• Title/Summary/Keyword: dynamic stand growth model

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Dynamic Growth Model for Pinus densiflora Stands in Anmyun-Island (안면도(安眠島) 소나무 임분(林分)의 동적(動的) 생장(生長)모델)

  • Seo, Jeong-Ho;Lee, Woo-Kyun;Son, Yowhan;Ham, Bo-Young
    • Journal of Korean Society of Forest Science
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    • v.90 no.6
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    • pp.725-733
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    • 2001
  • In this study, the relationship between growth factors for Pinus densiflora stands in Anmyun-Island was analyzed and dynamic growth model was prepared. A total of 96 sample plots was investigated in which dbh and height of individual trees were measured. From these plot data, quadratic mean dbh, mean height, dominant tree height, stem number per ha, basal area per ha and volume per ha were estimated. Several regression equations between growth factors were derived using NLIN and REG procedure of SAS. And dynamic growth model, in which the equations were interactively linked, was prepared for the prediction of stand growth and yield under different management regime. The predictions of dynamic growth model were found to be coincided with general growth principles. The dynamic growth model was considered as adequate for predicting growth and yield of Pinus densiflora stand in Anmyun-Island. In practice, the dynamic growth model can be applied for predicting the growth and development of stand for various forest treatments and for decision-making in forest management.

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Developing Dynamic DBH Growth Prediction Model by Thinning Intensity and Cycle - Based on Yield Table Data - (간벌강도 및 주기에 따른 동적 흉고직경 생장예측 모형개발 - 기존 수확표 자료를 기반으로 -)

  • Kim, Moonil;Lee, Woo-Kyun;Park, Taejin;Kwak, Hanbin;Byun, Jungyeon;Nam, Kijun;Lee, Kyung-Hak;Son, Yung-Mo;Won, Hyung-Kyu;Lee, Sang-Min
    • Journal of Korean Society of Forest Science
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    • v.101 no.2
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    • pp.266-278
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    • 2012
  • The objective of this study was developing dynamic stand growth model to predict diameter at breast height (DBH) growth by thinning intensity and cycle for major tree species of South Korea. The yield table, one of static stand growth models, constructed by Korea Forest Service was employed to prepare dynamic stand growth models for 8 tree species. In the process of model development, the thinning type was designated to thinning from below and equations for predicting the DBH change after thinning by different intensities was generated. In addition, stand density (N/ha), age and site index were adopted as explanatory variables for DBH prediction model. Thereafter, using the model, DBH growth under various silvicuture through integrating such equations considering thinning intensities, and cycles. The dynamic stand growth model of DBH developed in this study can provide understanding of effectiveness in forest growth and growing stock when thinning practice is performed in forest. Furthermore, results of this study is also applicable to quantitatively assess the carbon storage sequestration capability.

Stem and Stand Taper Model Using Spline Function and Linear Equation (Spline 함수(函數)와 선형방정식(線型方程式)을 이용한 수간(樹幹) 및 임분간곡선(林分幹曲線)모델)

  • Lee, Woo Kyun
    • Journal of Korean Society of Forest Science
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    • v.83 no.1
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    • pp.63-74
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    • 1994
  • One of the essential factors to estimate the stem and stand growth is to correctly portray a stem form (profile). It is also required to numerically approximate a stem form in order to dynamically grasp and represent a stand growth. A whole stem form seems to be a conical form but a stem outline at various positions tapers off differently. Accordingly it is difficult to model a whole stand form with single taper equation. A stem taper equation with different coefficients on each subinterval can be useful tools to accurately portray a stem form. This article presents the derivation method of individual stem taper curve using spline function. It is also in this paper aimed to study how a stand taper curve car, be derived from the population of single stem taper curve in a stand. These taper equations numerically formulated enable to dynamically represent and prognosticate the development process of a stand and prepare the foundation of variety on growth model study and rational forest planning model.

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The Estimation of Stand Biomass and Net Carbon Removals Using Dynamic Stand Growth Model (동적 임분생장모델을 이용한 임분 바이오매스 및 탄소흡수량 추정)

  • Seo, Jeong-Ho;Son, Yeong-Mo;Lee, Kyeong-Hak;Lee, Woo-Kyun;Son, Yo-Hwan
    • Journal of Korea Foresty Energy
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    • v.24 no.2
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    • pp.37-45
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    • 2005
  • This study presents a method how to estimate the change of stand volume, the stand biomass and the carbon removals, using dynamic stand growth model according to whether the practices for forest management are implemented or not. As a result, it shows that the rate of stand change was significantly high if the practices were implemented. Consequently, the change of carbon removals was also high. The carbon removals at the stand where the practices were not implemented, was estimated about 0.27tC/ha. And the carbon removals at the stand where the practices were implemented, was estimated 166.02tC/ha(thinning from above) and 163.75tC/ha(thinning from below). It is confirmed that the thinning activities has a great influence on the change of carbon removals and there was little difference of the carbon removals between thinning types. From this result, it is proved that forest management like thinning activities is prerequisite condition to improve the carbon removals of stand.

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Economic Analysis of Snow Damage on Sugi (Cryptomeria japonica) Forest Stands in Japan Within the Forest Stand Optimization Framework

  • Yoshimoto, Atsushi;Kato, Akio;Yanagihara, Hirokazu
    • Journal of Forest and Environmental Science
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    • v.24 no.3
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    • pp.143-149
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    • 2008
  • We conduct economic analysis of the snow damage on sugi (Cryptomeria japonica) forest stands in Toyama Prefecture, Japan. We utilize a single tree and distant independent growth simulator called "Silv-Forest." With this growth simulator, we developed an optimization model by dynamic programming, called DP-Silv (Dynamic Programming Silv-Forest). The MS-PATH (multiple stage projection alternative technique) algorithm was embedded as a searching algorithm of dynamic programming. The height / DBH ratio was used to constrain the thinning regime for snow damage protection. The optimal rotation age turned out to be 65 years for the non-restricted case, while it was 50 years for the restricted case. The difference in NPV of these two cases as the induced costs ranged from 179,867 to 1,910,713yen/ha over the rotation age of 20 to 75 years. Under the optimal rotation of 65 years, the cost became 914,226 yen/ha. The estimated annual payment based on the difference in NPV, was from 9,869 yen/ha/yr to 85,900 yen/ha/yr. All in all, 10,000 yen/ha/yr to 20,000 yen/ha/yr seems to cover the payment from the rotation age of 35 to 75 years.

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A Study on the Ecological Restoration Strategies for the Disturbed Landscapes (경관훼손지의 생태적 복구방안에 관한 연구)

  • Kim, Nam-Choon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.1 no.1
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    • pp.28-44
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    • 1998
  • This study was conducted to suggest the ecological restoration strategies for the disturbed landscapes by theoretical study. Especially, it is aimed to suggest three objectives for restoration by using native plants ; (1) prevention or reduction of wind and water erosion, (2) provision of food and cover for variety of animal species, (3) improvement of the visual or aesthetic quality of disturbed sites. The main results were summarized as follows. 1. Cooperation between restoration ecologists and restoration practitioners is needed to delineate a scientific approach to restoration ; (1) Being aware of published literature that describes similar work and/or establish general principles. (2) Preparedness to carry out proper experiments to test ideas. (3) Preparedness to monitor fundamental parameters in a restoration scheme. (4) Providing information about the behavior of species. (5) Publish results. 2. There are three models of succession in theories of plant succession. The tolerance and facilitation models were recommended to ecological restoration. The inhibition model applies in most secondary succession, but the actual species which are introduced first may inhibit the germination and growth of slower-growing species, or they may prevent the growth of other species whose propagules arrive later. 3. The objectives of erosion control, wildlife habitat provision, and visual quality improvement are not mutually exclusive. However, many revegetation practices in the past have emphasized one of these aspects at the expense of the others. 4. A native plant community can be the model of ecological restoration. By stylization/abstraction of native plant community, trying to learn the most essential characteristics of community types - environmental factors ; dominant, prevalent, and "visual essence" species composition - in order to use such information in restoration. 5. After developing mass/spaces plan, match plant communities to the mass/space plan. In utilizing community grouping, there needs aesthetic ability to understand design elements. 6. Several hydrophytes such as Pennisetum saccharifluous, Themeda triandra, Cirsium pendulum show relatively good germination rates. In case of mesophytes and xerophytes, Arundinella hina, Artemisia princeps, Oenothera odorata and legumes seem to have quick-germinating abilities at barren sites. Pinus thunbergii, Rhus chinensis, Evodia daniellii, Alnus firma and Albizzia julibrissin can be considered as "late succession" woody plants because they show low germinating rates and slow growing habitat. 7. The seeds used for restoration should be collected within a certain radius of where it will be planted. Consideration in genetic issues in the collection and use of germplasm can increase the odds for successful restoration efforts. 8. The useful model in the "drift" pattern occurs so abundantly in naturally evolving landscapes. As one species diminishes in density, a second or third species are increased. Thus, dynamic interactions between species are created. Careful using of "drift phenomenon" in planting was recommended. 9. Virtually no stand of vegetation today is immune from the introduction and/or spreading of exotic species. Therefore, the perpetuation of a restored sites requires conscious monitoring and management. Thus, management would be the most important process in ecological restoration. 10. In order to keep the sites "natural", alternative management strategies would be applied in management ; Atenative management strategies are decelerating successional process, accelerating successional processes or modifying species composition. As management tools, mechanical, chemical, biological or environmental factor manipulation, e.g., fire could be used.

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