scholarly journals Modeling stand basal area growth of Cryptomeria japonica D. Don under different planting densities in Taiwan

2020 ◽  
Vol 25 (3) ◽  
pp. 174-182
Author(s):  
Tzeng Yih Lam ◽  
Biing T. Guan
1988 ◽  
Vol 18 (7) ◽  
pp. 851-858 ◽  
Author(s):  
B. M. Cregg ◽  
P. M. Dougherty ◽  
T. C. Hennessey

A 10-year-old stand of loblolly pine (Pinustaeda L.) in southeastern Oklahoma was thinned to three target basal-area levels: 5.8, 11.5, and 23 m2•ha−1 (control). Specific gravity, latewood percentage, date of transition from earlywood to latewood, growth, and climate variables were measured for 2 years after thinning. Variation in the measured wood properties was more influenced by climatic variation than by the thinning treatments. Diameter growth and per-tree basal-area growth were significantly greater on the thinned treatments both years after thinning. However, stand basal-area growth was greatest on the unthinned treatment. Basal-area growth rates were significantly related to stand basal area, tree size, soil water potential, and air temperature. Early in the summer, growth was positively related to mean daily temperature, while later in the summer, growth was negatively related to mean daily temperature, reflecting the influence of high-temperature stress on growth. A year with high summer rainfall (1984) resulted in wood with a higher percentage of latewood and higher specific gravity than wood produced in a year with low summer rainfall (1985). The date of latewood initiation was significantly related to tree size, soil moisture, and evaporative demand. The date of transition from earlywood to latewood occurred 10–14 days sooner on the unthinned plots in both years. However, annual ring latewood percentage and specific gravity were not significantly affected by thinning. Increased late-season growth rates compensated for the later transition date on the thinned treatments, resulting in no net change in ring latewood percentage due to thinning. The results indicate that individual tree basal-area growth can be increased by thinning without reducing wood density.


2007 ◽  
Vol 9 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Hong-gang Sun ◽  
Jian-guo Zhang ◽  
Ai-guo Duan ◽  
Cai-yun He

1991 ◽  
Vol 8 (3) ◽  
pp. 104-107 ◽  
Author(s):  
Jeffrey S. Ward

Abstract Thirty pairs of thinned and unthinned plots in roadside fuelwood areas, and 12 plots in each of 2 commercial cordwood thinnings were located in Connecticut oak sawtimber stands. Thinning during 1969-82 reduced stocking on plots an average of 30%. Subsequent stand basal area growth, cubic-foot growth, and board-foot growth were similar among all treatments. There was no decrease in stem quality nor increase in epicormic branching associated with thinning. Thinning mature oak sawtimber stands provides forest managers an opportunity to capture volume of declining trees while increasing growth on residual oak sawtimber. North. J. Appl. For. 8(3):104-107.


2007 ◽  
Vol 64 (6) ◽  
pp. 609-619 ◽  
Author(s):  
Fernando Castedo-Dorado ◽  
Ulises Diéguez-Aranda ◽  
Marcos Barrio-Anta ◽  
Juan Gabriel Álvarez-Gonzàlez

1988 ◽  
Vol 5 (3) ◽  
pp. 221-222
Author(s):  
Arlyn W. Perkey ◽  
Kenneth L. Carvell

1973 ◽  
Vol 3 (4) ◽  
pp. 495-500 ◽  
Author(s):  
James A. Moore ◽  
Carl A. Budelsky ◽  
Richard C. Schlesinger

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.


Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 409
Author(s):  
Gheorghe Marin ◽  
Vlad C. Strimbu ◽  
Ioan V. Abrudan ◽  
Bogdan M. Strimbu

In many countries, National Forest Inventory (NFI) data is used to assess the variability of forest growth across the country. The identification of areas with similar growths provides the foundation for development of regional models. The objective of the present study is to identify areas with similar diameter and basal area growth using increment cores acquired by the NFI for the three main Romanian species: Norway spruce (Picea abies L. Karst), European beech (Fagus sylvatica L.), and Sessile oak (Quercus petraea (Matt.) Liebl.). We used 6536 increment cores with ages less than 100 years, a total of 427,635 rings. The country was divided in 21 non-overlapping ecoregions based on geomorphology, soil, geology and spatial contiguousness. Mixed models and multivariate analyses were used to assess the differences in annual dimeter at breast height and basal area growth among ecoregions. Irrespective of the species, the mixed models analysis revealed significant differences in growth between the ecoregions. However, some ecoregions were similar in terms of growth and could be aggregated. Multivariate analysis reinforced the difference between ecoregions and showed no temporal grouping for spruce and beech. Sessile oak growth was separated not only by ecoregions, but also by time, with some ecoregions being more prone to draught. Our study showed that countries of median size, such as Romania, could exhibit significant spatial differences in forest growth. Therefore, countrywide growth models incorporate too much variability to be considered operationally feasible. Furthermore, it is difficult to justify the current growth and yield models as a legal binding planning tool.


2000 ◽  
Vol 24 (2) ◽  
pp. 112-120 ◽  
Author(s):  
Michael M. Huebschmann ◽  
Lawrence R. Gering ◽  
Thomas B. Lynch ◽  
Onesphore Bitoki ◽  
Paul A. Murphy

Abstract A system of equations modeling the growth and development of uneven-aged shortleaf pine (Pinus echinata Mill.) stands is described. The prediction system consists of two main components: (1) a distance-independent, individual-tree simulator containing equations that forecast ingrowth, basal-area growth, probability of survival, total and merchantable heights, and total and merchantable volumes and weights of shortleaf pine trees; and (2) stand-level equations that predict hardwood ingrowth, basal-area growth, and mortality. These equations were combined into a computer simulation program that forecasts future states of uneven-aged shortleaf pine stands. Based on comparisons of observed and predicted stand conditions in shortleaf pine permanent forest inventory plots and examination of the growth patterns of hypothetical stands, the simulator makes acceptable forecasts of stand attributes. South. J. Appl. For. 24(2):112-120.


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