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Abstract

The study presents the results of an analysis of the pine tree growth increments (height increment, dbh increment, basal area increment and volume increment) for a 5-year period. The study involved Scots pine trees of Kraft’s class 1, 2 and 3 (dominant stand) in stands of different age classes (II, III, V) growing in fresh mixed coniferous (BMśw) and fresh coniferous (Bśw) forest habitats. The multivariate analysis of variance was performed to assess the statistical significance of age and dominance of trees within a stand on their increment. The dominance position was classified for each tree using Kraft’s criteria. The following characteristic were also measured: dbh of the trunk in two directions (N-S and W-E), and crown projection area on the basis of the characteristic tree crown points, projected using of a crown projector, characteristic points in tree crowns (7 to 14 on average). The actual height was determined after trees were felled. The following measurements of the single tree growing space were selected and determined: crown projection area - pk (m2), crown diameter - dk (m), Seebach’s growth space number - dk / d1.3, crown projection area to basal area ratio d 2 k / d 2 1.3, crown deflection coefficient dk / h, single tree space ppd = pk·h (m3). We assessed the strength of the relationships between tree growth parameters and tree growth space, crown length, relative crown length and slenderness. Both the age and dominance position of trees within the stand affected the growth increments. The strongest correlation among measured traits was between the 5-year volume increment and decreasing slenderness.

. Possibilities of competition indices to describe competitive differences between Scots pine families. Silva Fennica , 31: 43-52. Mailly D., Turbis S., Pothier D. 2003. Predicting basal area increment in a spatially explicit, individual tree model: a test of competition measures with black spruce. Canadian Journal of Forest Research , 33: 435-443. Pukkala T., Kolström T. 1987. Competition indices and the prediction of radial growth in Scots pine. Silva Fennica , 21: 55-67. Radtke P. J., Westfall J. A., Burkhart H. E. 2003. Conditioning a distance-dependent competition index

Abstract.

Relationships between the volume growth of mixed stands and their species composition were analyzed in order to examine the so-called “mixture effect” on stand productivity. The influence of co-species was studied using multiple linear regression analysis. Stand level basal area and height growth models were constructed in order to find out which stand characteristics can be used to describe mixture-effects. The study material originates from the Estonian network of permanent forest growth plots, only stands consisting of mainly (≥ 50% of volume) Scots Pine with Norway spruce and/or Birch spp. as co-species were used. Sample size was 139 5-year measurement periods on 88 plots; stand ages range from 14 to 167 years. The study results indicate that an increasing proportion of birch in the stand causes a negative effect on both basal area and height growth. Spruce seems to be a weaker competitor than other pines as its trend in the model is positive. Also, height growth is more rapid when the mean diameter of spruce is smaller than that of pine. Species composition coefficients for co-species (calculated by standing volume) proved to be the most significant variables that describe stand composition in the models

Abstract

We assessed the influence of some environmental conditions (temperature and rainfall) on the litterfall and BAI (basal area increment), in three close forests in the Montseny massif (NE part of the Iberian peninsula, Spain). Two of them are composed of deciduous species Fagus sylvatica and Quercus petraea, and the other one is a Mediterranean evergreen species, Quercus ilex. We have collected monthly data about litterfall and radial growth since 2007. For each forest there are tree plots, with litterfall traps and band dendrometers. This data has been related with the meteorological parameters of meteorological station closed to the study area. Our results show that F. sylvatica recorded the biggest drop in annual litterfall (6 Mg·ha−1·year−1), followed by Q. ilex (4.34 Mg·ha−1·year−1) and Quercus petraea (4.4 Mg·ha−1·year−1) and that all the values were similar to those observed in other forests and mountains with the same state of maturity. Regarding the litterfall, the investigation found a decline in the leaves fall in deciduous trees in years with hot summers. In addition, these warm summers produce a decline in the F. sylvatica BAI, but not in Q. petraea. Concerning growth, we found that Q. petraea increases the BAI on the study period while F. sylvatica does not. In conclusion, we believe that in the future Q. petraea will be more tolerant to the warm conditions than F. sylvatica, making the former a possible replacement of the second species.

Abstract

Forest growth is commonly used to explore tree vitality and ability to resist to environmental changes or climatic fluctuations. This paper illustrates and examines how regional climatic conditions can be related to the decline of tree growth, which were found to be more distinct in Quercus frainetto Ten. (Hungarian oak) and Fagus sylvatica L. (European beech) and less pronounced in Abies borissi-regis Matt f. (Bulgarian fir) on three long-term intensive monitoring plots (ICP Forests-Level II) in Greece during the period 1996–2009. Relative basal area increment and volume increment were calculated, expressing tree growth in terms of mean relative annual periodic increment. A decline in the growth of basal area and volume was observed after hot and dry periods, where annual temperatures and precipitation were far from the mean of the analyzed period. This observation was statistically confirmed in oak and beech plots regarding summer precipitation only and are in agreement with the findings of previous studies in Europe. The representativeness of the results at a national scale needs further investigation, although our results provide a good basis for further and more intensive monitoring programs to address various forest management scenarios against the background of potential climatic changes in the Mediterranean area.

Abstract

Although beech stands are usually regenerated naturally, an area of up to 5,000 ha year−1 is artificially regenerated by beech in the Czech Republic annually. Unfortunately, these stands often showed insufficient stand density and, consequently, lower quality of stems. Therefore, thinning methods developed for naturally regenerated beech stands are applicable with difficulties. The paper evaluates the data from two thinning experiments established in young artificially regenerated beech stands located in different growing conditions. In both experiments, thinning resulted in the lower amount of salvage cut in following years. Positive effect of thinning on periodic stand basal area increment and on periodic diameter increment of dominant trees was found in the beech stand located at middle elevations. On the other hand, thinning effects in mountain conditions were negligible. Thinning focusing on future stand quality cannot be commonly applied in artificially regenerated beech stands because of their worse initial quality and lower density. However, these stands show good growth and response to thinning, hence their management can be focused on maximising beech wood production.

Abstract

Thirteen Nordic stand growth models have been validated by use of a test data set from long-term research plots in Norway. The evaluated data was from time-series of even-aged, pure stands of Norway spruce, Scots pine and birch (silver birch and downy birch). In selected models from Finland, Norway and Sweden measures of site productivity, mean tree size and various stand characteristics are represented. Different models display both strengths and weaknesses in their predicting ability. Several measures of precision and bias have been calculated and the models are ranked due to their performance. We observed site quality, stand density and average tree size as the three main components in the models. Basal area increment model for spruce from Sweden had the lowest standard deviation with 23%. The mean R2 between residuals and stand characteristics from this model was also low (1.3%), which indicates that independent variables are well included. For Scots pine and birch, Finnish volume increment models showed the best fit to the Norwegian test data, with a R2 between residuals and stand characteristics of 2.8 and 6.7%, respectively. Several of the models from Sweden and Finland predicted the growth as well as stand models frequently in use in Norway. The results indicated that similar forest conditions and traditional even-aged forest management practice in the Nordic countries could be seen as a suitable basis for developing a joint family of growth models. By careful recalibration of existing models, a reasonable accuracy could be achieved and the prediction bias could be reduced.

. S. GREENWOOD (1999): Variation in lateral shoots elongation patterns and hybrid vigor in full-sib families and interspecific hybrids of larch. Tree Physiology 19: 131-136. BONNET-MASIMBERT, M., P. BALDET, L. E. PÂQUES and G. PHILIPPE (1998): From flowering to artificial pollination in larch for breeding and seed orchard production. For.Chron. 74 (2): 195-202. EMHART, V. I., T. A. MARTIN, T. L. WHITE and D. A. HUBER (2006): Genetic variation in basal area increment phenology and its correlation with growth rate in loblolly and slash pine families and clones. Can

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K. 2008. QC.Expert, ADSTAT. User‘s manual, TryloByte, Ltd., Pardubice. Lang A. 1938. Bestandes-Einheitshöhenkurven der Württ. Forsteinrichtungsanstalt. Allgemeine Forstund Jagdzeitung, 114, 168-176. Mehtätalo L. 2004. A longitudinal heigth-diameter model for Norway spruce in Finland. Canadian Journal of Forest Research, 34 (1), 131-140. Michailoff I. 1943. Zahlenmässiges Verfahren für die Ausführung der Bestandeshöhenkurven. Forstwissenschaftliches Centralbatt - Tharandter Forstliches Jahrbuch, 6, 273-279. Monserud R.A., Sterba, H. 1996. A basal area increment