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Namen prispevka je presoja raziskovalnega dela v rezervatih in tudi naravovarstvena ocena gozdnih rezervatov s poudarkom na ohranjanju naravne biotske pestrosti. Izmerili smo količino (volumen) in kakovost (debelinska struktura, struktura različnih razkrojnih stadijev) ostankov odmrlih dreves, ki sta lahko enostavna in dobra kazalnika naravnosti in biotske raznovrstnosti. Rezultati so jasno pokazali velike količine ostankov odmrlih dreves, nakopičenih v rezervatih s prostorninami od 21,4 m3/ha do 239 m3/ha in povprečjem 116,4 m3/ha (mediana = 106,0 m3/ha), kar je bilo bistveno več kot v okoliških gozdovih. Struktura odmrlega drevja v rezervatih je pokazala veliko kakovost, saj so debelejši ostanki različnih faz razkroja predstavljali velik delež. Glede na to in glede na aktualna evropska priporočila (30%50 m3/ha v gospodarskih gozdovih) lahko sklepamo, da relativno majhna mreža rezervatov (

The paper evaluates the role of the forest reserve network in Slovenia for both research purposes and conservation of biodiversity. In particular, we quantified the quantity and quality of dead wood in 16 forest reserves in Slovenia as a general indicator of conservation value. The total volume (standing and lying trees) ranged from 21,4 to 239 m3/ha, with a mean of 116,4 m3/ha, which is markedly higher than in surroundings managed forests. In most of the reserves, large dead trees in advanced stages of decay were present, indicating the high quality of dead wood in reserves. Given that recent recomendations from the literature call for 30-50 m3/ha of dead wood in managed forest to maintain the majority of saproxylic species, coupled with the small area of forest reserves in Slovenia (

This paper presents the status of non-native and invasive tree species in the forests of Slovenia. In the introductory part, the history of introduction of non-native tree species in Slovenia and experimental plantation of these species are presented. The main reasons for the introduction of these species and their benefits are also considered. According to currently available data of Slovenian Forest Service the growing stock of non-native tree species represents less than 1% of the total growing stock of forests in Slovenia. Among the non-native tree species, invasive black locust (Robinia pseudoacacia) is the most widespread (0.60% of the total growing stock of forests), followed by eastern white pine (Pinus strobus; 0.18%). Several forest management, silvicultural and forest protection problems are associated with these two species. Among other widespread non-native tree species are also Douglas fir (Pseudotsuga menziesii; 0.05%) and red oak (Quercus rubra; 0.03%). Non-native tree species have the largest share of the growing stock in Forest Regional Unit (FRU) Murska Sobota (8.9%) and FRU Sežana (3.9%). Among the non-native tree species, black locust is prevailing in both areas. By using different sources of information, the existence of 20 to 25 different non-native tree species was estimated in the Slovenian forests. In the future, in particularly the widespread black locust should be even more considered by the forestry professions. Furthermore, the dynamics of expansion of invasive tree of heaven (Ailanthus altissima) should be carefully monitored and appropriate measures for its constraint need to be explored. More forest management and silvicultural activities should be focussed also on the invasive shrub and herb species which significantly disturb the normal forest development in some regions. V prispevku je opisano stanje tujerodnih in invazivnih drevesnih vrst v gozdovih Slovenije. V uvodnem delu je opisana zgodovina vnosa tujerodnih drevesnih vrst pri nas in poskusi s temi drevesnimi vrstami. Predstavljeni so tudi glavni vzroki za vnos teh vrst in njihova uporabnost. Po trenutno dostopnih podatkih Zavoda za gozdove Slovenije je lesne zaloge tujerodnih drevesnih vrst nekaj manj kot 1 % celotne lesne zaloge gozdov v Sloveniji. Mednjimi je najbolj razširjena invazivna robinija (Robinia pseudoacacia; 0,60 % celotne lesne zaloge gozdov), sledi ji zeleni bor (Pinus strobus; 0,18 %). Stema vrstama so povezani tudi številni gozdnogospodarski, gozdnogojitveni in varstveni problemi. Med bolj razširjenimi tujerodnimi drevesnimi vrstami sta še zelena duglazija (Pseudotsuga menziesii; 0,05 %) in rdeči hrast (Quercus rubra; 0,03 %). Tujerodne drevesne vrste imajo največji delež v lesni zalogi gozdov v GGO Murska Sobota (8,9 %) in GGO Sežana (3,9 %). V obeh območjih med tujerodnimi prevladuje robinija. Z uporabo različnih virov smo lahko ocenili, da se v naših gozdovih še vedno pojavlja od 20 do 25 različnih tujerodnih drevesnih vrst. V prihodnosti bi bilo treba več strokovne pozornosti nameniti predvsem splošno razširjeni robiniji. Poleg tega bi bilo treba skrbno spremljati dinamiko širjenja in iskati ustrezne možnosti za omejevanje invazivnega visokega pajesena (Ailanthus altissima). V okviru gozdnogospodarskih in gozdnogojitvenih aktivnosti bo treba več načrtnega dela nameniti tudi invazivnim grmovnim in zeliščnim vrstam, ki v nekaterih predelih že zelo ovirajo normalen razvoj gozdov.

Basing on the example of 28 forest management units (FMU) comprising more than 90% state owned forests and of 60 FMU comprising more than 90% private forests, the article presents the analysis of the diameter structure of the trees selected for cutting in the state and private forests in the period 1995-2008. We analyzed the FMUs where the wood stocks were identified exclusively or almost exclusively on the constant sample planes; therefore, the analyzed forests were to some extent above the average with regard to the production capabilities of the habitats and stand conditions. The diameter structure of the trees selected for cutting is compared to the diameter structure of the trees in the forest stands and with the diameter structure of the trees in the model forest. The data on the forest stands are based on the stand measurements on the constant sample planes and the data on the modelforest on the Halaj tables (spruce: SI100 = 30, mountain spruce, production level 2, SP 10.2 and beech: SI100 = 28, production level 2, SP 8.2). The actual ratio of coniferous and deciduous trees wood stock, which is completely equal in the analyzed forests regardless of their ownership: 48.5 %: 51.5 %, was taken into account. V prispevku je na primeru 28 gozdnogospodarskih enot (GGE) z več kot 90 % državnih gozdov in 60 GGE z več kot 90 % zasebnih gozdov analizirana debelinska struktura izbranega drevja za posek v državnih in zasebnih gozdovih v obdobju 1995-2008. Analizirane so bile tiste GGE, kjer so lesne zaloge ugotavljane izključno ali skoraj izključno na stalnih vzorčnih ploskvah, zato so glede proizvodne sposobnosti rastišč in sestojnih razmer analizirani gozdovi nekoliko nadpovprečni. Debelinska struktura za posek izbranega drevja je primerjana z debelinsko strukturo drevja v gozdnih sestojih in z debelinsko strukturo modelnega gozda. Podatki o gozdnih sestojih temeljijo na meritvah sestojev na stalnih vzorčnih ploskvah, podatki modelnega gozda pa na Halajevih tablicah (smreka: SI100 = 30, gorska, proizvodna raven 2, PSR 10,2 ter bukev: SI100 = 28, proizvodna raven 2, PSR 8,2), upoštevajoč dejansko razmerje lesnih zalog iglavcev in listavcev, ki je v analiziranih gozdovih obeh lastništev povsem enako: 48,5 % : 51,5 %.