Effects of diameter distribution on the growth of simulated uneven-aged sugar maple stands

1987 ◽  
Vol 17 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Gerald D. Hansen ◽  
Ralph D. Nyland
Keyword(s):  
Sugar Maple ◽  
Basal Area ◽  
Tree Size ◽  
Diameter Distribution ◽  
Computer Simulation Model ◽  
Maximum Volume ◽  
Size Classes ◽  
Management Objectives ◽  
Stress Maximum ◽  
Volume Production

Effects of diameter distribution on the growth of simulated uneven-aged sugar maple (Acersaccharum Marsh.) stands are described using output from a computer simulation model. Results indicate that the combination of q ratio (a constant ratio between the numbers of trees present in adjacent diameters over the entire range of size classes present), maximum tree size, and basal area should vary depending on management objectives and cutting cycle length. A ratio of 1.2 appears best for describing a diameter distribution to maximize growth of large sawtimber, but larger q ratios are needed in the sapling and pole size classes to insure sufficient numbers of trees to sustain the distribution through the end of a cutting cycle. Retaining trees larger than a 40 cm diameter at breast height offers no advantage when objectives stress maximum volume production. A 50 cm maximum tree size appears better suited for maximizing large sawtimber volume and value growth, but a 40 cm maximum will yield a better compound rate of return on initial stand value. Under all options, longer cutting cycles require lower initial basal area levels.

scholarly journals Deriving Tree Size Distributions of Tropical Forests from Lidar

2021 ◽  
Vol 13 (1) ◽  
pp. 131
Author(s):  
Franziska Taubert ◽  
Rico Fischer ◽  
Nikolai Knapp ◽  
Andreas Huth
Keyword(s):  
Size Distribution ◽  
Spatial Scales ◽  
Basal Area ◽  
Tree Height ◽  
Tree Size ◽  
Diameter Distribution ◽  
Forest Inventories ◽  
Allometric Relations ◽  
Lidar Measurements ◽  
Derived Data

Remote sensing is an important tool to monitor forests to rapidly detect changes due to global change and other threats. Here, we present a novel methodology to infer the tree size distribution from light detection and ranging (lidar) measurements. Our approach is based on a theoretical leaf–tree matrix derived from allometric relations of trees. Using the leaf–tree matrix, we compute the tree size distribution that fit to the observed leaf area density profile via lidar. To validate our approach, we analyzed the stem diameter distribution of a tropical forest in Panama and compared lidar-derived data with data from forest inventories at different spatial scales (0.04 ha to 50 ha). Our estimates had a high accuracy at scales above 1 ha (1 ha: root mean square error (RMSE) 67.6 trees ha−1/normalized RMSE 18.8%/R² 0.76; 50 ha: 22.8 trees ha−1/6.2%/0.89). Estimates for smaller scales (1-ha to 0.04-ha) were reliably for forests with low height, dense canopy or low tree height heterogeneity. Estimates for the basal area were accurate at the 1-ha scale (RMSE 4.7 tree ha−1, bias 0.8 m² ha−1) but less accurate at smaller scales. Our methodology, further tested at additional sites, provides a useful approach to determine the tree size distribution of forests by integrating information on tree allometries.

scholarly journals Ertragskundliche Aspekte und Strukturdynamik der Buchen-Lichtwuchsdurchforstung

2018 ◽  
Vol 169 (6) ◽  
pp. 332-339 ◽  
Author(s):  
Joachim Klädtke
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Structural Diversity ◽  
Maximum Volume ◽  
Negative Effects ◽  
Single Tree ◽  
Stand Productivity ◽  
Single Tree Selection ◽  
Volume Production ◽  
Equilibrium Growth

Effects of heavy selective thinnings in beech stands with regard to stand productivity and structural diversity Based on thinning trials in beech stands initiated in the early 1970s, the effects of selective thinnings in favour of 100 to 120 future crop trees were analysed with regard to volume productivity and the stands' structural diversity. The results show that these kinds of thinnings reduce volume productivity by approximately 6% compared to the maximum volume growth. The reduction in volume growth is mostly caused by the fact that the strongly released crop trees have reduced their height growth for the benefit of a lateral crown expansion, while basal area growth was not affected. Calculations indicate that silvicultural systems working with only 50 future crop trees per hectare may decrease the maximum volume production by about 12%. Furthermore, the results show that the intense crown releases caused by selection thinnings increase the horizontal and vertical diversity of beech stands, since the trees in the understorey profit from better light conditions. The indices calculated for diameter and height diversity of the selection thinning plots approach the values being typical for single tree selection forests (“Plenterwälder”). Already after three to four consecutive selection thinnings, the beech stands' diameter distributions displayed an exponentionally decreasing shape typical for single tree selection forests close to equilibrium. Growth simulations revealed that it might even be possible to directly transform beech stands by selection thinnings into single tree selection structures. However, presumably negative effects on timber quality to be expected under single tree selection structures should be considered as a critical aspect with regard to theoretically possible transformation.

scholarly journals Cavity Trees, Snags, and Selection Cutting: A Northern Hardwood Case Study

2007 ◽  
Vol 24 (3) ◽  
pp. 192-196 ◽  
Author(s):  
Laura S. Kenefic ◽  
Ralph D. Nyland
Keyword(s):  
Sugar Maple ◽  
Stand Structure ◽  
Basal Area ◽  
Diameter Distribution ◽  
Maximum Diameter ◽  
Northern Hardwoods ◽  
Selection System ◽  
Habitat Features ◽  
Northern Hardwood ◽  
Selection Cutting

Abstract Although traditional application of the selection system includes a focus on high-value trees that may reduce cavities and snags, few studies have quantified those habitat features in managed uneven-aged stands. We examined the effects of single-tree selection cutting on cavity trees and snags in a northern hardwood stand immediately prior to the second cutting. Marking followed guidelines proposed by Arbogast, C., Jr. (1957. Marking guides for northern hardwoods under selection system. US For. Serv. Res. Pap. 56, Lake States Forest Experiment Station. 20 p.), with the objective of improving stand quality for timber production while maintaining a balanced diameter distribution. The stand contained seven species of cavity trees and snags; sugar maple and American beech were most common, the latter comprising 20% of snags and 26% of cavity trees despite its relatively minor (7%) contribution to stand basal area. We found that 92% of cavity trees were live, underscoring the value of living trees as sources of cavities. Precut cavity tree density (25.2 live cavity trees per hectare) was more than twice that found in other studies of selection stands, although density of snags (11.0 snags per hectare) was comparable or lower. More than 50% of sampled cavity trees were designated for removal in the second selection cut, reducing projected postcut density to 11.0 live cavity trees per hectare, a density similar to that found in other studies. Postcut density of large cavity trees (3.3 live trees >45 cm dbh per hectare) exceeded published guidelines for northern hardwoods (0.25 to 2.5 live cavity trees >45 cm dbh per hectare). We speculate that the relatively high maximum diameter (61 cm dbh) and long cutting cycle (20 years) used to define the target stand structure may have contributed to the number of cavity trees observed. Nevertheless, selection cutting as applied in this study will likely reduce cavity abundance unless retention of trees with decay is explicitly incorporated into the management strategy.

Effect of Hexazinone Rate and Formulation on Loblolly Pine in Broadcast Release Applications

1991 ◽  
Vol 15 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Glenn R. Glover ◽  
Bruce R. Zutter ◽  
Patrick J. Minogue ◽  
Dean H. Gjerstad
Keyword(s):  
Loblolly Pine ◽  
Growth Response ◽  
Foliar Spray ◽  
Basal Area ◽  
Soil Characteristics ◽  
Liquid Formulation ◽  
Maximum Volume ◽  
Sand Surface ◽  
Volume Production ◽  
Pellet Formulation

Abstract Growth response and mortality of loblolly pine were examined 5 or 6 years after broadcast applications of four rates of pellet and liquid (applied as a foliar spray) hexazinone formulations for pine release at seven locations across the South varying in soil characteristics. Adjusted hardwood rootstock density 2 years following treatment was significantly affected by treatment and rate at all locations, and by formulation at five of the seven locations. Pine mortality was positively related to hexazinone rate at four of the study locations. Mortality was significantly higher for the pellet formulation compared to the liquid at the two locations with loamy sand surface soils. Mortality averaged less than 10% for the prescribed rate of both formulations at five of the seven locations, and at a sixth location for the pellet formulation. Mean pine height and dbh responses across hexazinone rates were greater than no treatment (check) at three and five locations, respectively. Response in dbh was positively related to hexazinone rate at three locations, and inversely related to rootstock density 2 years after treatment at six of seven locations. Mean treatment response for pine basal area and total volume (outside bark) per acre were significantly greater than the check at only two locations due to high pine mortality at some locations for 1.4X and 2.0X the prescribed rate. Mean increases in volume of the prescribed rate over the check were 9 and 7% for the pellet and liquid formulations, respectively. Maximum volume production increases across locations were 13% for the pellet formulation and 15% for the liquid formulation. South J. Appl. For. 15(1):54-61.

Properties of the quadratic mean diameter in balanced diameter distributions

1985 ◽  
Vol 15 (2) ◽  
pp. 474-476
Author(s):  
Donald J. Weatherhead ◽  
Roger C. Chapman ◽  
John H. Bassman
Keyword(s):  
Stand Structure ◽  
Basal Area ◽  
Tree Size ◽  
Diameter Distribution ◽  
Quadratic Mean ◽  
Growing Stock ◽  
Mean Diameter ◽  
Quadratic Mean Diameter ◽  
Stand Basal Area ◽  
Diameter Distributions

Balanced diameter distributions are widely used to describe stand structure goals for residual growing stock in uneven-aged forests. The quadratic mean diameter is frequently used as a descriptor of a balanced diameter distribution. In this paper the quadratic mean diameter is shown to be independent of stand basal area for balanced diameter distributions with a common class width, maximum and minimum diameters, and de Liocourt's q ratio. Additionally it is shown that the quadratic mean diameter is relatively insensitive to changes in maximum tree size and q ratios for q ratios 1.5 and larger.

scholarly journals Stand Structure in Evenaged Northern Hardwoods: Development and Silvicultural Implications

1999 ◽  
Vol 16 (2) ◽  
pp. 115-119
Author(s):  
William B. Leak
Keyword(s):  
New Hampshire ◽  
Stand Structure ◽  
Canopy Structure ◽  
Basal Area ◽  
Diameter Distribution ◽  
Northern Hardwoods ◽  
Gradual Transition ◽  
Northern Hardwood ◽  
Size Classes ◽  
Paper Birch

Abstract Stand structure was examined in evenaged northern hardwoods in New Hampshire in terms of diameter distribution (numbers of trees by dbh class) and spatial distribution of basal area by species. Diameter distributions by species and for all species combined were graphed for stands varying in age class from 7-9 yr up to 60-68 yr. Over time, these northern hardwood stands develop a layered canopy structure with the intolerant and short-lived paper birch and aspen dominating the larger size classes and exhibiting a bell-shaped diameter distribution. Longer lived species, most abundant in the smaller size classes, exhibit flat or very skewed bell-shaped distributions. The usual silvicultural recommendation in such stands is to thin to prescribed stocking levels, leaving adequate stocking in larger stems of the longer lived species and gradually removing the intolerants as they reach maturity. However, appreciable spatial variation in the abundance of aspen-birch and longer lived species may prevent uniform application of this approach; i.e., some areas in certain stands do not have adequate stocking of the longer lived species once the aspen-birch is removed.In variable stands such as this, a gradual transition to group selection may be a better tactic. North. J. Appl. For. 16(2):115-119.

scholarly journals Field Note—Comparison of Three Dendrometers in Measuring Diameter at Breast Height Field Note

2002 ◽  
Vol 19 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Leigh Ann Moran ◽  
Roger A. Williams
Keyword(s):  
Sugar Maple ◽  
Geometric Mean ◽  
Basal Area ◽  
Tree Size ◽  
Red Oak ◽  
Northern Red Oak ◽  
Diameter At Breast Height ◽  
White Ash ◽  
Breast Height ◽  
Field Note

Abstract Three dendrometers—d-tape, calipers, and Biltmore stick—were used to measure diameter at breast height (dbh), and discrepancies that occurred among these instruments were compared. Three methods of dbh estimation with calipers—the quadratic, arithmetic, and geometric mean of the major and minor axis diameter—were compared. Trees were grouped into four broad dbh classes of 1–5, 6–10, 11–15, and 16–20 in. and three species—northern red oak, sugar maple, and white ash—to determine the effect of tree size and species on discrepancies. The d-tape consistently recorded a larger dbh than the three caliper methods, but was not statistically different nor practically important. The differences in recorded dbh between the d-tape and calipers increased with tree size and were similar among northern red oak and sugar maple trees, but dbh differences in white ash trees were significantly less than in the other two species. The Biltmore stick's accuracy in classifying trees into the same dbh class as determined by the d-tape decreased as tree size increased. When examined by species, the Biltmore stick was less accurate in this regard with northern red oak and most accurate with sugar maple. Because the geometric principle of the d-tape assumes a tree to have a circular shape, its diameter estimation and subsequent basal area will usually be greater than the true diameter and area. The use of calipers reduces this bias, but the differences are not statistically significant.

Exploring the Recruitment Dynamics of Sugar Maple and Yellow Birch Saplings into Merchantable Stems Following Harvesting in the Acadian Forest Region of New Brunswick, Canada

2021 ◽  
Author(s):  
Alex Noel ◽  
Jules Comeau ◽  
Salah-Eddine El Adlouni ◽  
Gaetan Pelletier ◽  
Marie-Andrée Giroux
Keyword(s):  
New Brunswick ◽  
Sugar Maple ◽  
Basal Area ◽  
Stem Density ◽  
Yellow Birch ◽  
Probability Of Occurrence ◽  
Silvicultural Treatment ◽  
Forest Region ◽  
Wide Range ◽  
Acadian Forest

The recruitment of saplings in forest stands into merchantable stems is a very complex process, thus making it challenging to understand and predict. The recruitment dynamics in the Acadian Forest Region of New Brunswick are not well known or documented. Our objective was to draw an inference from existing large scale routine forest inventories as to the different dynamics behind the recruitment from the sapling layer into the commercial tree size layer in terms of density and occurrence of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britt.) following harvesting, by looking at many factors on a wide range of spatial and temporal scales using models. Results suggest that the variation in density and probability of occurrence is best explained by the intensity of silvicultural treatment, by the merchantable stem density in each plot, and by the proportion of merchantable basal area of each group of species. The number of recruits of sugar maple and yellow birch stems tend be higher when time since last treatment increases, when mid to low levels of silvicultural treatment intensity were implemented, and within plots having intermediate levels of merchantable stem density. Lastly, our modeling efforts suggest that the probability of occurrence and density of recruitment of both species tend to increase while its share of merchantable basal area increases.

A New Index Representing Individual Tree Competitive Status

1973 ◽  
Vol 3 (4) ◽  
pp. 495-500 ◽  
Author(s):  
James A. Moore ◽  
Carl A. Budelsky ◽  
Richard C. Schlesinger
Keyword(s):  
Spatial Distribution ◽  
Strong Correlation ◽  
Basal Area ◽  
Tree Size ◽  
Competition Index ◽  
Individual Tree ◽  
Silvicultural Practices ◽  
Basal Area Growth ◽  
Hardwood Species ◽  
Area Growth

A new competition index, modified Area Potentially Available (APA), was tested in a complex unevenaged stand composed of 19 different hardwood species. APA considers tree size, spatial distribution, and distance relationships in quantifying intertree competition and exhibits a strong correlation with individual tree basal area growth. The most important characteristic of APA is its potential for evaluating silvicultural practices.

Present-day expansion of American beech in northeastern hardwood forests: Does soil base status matter?

2009 ◽  
Vol 39 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
Louis Duchesne ◽  
Rock Ouimet
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Basal Area ◽  
Base Cation ◽  
Hardwood Forests ◽  
Fagus Grandifolia ◽  
Soil Base ◽  
Large Area ◽  
American Beech ◽  
Permanent Sample Plots

Recently, sugar maple ( Acer saccharum Marsh.) decline in northeastern North America has been regarded as a major factor structuring hardwood forests by favouring American beech ( Fagus grandifolia Ehrh.) in the understory of maple-dominated stands. To determine whether soil fertility differences associated with sugar maple decline may have promoted the expansion of American beech, we explored the relationships between the soil base status and the sapling and tree strata density and composition, using data from 426 permanent sample plots distributed throughout Quebec. Our results indicate that American beech is currently expanding in the sugar maple range of Quebec. The abundance and proportion of American beech in the sapling stratum are mainly associated with the proportion of American beech in the tree stratum, the relative basal area of dead sugar maple trees, and the base status of soils. In accordance with the many studies reporting on the high sensitivity of sugar maple to the acid–base status of soils and the decline of the sugar maple population, this study supports the hypothesis that soil base cation depletion, caused in part by atmospheric acid deposition, is among the main factors involved in the present-day expansion of American beech over a large area in Quebec.

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