The article presents a state of art of forest decline inventories in Slovenia. The first part deals with methodological and technological aspects of forest health inventories, while the second one describes some hints and directions of further forest inventories development.

Research was carried out in EMFT, II-G-10 (common oak and common hornbeam zone) and in main EMFT-s on the karst (pubescent oak and oriental hornbeam, and holly oak zones) in which forest fuel loads were determined too. Soil and structure elements were sampled and measured, stand vitality and quality were measured and evaluated. Chemical and physical analyses of soil samples were performed. The samples of precipitation's and plant material were chemically analyzed. It contains the data of normal and changed forest conditions (first measurement 1969-1981, second measurement 1991-1993). In second measurement the research that deals with tree breeding and fructification was added to the project. The aim of this recently introduced research is to determine the dynamics of flowering and phenotype damage degree. Cytogenetic and some biochemical analyses were carried out with the aim of determining and establishing methodology of work. The data base was built up and data search programs were developed. The relations of ecological and structural stand elements for normal and changed stand conditions were determined. The results achieved are the basis for building up the diagnostic stand models and the evaluation model of ecological-environmental ecosystem value. The main purpose is to support decision making on different management levels.

The Forest Research Plot was chosen on a typical site for the Pokljuka plateau. It is covered by a supposedly autochthonous old Norway spruce stand with rejuvenation centres. Data on the physiological parameters can be used as representation values for a subalpine Norway spruce stand. The studies include: standard site and dendrological parameters, physiological parameters (foliar analysis, antioxidants, hormones and aminoacids in spruce needs), genetical and biochemical analysis (isoenzymes and molecular markers), microbiological activity (acid phosphatase, rate of decomposition, number and occurrence of fungal decomposers of wood and litter) and studies of symbionts and pathogens of Norway spruce (mapping of fruitbodies of mycorrhizal fungi, types of ectomycorrhizae, endophytes, epiphytes - lichens and phytopathological surveys). All physiological and ecological studies are planned to be repeated at certain time periods in order to understand better the functioning of the forest ecosystems on Pokljuka.

Mechanisms of air pollution toxicity are very complex and depend on various physiological and biochemical properties of plants. These mechanisms (including formation of free radicals) are still poorly understood. In addition, physiological responses of forest plants to air pollution stress can be modified by various biotic (e.g., insects, pathogens, mycorrhizae associations, genetic variation) and abiotic (e.g., increasing CO2 concentrations, ultraviolet-B radiation, nitrogen desposition, nutrient deficiencies, drought) factors. An example of air pollution effects on forest trees may be responses of ponderosa pine seedlings to elevated concentrations of ozone: various physiological changes in trees (lowered net photosynthesis, altered carbon allocation, deterioration of photosynthetic pigments, etc.) have led to reduced growth and biomass of plants.

Plant hormones play a major role in the development and control of a wide range of plant physiological processes. Here we examine the ways in which they may influence the response of plants to air pollutants both indirectly, for example through the control of stomatal behaviour by ABA and directly, through their reactions with oxidising pollutants, which can lead to the formation of further damaging molecular species.

The evaluation of data on the forest tree condition is weak point in forest decline monitoring as it enables only a very rough estimation of the state of forest health. The paper analyses the interpretation of the forest tree defoliation data in order to estimate their relevance and applicability. Quality control results of defoliation assessment in Slovenia are presented and the state of defoliation with its changes in the year 1987, 1991, 1993, 1994 on the 16 km grid.

We have been isolating AC/GT and AG/CT SSRs from the Norway spruce (Picea abies K.) nuclear genome. We isolated several hundreds positive clones from a small-insert genomic library and following sequence analysis we designed primers for 36 of them, 24 containing AG and 12 AC SSRs. After testing them on a panel of spruce individuals 25 of the primer pairs producted a single-locus hypervariable pattern, with the remaining ones giving either a single monomorphic product (18) or very poor amplification (19) or amplification of multiple bands (38). Segregation in accordance with a simple Mendelian model of inheritance was demonstrated for all the loci amplified with the primer pairs giving a simple variable pattern. We screened a panel of 19 spruce trees at these loci. The average number of alleles per locus was 14 and expected heterozygosity 0.80, with up to 23 alleles per locus and heterozygosities exceeding 0.94. This shows that nuclear SSRs can be very useful markers in the population genetics of trees even though the overall efficiency of the marker identification process is quite low due to the high percentage of primer pairs producting complex or "dirty" patterns. We attribute this phenomenon to the high complexity of the spruce genome. Other methods, including the construction of libraries highly enriched for SSR sequences, that we developed in order to make SSR retrival and typing easier and faster will be discussed. We recently extended the use of PCR amplified SSR markers to the chloroplast genome. We demonstrated that mononucleotide poly(A/T) stretches are frequent in the chloroplast genomes of plants and show high levels of between and within population variation, making them ideal tools for cytoplasmic population genetic overcoming the difficulties in finding within species variation that are frequently encountered when analysing the cpDNA molecule by RFLPs or PCR-RFLPs. We will present results of the analysis of mediterranean pine species populations by using a set of cpSSRs that are distributed over the whole cpDNA molecule and discuss the possible applications of such markers for studying gene flow and for paternity analysis.

Giemsa C-banding method was applied on chromosomes in the female gametophyte tissue of Norway spruce (Picea abies (L.) Karesten). A karyogram of one single tree growing in the Botanical Garden of the University of Graz, Austria, was made by using an image analysis system. All chromosomes (n=12) showed pericentic C-bands. Chromosomes II, V and IX possed intercalary C-bands located at secondary constrictions. Telomeric C-bands appeared in chromosomes II and III on both arms.

Cytogenetical and biochemical investigations of common oak (Quercus robur L.) were applied in order to find suitable markers in bioindication of oak populations. In cytogenetical analyses the chromosome aberration and mitotic index were recorded. Chromosome banding, B-chromosomes, location and number of nuclear organizer regions were indicated using Giemsa C-banding method, fluorescence staining and silver impregnation. In biochemical analyses SDS-electrophoresis of soluble proteins and isoelectric focusing of isoperoxidases were used.

It was our aim to investigate whether the cytokinin status of Norway spruce seedlings (Picea abies L. Karst.) was changed when the plants were grown under nutritive stress. Cytokinins in shoots and roots from spruce seedlings, grown in various hydrocultural media with complete (control) or poor nutrient supply (stress), were determined by an indirect competitive enzyme-liked immunosorbent assay. The shoots of spruce seedlings grown in a poor acidic culture medium, to which aluminium ions (AlCl3, 0.8 mM) were added, showed up to 5-fold higher concentrations of zeatin riboside and isopentenyladenosine (iPa). When adding naphtylacetic acid to the nutrient medium also higher levels of cytokinin ribosides were measured in the shoots. In the roots however cytokinin riboside levels did not increase significantly under Al- or auxin treatment. Feeding experiments using tritiated iPA have shown that the metabolism of this cytokinin is strongly retarded in the roots of stressed seedlings. The experiments show that acid conditions and nutrient shortage together with aluminium ions in the rhizosphere increase the number of lateral roots in Norway spruce seedlings. It is assumed that the increased number of sites of cytokinin biosynthesis and the reduced metabolism of iPA result in the higher content of cytokinin ribosides in the shoots of seedlings.