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Ludwisiak L.,Samodzielna Pracownia Dendrometrii i Nauki o Produkcyjnosci Lasu | Nasiadka P.,Samodzielny Zaklad Zoologii Lesnej i Lowiectwa
Sylwan | Year: 2014

The paper presents the selected indicators of hare populations in Poland. The material consisted of 528 hares acquired during traditional hunts. For each hunted hare we specified its weight, sex and age. All individuals were classified into two age groups: the first comprised juveniles (up to 12 months of age), while the other-adults (over 12 months). The ratio of young individuals in relation adults vaties a lot (26-56%). The males to females ratio was approximately 1:1 with a slight advantage in favor of females. Reproductive rate was between 0.36 and 1.26, while reproductive success-0.7-2.7. Average weight of hunted hares ranged between 3.42 and 4.32 kg. No significant differences in body weight were noticed within gender groups (Z=1.298, p>0.05, Mann-Whitney U test). However, they were found within the age groups (Z=-9.657, p>0.05, Mann-Whitney U test). Source

The study describes allometric relationships between stand density and tree dimensions in birch stands on post-agricultural lands. The research material consisted of measurements carried out on 120 sample plots located in birch stands on post-agricultural lands of Central Poland. The investigated relationship was analyzed using ordinary least squares (OLS), dynamical formulation of allometric function (DFA), stochastic frontier production function (SFF) as well as quantile regression (QR) methods. Similar effects of modeling maximum density were obtained as a result of applying FFP and QR methods with 0.9 quantile. SFF was found to be the most adequate method for modeling maximum density. © 2014, Polish Forest Society. All rights reserved. Source

Paper analyses relationships between radial growth and seven crown-related parameters (crown length, relative length, width, slenderness, projection area and volume as well as single tree space) for ten alien and native tree species growing in 'common garden' conditions in the WULS-SGGW Forest Experimental Station in Rogdw (central Poland). Significant correlation was found between 10- and 15-years mean tree-ring width and all analysed crown parameters as well as single tree space for Abies grandis, Abies nordmanniana and, except for crown length and its relative length, for Pin us sy/vestris. No relationship was observed between radial increment of Larix decidua, Pseudotsuga menziesii and Quercus rubra and any of analysed crown parameters. Source

When using such methods as terrestrial laser scanning (TLS), one of the major factors influencing the accuracy of stand characteristics determination is the visibility of trees on a sample plot, which is often obscured by the shadow effect caused by trees located closer to the plot center. Because of this, the percentage of the identified trees and basal area depends on the distance from the plot center: the accuracy of stocking determination decreases as the plot radius increases. The values of such stand characteristics as average breast height diameter, standard deviation of tree diameters and percentiles of the tree diameters' distributions assessed based on all trees and the visible trees only are not significantly different from each other for circular sample plots with 20 m radius. Skewness and kurtosis are not significantly different in plots with radius of 5 and 10 meters. For the 15 m plot radius the difference was significant for about 15% of the analyzed plots. The obtained results correspond with previous findings that report that on the circular sample plots with radius up to 15 m the errors for the number of trees and basal area are relatively small and can be accepted in the practical inventory. The results support the circular sample plots size optimization, including measurements performed using a point cloud. Source

Magnuszewski M.,Samodzielna Pracownia Dendrometrii i Nauki o Produkcyjnosci Lasu | Nowakowska J.A.,Zaklad Hodowli Lasu i Genetyki Drzew Lesnych | Zasada M.,Samodzielna Pracownia Dendrometrii i Nauki o Produkcyjnosci Lasu | Orozumbekov A.,Kirgiski Narodowy University Rolniczy
Sylwan | Year: 2014

The study showed the genetic structure of nine Schrenk spruce stands, which represented altitude and geographical variants in the Tien-Shan mountains in Kyrgyzstan. Comparison between genetic structure of stands was based on frequencies of nuclear microsatellite (SSR) alleles occurring in three DNA loci. The total genetic differentiation of Schrenk spruce populations was low (FST=0.0651). Eight main groups of populations were distinguished in the dendrogram defined by Nei's genetic distances based on micro-satellite markers. © 2014, Polish Forest Society. All rights reserved. Source

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