Verification of a Model of Stand Density Control Diagram for Austrian Black Pine Plantations in Bulgaria

Tatiana Stankova* and Tzvetan Zlatanov**

Researchers

*Department of Forest Genetics, Physiology and Plantations

 **Department of Silviculture

 Forest Research Institute of Bulgarian Academy of Sciences. 132, St. Kliment Ohridski Blvd., 1756 Sofia, BULGARIA

 

 

 

Abstract. The Stand Density Control Diagram (SDCD) is an average stand-level model which is primarily used to derive density control schedules by management objective. One of its applications is to evaluate stand growth parameters at any time of stand development. The main objective of the present investigation is to examine a model of SDCD estimated for Austrian black pine (Pinus nigra Arn.) plantations in Bulgaria with a representative validation data set and to illustrate its application for estimation of density, mean breast height diameter and stand stock.

Equivalent mean diameter curves proved to be very good predictors for all studied growth parameters, having smaller relative errors than the Equivalent height curves. A result of practical importance is the insignificant difference between the direct (experimental dominant height) and the indirect (predicted dominant height) way of parameter estimation. Among all six examined ways of determination of the stand stock the Equivalent mean diameter curves based on the experimental values of basal area and dominant height showed best performance. The proposed model of SDCD avoids some disadvantages of the existing growth and yield models and supplies a reliable method for estimation of the stand growth parameters.

Key words: growth parameters; mean-dominant height relationship; yield prediction models; stand-level models

 

 

Verificação de um Modelo de Diagrama de Controlo de Densidade do Povoamento para Pinheiro Larício (Pinus nigra Arn.) em Plantações na Bulgária

Sumário. O Diagrama de Controlo de Densidade do Povoamento (DCDP) é um modelo de povoamento cujo principal objectivo é desenvolver esquemas de controlo da densidade, de acordo com o objectivo de gestão. Uma das suas aplicações principais é a avaliação dos parâmetros de crescimento do povoamento em qualquer momento da sua vida. O presente estudo tem como objectivo principal testar um modelo de DCDP desenvolvido para plantações de Pinus nigra Arn. na Bulgária, por comparação com um conjunto representativo de dados de validação e ilustrar as possibilidades da sua aplicação na estimação da densidade, diâmetro médio à altura do peito e volume em pé.

As curvas equivalentes de diâmetro médio demonstraram ser boas preditoras para todos os parâmetros de crescimento estudados, tendo apresentado erros relativos mais pequenos do que as curvas equivalentes de altura. Um resultado com interesse prático é a ausência de diferenças significativas entre os valores das estimativas dos parâmetros obtidos pelo método directo (medição da altura dominante) e pelo método indirecto (altura dominante estimada).

De todos os seis métodos testados para avaliação do volume em pé, o método das curvas equivalentes de diâmetro médio, baseadas na determinação experimental da área basal e da altura dominante apresentou a melhor prestação. O modelo proposto (DCDP) evita algumas desvantagens dos modelos de crescimento e produção existentes e fornece uma ferramenta fiável para a estimação dos parâmetros de crescimento do povoamento.

Palavras-chave: parâmetros de crescimento; altura média; altura dominante; modelos de produção; modelos de povoamento

 

 

Vérification et Preuve d'un Modèle de Diagramme de Commande de Densité de Peuplement pour les Plantations de Pin Noir en Bulgarie

Résumé. Le diagramme de commande de densité de peuplement (DCDP) est un modèle au niveau de plantation qui est principalement employé pour la planification des programmes de commande de la densité avec pour objectif le contentement de critères économiques précis. Une de ses applications principales est d'évaluer des paramètres de croissance des plantations à tout moment de leur développement. L'objectif principal de la recherche actuelle est d'examiner un modèle de DCDP estimé pour les plantations de pin noir (Pinus nigra Arn.) en Bulgarie avec un modèle représentatif de validation et d'illustrer sa possibilité d'évaluation de densité, de diamètre moyen à hauteur de poitrine et de réserve des plantations.

Les courbes moyennes de diamètre avérées équivalentes montrent les facteurs prédictifs très bons pour tous les paramètres étudiés de croissance, ayant de plus petites erreurs relatives que la courbe équivalente de taille. Un résultat d'importance pratique est la différence insignifiante entre la manière directe (taille dominante mesurée) et indirecte (taille dominante estimée) de l'évaluation de paramètre. Parmi chacune des six manières examinées de la détermination de la réserve des plantations les équivalentes courbes moyennes de diamètre basées sur les valeurs mesurées du secteur basique et de la taille dominante ont montré la meilleure exactitude. Le modèle proposé de DCDP permit l'évasion de quelques inconvénients des modèles existants de croissance et de productivité et propose une méthode fiable pour l'évaluation des paramètres de croissance des plantations.

Mots clés: paramètres de croissance; rapport signifié-dominant de taille; modèles de prévision de la réserve; modèles au niveau plantations

 

 

 

Texto completo disponível apenas em PDF.

Full text only available in PDF format.

 

 

 

References

Alexandrov, A., Tsakov, H., Genov, K., Stojkov, H., Tsankov, G., Djorgov, I., Tiholov, B., Asparuhova, E., Andonova, E., Dakov, A., Hristova, H., 2002. Project "Management of the forest and changes in the biodiversity of burnt forest areas", Bulgarian-Swiss Forestry Program, "Sylvica" foundation.

Hagihara, A., 1998. Mathematical and biological considerations on yield and competition-density effects in self-thinning plant populations. Bull. Fac. Sci., Univ. Ryukyus 66: 71-79.        [ Links ]

Marinov, I., 1999. Investigation on erosion in forest ecosystems. Research report for the period 1996-1999. Forest Research Institute of BAS, Sofia. (in Bulgarian)

Marinov, I., 2002. Stationary studies of hydrological and erosion processes in forest ecosystems. Research report for the period 2000-2002, Forest Research Institute of BAS, Sofia. (in Bulgarian)

Marinov, I., Mandev, A., Grozeva, M., Timousheva, S., Markov, I., Genov, K., 1997. Investigation on the hydrological effectiveness against erosion of the coniferous plantations in western Bulgaria. Report on the project with National Forestry Board. Forest Research Institute of BAS, Sofia.  (in Bulgarian)

Nedyalkov, S., 1983. Growth and yield tables for Austrian black pine stands. In Nedyalkov, S., Rashkov, R. and R. Tashkov. Reference book in dedrobiometry, Zemizdat, Sofia, pp. 384-387. (in Bulgarian)

Nedyalkov, S., Krastanov, K., Tsakov, H., 1983. Volume and assortment tables for Austrian black pine plantations. In Nedyalkov, S., Rashkov, R. and R. Tashkov. Reference book in dedrobiometry, Zemizdat, Sofia, pp. 84-97. (in Bulgarian)

Newton, P.F., 1997. Stand density management diagrams: Review of their development and utility in stand-level management planning. For. Ecol. Manage. 98: 251-265.

Shibuya, M., 1995. A simple and practical model for mean size-density trajectories of tree stands. J. Jpn. For. Soc. 77: 247-253.

Shinozaki, K,. Kira, T., 1956. Intraspecific competition among higher plants.VII. Logistic theory of the C-D effect. J. Inst. Polytech., Osaka City Univ., Series D (Biology) 7: 35-72.

Stankova, T., 2005. A density control model for Austrian black pine plantations in Bulgaria. Nauka za gorata (Forest Science, Sofia) 3: 29-50. (In Bulgarian with English summary)

Stankova, T., 2006. Possibilities for density optimization of Scots pine and Austrian black pine plantations by mathematical models. PhD thesis, Forest Research Institute of BAS (Sofia, Bulgaria), 168 pp. (with extended summaries in English (35pp.) and Bulgarian (40 pp.)

Stankova, T., Shibuya, M., 2003. Adaptation of Hagihara's competition-density theory for practical application to natural birch stands. For. Ecol. Manage. 186: 7-20.

Stankova, T., Shibuya, M., 2007. Stand Density Control Diagrams for Scots pine and Austrian black pine plantations in Bulgaria. New Forests 34: 123-141.

Stankova, T., Stankov, H., Shibuya, M., 2005. Mean-dominant height relationships for Scotch pine and Austrian black pine plantations in Bulgaria. Ecological engineering and environmental protection. 2: 59-66.

Tsakov, H., 1983. Growth and yield tables for Austrian black pine plantations. In Nedyalkov, S., Rashkov, R. and R. Tashkov. Reference book in dedrobiometry, Zemizdat, Sofia, pp. 388-392. (in Bulgarian)

Yoda, K., Kira, T., Ogawa, H., Hozumi, K., 1963. Self-thinning in overcrowded pure stands under cultivated and natural conditions. Intraspecific competition among higher plants XI. J. Biol. Osaka City Univ. 14: 107-129.

 

 

Entregue para publicação em Agosto de 2006

Aceite para publicação em Abril de 2007