Aboveground and belowground interactions in mixed plantations of Eucalyptus globulus and Acacia mearnsii

2000 ◽  
Vol 30 (12) ◽  
pp. 1886-1894 ◽  
Author(s):  
J Bauhus ◽  
P K Khanna ◽  
N Menden
Keyword(s):  
Eucalyptus Globulus ◽  
Root Architecture ◽  
Fine Root ◽  
Tree Height ◽  
Stem Volume ◽  
Niche Separation ◽  
N Fixation ◽  
Acacia Mearnsii ◽  
N Nutrition ◽  
Mixed Plantations

This study investigated whether increased productivity in mixed plantations of Eucalyptus globulus Labill. and Acacia mearnsii de Wild when compared with monocultures could be explained by niche separation of the fine-root systems. For this purpose fine-root architecture, nutrient concentration, and fine-root distribution were examined in two horizons (0-15 and 15-30 cm) of mixed and pure stands. Investigations were carried out in 6.5-year-old plantations consisting of 100% eucalypts, 75% eucalypts + 25% acacia, 50% eucalypts + 50% acacia, 25% eucalypts + 75% acacia, and 100% acacia. Aboveground the two species interacted synergistically. Stem volume and tree height was highest in the 50:50 mixtures. For acacias, intraspecific competition was stronger than interspecific competition with eucalypts. Fine-root biomass and length density were similar for all species combinations, and there was no synergistic effect. The vertical distribution of fine roots and fine-root architecture were similar for acacias and eucalypts. This indicated that soil exploitation strategies may be similar, which can result in strong competition for soil resources. Fine-root nitrogen concentrations of eucalypts were highest in the 50:50 mixture. Improved productivity of mixtures appears to be a result of both canopy stratification and improved N nutrition of eucalypts through N fixation by acacias.

Aboveground interactions and productivity in mixed-species plantations of Acacia mearnsii and Eucalyptus globulus

2004 ◽  
Vol 34 (3) ◽  
pp. 686-694 ◽  
Author(s):  
Jürgen Bauhus ◽  
Aaron P van Winden ◽  
Adrienne B Nicotra
Keyword(s):  
Eucalyptus Globulus ◽  
Net Photosynthesis ◽  
Stem Volume ◽  
Niche Separation ◽  
Mixed Species ◽  
Acacia Mearnsii ◽  
Replacement Series ◽  
Crown Volume ◽  
Lower Light ◽  
Productivity Gains

This study compared productivity in mixed-species plantations of Eucalyptus globulus ssp. pseudoglobulus (Naudin ex Maiden) Kirkpatr. and Acacia mearnsii de Wild with pure stands of each species and investigated how this might be explained by canopy stratification between species and changes in leaf characteristics of eucalypts. Investigations were carried out at a trial using the replacement series design, which consisted of the following combinations: 100% eucalypts (100%E), 75% eucalypts + 25% acacia (75%E:25%A), 50% eucalypts + 50% acacia (50%E:50%A), 25% eucalypts + 75% acacia (25%E:75%A), and 100% acacia (100%A). At 9.5 years, stem volume and biomass were highest in 50%E:50%A treatments. Canopy stratification occurred in all mixtures, with acacias in the lower and eucalypts in the upper canopy stratum. This and the increasing canopy light interception with increasing proportion of acacia in the mixture indicated that A. mearnsii is substantially more shade tolerant than E. globulus. Midcanopy foliage of E. globulus in the 50%E:50%A mixture had higher foliage nitrogen (N) but lower phosphorus (P) concentrations and lower light-saturated net photosynthesis rates (Amax) than those in the 100%E treatment. In addition, similar relationships between eucalypt crown volume and stem biomass across treatments indicated that eucalypt crowns were not more efficient in mixture. Our study indicates that the productivity gains in these mixtures may be partially attributable to aboveground niche separation between species.

scholarly journals Estimation of Genetic Parameters and Wood Yield Selection Index in a Clonal Trial of Korean Pine (Pinus koraiensis) in Northeastern China

2021 ◽  
Vol 13 (8) ◽  
pp. 4167
Author(s):  
David Kombi Kaviriri ◽  
Huan-Zhen Liu ◽  
Xi-Yang Zhao
Keyword(s):  
Selection Index ◽  
Tree Height ◽  
Stem Volume ◽  
Korean Pine ◽  
Branch Number ◽  
Basal Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Stem Straightness ◽  
Clonal Trial

In order to determine suitable traits for selecting high-wood-yield Korean pine materials, eleven morphological characteristics (tree height, basal diameter, diameter at breast height, diameter at 3 meter height, stem straightness degree, crown breadth, crown height, branch angle, branch number per node, bark thickness, and stem volume) were investigated in a 38-year-old Korean pine clonal trial at Naozhi orchard. A statistical approach combining variance and regression analysis was used to extract appropriate traits for selecting elite clones. Results of variance analysis showed significant difference in variance sources in most of the traits, except for the stem straightness degree, which had a p-value of 0.94. Moderate to high coefficients of variation and clonal repeatability ranged from 10.73% to 35.45% and from 0.06% to 0.78%, respectively. Strong significant correlations on the phenotypic and genotypic levels were observed between the straightness traits and tree volume, but crown breadth was weakly correlated to the volume. Four principal components retaining up to 80% of the total variation were extracted, and stem volume, basal diameter, diameter at breast height, diameter at 3 meter height, tree height, and crown height displayed high correlation to these components (r ranged from 0.76 to 0.98). Based on the Type III sum of squares, tree height, diameter at breast height, and branch number showed significant information to explain the clonal variability based on stem volume. Using the extracted characteristics as the selection index, six clones (PK105, PK59, PK104, PK36, PK28, and K101) displayed the highest Qi values, with a selection rate of 5% corresponding to the genetic gain of 42.96% in stem volume. This study provides beneficial information for the selection of multiple traits for genetically improved genotypes of Korean pine.

WITHIN–TREE VARIATION IN PHLOEM CELL DIMENSIONS AND PROPORTIONS IN EUCALYPTUS GLOBULUS

IAWA Journal ◽  
2000 ◽  
Vol 21 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Teresa Quilhó ◽  
Helena Pereira ◽  
Hans Georg Richter
Keyword(s):  
Wall Thickness ◽  
Eucalyptus Globulus ◽  
Tree Height ◽  
Sieve Tube ◽  
Bark Thickness ◽  
Cell Type ◽  
Fibre Width ◽  
Axial Variation ◽  
Sieve Tubes ◽  
Old Trees

The axial variation of bark thickness and quantitative anatomical features of Eucalyptus globulus bark were analysed for one site based on individual measurements of ten 15-year-old trees at six height levels (DBH, 5%, 15%, 35%, 55% and 75% of total tree height). The parameters studied were: length, tangential diameter and percentage of sieve tubes; length, width, cell wall thickness and percentage of fibres; height and percentage of rays; percentage of sclereids in the secondary phloem. Bark thickness decreases from base to top of the tree. Fibre width and wall thickness decrease from base upwards. No distinct axial patterns of variation were observed for the other biometric variables studied. Parenchyma is the main cell type of the bark (50%) followed by fibres (27.9%), rays (12.1%), sieve tubes (2.7%), and sclereids (7.3%). The cell type proportions vary significantly within the tree, i.e., parenchyma, ray and sclereid proportions decrease, fibre and sieve tube proportions increase towards the top of the tree.

Estimating Pinus palustris tree diameter and stem volume from tree height, crown area and stand-level parameters

2014 ◽  
Vol 25 (1) ◽  
pp. 43-52 ◽  
Author(s):  
C. A. Gonzalez-Benecke ◽  
Salvador A. Gezan ◽  
Lisa J. Samuelson ◽  
Wendell P. Cropper ◽  
Daniel J. Leduc ◽  
...  
Keyword(s):  
Pinus Palustris ◽  
Tree Height ◽  
Stem Volume ◽  
Crown Area ◽  
Tree Diameter

scholarly journals A predictive nondestructive model for the covariation of tree height, diameter and stem volume scaling relationships

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhongrui Zhang ◽  
Quanlin Zhong ◽  
Karl J. Niklas ◽  
Liang Cai ◽  
Yusheng Yang ◽  
...  
Keyword(s):  
Tree Height ◽  
Stem Volume ◽  
Scaling Relationships

Fine root architecture, morphology, and biomass of different branch orders of two Chinese temperate tree species

2006 ◽  
Vol 288 (1-2) ◽  
pp. 155-171 ◽  
Author(s):  
Zhengquan Wang ◽  
Dali Guo ◽  
Xiangrong Wang ◽  
Jiacun Gu ◽  
Li Mei
Keyword(s):  
Tree Species ◽  
Root Architecture ◽  
Fine Root

Linking fine‐root architecture, vertical distribution and growth rate in temperate mountain shrubs

Oikos ◽  
2021 ◽  
Author(s):  
Yu Yang ◽  
M. Luke McCormack ◽  
Hui Hu ◽  
Weikai Bao ◽  
Fanglan Li
Keyword(s):  
Growth Rate ◽  
Vertical Distribution ◽  
Root Architecture ◽  
Fine Root

scholarly journals Container and Landscape Planting Depth and Root Ball Shaving Affects Magnolia grandiflora Root Architecture and Landscape Performance

2015 ◽  
Vol 41 (5) ◽  
Author(s):  
Edward Gilman ◽  
Maria Paz ◽  
Chris Harchick
Keyword(s):  
Root Architecture ◽  
Mechanical Stability ◽  
Tree Height ◽  
Root Pruning ◽  
Weather Event ◽  
Planting Depth ◽  
Trunk Diameter ◽  
Magnolia Grandiflora ◽  
Landscape Performance ◽  
Tree Height Growth

Plants were grown in a 2 × 2 factorial combination of planting depth in nursery containers and at a landscape installation to study effects on root architecture, growth, and mechanical stability of Magnolia grandiflora L. Planting depth into containers or landscape soil had no impact on bending stress to tilt trunks 40 months after landscape planting, and impacted neither trunk diameter nor tree height growth 68 months later. Trees planted 128 mm deep into 170 L containers had more circling roots at landscape planting and 68 months later than trees planted shallow in containers. Root pruning at landscape planting reduced the container imprint rating on the root system to one-third of that absent root pruning with only a 4 mm reduction in trunk diameter growth over 68 months. Improvement in root architecture from root pruning likely outweighs the rarely encountered downside of slightly less anchorage in an extreme weather event simulated by winching trunks. Trees planted 5 cm above grade were slightly—but significantly—less stable in landscape than trees planted deeper (10 cm below grade). Root pruning at planting to remove roots on root ball periphery appeared to improve root architecture while only slightly impacting growth and anchorage.

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