Journal of Forest Science, 2016 (vol. 62), issue 2
Impact of climatic conditions on the reproductive phenological phases of European hazel (Corylus avellana L.) in SlovakiaOriginal Paper
J. Škvareninová
J. For. Sci., 2016, 62(2):47-52 | DOI: 10.17221/55/2015-JFS 
The work presents the results of phenological observations of flowering and fruit ripeness of the European hazel (Corylus avellana L.) in Slovakia in two time periods: 1964-1983, and 1994-2013. The phenological stations at elevations from 100 to 875 m a.s.l. were grouped to 7 elevation zones, each 100 m wide. In the first studied period, flowering started on 19 March on average, while in the second period it started 5 days earlier. The average duration of flowering equal to 7-9 days did not depend on the elevation, but on the air temperature and weather patterns in the different elevation zones. During the first period, the average elevation...
Contrasting growth and water use efficiency after thinning in mixed Abies pinsapo-Pinus pinaster-Pinus sylvestris forestsOriginal Paper
R.M. Navarro-Cerrillo, R. Sánchez-Salguero, R. Herrera, C.J. Ceacero Ruiz, J.M. Moreno-Rojas, R.D. Manzanedo, J. López-Quintanilla
J. For. Sci., 2016, 62(2):53-64 | DOI: 10.17221/104/2015-JFS
Foresters frequently lack sufficient information about thinning intensity effects to optimize semi-natural forest management and their effects and interaction with climate are still poorly understood. In an Abies pinsapo-Pinus pinaster-Pinus sylvestris forest with three thinning intensities, a dendrochronologial approach was used to evaluate the short-term responses of basal area increment (BAI), carbon isotope (δ13C) and water use efficiency (iWUE) to thinning intensity and climate. Thinning generally increased BAI in all species, except for the heavy thinning in P. sylvestris. Across all the plots, thinning increased 13C-derived water-use efficiency...
Comparison of different non-linear models for prediction of the relationship between diameter and height of velvet maple trees in natural forests (Case study: Asalem Forests, Iran)Original Paper
I. Hassanzad Navroodi, S.J. Alavi, M. K. Ahmadi, M. Radkarimi
J. For. Sci., 2016, 62(2):65-71 | DOI: 10.17221/43/2015-JFS
Velvet maple (Acer velutinum) is one of the woody species in the Hyrcanian forests. In this study, the relationship between height and diameter of velvet maple was surveyed. A complete list of the selected height-diameter models was used and nineteen candidate models were considered. Various criteria were chosen and applied to evaluate the predictive performance of the models. These criteria include Akaike information criterion (AIC), Bayesian information criterion (BIC), root mean square error (RMSE), mean error (ME), and adjusted coefficient of determination (R2adj). Fitting of nineteen height-diameter...
Changes of agricultural land characteristics as a result of afforestation using introduced tree speciesOriginal Paper
V. Podrázský, M. Fulín, H. Prknová, F. Beran, M. Třeštík
J. For. Sci., 2016, 62(2):72-79 | DOI: 10.17221/96/2015-JFS
The paper documents the mid-term changes of the soil characteristics and upper soil dynamics in the stands of introduced tree species, grand fir and Douglas-fir, on the former agricultural lands. These species were compared with Norway spruce stand and original grassland in the same site conditions at the Hrubá Skála locality (Eastern Bohemia). The plot was established in 1980 on Luvisol type of soil, sandy clay. Altitude ranges between 350 and 360 m a.s.l., mean annual temperature was 7.8°C, mean annual precipitation 703 mm. Results confirmed the starting process of the development of humus forms typical for forest ecosystems, despite the initial...
Determination of forest skid trail density in Caspian forests, IranOriginal Paper
M. Lotfalian, S. Khosrozadeh, S.A. Hosseini, M. Kazemi, N. Zare
J. For. Sci., 2016, 62(2):80-87 | DOI: 10.17221/84/2015-JFS
Calculation of Skid Trail Spacing (STS) is an important option to minimize the total costs of skidding. Construction of many skid trails increases the construction cost, it also results in more degradation on different levels in forests. On the other hand, by constructing less skid trails, winching cost will increase, and in many cases, the skidders will exit from skid trails. This research was carried out in four districts under management of Mazandaran Wood and Paper Industry Company with the aim of determination of Optimum Skid Trail Spacing (OSTS) for an HSM skidder. In this study, a continuous time study method to the nearest second with stop...
The assessment of economic indicators of National Park AdministrationsOriginal Paper
D. Březina, P. Hlaváčková
J. For. Sci., 2016, 62(2):88-96 | DOI: 10.17221/61/2015-JFS
In the territory of the Czech Republic there are four national parks managed by their administrators. National parks are areas designed for the protection of nature and landscape, or biodiversity, i.e. rendering of public goods. National Park Administrations (NP Administrations) are specific organizations aimed at the provision of public goods; they are established by Ministry of the Environment of the Czech Republic and their activities are principally financed from the state budget. Since the main objective of these organisations is not the generation of profit, their economic indicators cannot be compared with those of other types of entities. The...