Journal of Forest Science, 2012 (vol. 58), issue 9
Efficiency of adaptive cluster sampling and traditional sampling for coastal mangrove in Hainan of China
Y. Lei, J. Shi, T. Zhao
J. For. Sci., 2012, 58(9):381-390 | DOI: 10.17221/80/2011-JFS 
Based on two species of Coastal Mangrove in Hainan of China, Sonneratia Apetala Buch-Ham and Sonneratia caseoli, we estimated the density of the two species to evaluate the efficiency of adaptive cluster sampling (ACS), simple random sampling (SRS) and traditional systematic sampling (SYS). Our initial experimental designs for ACS consisted of 5 unit areas, 6 initial sampling proportions, 4 initial sample sizes and 5 criterion values in 1,000 repetitions. From the aspect of factors influencing efficiency, we analysed the efficiency of ACS in various designs. We also compared the efficiencies of the three methods on the indexes of...
Effects of nitrogen on growth properties and phenology of silver birch (Betula pendula Roth)
E. Kula, A. Pešlová, P. Martinek
J. For. Sci., 2012, 58(9):391-399 | DOI: 10.17221/109/2011-JFS
Effects of stress caused by differentiated inputs of nitrogen after the application of ammonium nitrate (NH4NO3) on silver birch (Betula pendula Roth) were monitored in a greenhouse. The applied ammonium nitrate did not affect pH values but increased differently the content of nitrogen in soil and leaves. With increased inputs of nitrogen the height and diameter increment of birch also decreased, budbreak was delayed and the autumn leaf-fall slowed down. Frost heaving of shoots occurred particularly in the lower half of the birch stem. With the increasing content of nitrogen in leaves the content of phosphorus decreased...
Root system development in Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) on fertile sites
O. Mauer, E. Palátová
J. For. Sci., 2012, 58(9):400-409 | DOI: 10.17221/94/2011-JFS
The paper analyses the root system development in the artificially established stands of Douglas fir aged 10, 20, 30, 60 and 80 years on aerated soils (Cambisols) without skeleton. On these sites, the Douglas fir develops a uniform root system of substitute taproots and anchors, which has great predispositions to assure the good mechanical stability of trees as well as its resistance to sudden changes in upper soil horizons. Several anchors growing in positive geotropic direction shoot from the stem base, several slant anchors shooting from the side of the stem base turn into the positive geotropic direction of growth. In humus horizons, horizontal...
Sustainable forestry and iron compounds in karstic soils: qualitative and semi-quantitative results focused on the occurrence of Fe-compounds on mineral particles
K. Rejšek, M. Mišič, F. Eichler
J. For. Sci., 2012, 58(9):410-424 | DOI: 10.17221/106/2011-JFS
Relic karstic soils in nine localities in the Dinaric Karst in Slovenia, five localities in the Moravian Karst and four localities in the Bohemian Karst were sampled for soil scientific, mineralogical and petrological studies focused on the presentation of descriptive aspects of particular iron compounds. The macroscopy and microscopy of Fe2+ and Fe3+ compounds were determined and an interpretation of these data was performed aimed at describing sources and their palaeotransports. The presented results show that the studied karstic soils have a heterogeneous petrographical and mineralogical composition when, depending on circumstances,...