TREE DISEASES DETERMINED BY THE REPORTING , PROGNOSTIC AND DIAGNOSTIC SERVICE FOR FORESTS IN SLOVENIA 1982 – 2012

The Reporting, Prognostic and Diagnostic (RPD) service for forests is a legal forest protection organization in Slovenia and part of the public forest service. The aim of our study was to analyse RPD reports from 1982 to 2012. We analysed 120 reports that contained 992 records of tree diseases encompassing 189 species and genera. The most frequently recorded were foliage diseases (351 records, 42 species), needle diseases (162 records, 23 species), rots (111 records, 56 species), cankers (73 records, 9 species), and shoot diseases (72 records, 14 species). Ten most frequently recorded species were the following fungi: Erysiphe alphitoides, Lophodermium spp., Cryphonectria parasitica, Rhytisma acerinum, Sawadaea bicornis, Diplodia pinea, Hymenoscyphus pseudoalbidus, Mycosphaerella pini, Blumeriella jaapii, and Cronartium ribicola.


INTRODUCTION UVOD
The Reporting, Prognostic and Diagnostic (RPD) service for forests represents a basic organizational structure for forest protection in Slovenia from 1965 on (Zakon o varstvu rastlin pred boleznimi in škodljici, 1965).It is managed by the Slovenian Forestry Institute (SFI) and performed in cooperation with the Slov- The aim of the study was to analyse RPD reports from 1982 to 2012, which will give us an insight into tree diseases diversity, frequency and distribution in Slovenia.

MATERIALS AND METHODS MATERIALI IN METODE
We collected all available RPD reports from 1982 to 2012.The reports were digitalised, converted to Portable Document Format and published on a website of forest protection in Slovenia (Poročila in elaborati Poročevalske, diagnostične in prognostične službe za varstvo gozdov, 2013).Tree diseases occurrences data from RPD reports were organized with the aid of information system called Boletus informaticus, which represents a central database of fungi in Slovenia (Jurc et al., 2005).The following data were recorded: species or genus, sampling date, host and location.Descriptive statistics was performed by Microsoft SQL Server 2008 R2 and Microsoft Excel 2010.A map was prepared with ESRI ArcGIS for Desktop 10.1.

REZULTATI
We analyzed 120 RPD reports that contained 992 records of tree diseases encompassing 189 species and genera (Appendix 1).There were 13 yearly reports, which encompassed the majority of records (637) (Appendix 1, Figure 1).Therefore, records frequency per year depended on report type (Figure 1).Up to 210 occurrences (average 39.7) and 66 species (average 18.2) per year were recorded.Single report contained 8.3 records and 4.1 species on average.
The most causative agents of tree diseases (173) were found in the Sub-Pannonian phytogeographical region (Figure 2).The Alpine, Pre-Alpine and Sub-Mediterranean regions included 128, 122 and 116 species, respectively.The least causative agents of tree diseases were found in the Pre-Dinaric (89) and Dinaric regions (28).

DISCUSSION RAZPRAVA
Tree diseases in Slovenia are caused by about 322 species and genera mostly consisting of fungi (Maček, 2008).During 1982-2012, RPD registered 58.7% of known species causing tree diseases in Slovenia.Many occurrences of tree diseases found by RPD are reported in journal articles and other ways of communication, e.g. by phone, which we did not include into our analysis.Therefore, the number of records and species found by the RPD service is higher than presented here.
The Sub-Pannonian phytogeographical region has low yearly precipitation, cold winters and warm summers.Therefore, climatic and ecological attributes may have a great impact on vitality of the hosts and consequently they could be the cause for the highest number of tree diseases established in the region (Figure 2).Such extreme ecological conditions are also present in the Alpine and Sub-Mediterranean regions, where high numbers of tree diseases were recorded.Surprisingly, the Pre-Dinaric and Dinaric regions had the lowest number of tree diseases recorded in spite of calcium carbonate grounds, which are prone to drought stress.
Among 12 tree diseases types, the most frequently recorded were leaf diseases, needle diseases and rots (Table 1).However, rots were comprised of most species, indicating importance of saprophytic function of fungi.High frequency of foliage diseases could be explained by the fact that they are easily observable and by their highest species richness, in general (Maček, 2008).Surprisingly, rusts were not so frequently recorded as expected.
RPD was successful at finding several organisms from the lists of Council directive on protective measures against the introduction into the Community of organisms harmful to plants or plant products and against their spread within the Community (2000) and other invasive harmful organisms to trees, e.g.Cronartium ribicola, Cryphonectria parasitica, Eutypella para-sitica, Hymenoscyphus pseudoalbidus, Mycosphaerella dearnessii, M. pini, Ophiostoma ulmi, Phytophthora ramorum.
The most frequent hosts of the tree diseases were Pinus nigra, Acer pseudoplatanus and Picea abies.However, most tree diseases were found on Picea abies (23) and Fagus sylvatica (21), which had the highest wood stock among all tree species in Slovenian forests (ZGS, 2012).The hosts Pinus nigra, Acer pseudoplatanus and Pinus sylvestris followed by 16, 15 and 14 tree diseases, respectively (Appendix 2).
All republics of the former Yugoslavia had the same organization of forest protection, i.e.RPD.Therefore, the data from our study could be compared to the data from other former Yugoslav countries, like Croatia, Serbia, and Bosnia and Herzegovina.However, at this time the data were not accessible in electronic format.Therefore, the comparison was not possible due to the lack of resources.Other countries in Europe do not have this kind of organizational structure for forest protection.The groundwork for RPD in Yugoslavia was prepared by Vasić (1981), who had described the most important pests (188), diseases (29), and rodents (8) for forests in Yugoslavia.Our analysis covered 26 out of 29 tree diseases treated by Vasić (1981).

Table 1 :
Tree disease types, number of records and causative agents as reported by RPD during 1982-2012