scholarly journals Analysing effects of thinning on stand volume growth in relation to site conditions: A case study for even-aged Sitka spruce (Picea sitchensis (Bong.) Carr.)

2009 ◽  
Vol 82 (1) ◽  
pp. 87-104 ◽  
Author(s):  
J.P. Skovsgaard
Keyword(s):  
Volume Growth ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Site Conditions ◽  
Stand Volume

scholarly journals Growth, Carbon Storage, and Optimal Rotation in Poplar Plantations: A Case Study on Clone and Planting Spacing Effects

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 842
Author(s):  
Yanhua Zhang ◽  
Ye Tian ◽  
Sihui Ding ◽  
Yi Lv ◽  
Wagle Samjhana ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Biomass Production ◽  
Volume Growth ◽  
Middle Latitude ◽  
Stand Volume ◽  
Single Tree ◽  
Spacing Effects ◽  
Optimal Rotation ◽  
Poplar Plantations

Poplar, as the most widely cultivated fast-growing tree species in the middle latitude plain, provides important wood resources and plays an important role in mitigating climate change. In order to understand the response of growth, biomass production, carbon storage to poplar clones, planting spacings, and their interaction, a field trial was established in 2007. In 2018, we destructively harvested 24 sample trees for biomass measurements and stem analyses. Biomass production and carbon storage for the single tree of three clones enhanced as planting spacing increasing at the age of 13, but both the biomass production and carbon storage of clones NL-895 and NL-95 were higher than the clone NL-797 at the spacings of 6 × 6 m and 5 × 5 m. The average carbon concentration of the tested clones was in the order of stem > branches > leaves, and showed significant variation between different components (p < 0.05). Large spacing stimulated more biomass to be partitioned to the canopy. Based on the prediction values of tree volume growth by established Chapman–Richards models, the quantitative maturity ages of stand volume varied among the investigating plantations, ranging from 14 to 17 years old. Our results suggest that the selecting clones NL-895 and NL-95 with 6 × 6 m spacing would be recommended at similar sites for future poplar silviculture of larger diameter timber production, as well as for carbon sequestration.

scholarly journals Developing Growth Models of Stand Volume for Subtropical Forests in Karst Areas: A Case Study in the Guizhou Plateau

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Yuzhi Tang ◽  
Quanqin Shao ◽  
Tiezhu Shi ◽  
Guofeng Wu
Keyword(s):  
Growth Models ◽  
Volume Growth ◽  
Site Quality ◽  
Rocky Desertification ◽  
Stand Volume ◽  
Subtropical Forests ◽  
Karst Areas ◽  
Growth Equations ◽  
Global Carbon ◽  
Guizhou Plateau

Forest stand volume is one of the key forest structural attributes in estimating and forecasting ecosystem productivity and carbon stock. However, studies on growth modeling and environmental influences on stand volume are still rare to date, especially in subtropical forests in karst areas, which are characterized by a complex species composition and are important in the global carbon budget. In this paper, we developed growth models of stand volume for all the dominant tree species (groups) (DTSG) in a subtropical karst area, the Guizhou Plateau based on an investigation of the effects of various environmental factors on stand volume. The Richards growth function, space-for-time substitution and zonal-hierarchical modeling method were applied in the model fitting, and multiple indices were used in the model evaluation. The results showed that the climatic factors of annual temperature and precipitation, as well as the site factors of stand origin, elevation, slope gradient, topsoil thickness, site quality degree, rocky desertification type and rocky desertification degree, have significant influences on stand volume, and the topsoil thickness and site quality degree have the strongest positive effect. A total of 959 growth equations of stand volume were fitted with a five-level stand classifier (DTSG–climatic zone–site quality degree–stand origin–rocky desertification type). All the growth equations were qualified, because all passed the TRE test (≤30%), and the majority of the R2 ≥ 0.50, above 70% of the RMSE were between 5.0 and 20.0, and above 80% of the P ≥ 75%. These findings provide updated knowledge about the environmental effect on the stand volume growth of subtropical forests in karst areas, and the developed stand volume growth models are convenient for forest management and planning, further contributing to the study of forest carbon storage assessments and global carbon cycling.

Assessment of site conditions for disposal of low- and intermediate-level radioactive wastes: A case study in southern China

2012 ◽  
Vol 414 ◽  
pp. 624-631 ◽  
Author(s):  
Shuping Yi ◽  
Haiyi Ma ◽  
Chunmiao Zheng ◽  
Xiaobin Zhu ◽  
Hua'an Wang ◽  
...  
Keyword(s):  
Southern China ◽  
Radioactive Wastes ◽  
Intermediate Level ◽  
Site Conditions

Predicting the longitudinal modulus of elasticity of Sitka spruce from cellulose orientation and abundance

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
J. Paul McLean ◽  
Robert Evans ◽  
John R. Moore
Keyword(s):  
Bulk Density ◽  
Modulus Of Elasticity ◽  
Microfibril Angle ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Model Parameters ◽  
Bending Tests ◽  
Wood Stiffness ◽  
Using Data ◽  
Longitudinal Modulus

Abstract Sitka spruce (Picea sitchensis) is the most widely planted commercial tree species in the United Kingdom and Ireland. Because of the increasing use of this species for construction, the ability to predict wood stiffness is becoming more important. In this paper, a number of models are developed using data on cellulose abundance and orientation obtained from the SilviScan-3 system to predict the longitudinal modulus of elasticity (MOE) of small defect-free specimens. Longitudinal MOE was obtained from both bending tests and a sonic resonance technique. Overall, stronger relationships were found between the various measures of cellulose abundance and orientation and the dynamic MOE obtained from the sonic resonance measurements, rather than with the static MOE obtained from bending tests. There was only a moderate relationship between wood bulk density and dynamic MOE (R2=0.423), but this relationship was improved when density was divided by microfibril angle (R2=0.760). The best model for predicting both static and dynamic MOE involved the product of bulk density and the coefficient of variation in the azimuthal intensity profile (R2=0.725 and 0.862, respectively). The model parameters obtained for Sitka spruce differed from those obtained in earlier studies on Pinus radiata and Eucalyptus delegatensis, indicating that the model might require recalibration before it can be applied to different species.

Heritability of height growth in 10-year-old Sitka spruce

1985 ◽  
Vol 27 (6) ◽  
pp. 729-734 ◽  
Author(s):  
Francis C. Yeh ◽  
Sven Rasmussen
Keyword(s):  
Sitka Spruce ◽  
Height Growth ◽  
Picea Sitchensis ◽  
Breeding Program ◽  
Progeny Test ◽  
Northwest Coast ◽  
Phenotypic Variance ◽  
Family Selection ◽  
Sources Of Variation

Ten-year height growth for Picea sitchensis (Bong.) Carr. was studied in a progeny test of 42 wind-pollinated families from seven stands on the northwest coast of Vancouver Island. Although stand and family-within-stand effects were significant sources of variation, 79% of the phenotypic variance in 10-year height was associated with differences among trees within family plots. Estimates of heritability ([Formula: see text], [Formula: see text], and [Formula: see text]) indicate that a combination of stand, family-within-stand, and progeny-within-family selection will be effective for a long-term breeding program to increase tree heights in Sitka spruce.Key words: Picea, heritability, quantitative.

Genetic relationships between wood quality traits and diameter growth of juvenile core wood in Sitka spruce

2013 ◽  
Vol 43 (1) ◽  
pp. 1-6 ◽  
Author(s):  
S.G. Kennedy ◽  
A.D. Cameron ◽  
S.J. Lee
Keyword(s):  
Growth Rate ◽  
Genetic Correlation ◽  
Modulus Of Elasticity ◽  
Genetic Relationships ◽  
Wood Quality ◽  
Wood Properties ◽  
Sitka Spruce ◽  
Acoustic Velocity ◽  
Picea Sitchensis ◽  
Good Growth

The trend towards shorter rotations in planted conifer stands has resulted in a reduction in the proportion of mature wood relative to juvenile core wood, raising concerns that the mechanical performance of sawn battens will be affected. The potential to improve the wood quality of the juvenile core of Sitka spruce (Picea sitchensis (Bong.) Carrière) without compromising growth rate was investigated. Rapid and inexpensive indirect methods of assessing wood properties on standing trees using a Pilodyn gun and acoustic velocity were compared with direct measurements made on wood samples cut from the juvenile core. Strong genetic correlations were observed between Pilodyn gun values and direct measures of density (–0.76) and between the square of acoustic velocity and modulus of elasticity (0.73). The genetic correlation between the square of acoustic velocity and microfibril angle was also strong (–0.84). These results suggest that indirect assessments of wood properties within juvenile core wood are sufficiently reliable for these techniques to be used in the Sitka spruce breeding programme. Although a strong negative genetic correlation between diameter at breast height and density was noted (–0.79), sufficient variation exists within the breeding population to select families with both good growth rate and high modulus of elasticity wood.

scholarly journals Defoliation and dieback of Sitka spruce in Reykjavík, Iceland

2021 ◽  
Vol 34 ◽  
pp. 15-28
Author(s):  
Juliane Kuckuk ◽  
Sibren van Manen ◽  
Ólafur Eggertsson ◽  
Edda Sigurdís Oddsdóttir ◽  
Jan Esper
Keyword(s):  
Heavy Traffic ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Urban Trees ◽  
Tree Ring Data ◽  
Winter Temperatures ◽  
Elatobium Abietinum ◽  
One Year ◽  
Spruce Needles ◽  
Aphid Populations

The green spruce aphid Elatobium abietinum is an important defoliating pest of Sitka spruce (Picea sitchensis) in Iceland. A comparison of two urban Sitka stands in Reykjavík, from 2013-2017, reveals a distinct defoliation difference between trees located near a main road (94% defoliated) and several hundred meters away from heavy traffic (47%). Chemical analyses of the spruce needles demonstrate substantially higher nitrogen ratios in trees near traffic. Furthermore, the recently warming winter temperatures promoted larger overwintering aphid populations since 2003, as well as a shift of mass outbreaks from autumn to spring, accompanied by distinct growth suppressions one year after an aphid population spike in the post-2003 tree-ring data. The results of this study indicate that the mechanisms triggering Sitka spruce dieback in Reykjavík include a combination of increasing winter temperatures, more frequent and severe green spruce aphid outbreaks, as well as elevated N values in the needles of urban trees.

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