Template-Type: ReDIF-Article 1.0 Author-Name: R. Sedmák Author-Workplace-Name: Department of Forest Management and Geodesy, Faculty of Forestry, Technical University in Zvolen, Zvolen, Slovak Republic Author-Name: L. Scheer Author-Workplace-Name: Department of Forest Management and Geodesy, Faculty of Forestry, Technical University in Zvolen, Zvolen, Slovak Republic Title: Modelling of tree diameter growth using growth functions parameterised by least squares and Bayesian methods Abstract: The purpose of this paper is to present a new growth and yield function (denoted as KM-function), which was empirically derived from the cumulative density function of the Kumaraswamy probability distribution. KM-function is theoretically well disposed for the prediction of future growth; however, the function also has other theoretical features that make it useful also for retrospective estimation of the past growth frequently used in biological analyses of growth in the initial life stages. In order to demonstrate the practical applicability of the KM-function for growth reconstruction, an investigation of the accuracy of five-year retrospective projections of the real tree diameters obtained by stem analyses of 35 beech trees was done. Bias and accuracy of the new function were compared with bias and accuracy of some well-known growth functions on the same database. Compared functions were parameterised in two ways: by the method of nonlinear least squares and Bayesian methods. Empirical validation of the KM-function confirmed its good theoretical properties when it was used for retrospective estimation of the tree diameter growth. The valuable knowledge of this research is also a finding that the incorporation of a great deal of a priori known facts about the growth of trees and stands in natural conditions of Slovakia into Bayesian parameter estimation led to a decrease in the bias and magnitude of reconstruction errors. Keywords: growth function, nonlinear least squares, Bayes, diameter, estimation Journal: Journal of Forest Science Pages: 245-252 Volume: 58 Issue: 6 Year: 2012 DOI: 10.17221/66/2011-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/66/2011-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201206-0001.txt Handle: RePEc:caa:jnljfs:v:58:y:2012:i:6:id:66-2011-JFS Template-Type: ReDIF-Article 1.0 Author-Name: O. Špulák Author-Workplace-Name: Forestry and Game Management Research Institute, Forest Research Station Opočno, Opočno, Czech Republic Title: Aboveground biomass and nutrients in an 18-years-old stand of blue spruce (Picea pungens Engelm.) as a substitute tree species Abstract: Sample trees were taken for analyses from an 18-years-old blue spruce stand growing in the summit part of the Jizerské hory Mts. (Czech Republic). The sample trees were measured and dry matter and nutrient contents were analysed in needles, branches, bark and stem wood. Based on the actual stand structure, correlations were calculated between the diameter, dry weight of components and nutrient reserves. Dry matter of the stand constituted 46% of the stand fresh weight. The highest amount of nutrients was accumulated in needles (from 42% in magnesium to 82% in phosphorus) and the lowest in the stem wood (from 2% in phosphorus to 15% in potassium). Regarding the character of the locality, the complete removal of aboveground biomass during tending operations represents a considerable loss of nutrients. If only the merchantable timber volume is processed, the loss of the elements from the ecosystem could be reduced to 8% (phosphorus) to 22% (calcium and potassium) of the total content of these elements in the aboveground biomass of removals. Keywords: aboveground biomass, nutrients, blue spruce, substitute tree species stands Journal: Journal of Forest Science Pages: 253-264 Volume: 58 Issue: 6 Year: 2012 DOI: 10.17221/82/2011-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/82/2011-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201206-0002.txt Handle: RePEc:caa:jnljfs:v:58:y:2012:i:6:id:82-2011-JFS Template-Type: ReDIF-Article 1.0 Author-Name: W.L. Mason Author-Workplace-Name: Forest Research, Northern Research Station, Roslin, United Kingdom Author-Name: M. Petr Author-Workplace-Name: Forest Research, Northern Research Station, Roslin, United Kingdom Author-Name: S. Bathgate Author-Workplace-Name: Forest Research, Northern Research Station, Roslin, United Kingdom Title: Silvicultural strategies for adapting planted forests to climate change: from theory to practice Abstract: Adapting forests to climate change involves silvicultural measures such as use of a range of species and the fostering of mixed stands. We tested these in a Sitka spruce forest in southern Scotland, employing the Ecological Site Classification to match suitability of 24 species to six climatic and edaphic variables under values of accumulated temperature and moisture deficit projected for a medium emissions scenario for the present century. Both median and 90th percentile values were contrasted. In the first case there was a small change in species suitability with Sitka spruce, noble fir, downy birch, sycamore and aspen being the most suitable species. When the 90th percentile values were employed, the suitability of Sitka spruce and similar conifers had declined by the 2050's due to soil moisture deficits. The actual performance of a range of species in a long-term experiment on a similar, warmer site showed several productive conifers including Sitka spruce that maintained reasonable growth when planted in mixture. Mixed plots were developing into pure stands of the most productive species. Species diversification was the most practical adaptation measure for this forest and should concentrate on areas of the greatest risk like south-facing slopes with free-draining soils. Keywords: climate change, silviculture, adaptive management, species choice, species mixtures Journal: Journal of Forest Science Pages: 265-277 Volume: 58 Issue: 6 Year: 2012 DOI: 10.17221/105/2011-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/105/2011-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201206-0003.txt Handle: RePEc:caa:jnljfs:v:58:y:2012:i:6:id:105-2011-JFS Template-Type: ReDIF-Article 1.0 Author-Name: J. Jonczak Author-Workplace-Name: Department of Geomorphology and Quaternary Geology, Institute of Geography and Regional Studies, Pomeranian University in Słupsk, Słupsk, Poland Author-Name: A. Parzych Author-Workplace-Name: Environmental Chemistry Research Unit, Institute of Biology and Environmental Protection, Pomeranian University in Słupsk, Słupsk, Poland Title: Impact of Scots pine admixture in European beech stand on dissolved organic carbon and nitrogen leaching from organic and humic horizons of Dystric Arenosols in Northern Poland Abstract: The effect of Scots pine admixture in European beech stand on the leaching of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), nitrate nitrogen (NO3-N) and ammonium nitrogen (NH4-N) from organic and humic horizons of Dystric Arenosols was studied in northern Poland in 2008-2009. Three zero-tension lysimeters under organic and humic horizons were installed in pure beech and mixed pine-beech stands. Water samples were collected after each rainfall, measured volumetrically, filtered and analysed. In each sample pH and concentrations of DOC, DON, NH4-N and NO3-N were analysed. Stronger acidification of leachates was observed in mixed stand compared to pure beech. About twice higher concentration of DOC and its fluxes per unit area were determined in mixed stand. The fluxes of DOC from unit mass of soil were less varied. In general, lower concentrations of DON, NH4-N and NO3-N as well as fluxes of the components (calculated in mg.kg-1DM.year-1 and mg.m-2.year-1) were observed in mixed stand. Keywords: European beech, Scots pine, leaching, carbon cycling, nitrogen cycling Journal: Journal of Forest Science Pages: 278-286 Volume: 58 Issue: 6 Year: 2012 DOI: 10.17221/7/2012-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/7/2012-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201206-0004.txt Handle: RePEc:caa:jnljfs:v:58:y:2012:i:6:id:7-2012-JFS Template-Type: ReDIF-Article 1.0 Author-Name: O. Skoupý Author-Workplace-Name: Department of Geoinformation Technologies, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Author-Name: L. Zejdová Author-Workplace-Name: Department of Geoinformation Technologies, Faculty of Forestry and Wood Technology, Mendel University in Brno, Brno, Czech Republic Author-Name: J. Hanuš Author-Workplace-Name: Global Change Research Centre AS CR, Brno, Czech Republic Title: The use of hyperspectral remote sensing for mapping the age composition of forest stands Abstract: The paper deals with the issue of mapping the age composition of stand groups using hyperspectral imagery acquired by the AISA Eagle VNIR sensor in the Bílý Kříž locality in the Moravian-Silesian Beskids Mts. An object-oriented approach was employed through segmentation and subsequent classification by means of Nearest Neighbour (NN) algorithm in the environment of eCognition Developer 8 and artificial neural network (ANN) classification provided by ENVI 4.7 software. Because of the dominant occurrence of Norway spruce (Picea abies [L.] Karst.) monocultures in the studied locality the work focuses primarily on the distinguishability of two selected age classes of Norway spruce (10-20 years and 70-80 years). It studies possibilities of a more detailed age estimation of stand groups aged from 10 to 80 years based on the classification into the boundary classes, which shows similarity to dithering based on random algorithm. Comparison with the outline map of the Forest Management Plan shows a correlation (r2 = 0.83) between the spectral characteristics of Norway spruce stands and their age composition. Keywords: age classification, forestry, hyperspectral, object oriented, segmentation, spruce Journal: Journal of Forest Science Pages: 287-297 Volume: 58 Issue: 6 Year: 2012 DOI: 10.17221/86/2011-JFS File-URL: http://jfs.agriculturejournals.cz/doi/10.17221/86/2011-JFS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/jfs-201206-0005.txt Handle: RePEc:caa:jnljfs:v:58:y:2012:i:6:id:86-2011-JFS