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.

Growth Response to Fertilization in Young Douglas-Fir Stands

1989 ◽  
Vol 4 (4) ◽  
pp. 116-119 ◽  
Author(s):  
Linda S. Heath ◽  
H. N. Chappell
Keyword(s):  
Pseudotsuga Menziesii ◽  
Growth Response ◽  
Volume Growth ◽  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Intermediate Region ◽  
Fertilizer Response ◽  
Breast Height ◽  
Inverse Effect

Abstract Response surface methodology was used to estimate six-year volume growth response to 1 application of 200 lb nitrogen per acre in unthinned and thinned Douglas-fir (Pseudotsuga menziesii) stands of breast height age (bha) 25 years or less. Regional mean fertilizer response was 16% in unthinned stands and 20% in thinned stands. Site index had an increasingly inverse effect on response as basal area increased in both unthinned and thinned stands. Response varied little over site index in regions of low basal area, decreased moderately as site index increased in the intermediate region, and decreased rapidly in the high basal area region. West. J. Appl. For. 4(4):116-119, October 1989.

Contrasting current and potential productivity and the influence of fire and species composition in the boreal forest: a case study in eastern Canada

2015 ◽  
Vol 45 (5) ◽  
pp. 541-552 ◽  
Author(s):  
Rija Rapanoela ◽  
Frédéric Raulier ◽  
Sylvie Gauthier ◽  
Hakim Ouzennou ◽  
Jean-Pierre Saucier ◽  
...  
Keyword(s):  
Black Spruce ◽  
Relative Difference ◽  
Minimum Size ◽  
Forest Site ◽  
Productive Capacity ◽  
Large Area ◽  
Site Factors ◽  
Eastern Canada ◽  
Potential Productivity ◽  
Forest Management Planning

The capacity of a forest stand to produce timber is related to the interactions that exist between its regeneration capacity, physical site characteristics (climate, surficial deposit, drainage), and disturbances. Minimally, to be sustainably managed, a forest needs to be sufficiently productive and able to regenerate after a disturbance so that its productive capacity is maintained or enhanced. To this effect, we evaluated timber productivity over a large area (175 000 km2) covering the latitudinal extent of closed-canopy black spruce (Picea mariana (Mill.) B.S.P) forest. Site index and relative density index were used to identify stands that cannot reach a minimum volume of trees of minimum size over one rotation. A nonparametric method was used to estimate their values for all stands within the study area. This imputation used either physical site attributes alone to assess potential productivity independent of stand history or physical and vegetation site attributes to assess current productivity. The proportion of productive stands was then estimated at the scale of landscapes ranging from 39 to 2491 km2. Physical site factors alone explain 84% of the variability in the percentage of potentially productive stands (78% for currently productive stands); their combination resulted in an abrupt transition in productivity over the study area. However, burn rate alone also explains 63% of variation in the proportion of currently productive stands and 41% of the relative difference between percentages of potentially or currently productive stands. These results have implications for strategic forest management planning at land classification stage, as timber production area is assumed to remain stable through time, whereas it is apparently related to the disturbance rate.

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.

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

Site Index Curves and Site Factors Affecting the Growth of White Pine in Southern Ontario

1990 ◽  
Vol 7 (4) ◽  
pp. 183-186
Author(s):  
Peter A. Williams ◽  
Andrew M. Gordon ◽  
Edward P. Taylor
Keyword(s):  
New England ◽  
Norway Spruce ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
White Pine ◽  
Site Factors ◽  
Southern Ontario ◽  
Factors Affecting ◽  
Breast Height

Abstract The objectives of this project were to develop site index curves and provide soil-site information for southern Ontario white pine and to compare that information to similar information on white pine from other regions and to information on Norway spruce in the study area. Sampling points were selected in unthinned white pine plantations and classified by sod textural class (course, medium, and free) and depth to distinct mottling (0-16, 16-40, and 40 + in.). Two sets of anamorphic site index curves were constructed from stem analysis data, using a total age of 30 years (SI30) and a breast height age of 25 years (SIBH25) as base ages. Significant differences due to soil factors were found in the number of years it took seedlings to reach breast height (BH) (mean = 6 5 years; range = 3 to 11 years) but not in SIBH25. Years to BH was significantly greater on clayey sites than those with loamy or sandy textures (6.1 vs. 5.0 and 4.9 years). White pine height growth in the study area compared favorably with white pine height growth in New England, Wisconsin, and Ohio. When white pine height growth was compared to the growth of Norway spruce in the study area, SIBH25 values were significantly higher for Norway spruce but years to BH were significantly lower for white pine. On poorly drained sites, site index values for white pine and Norway spruce were similar, but it took 2.2 years less for white pine to reach breast height (7.2 vs. 5.0 years). On imperfectly and well-drained sites, white pine seedlings took less time than Norway spruce to reach BH, but the site index of Norway spruce was much greater. North. J. Appl. For. 7:183-186, December 1990.

Leaf area – sapwood area relationships in adjacent young Douglas-fir stands with different early growth rates

1987 ◽  
Vol 17 (2) ◽  
pp. 174-180 ◽  
Author(s):  
M. A. Espinosa Bancalari ◽  
D. A. Perry ◽  
John D. Marshall
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Ring Width ◽  
Basal Area ◽  
Early Growth ◽  
Douglas Fir ◽  
Sapwood Area ◽  
Breast Height ◽  
Pipe Model ◽  
The Relationship

The relationship between foliage area and sapwood basal area was studied in three adjacent 22-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stands that differed in early growth rates. Sapwood width was fairly constant for most of the stem above the stump, but the number of annual rings in the sapwood decreased gradually with height. Sapwood area also decreased with increasing height in the tree, the stands differing significantly only at breast height. The proportion of heartwood from stump to near the base of the crown was significantly higher for the stand of fastest early growth. Ratios of leaf area to sapwood area were significantly higher for that stand and varied in every stem section, the ratio lower at breast height than at the base of the live crown. At the base of the crown, the ratio of leaf area to sapwood area was 1.33 and 1.57 times greater in the fast-growing stand than in the intermediate- and slow-growing stands, respectively. Leaf area was as closely related to dbh as to sapwood area at breast height. Sapwood area at the crown base was more accurate than sapwood area at breast height for predicting leaf area in the fast stand and was equally accurate in the other two stands. Ratios of leaf area to sapwood area correlated positively with sapwood ring width. However, because sapwood ring width also correlated closely with sapwood area, it did not improve predictive equations. The results suggest that the "pipe model" theory must be modified to account for the internal structure of the "pipe" and that caution should be exercised when using published leaf area to sapwood area ratios.

scholarly journals Inconsistent Growth Response to Fertilization and Thinning of Lodgepole Pine in the Rocky Mountain Foothills Is Linked to Site Index

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Bradley D. Pinno ◽  
Victor J. Lieffers ◽  
Simon M. Landhäusser
Keyword(s):  
Pinus Contorta ◽  
Growth Response ◽  
Lodgepole Pine ◽  
Rocky Mountain ◽  
Site Index ◽  
Basic Site ◽  
Nutrient Concentrations ◽  
Diameter Growth ◽  
Growth Responses ◽  
Site Factors

Fertilization of conifers often results in highly variable growth responses across sites which are difficult to predict. The goal of this study was to predict the growth response of lodgepole pine (Pinus contorta var. latifolia) crop trees to thinning and fertilization using basic site and foliar characteristics. Fifteen harvest-origin stands along the foothills of the Rocky Mountains of Alberta were subjected to six treatments including two levels of thinning (thinning to 2500 stems per hectare and a control) and three types of fertilization (nitrogen-only fertilization, complete fertilization including nitrogen with added P, K, S, Mg, and B, and no fertilization). After three growing seasons, the growth response and foliar status of the crop trees were examined and this response was related to site and foliar characteristics. There was a small and highly variable additive response to fertilization and thinning; diameter growth of crop trees increased relative to the controls an average of 0.3 cm with thinning, 0.3 cm with either N-only or complete fertilization and 0.6 cm when thinned and fertilized. The increase in diameter growth with thinning and nitrogen-only fertilization was positively related to site index but not to any other site factors or pretreatment foliar variables such as nutrient concentrations, ratios, or thresholds.

Wachstum und Wertleistung der Douglasie in Abhängigkeit von der Standraumgestaltung

2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  
Keyword(s):  
Wood Quality ◽  
Volume Growth ◽  
Static Stability ◽  
Douglas Fir ◽  
Breast Height ◽  
Monetary Analysis ◽  
Starting Conditions ◽  
Tree Number ◽  
Clear Differentiation ◽  
Further Development

Growth and value production of Douglas-fir under varying stand densities The investigation is focused on the effects of initial tree number and thinning on growth and value performance of Douglas-fir stands. Data base is a coordinated Douglas-fir spacing experiment in South Germany, started 40 years ago and comprising variants of tree numbers with 500, 1,000, 2,000 and 4,000 Douglas-firs per hectare. The treatment was performed according to a standardized experiment program. The results show that at low initial tree numbers, the diameter on breast height (DBH) of (pre)dominant trees at the beginning of the observations (with 12 m top height) is bigger than at higher initial plant numbers. Accordingly, the quotient of height (H) to DBH (as an indicator for tree's static stability) is lower. The further development of DBH and H/DBH quotient is decisively determined by stand treatment, which superimposes the effect of the initial tree number. The total volume growth shows a clear differentiation, too, the variants with initially high tree numbers appearing on top. In the monetary analysis, this ranking is reversed: despite a supposed inferior wood quality, the variants with lower initial tree numbers clearly outperform the ones with higher numbers in terms of value. From these results, the following silvicultural recommendations for Douglas-fir can be derived: the initial tree numbers should be in the range from 1,000 to 2,000 plants per hectare. On technically not accessible sites, even lower tree numbers may come into question. The strong influence of stand treatment on DBH and H/DBH development highlights the problem of postponed thinnings, for this causes growth and stability losses even under favorable starting conditions in terms of competition.

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