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zis ovanie trvá až nieko¾ko dní. Ïalej sú k¾úèové znaky vyjadrujúce fyziologickú kvalitu ovplyvòované nielen samotným poškodením sadbového materiálu, ale aj ïalšími faktormi (podrezávanie, škôlkovanie, zaèiatok a koniec dormancie atï.). Meranie straty elektrolytu je metóda, ktorá je ve¾mi èasto používaná na urèenie aktuálnej fyziologickej kvality sadbového materiálu. Vo všeobecnosti viacero štúdií potvrdilo možnosti urèenia fyziologického poškodenia semenáèikov a sadeníc lesných drevín pomocou merania straty elektrolytu. Výhodou tejto metódy je jej rýchlos (výsledky sú k dispozícii do 48 hodín) a malé nároky na laboratórne vybavenie. Je ale problematické uskutoèni porovnanie jednotlivých dosiahnutých výsledkov (rozdielne metodiky vlastného merania). Cie¾om štúdie bolo zisti vplyv rôzneho èasového intervalu autoklávovania a rozdielneho èasového intervalu Corresponding author: po stresovom faktore na rozsah straty elektrolytu. Špeciálnym cie¾om bolo testovanie zmien úrovne straty elektrolytu po stresovom faktore rovnakej intenzity v závislosti od fyziologickej aktivity sadbového materiálu. Na testovanie boli použité vzorky z hlavného koreòa dvojroèných semenáèikov duba letného. Výsledky štúdie ukázali, že na úroveò straty elektrolytu z hlavného koreòa nevplýva len rozsah poškodenia, ale aj samotný postup vlastného merania. Preto je problematické porovnáva výsledky získané rozdielnymi postupmi vlastného merania. Ïalej boli zistené štatisticky významné zmeny v strate elektrolytu z hlavného koreòa duba po strese mrazom a suchom v závislosti od fyziologickej aktivity sadbového materiálu. Z dosiahnutých výsledkov je zrejmé, že je potrebné používa rovnakú metodiku merania straty elektrolytu na urèenie fyziologickej kvality sadbového materiálu. Ing. MILAN SARVAŠ, PhD., Lesnícky výskumný ústav, T. G. Masaryka 22, 960 92 Zvolen, Slovenská republika, tel.: + 421 45 536 12 43, fax: + 421 45 536 11 92, e-mail: sarvas@fris.sk 306 J. FOR. SCI., 47, 2001 (7): 301–306
JOURNAL O OREST SCIENCE, 47, 2001 (7): 307–313 A spatially explicit decision support system for locating forest roads E. PACOLA 1 , J. TUÈEK 2 1Technical University, Faculty of Forestry, Department of Forest Exploitation and Mechanization, Zvolen, Slovak Republic 2Technical University, Faculty of Forestry, Department of Forest Management and Geodesy, Zvolen, Slovak Republic ABSTRACT: The paper presents theoretical elements of cartographic modelling of skyline yarding distances, and their implementation in a raster digital elevation model (DEM) within the ArcInfo TM environment. Modules for yarding distances are programmed in the Arc Macro Language (AML). The concept of Spatial Decision Support System (SDSS) for laying out forest roads with concern to terrain and technological criteria is also presented. The most important data source for SDSS is a cartographic model of skyline yarding distances. Powerful tools of map algebra programmed in AML with implementation of fuzzy logic are used in data processing. Keywords: skyline yarding distances; digital terrain model; ArcInfo TM ; spatial decision support system; fuzzy logic Typical forest areas in Slovakia have fairly extensive road network density (in some areas over 100 m/ha). However, the road class and the spacing of existing forest roads are very unfavourable. or example the ratio between main forest roads (asphalt surfaced) and other roads is 1:3 to 1:5. Another problem is the predominance of tractor skidding technologies. Tractor skidding has recently spread to mountainous terrain conditions (45% of the territory of Slovakia). In such conditions it is preferable to use skyline yarding technologies since, from an ecological perspective, it is essential to restrict the density of ground skidding trails. Thus the primary issue concerning the siting of forest roads in Slovakia is not to develop a road network in previously unaccessible areas. On the contrary, transport planning in these conditions is focused on: (1) the placement of new hauling roads into the existing forest road network where areas are not fully opened up, (2) the reconstruction of selected skidding trails and some hauling roads (not asphalt surfaced) to main hauling roads and (3) the rehabilitation of skidding trails which are not worth rebuilding and using skyline technologies. The forest road planning manager in these cases focuses on judging the efficiency of the existing forest network. One of the basic criteria for this judgment is skidding and yarding distance. In previous studies (TUÈEK, PACOLA 1999) we concentrated on the evaluation of skidding and yarding distances using DEM. The proposed distance models linked with IDRISI geographic information system were not fully optimized models for opening up of a forest. The program lacked the means to rapidly develop and evaluate route location based on the digital elevation model. In the present study we have focused on removing model limitation described in TUÈEK and PACOLA (1999) and designing future SDSS for laying out forest hauling roads with respect to technological criteria as skyline yarding distance. At the same time, we have developed the theory of building a cartographic yarding distance model according to that described in TOMLIN (1990). METHOD The modules described here were created for the ESRI’S UNIX based ArcInfo environment. Powerful map algebra tools, tools for surface modelling and Arc Macro Language (AML) were used in the process of building specific models. The analytical process is simply presented as follows. The source of information for building DEM was a forest topographic map in scale 1:10,000 with contour intervals of 20 m. Contours and geographic objects (compartment boundaries, roads, stream network) were digitized on-screen in the ArcView 3.0a. DEM used in calculating skyline yarding distances was built by ap- J. FOR. SCI., 47, 2001 (7): 307–313 307
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