• Title/Summary/Keyword: Stand density

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Development of a Stand Density Management Diagram for Teak Forests in Southern India

  • Tewari, Vindhya Prasad;Alvarez-Gonz, Juan Gabriel
    • Journal of Forest and Environmental Science
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    • v.30 no.3
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    • pp.259-266
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    • 2014
  • Stand Density Diagrams (SDD) are average stand-level models which graphically illustrate the relationship between yield, density and mortality throughout the various stages of forest development. These are useful tools for designing, displaying and evaluating alternative density regimes in even-aged forest ecosystems to achieve a desired future condition. This contribution presents an example of a SDD that has been constructed for teak forests of Karnataka in southern India. The relationship between stand density, dominant height, quadratic mean diameter, relative spacing and stand volume is represented in one graph. The relative spacing index was used to characterize the population density. Two equations were fitted simultaneously to the data collected from 27 sample plots measured annually for three years: one relates quadratic mean diameter with stand density and dominant height while the other relates total stand volume with quadratic mean diameter, stand density and dominant height.

Optimum Stand Density Control Considering Stability in Larix kaempferi Forests (임분 안정성을 고려한 일본잎갈나무 임분밀도 관리의 적정 수준)

  • Park, Joon Hyung;Chung, Sang Hoon;Kim, Sun Hee;Lee, Sang Tae
    • Journal of Korean Society of Forest Science
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    • v.109 no.2
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    • pp.202-210
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    • 2020
  • This study investigated the optimal levels of stand density control considering the stability of Larix kaempferi stands. A stand density management diagram was developed from 259 sample plots. Based on these data, we determined an optimal level of the stand density control by identifying the relationship between the relative yield index (Ry) and height-to-diameter ratio. The estimated r-square (R2) of the stand density management diagram is 0.600. The analysis of the relationship between Ry and the slender tree incidence showed that when the stand density exceeded a certain threshold and the ratio of slender trees rapidly increased. The critical value of Ry was 0.63. The results of this study are expected to contribute to the establishment of stand management strategies that can reduce damage from natural causes, such as wind and snow, and to develop stand practice systems for the improved productivity of commercial forests.

The Effect of Birds in the Families Ardeidae and Corvidae on Stand Structure in Bamboo Groves

  • Seo, Myoung-Won;Woo, Hyo-Jin;Lee, Gil-Seong;Choo, Yeon-Sik;Lee, Ki-Sup;Choi, Kee-Ryong;Park, Yong-Mok
    • Journal of Ecology and Environment
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    • v.31 no.4
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    • pp.333-339
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    • 2008
  • We investigated death rates, growth rates and recruitment of culms in two neighboring bamboo (Phyllostachys bamboosoides) stands nested in by two different bird species to analyze stand structure and to design conservation strategies. A third bamboo grove not used by birds, the Taewha stand, was included as a control stand. The bamboo stand occupied by birds in the family Ardeidae (the Ardeidae stand) had an approximately 1.5 times higher culm density than the stand occupied by birds in the family Corvidae (the Corvidae stand). The crude death rate and the number of newly emerged shoots were also higher in the Ardeidae stand than the Corvidae stand. The death rate for bamboo in the Ardeidae stand was not dependent on diameter at breast height (DBH) and was almost 40% for culms of all sizes, whereas most dead culms in the Corvidae stand were < 4 cm DBH. Consequently, we conclude that in the Ardeidae stand, density-independent causes of death are operating, while density-dependent factor are more important in the Corvidae site. The results of soil analysis in these stands suggest that the density-independent death pattern observed in the Ardeidae stand may be due to soil acidification resulting from wastes produced by the birds during breeding. On the other hand, the culm distribution and death patterns in the Corvidae stand suggest that the stand characteristics were not affected by the nesting birds. These results suggest that different conservation strategies must be applied to conserve bamboo groves used by ardeids and corvids for nesting.

Investigating the Effect of Planting Density on Parameter Estimation of Stand Growth Models (식재(植栽) 밀도(密度)가 임분생장(林分生長)모델 모수(母數) 추정(推定)에 미치는 효과(效果)에 관(關)한 연구(硏究))

  • Li, Fengri;Kwon, Soonduk;Chung, Joosang
    • Journal of Korean Society of Forest Science
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    • v.88 no.4
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    • pp.446-453
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    • 1999
  • In this study, the effects of stand planting density on parameters of stand height and basal area growth models were investigated. We used the Korf equation as the base model in estimating the parameters of the growth models for cryptomeria plantation forest stands. Then, in order to investigate the effects of the change in plantation density on the parameter estimates, the "extra sums of square" principle, which provided a reasonable statistical procedure for a performance test, was used. The results of the test coincide with the understandings that stand height growth is not affected significantly by the planting density and the growth curves of stand basal area approaches a common asymptote regardless of the stand density for a given site. However, the shapes of the basal area growth curves were affected significantly by the planting density. Based on the results of the test, we developed a basal area growth model to account for the effects of initial planting density in cryptomeria plantation forest stands.

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The Comparison of Tree Growth by the Residual Stand Density in Artificial Coniferous Forests (침염수 조림지에서의 잔존임분밀도에 따른 임목생장 비교에 관한 연구)

  • 강성기;김완수;이원섭;김지홍
    • Journal of Korea Foresty Energy
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    • v.20 no.2
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    • pp.46-57
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    • 2001
  • This study was conducted to provide tending operation information for the effective management in unmanaged artificial forests of Pinus densiflora for. erecta, Pinus rigida, and larix leptolepis, based on the study of the comparison of tree growth pattern by residual stand density after thinning practices. Followings are summarized results of this study. 1. The diameter growth of residual trees was increased as residual stand density decreased by thinning practices in the stands of Pinus densiflora for. erecta, and Pinus rigida, and subcompartment (Ga) and (Na) of Larix leptolepis. The statistical analysis noted that the tree growth was significantly different by the residual stand density. 2. The height growth did not show corresponding results by stand density treatment pattern, which indicated that the height growth was not directly influenced by residual stand density, but by site quality of the stand. 3. The diameter increment for the last six years was proportionately increased in larger diameter classes and less dense stands.

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Allometric Equations and Biomass Expansion Factors by Stand Density in Cryptomeria japonica Plantations (삼나무 조림지의 임분밀도에 따른 상대생장식과 현존량 확장계수)

  • Gwon, Jung-Hwa;Seo, Huiyeong;Lee, Kwang-Soo;You, Byung-Oh;Park, Yong-Bae;Jeong, Jaeyeob;Kim, Choonsig
    • Journal of Korean Society of Forest Science
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    • v.103 no.2
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    • pp.175-181
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    • 2014
  • This study was conducted to evaluate stand density-specific and generalized allometric equations, and biomass expansion factors (BEFs) for two stand densities (high density of 47-year-old: $667tree{\cdot}ha^{-1}$; low density of 49-year-old: $267tree{\cdot}ha^{-1}$) of Cryptomeria japonica plantations in Namhae-gun, located in the southern Korea. Biomass in each tree component, i.e. foliage, branch, and stem, was quantified by destructive tree harvesting. Allometric regression equations of each tree component were significant (P<0.05) with diameter at breast height (DBH) accounting for 80-96% of the variation except for branch biomass in high density or foliage and cone biomass in low density. Generalized allometric equations can be used to estimate the biomass of C. japonica plantations because the slopes of allometric equations were not significantly different by the stand density. The biomass expansion factors (BEFs) were significantly lower in the high stand density (1.33) than in the low stand density (1.50). The results indicate that BEFs were affected by different stand density, while allometric equations were little related to the stand density.

Biomass Productivity and its Vertical Allocation of Natural Pinus densiflora Forests by Stand Density (백두산 동북부지역 소나무 천연림에서 밀도에 따른 임분의 Biomass 생산성 및 수직 배분)

  • ;Xianyu Meng
    • Journal of Korea Foresty Energy
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    • v.18 no.2
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    • pp.92-99
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    • 1999
  • This study was carried out to understand the primary production of biomass, vertical biomass distribution in the stand and the difference of biomass production for part of the trees by stand density for natural Pinus densiflora forest at Mt. Baekdoo located in northeastern China. The primary production of biomass was estimated by the layers of trees, shrubs, herbs for five density classes. For the biomass estimation of the Pinus densiflora trees in stern, stembark and the above-ground tree, the regression model of logW = a + blog(D$^2$H) + c(D$^2$H) was adapted for all of the density classes where W is dry weight, D$_1$ diameter at breast height, and H, tree height. For the biomass estimation in branch and needle, and the needle area, the regression model of logW=a+blogD+cD was adapted for all of the density classes. With increasing stand density the biomass of trees increased but that of shrubs and herbs decreased. Net primary production of biomass in parts of the tree also increased with increasing stand density. However the percentage of the needle biomass among the total biomass in the above-ground tree decreased with increasing stand density. Consequently, primary production rate of biomass in the above-ground tree increased. The primary production of biomass for each part of the trees in natural Pinus densiflora natural forests showed in descending order : stern, needle, branch, and stembark regardless of stand density.

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Stand Density Effects on Herbage Yield and Forage Quality of Alfalfa

  • Min, D.H.;King, J.R.;Kim, D.A.;Lee, H.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.7
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    • pp.929-934
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    • 2000
  • Optimum stand density of alfalfa (Medicago sativa L.) varies with locations and climates. Stand density is one of the factors that determines herbage yield, forage quality and persistence of alfalfa. As establishment costs increase, the question arises whether present population densities are optimum for obtaining maximum herbage yield and forage quality. The objectives of this study were: 1) to determine the optimum plant density for highest herbage yield and forage quality for the dehydrated alfalfa industry under Edmontons climatic conditions in Alberta, Canada; 2) to compare herbage yield and forage quality of the cultivars 'Algonquin' and 'Vernal' grown at a range of stand densities. Alfalfa seedlings of both cultivars were either transplanted at spacings of 6, 10, 15 and 25 cm or direct seeded at the 4.5 cm plant spacings, providing population densities of 494, 278, 100, 45 and $16plants/m^2$. The experimental design was a randomized complete block with a split-plot arrangement having three replicates; the main plots consisted of two alfalfa cultivars Algonquin and Vernal, and the sub-plots were the five population densities. The cultivar Vernal had significantly higher annual yield than did the cultivar Algonquin. There was no significant effect of plant density on herbage yield. There was no difference in crude protein (CP) between the two cultivars. At the first cut, there was a significant quadratic effect of plant density on CP content and the greatest CP occurred at the 100 plants/m2 density. Crude protein was not affected by plant density at the second cut. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) were not affected by plant density. The cultivar Algonquin usually had a lower ADF and NDF than cultivar Vernal. In conclusion, high population densities ($278plants/m^2$ or more) of alfalfa did not improve herbage yield and forage quality compared with low plant population densities ($100plants/m^2$ or less) of alfalfa.

Biomass and Nutrient Stocks of Tree Components by Stand Density in a Quercus glauca Plantation (종가시나무 조림지의 임분밀도에 따른 임목 바이오매스 및 양분축적량)

  • Choi, Bong-Jun;Baek, Gyeongwon;Jo, Chang-Gyu;Park, Seong-Wan;Yoo, Byung Oh;Jeong, Su-Young;Lee, Kwang Soo;Kim, Choonsig
    • Journal of Korean Society of Forest Science
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    • v.105 no.3
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    • pp.294-302
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    • 2016
  • This study was conducted to evaluate aboveground tree biomass and nutrient (C, N, P, K, Ca, and Mg) response of tree components by high (1,933 trees $ha^{-1}$) and low (1,200 tree $ha^{-1}$) stand densities in a 27-year-old Quercus glauca plantation. The study site was located in Goseong county, Gyeongsangnam-do, southern Korea. Total 12 trees (6 high and 6 low stand densities) were cut to develop allometric equations and to measure nutrient concentration of tree components. Stand density-specific allometric equations in the high and low stand densities were significant (P < 0.05) in tree components with diameter at breast height (DBH). Also, generalized allometric equations could be applied to estimate tree biomass regardless of the difference of stand density because of no significant effect on slope of stand density-specific allometric equations. Aboveground tree biomass estimated by the allometric equations was significantly higher in the high stand density (177 Mg $ha^{-1}$) than in the low stand density (114 Mg $ha^{-1}$). However, nutrient concentration of tree components was not significantly affected by the difference of stand density. Nutrient stocks in tree components were not significantly between the high stand density and the low stand density, except for the N and P stocks of stem wood. These results indicate that aboveground tree biomass could be significantly affected by stand density, but nutrient concentration among the tree components was not affected by the difference of stand density in a Quercus glauca plantation.

Prediction of Mortality and Yield for Chamaecyparis obtusa Using Stand Density Management Diagram (임분밀도관리도를 이용한 편백림의 고사량 및 수확량 예측)

  • Park, Joon Hyung;Yoo, Byung Oh;Lee, Kwang Soo;Park, Yong Bae;Kim, Hyung-Ho;Jung, Su Young
    • Journal of Korean Society of Forest Science
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    • v.107 no.2
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    • pp.174-183
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    • 2018
  • This study aims to make the stand density management diagram which is useful for establishing stand density management system in Chamaecyparis obtusa forest. By using 216 sample plots to estimate Yield-Density relationship ($R^2=0.743$), the stand density management diagram was modeled by the estimated parameters. As a result of this diagram, after planting 3,000 trees per hectare the mortality rate of this unthinned C. obtusa stands over 80 years was estimated to be equal to $12.0{\sim}18.1trees{\cdot}ha^{-1}{\cdot}year^{-1}$, and stand volume was $463.1{\sim}695.4m^3{\cdot}ha^{-1}$, and stand density was $1,555{\sim}2,038trees{\cdot}ha^{-1}$. Developed stand density management diagram for C. obtusa is effective to establish the management criteria and production objective. Therefore, this study allowed us to make the optimal forest working plan.