The ectomycorrhizal biodiversity of selected Norway spruce stands on an Alpine limestone mountain was studied by inventories of occurring fruitbodies and descriptions of new ectomycorrhizal types. Based on fruitbody surveys a total of 137 ectomycorrhizal and 48 saprophytic species was recorded. Dependent on elevations as well as microclimatic, soil, and stand conditions there were significant differences in the fungal composition and number of species between the investigated forest plots.

In 1992, a monitoring survey on a national scale was carried out using Hypogymnia physodes (L.) Nyl. as a biomonitor for trace element air pollution. The primary aim was to analyse epiphytic lichens collected at 86 sampling locations of the 16 x 16 km bioindication grid using k(0)-based instrumental neutron activation analysis (k(0)-INAA), and X-ray fluorescence spectrometry (XRF) for sulphur and lead, to obtain information about the levels of elements in the atmosphere and to identify significant pollution sources. The geographical concentration patterns of the trace elements obtained from the lichen data were mapped and compared with the index of atmospheric purity (IAP) calculated on the basis of data from lichen thalli type mapping, obtained on a more dense bioindication grid in 1991. The results obtained showed good agreement between the mapping of sulphur and trace elements with the status of lichen vegetation. The most exposed regions with elevated trace element levels and lower values of IAP were in the north-western Alpine part of Slovenia which coincides with high precipitation, and in the east of Slovenia, where many local pollution sources are situated.

The use of ectomycorrhizal fungi as possible indicators of ecosystem response to disturbance is discussed with emphasis on the analysis of individual species by direct observation of their mycorrhizas. Some examples of such studies are given. The possible role of fungal diversity and differential tolerance by individual species to pollutants are also discussed in relation to observed changes within ectomycorrhizal fungal communities.

Types of ectomycorrhizae on Norway spruce were determined in soil cores from two differently polluted forest research plots from the emission zone of Sostanj Thermal Power Plant (TPP). The two plots are comparable regarding site characteristics, but are differently polluted by the emmissions from the TPP. During the vegetations season 1993, 21 soil cores were taken from each plot. In these all fine roots and ectomycorrhizal roots tips were counted and the percentages of different types were calculated. Additionally, soil mycorrhizae from underneath fungal fruit bodies were taken in order to characterize new types of ectomycorrhizae. Classical anatomical methods and molecular tools were applied for identification. 17 types of ectomycorrhizae were determined on 28443 root tips in soil cores from the heavily polluted plot (Zavodnje). The predominant types were Paxillus involutus, Xerocomus badius, Piceirhiza parallela and Piceirhiza inflata. On the less polluted plot (Mislinja) 24 different types were determined on 38502 root tips in equal volume and number of soils cores. The most frequent types were Hydnum rufescens, Amphinema byssoides, Piceirhiza oleiferans, Cenococcum geophilum and Lactarius lignyotus. Mycobioindication of forest site pollution through selective sensitive (here Hydnum rufescens), in comparison to unsensitive (here Paxillus involutus), fungal species in ectomycorrhizae is discussed.

Seven ectomycorrhizae on oak (Quercus robur L.) from a Slovenian forest stand are described, five of them for the first time in detail. Four of these species could be identified (Lactarius chrysorrheus (Fr.) Fr., L. serifluus DC. ex Fr., Xerocomus subtomentosus (L. ex Fr.) Quel., X. armeniacus (Quel.) Quel., one unidentified species was given a preliminary name ("Quercirhiza squamosa"). Two identified species, already comprehensively characterized on other tree species, are presented shortly (Laccaria amethystina (Bolt ex Hooper) Murr., Cenococcum geophilum Fr.). Whereas some of the encountered species show considerable host specifity with oak (Lactarius chrysorrheus, L. serifluus and, in a lesser degree Xerocomus armeniacus), other species have a broader host range and can even grow with conifers (Xerocomus subtomentosus, Laccaria amethystina, Cenococcum geophilum). A key for all species was established. A possible use of ectomycorrhizal species as bioindicators is discussed.

Endophytic fungi species composition in healthy needles of Austrian pine (Pinus nigra Arn.) was investigated at eight locations in Slovenia. Results from October 1994 and January 1995 isolations were compared with analyses of macronutrients, sulphur and lead content of the needles. About 80 species of microfungi were revealed. From the observations and measurements described it was not possible to discriminate between the effect of environmental factors and effect of air pollutants. The pollutants load of all measured elements is low and the environmental factors are very diverse. From the dendogram of isolation frequencies it seems that the age of the tree affects the species composition and frequencies of endophytes to the greatest extent.

This article deals with use of several bioindication methods in forest decline studies within an international TEMPUS project carried out in Slovenia. The aim of the project was to introduce and connect different bioindication methods in order to improve methods and qualify the research staff working in this research field in Slovenia. The following bioindication methods were introduced or adapted for forest decline research in Slovenia: biochemical and physiological markers of air pollution / stress impact on forest trees (Graz Univ.: photosynthetic pigments, thiols, ascorbic acid, protective enzyme systems; Cambridge Univ.: plant hormones; Munich Univ.: mineral nutrition of forest trees); epiphytic lichens as indicators of air quality on forest sites (Graz Univ., Ljubljana Univ); determination of types of ectomycorrhizae as indicators of forest soil condition (Munich Univ., Ljubljana Univ.). The significance and practical use of bioindication methods in environmental studies is also discussed.