand age, growing stock and site index

2009 ◽  
Vol 257 (3) ◽  
pp. 1004-1013 ◽  
Author(s):  
Maurizio Teobaldelli ◽  
Zoltan Somogyi ◽  
Mirco Migliavacca ◽  
Vladimir A. Usoltsev
Keyword(s):  
Site Index ◽  
Generalized Functions ◽  
Stand Age ◽  
Growing Stock ◽  
Biomass Expansion Factors

Yields of Southwestern Pinyon-Juniper Woodlands

1988 ◽  
Vol 3 (3) ◽  
pp. 70-74 ◽  
Author(s):  
Frederick W. Smith ◽  
Thomas Schuler
Keyword(s):  
Maximum Yield ◽  
Stand Density ◽  
Site Index ◽  
Average Density ◽  
Pinus Edulis ◽  
Site Quality ◽  
Mixed Species ◽  
Growing Stock ◽  
Highly Correlated ◽  
Utah Juniper

Abstract Site quality and growth-growing stock relations were developed for southwestern woodlands of pinyon (Pinus edulis) and one-seed juniper (Juniperus monosperma) or Utah juniper (J. osteosperma). Anamorphic height-age site index curves for pinyon were developed from a regional sample of 60 woodlands. Site index was unaffected by variation in stocking and was correlated with woodland yield when used in conjunction with density. Pinyon and juniper PAI, when taken separately, were highly correlated with stand density and pinyon site index. Pinyon was twice as productive as juniper at similar stand densities. Pinyon and juniper yields in woodlands of average density and site index were estimated at 0.29 and 0.15 m3ha-1y-1. At high densities pinyon and juniper yields increased to 0.61 and 0.31 m3ha-1y-1 Pinyon and juniper yields appeared independent of the density of the other species in an individual woodland. Maximum yield of dense mixed species woodlands on average sites was 0.78 m3ha-1y-1, and occurred when pinyon constituted 65% of woodland density. West. J. Appl. For. 3(3):70-74, July 1988.

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 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.

Biomass expansion factors (BEFs) for Scots pine, Norway spruce and birch according to stand age for boreal forests

2004 ◽  
Vol 188 (1-3) ◽  
pp. 211-224 ◽  
Author(s):  
A Lehtonen ◽  
R Mäkipää ◽  
J Heikkinen ◽  
R Sievänen ◽  
J Liski
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Boreal Forests ◽  
Stand Age ◽  
Biomass Expansion Factors

Assessing the effect of measurement error in age on dominant height and site index estimates

2011 ◽  
Vol 41 (8) ◽  
pp. 1698-1709 ◽  
Author(s):  
Chengcai Ni ◽  
Gordon Nigh
Keyword(s):  
Measurement Error ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Site Index ◽  
Stand Age ◽  
Initial Value ◽  
Dominant Height ◽  
Projection Length ◽  
Age Model ◽  
Projection Error

Stand age is often hard to measure accurately. Measurement error in age affects height estimates when height is projected from one age to another age. In this study, our objective was to derive an estimator for the variance of the component of projection error associated with the error in age. To evaluate the estimator, a simulation approach was employed and the results showed that the estimator worked well in most cases. When the variance of the error in age increases and the projection is forward, however, the estimator might not work as well as in other cases. Another objective was to examine how the error in age behaved under different height–age models and to what extent it affected height and site index estimates. The effect of the error in age depended on its magnitude, the height–age model, initial value of dominant height and age, and projection length. It was also shown that the effect was sometimes negligible, but it could be considerable in other cases. Data from 80 ponderosa pine ( Pinus ponderosa Dougl. ex Laws.) trees in British Columbia, Canada, were used in an illustrative example.

A calibrateable site index model for Pinus kesiya plantations in southeastern Africa

2002 ◽  
Vol 32 (11) ◽  
pp. 1916-1928 ◽  
Author(s):  
Kalle Eerikäinen ◽  
Danaza Mabvurira ◽  
Ladislaus Nshubemuki ◽  
Jussi Saramäki
Keyword(s):  
Random Parameter ◽  
Site Index ◽  
Stand Age ◽  
Random Parameters ◽  
Index Model ◽  
Forest Inventories ◽  
Pinus Kesiya ◽  
Dominant Height ◽  
Random Parameter Model ◽  
Site Index Model

The aim of the study was to develop a site index model for Pinus kesiya Royle ex Gordon plantations in southeastern Africa based on the relationship between the dominant height and stand age. Conversely, analysis of dominant height and age data showed that the growth patterns of plantations were different. In addition, the asymptotes and forms of standwise dominant height curves varied within plantations. In developing a common site index model, instead of using the more common approach of estimating separate dominant height–age models for different plantations or sites, a mean curve approach based on a linear random parameter model with fixed and random parameters was applied. The random parameter model of this study was calibrated by predicting random parameters for the plantation and stand effects, in accordance with the standard linear prediction theory. The analyses showed that the calibration of the dominant height model was an efficient method to obtain reliable dominant height predictions of a stand, particularly when several dominant height–age observations from different stands of a plantation and at least one measured dominant height and stand age of a target stand are available. This is the case in many forest inventories based on temporary samples, i.e., cross-sectional data. The new site index model is a useful tool for use in different mensurational applications, and its properties can efficiently be utilized for example in forest inventories of P. kesiya plantations in southeastern Africa.

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.

scholarly journals Modeling dominant height growth using permanent plot data for Pinus brutia stands in the Eastern Mediterranean region

2021 ◽  
Vol 30 (1) ◽  
pp. eSC03
Author(s):  
Tammam Suliman ◽  
Uta Berger ◽  
Marieke Van der Maaten-Theunissen ◽  
Ernst Van der Maaten ◽  
Wael Ali
Keyword(s):  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Site Index ◽  
Permanent Plots ◽  
Stand Age ◽  
Pinus Brutia ◽  
Dominant Height ◽  
Algebraic Difference ◽  
Generalized Algebraic Difference Approach

Aim of the study: At current, forest management in the Eastern Mediterranean region is largely based on experience rather than on management plans. To support the development of such plans, this study develops and compares site index equations for pure even-aged Pinus brutia stands in Syria using base-age invariant techniques that realistically describe dominant height growth.Materials and methods: Data on top height and stand age were obtained in 2008 and 2016 from 80 permanent plots capturing the whole range of variation in site conditions, stand age and stand density. Both the Algebraic Difference Approach (ADA) and the Generalized Algebraic Difference Approach (GADA) were used to fit eight generalized algebraic difference equations in order to identify the one which describes the data best. For this, 61 permanent plots were used for model calibration and 19 plots for validation.Main results: According to both biological plausibility and model accuracy, the so-called Sloboda equation based on the GADA approach showed the best performance.Research highlights: The study provides a solid classification and comparison of Pinus brutia stands growing in the Eastern Mediterranean region and can thus be used to support sustainable forest management planning.Keywords: site index; Generalized Algebraic Difference Approach (GADA); Sloboda equation.

scholarly journals Plonski's (metric) yield tables formulated

1991 ◽  
Vol 67 (5) ◽  
pp. 545-546 ◽  
Author(s):  
Bijan Payandeh
Keyword(s):  
Growth Model ◽  
Computer Use ◽  
Site Index ◽  
Stand Age ◽  
Sigmoidal Growth

A four-parameter sigmoidal growth model was employed to express various characteristics of interest in Plonski's metric yield tables as functions of stand age and site index. Except in a few cases, excellent fits were obtained. The resulting equations will facilitate direct computer use of Plonski's metric yield tables.

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