Journal of Forest Science, 2011 (vol. 57), issue 11

Calculating the correction factor of skidding distance based on forest road network

M. Lotfalian, E. H. Zadeh, S. A. Hosseini

J. For. Sci., 2011, 57(11):467-471 | DOI: 10.17221/1/2011-JFS  

Average skidding distance for forest stands is an important parameter for the determination of the optimum road density and spacing. In this research the real mean skidding distance and theoretical mean skidding distance were measured to calculate the correction factor of skidding distance for Chafrood forest in Hyrcanian zone. The length and azimuth of skid trails from road and depot junction to forest interior were measured. Moreover, the position of skid trail was recorded by GPS. These skid trails with a buffer of 140 m were designed on a topographical map using Arc GIS software. Results indicated that the road spacing of 500 m in the study area...

Does intraguild predation of Cosmia trapezina L. (Lep.: Noctuidae) influence the abundance of other Lepidoptera forest pests?

M. Turčáni, J. Patočka

J. For. Sci., 2011, 57(11):472-482 | DOI: 10.17221/99/2010-JFS  

The noctuid C. trapezina (CT) has been considered an occasional predator of other Lepidoptera larvae. Functional/numerical response of predator and/or prey was estimated using 27 years of time-series data from Slovakia and stepwise multiple regression models (SMRM). SMRM were used to examine a possible delayed density-dependent feedback. We constructed 12 order-three autoregressive models [AR(3)] for CT and candidate prey. Independent variables were abundance of C. trapezina and abundance of candidate prey in lags 1, 2, and 3. Model variants were: (1) predation on free feeder models (FFM); (2) predation on shelter feeder...

Soil fertility status of 20 seed production areas of Tectona grandis Linn. f. in Karnataka, India

R.P. Gunaga, A.H. Kanfade, R. Vasudeva

J. For. Sci., 2011, 57(11):483-490 | DOI: 10.17221/119/2010-JFS  

The seed production area (SPA) is an improved plantation managed for production of quality seeds for a large-scale plantation programme. The soil nutrient is one of several factors affecting seed production among SPAs. The status of soil nutrients and their effect on seed production are poorly understood. Hence, the present study was undertaken in 20 seed production areas located in different seed zones of Karnataka, South India. Results showed that there was a greater variation among SPAs in various soil properties like soil pH, organic carbon, available NPK (nitrogen, phosphorus and potassium). Some of the studied parameters recorded significant...

Detrending ability of several regression equations in tree-ring research: a case study based on tree-ring data of Norway spruce (Picea abies [L.])

M. Bošeľa, L. Kulla, R. Marušák

J. For. Sci., 2011, 57(11):491-499 | DOI: 10.17221/134/2010-JFS  

The aim of this study was to investigate tree-ring width variability and to distinguish groups of trees with similar growth trends in order to study tree growth responses to various stand and site conditions. The methods of cluster analysis were employed for this purpose. Four distinct groups of trees were identified. For each group, the mean tree-ring curve was calculated in order to look for the main signals that distinguish the groups from one another. The idea behind this was to divide the samples into homogeneous groups with similar growth trends, representing typical examples of variability of the studied Norway spruce population. In the next...

Findings regarding ectotrophic stability of Norway spruce forest of the Krkonoše and Orlické Mountains based on mycorrhiza studies

V. Pešková, J. Landa, F. Soukup

J. For. Sci., 2011, 57(11):500-513 | DOI: 10.17221/139/2010-JFS  

Analyses of root mycorrhizal samples and monitoring of fruiting bodies of macromycetes from Norway spruce stands at mountain and foothill localities in the Krkonoše and Orlické Mts. provided several data series allowing to assess and compare (albeit somewhat preliminarily) mycorrhizal conditions and macromycete incidence related to stand ages and location conditions. The overall mycorrhizal conditions in young (10 years old) and older (80 years old) stands on formerly agricultural soils are comparable to those in 80- and 90-year-old forests growing on standard forest soils, but young spruce stands in the Orlické Mts. replanted on forest soils do not...

Norway spruce in forest ecosystems of the Czech Republic in relation to different forest site conditions

V. Mansfeld

J. For. Sci., 2011, 57(11):514-522 | DOI: 10.17221/14/2011-JFS  

The paper analyses the representation of Norway spruce (Picea abies [L.] Karst.) (hereinafter spruce) in relation to different conditions of forest sites. The analysis is based on data from the National Forest Inventory conducted in the Czech Republic in 2001-2004 (hereinafter NFI), stratified according to units of the Forest Site Classification System (Plíva 1971, 2000). Results of the analysis provide a structured image of the current share of spruce. The formerly published information on the natural share of spruce was corroborated and the recommended share of spruce in the target species composition of the spruce management system was...