Submit to Forests Review for Forests Propose a Special Issue

Journal Menu

Journal Browser

Tree Crown Dynamics and Morphology

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Forests (ISSN 1999-4907). This special issue belongs to the section "Forest Ecophysiology and Biology".

Deadline for manuscript submissions: closed (31 December 2019) | Viewed by 19946

Share This Special Issue

Special Issue Editor

Prof. Dr. Thomas J. Dean

E-Mail Website
Guest Editor

School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA
Interests: crown dynamics; stem mechanics; population biology; competition; size–density relationships
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Crown morphology determines the internal arrangement of foliage within the bulk canopy, which affects carbon assimilation and ultimately forest production. Trees display a wide variety of crown morphologies, which create a wide range of effects on the structure and functioning of forests, especially in mixed and multi-aged stands. Basic crown structure is modified by light attenuation and by intercrown abrasions. Foliage is ephemeral, dying from old age and shade, replacing itself at the top and sides of the crown. Various growth models are based on the functional relationships between foliage and the stem and branches. Growth occurs because of the redistribution of foliage and the need to add sapwood to accommodate new foliage and cross-sectional area to accommodate new mechanical forces. Better understanding the functional relationships between crown morphology and crown dynamics will improve not only the basic knowledge of tree function and structure, but also the practical application of density management and growth–growing stock relations in pure and mixed stands and in single- and multi-aged stands. For this Special Issue, I invite papers that contribute to our understanding of canopy dynamics and the functional relationships between foliage and stem growth and canopy structure, both physiological and mechanical.

Prof. Dr. Thomas J. Dean
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Forests is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

leaf area
growth
pipe model
biomechanics
stand density
composition
age structure

Published Papers (6 papers)

Download All Papers

Research

17 pages, 2429 KiB

Open AccessArticle

Modelling the Crown Profile of Western Hemlock (Tsuga heterophylla) with a Combination of Component and Aggregate Measures of Crown Size

by Ian R. Cameron, Roberta Parish, James W. Goudie and Catherine A. Bealle Statland

Forests 2020, 11(3), 281; https://0-doi-org.brum.beds.ac.uk/10.3390/f11030281 - 28 Feb 2020

Cited by 3 | Viewed by 1995

Abstract

Research Highlights: We present statistical methods for using crown measurement data from multiple destructive sampling studies to model crown profiles in the Tree and Stand Simulator (TASS) and evaluate it using component (branch-level) and aggregate (tree-level) predictions. Combining data collected under different sampling protocols offered unique challenges. Background and Objectives: The approach to modelling crown profiles was based on Mitchell’s monograph on Douglas-fir growth and simulated dynamics. The functional form defines the potential crown size and shape and governs the rate of crown expansion. With the availability of additional data, we are able to update these functions as part of ongoing TASS development and demonstrate the formulation and fitting of new crown profile equations for stand-grown western hemlock (Tsuga heterophylla (Raf.) Sarg. Materials and Methods: Detailed measurements on 1616 branches from 153 trees were collected for TASS development over a 40-year period. Data were collected under two different sampling protocols and the methods were designed to allow the use of data from both protocols. Data collected on all branches were then introduced through the application of the ratio of length of each of the selected branches to the largest branch in the internode (RL). Results: A mixed-effects model with two random effects, which accounted for tree-level variation, provided the best fit. From that, a model that expressed one parameter as a function of another with one random effect was developed to complement the structure of the Tree and Stand Simulator (TASS). The models generally over-estimated crown size when compared to the projected crown area recorded from field measurements, and a scalar adjustment factor of 0.89 was applied that minimised mean-squared error of the differences. The new model is fit from direct measures of crown radius and predicts narrower crown shapes than previous functions used in TASS. Full article

(This article belongs to the Special Issue Tree Crown Dynamics and Morphology)

► Show Figures

Figure 1

16 pages, 3345 KiB

Open AccessArticle

Leaf and Crown Optical Properties of Five Early-, Mid- and Late-Successional Temperate Tree Species and Their Relation to Sapling Light Demand

by Marc Hagemeier and Christoph Leuschner

Forests 2019, 10(10), 925; https://0-doi-org.brum.beds.ac.uk/10.3390/f10100925 - 21 Oct 2019

Cited by 9 | Viewed by 2697

Abstract

The optical properties of leaves and canopies determine the availability of radiation for photosynthesis and the penetration of light through tree canopies. How leaf absorptance, reflectance and transmittance and radiation transmission through tree canopies change with forest succession is not well understood. We measured the leaf optical properties in the photosynthetically active radiation (PAR) range of five Central European early-, mid- and late-successional temperate broadleaf tree species and studied the minimum light demand of the lowermost shade leaves and of the species’ offspring. Leaf absorptance in the 350–720 nm range varied between c. 70% and 77% in the crown of all five species with only a minor variation from the sun to the shade crown and between species. However, specific absorptance (absorptance normalized by mass per leaf area) increased about threefold from sun to shade leaves with decreasing leaf mass area (LMA) in the late-successional species (Carpinus betulus L., Tilia cordata Mill., Fagus sylvatica L.), while it was generally lower in the early- to mid-successional species (Betula pendula Roth, Quercus petraea (Matt.)Liebl.), where it changed only a little from sun to shade crown. Due to a significant increase in leaf area index, canopy PAR transmittance to the forest floor decreased from early- to late-successional species from ~15% to 1%–3% of incident PAR, linked to a decrease in the minimum light demand of the lowermost shade leaves (from ~20 to 1%–2%) and of the species’ saplings (from ~20 to 3%–4%). The median light intensity on the forest floor under a closed canopy was in all species lower than the saplings’ minimum light demand. We conclude that the optical properties of the sun leaves are very similar among early-, mid- and late-successional tree species, while the shade leaves of these groups differ not only morphologically, but also in terms of the resource investment needed to achieve high PAR absorptance. Full article

(This article belongs to the Special Issue Tree Crown Dynamics and Morphology)

► Show Figures

Figure 1

13 pages, 2255 KiB

Open AccessArticle

Maximum Branch Diameter in Black Spruce Following Partial Cutting and Clearcutting

by Audrey Lemay, Émilie Pamerleau-Couture and Cornelia Krause

Forests 2019, 10(10), 913; https://0-doi-org.brum.beds.ac.uk/10.3390/f10100913 - 17 Oct 2019

Cited by 4 | Viewed by 2104

Abstract

Branch diameter is an important aspect of wood quality, as lumber grades can be determined based on the maximum diameter of branches. Crown and branch development can be influenced by the environment surrounding the trees, and silvicultural interventions, which reduce stand density and increase the growth of residual trees, could therefore alter branch properties. We evaluated maximum branch diameter within the crown of residual black spruce (Picea mariana (Mill.) B.S.P.) subjected to five types of silvicultural intervention—three partial-cutting and two clearcutting treatments—as well as trees within unmanaged control stands. We sampled a total of 41 stands and 223 trees. We collected 15 whorls from the live crown of each tree and measured the diameters of the largest branches. For all treatments, we observed a curvilinear relationship between maximum branch diameter and distance from the stem apex, and the largest branches were located in the lower third of the live crown. DBH before treatment and treatment were the variables that best explained maximum branch diameter in the lowest portion of the crown. A generalized additive model showed that maximum branch diameter in black spruce following silvicultural treatment will not differ significantly from trees of unmanaged control stands. Therefore, the studied partial cutting and clearcutting treatments do not have adverse effects on maximum branch diameter when compared to unmanaged control stands. However, DBH prior to treatment must be considered before any treatment is applied in forest management operations if maximum branch diameter is an important wood quality factor at the time of the final harvest of the stands. Full article

(This article belongs to the Special Issue Tree Crown Dynamics and Morphology)

► Show Figures

Figure 1

17 pages, 1628 KiB

Open AccessArticle

Phenotypic Correlations among Growth and Selected Wood Properties in White Spruce (Picea glauca (Moench) Voss) ^†

by Cyriac S. Mvolo, Ahmed Koubaa, Jean Beaulieu, Alain Cloutier, Maurice Defo and Martin-Claude Yemele

Forests 2019, 10(7), 589; https://0-doi-org.brum.beds.ac.uk/10.3390/f10070589 - 16 Jul 2019

Cited by 11 | Viewed by 2964

Abstract

We examined phenotypic relationships among radial growth-related, physical (i.e., related to wood density), and anatomical (i.e., related to tracheid dimensions) wood properties in white spruce (Picea glauca (Moench) Voss), in order to determine the strength and significance of their correlations. Additionally, principal component analysis (PCA) was used to establish if all of the properties must be measured and to determine the key properties that can be used as proxies for the other variables. Radial growth-related and physical properties were measured with an X-ray densitometer, while anatomical properties were measured with a Fiber Quality Analyzer. Fifteen wood properties (tracheid length (TL) and diameter (TD), earlywood tracheid length (ETL) and diameter (ETD), latewood tracheid length (LTL) and diameter (LTD), ring width (RW), ring area (RA), earlywood width (EWW), latewood width (LWW), latewood proportion (LWP), ring density (RD), intra-ring density variation, earlywood density (EWD), and latewood density (LWD)) were assessed. Relationships were evaluated at intra-ring and inter-ring levels in the juvenile wood (JW) and mature wood (MW) zones. Except for a few cases when mature tracheid diameter (TD) was involved, all intra-ring anatomical properties were highly and significantly correlated. Radial growth properties were correlated, with stronger relationships in MW compared to JW. Physical properties were often positively and significantly correlated in both JW and MW. A higher earlywood density coupled with a lower latewood density favored wood uniformity, i.e., the homogeneity of ring density within a growth ring. Managing plantations to suppress trees growth during JW formation, and enhancing radial growth when MW formation starts will favor overall wood quality. In order, RW-EWW-RA, TL-ETL-LTL, and RD-EWD-LWP are the three clusters that appeared in the three wood zones, the whole pith-to-bark radial section, the juvenile wood zone, and the mature wood zone. Full article

(This article belongs to the Special Issue Tree Crown Dynamics and Morphology)

► Show Figures

Figure 1

18 pages, 4000 KiB

Open AccessArticle

Intra-Ring Variations and Interrelationships for Selected Wood Anatomical and Physical Properties of Thuja Occidentalis L.

by Besma Bouslimi, Ahmed Koubaa and Yves Bergeron

Forests 2019, 10(4), 339; https://0-doi-org.brum.beds.ac.uk/10.3390/f10040339 - 16 Apr 2019

Cited by 8 | Viewed by 3796

Abstract

Intra-ring variation in wood density and tracheid anatomical properties and wood property interrelationships were investigated in Thuja occidentalis L. Samples were taken from three stands in Abitibi–Témiscamingue, Quebec, Canada. The structure of T. occidentalis wood is simple, homogeneous and uniform, which is desirable for wooden structures that require wood uniformity. From early- to latewood, cell and lumen diameter decreased, while cell wall thickness increased. These changes led to an increase of the cell wall proportion. Wood ring density and width interrelationships were weaker in mature wood compared to juvenile wood. Earlywood density is the more important in determining mature wood density than latewood density and proportion. Earlywood density explains 92% and 89% of the variation in juvenile and mature wood density, respectively. The negative relationship between ring density and width, although significant, was low and tends to weaken with increasing tree age, thus providing the opportunity for silvicultural practices to improve both growth and wood density. Ring width was positively and strongly correlated to early- and latewood width, but negatively correlated to tracheid length and latewood proportion. Accordingly, increases in ring width produce smaller tracheids and wider earlywood without a corresponding increase in latewood. Practical implications of the results are discussed. Full article

(This article belongs to the Special Issue Tree Crown Dynamics and Morphology)

► Show Figures

Figure 1

16 pages, 2947 KiB

Open AccessArticle

Functional Crown Architecture of Five Temperate Broadleaf Tree Species: Vertical Gradients in Leaf Morphology, Leaf Angle, and Leaf Area Density

by Marc Hagemeier and Christoph Leuschner

Forests 2019, 10(3), 265; https://0-doi-org.brum.beds.ac.uk/10.3390/f10030265 - 15 Mar 2019

Cited by 26 | Viewed by 5647

Abstract

The morphology, inclination, and spatial distribution of leaves in different parts of tree crowns are important determinants of the radiation, momentum, and gas exchange between the canopy and the atmosphere. However, it is not well known how these foliage-related traits vary among species differing in successional status. We measured leaf size, leaf mass area (LMA), leaf inclination (angle to the horizontal), leaf area density (LAD), total leaf area (leaf area index, LAI), and leaf area distribution across the crown in adult trees of five common, early to late-successional tree species (Betula pendula Roth, Quercus petraea (Matt.) Liebl., Carpinus betulus L., Tilia cordata Mill., and Fagus sylvatica L.) using different canopy access techniques and the harvest of foliated trees (29 trees in total). Leaf size increased continuously with crown depth in B. pendula and T. cordata but peaked at mid-crown in Q. petraea, C. betulus, and F. sylvatica to decrease toward the shade crown. By contrast, LMA and leaf angle decreased continuously with crown depth in all species, but the pattern of vertical change varied. The mid/late- and late-successional species had higher LAI, lower shade-leaf LMA, lower leaf angles (shade and sun crown), and higher LAD in the uppermost sun crown in comparison to early successional B. pendula. We assume that the most peripheral sun leaf layer is partly acting as a shield against excess radiation, with foliage properties depending on the structure of the shade crown. We conclude that the vertical change in leaf morphology, inclination, and spatial distribution in tree crowns is highly species specific, with partial dependence on the species’ position in succession. Full article

(This article belongs to the Special Issue Tree Crown Dynamics and Morphology)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Tree Crown Dynamics and Morphology

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (6 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI