scholarly journals DEVELOPING AN INDEX FOR FOREST PRODUCTIVITY MAPPING - A CASE STUDY FOR MARITIME PINE PRODUCTION REGULATION IN PORTUGAL

2018 ◽  
Vol 41 (3) ◽  
Author(s):  
Susana Mestre ◽  
Cristina Alegria ◽  
Maria Teresa Durães Albuquerque ◽  
Pierre Goovaerts
Keyword(s):  
Control Method ◽  
Methodological Approach ◽  
Forest Productivity ◽  
Site Index ◽  
Maritime Pine ◽  
Productivity Index ◽  
Forest Site ◽  
Factorial Correspondence Analysis ◽  
Site Productivity ◽  
Index Model

ABSTRACT Productivity is very dependent on the environmental and biotic factors present at the site where the forest species of interest is present. Forest site productivity is usually assessed using empirical models applied to inventory data providing discrete predictions. While the use of GIS-based models enables building a site productivity distribution map. Therefore, the aim of this study was to derive a productivity index using multivariate statistics and coupled GIS-geostatistics to obtain a forest productivity map. To that end, a study area vastly covered by naturally regenerated forests of maritime pine in central Portugal was used. First, a productivity index (PI) was built based on Factorial Correspondence Analysis (FCA) by incorporating a classical site index for the species and region (Sh25 - height index model) and GIS-derived environmental variables (slope and aspect). After, the PI map was obtained by multi-Gaussian kriging and used as a GIS layer to evaluate maritime pine areas by productivity class (e.g., low, intermediate and high). In the end, the area control method was applied to assess the size and the number of compartments to establish by productivity class. The management compartments of equal productivity were digitized as GIS layer and organized in a temporal progression of stands’ age regularly available for cutting each year during a 50-year schedule. The methodological approach developed in this study proved that can be used to build forest productivity maps which are crucial tools to support forest production regulation.

A Multipoint Felled-Tree Validation of Height–Age Modeled Growth Rates

2020 ◽  
Vol 66 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Halli Hemingway ◽  
Mark Kimsey
Keyword(s):  
Growth Rates ◽  
Rocky Mountain ◽  
Site Index ◽  
Douglas Fir ◽  
Alternative Methods ◽  
Forest Site ◽  
Site Productivity ◽  
Site Factors ◽  
Forest Management Planning ◽  
Breast Height

Abstract Accurate measures of forest site productivity are essential for forest-management planning. The most common measure of site productivity is breast height–age site index (BHASI)—the expected height at a reference age. Error from including early growth in productivity estimates and limited applicability of any one BHASI model warrant development of alternative methods. Exploring alternatives may only be necessary if regional BHASI models are not accurately predicting growth rates. We compared modeled height growth rates for Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) to felled-tree measurements to evaluate relative performance of a regional BHASI model. An orthogonal sampling design ensured samples were collected across a range of site factors known to influence Douglas-fir growth rates. Growth rates for each 10 m section were calculated and compared to BHASI modeled growth rates. The regional BHASI model underpredicted growth rates from breast height to 30 m. Observed growth rates from 10 to 30 m accounted for the majority of underprediction relative to BHASI modeled growth rates. An alternative multipoint method of defining site productivity is described. More research comparing BHASI and alternative methods is needed, given the growth rate error associated with one-point site productivity assessment.

scholarly journals Variable stocking yield functions for the boreal mixedwood in Ontario

1996 ◽  
Vol 72 (4) ◽  
pp. 416-419 ◽  
Author(s):  
Bijan Payandeh ◽  
Yonghe Wang
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Eastern United States ◽  
Site Productivity ◽  
Area Index ◽  
Permanent Sample Plots ◽  
Index Model ◽  
Index Site ◽  
Yield Functions ◽  
Site Index Model

A measure of utilized site productivity, "basal area index" was recently developed and used to construct variable stocking yield functions and tables for the boreal mixedwood of northcentral Ontario. Data from 197 permanent sample plots supplied by the James River/Marathon Paper Company Ltd. were used. The resulting yield equations compare favourably with previous ones and are more appropriate for the boreal mixedwood. In addition, the basal area index employed has several advantages: 1) it serves as a valid measure of utilized site productivity which is better correlated with the main stand attributes than site index; 2) it produces variable stocking yield tables suitable for uneven-aged mixed species cover types; 3) unlike the site index, the basal area index may be estimated quickly, easily and inexpensively. The basic improvement in mixedwood yield estimation via basal area index should have broad applications for other stand types particularly for the disturbed hardwoods of southern Ontario and those in eastern United States. Key words: Basal area index, site index model, numerical method

Predicting lodgepole pine site index from climatic parameters in Alberta

2006 ◽  
Vol 82 (4) ◽  
pp. 562-571 ◽  
Author(s):  
Robert A Monserud ◽  
Shongming Huang ◽  
Yuqing Yang
Keyword(s):  
Climate Model ◽  
Lodgepole Pine ◽  
Predictor Variable ◽  
Site Index ◽  
Climatic Variables ◽  
Climatic Data ◽  
Forest Site ◽  
Site Productivity ◽  
Variable Site ◽  
The Impact

We sought to evaluate the impact of climatic variables on site productivity of lodgepole pine (Pinus contorta var. latifolia Engelm.) for the province of Alberta. Climatic data were obtained from the Alberta Climate Model, which is based on 30- year normals from the provincial weather station network. Mapping methods were based on ANUSPLIN, Hutchinson's thin-plate smoothing spline in four dimensions (latitude, longitude, elevation, climatic variable). Site indices based on stem analysis (observed dominant height at an index age of 50 years at breast height) were used as a measure of forest site productivity. A total of 1145 site index plots were available for lodgepole pine, the major forest species in Alberta. Regression analyses were used to predict site index as a function of climatic variables for each plot. The strongest linear predictors of site index were growing degree days > 5° (GDD5), the Julian date when GDD5 reaches 100 (D100), and July mean temperature (MTWM).A nonlinear model with D100 as the predictor variable was chosen as the final model. Both the observed and the predicted site indices from the 1145 locations were interpolated using ANUSPLIN and mapped using ArcView. We concluded that climate is an important component of site productivity, accounting for about one quarter of the variation in lodgepole pine site index across the province. Key words: site index, climate variable, Alberta Climate Model, ANUSPLIN, site productivity map, lodgepole pine

An ecological land classification approach to modeling the production of forest biomass

2011 ◽  
Vol 87 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Bharat Pokharel ◽  
Jeffery P Dech
Keyword(s):  
Forest Management ◽  
Forest Biomass ◽  
Site Index ◽  
Site Classification ◽  
Forest Site ◽  
Land Classification ◽  
Site Productivity ◽  
Ecological Land Classification ◽  
Site Evaluation ◽  
Forest Site Classification

Forest site classification is a prerequisite to successful integrated forest resources planning and management. Traditionally,site classification has emphasized a phytocentric approach, with tools such as the site index having a rich and longhistory in forest site evaluation. The concept of site index was primarily devised to assess site productivity of an even-aged,single-species stand. Site index has been the primary method of forest site evaluation in support of management for traditionalforest products. However, this method of site classification has been criticized as the needs, perspectives andsocial values of the public regarding forest management have changed the emphasis from timber production to multiplevalueforestry practices. There are alternative approaches to forest site classification that have the potential to meet thegrowing demands placed on forest information for inventory and modeling purposes. Ecological Land Classification(ELC), is a phytogeocentric approach that stratifies the landscape into ecologically meaningful units (ecosites) based onsubstrate characteristics, moisture regime and canopy composition. This approach offers a more holistic view of site productivityevaluation; however, until recently it has been difficult to acquire data to support widespread mapping ofecosites. Remote sensing technology along with predictive modeling and interpretive mapping techniques make the applicationof an ecosite-based approach at the forest landscape level possible. As forest management moves towards the considerationof a broader set of resources (e.g., woody biomass), there is an opportunity to develop new tools for linking forestproductivity to the sustainable production of forest bioproducts with forest ecosites as a solid foundation forsegmenting the landscape. Key words: forest site classification, site index, site productivity, Ecological Land Classification (ELC), ecosites, forest biomass,bioproducts

Height development of Scots pine on peatlands: describing change in site productivity with a site index model

2004 ◽  
Vol 34 (5) ◽  
pp. 1081-1092 ◽  
Author(s):  
Hannu Hökkä ◽  
Risto Ojansuu
Keyword(s):  
Scots Pine ◽  
Site Index ◽  
Stand Age ◽  
Variance Component Model ◽  
Moderate Increase ◽  
Site Productivity ◽  
Permanent Sample Plots ◽  
Index Model ◽  
Site Water ◽  
Site Index Model

The effect of site properties and forest drainage on the dominant height development of Scots pine (Pinus sylvestris L.) stands in peatland sites was studied using data from permanent sample plots located in natural and drained sites in northern Finland. The Korf model was used to describe the height development of dominant trees in natural sites. The effect of drainage on height development was accounted for by a term giving a nonlinear height increase for drained sites as a function of the time elapsed since drainage. The variance component model was applied to account for the hierarchical data structure. Natural height development after 30 years of age at DBH was significantly slower in PF sites (sparsely forested pine fens) than in PS sites (genuine forested pine swamps). Within PF sites, there were further differences in relation to nutrient availability. Temperature sum explained the variation in the intercept. In PS sites, drainage resulted in a moderate increase in the maximum attainable height, while in PF sites, drainage improved site productivity by 80%–85% in terms of the attainable height. The asymptote for drained stands was dependent on stand age at the time of drainage. Differences between the two major groups were assumed to be due to initial differences in site water regime.

scholarly journals 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 ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1155 ◽  
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.

scholarly journals Modeliranje višinske in debelinske rasti dominantnih dreves ter ocenjevanje indeksov produkcijske sposobnosti gozdnih rastišč

2021 ◽  
Vol 125 ◽  
pp. 1-12
Author(s):  
Andrej Bončina ◽  
Vasilije Trifković ◽  
Živa Bončina
Keyword(s):  
Growth Models ◽  
Tree Height ◽  
European Beech ◽  
Productivity Index ◽  
Silver Fir ◽  
Forest Types ◽  
Site Productivity ◽  
Beech Forests ◽  
Sessile Oak ◽  
Diameter Increment

Modeling the height and diameter growth of trees is an important part of forest management. Growth models provide the basis for determining the thinning regime, target tree dimensions and optimal proportions of developmental phases of forest stands. We developed individual height growth models for dominant Norway spruce (Picea abies (L.) Karst) and European beech (Fagus sylvatica L.) in two forest types (sessile oak-European beech forests and pre-Alpine silver fir-European beech forests). Based on the models, the site productivity index (SPI), defined as the dominant tree height at a diameter of 45 cm, was determined for spruce and beech in both forest types. Based on the diameter increment of the dominant trees, the age of trees in regard to their diameter was calculated, which was the basis for Height-Age modeling. The site productivity index (SPI) of spruce in sessile oak-beech forests and pre-Alpine silver fir-European beech forests is higher than that of beech: 31.3 and 29.7 vs 28.7 and 27.9, respectively. Estimated site indices (SI; dominant tree height at the age of 100 years) in sessile oak- European beech forests and pre-Alpine silver fir-European beech forests were 33.4 and 32.0 for spruce, and 29.0 and 27.0 for beech, respectively. Using the described procedure, it is possible to determine indices of site productivity of spruce and beech (SI and SPI) in the selected forest habitat types. Testing the procedure in other forest types and for other tree species is suggested.

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