Since 1990, the FTDM was tested and improved, working especially on formation of forest personnel to standardise the collection of data. Nowadays, the main pathogens monitored are the following: Armillaria spp., Crysomyxa spp., Sphaeropsis sapinea, Cenangium
ferruginosum. Heterobasidion annosum, Lirula nervisequia, Phytophthora cambivora, Ophiostoma ulmi, Cryphonectria parasitica, plus some dieback as Alnus viridis wilting and
Quercus decline. The data collected for each of them can be the simple presence, the estimated forest area infected, the estimated damage evaluated in m3 of felled trees.
The integration of these data in the GIS system proved to be very effective and it was possible to obtain thematic maps (fig. 2) as well as a comparative examination of damaged and healthy forest compartments (Ambrosi et al., 1998) or a quick review of site condition (tab. 1)
(Maresi et al. 1999).
Fig. 2 - Particular of a thematic map showing the forest compartments interested by Alnus viridis wilting in 1998.
- Presence ofwilting c:J Absence of symptoms
Tab. 2-Main site conditions of 41 pine compartment affected by Sphaeropsis sapinea and Cenangium ferruginosum attacks, as described in woodland management plans (from Maresi et al., 1999, modified).
SITE CONDffiONS %
Exposure 22% North; 2% East;
39% South; 37% West
Location 30 %Valley bottom; 48% Slope;
7% Terrace; 15% Ridge
Slope 15% Plain; 80% Slope;
5% Steep
Type of soil 58% Brown forest soil
42 % Rendzina
Soil depth 83% Superficial;
17 % Little depth.
Soil humidity 55 %Arid; 43 %Dry;
2% Wet.
The thematic maps will be useful both to organise the monitoring of the spread of diseases and to follow the expansion of foci. The examination of data about the severe shoot and branches dieback on pine, due to S. sapinea and C. ferruginosum, confirmed that the action of these weak parasites was enhanced by the poor sites conditions and by the hydric stress
periods, which occurred in the last years, 96-97 (Maresi et al., 1999). The two parasites proved to be good indicators of stress situation and may act as agents ofthe natural evolution towards more natural stands. As a consequence, the Forest Service had to operate in about 700 ha of artificial stands of P. nigra in Trentino, where nearly 11.000 me were felled.
Discussion and conclusion
Use ofGis is increasing in the management of many natural resources and especially in forest management (Ciolli, 1996; Nresset, 1997) and several application were already tested both for pest and pathogens management (Nelson et al., 1999; Taylor et al., 1996; Wilds, 1997;
Liebhold et al. 1998) and for other hazards models (Ciolli et al., 1998). Started as a way of answer to geographical questions, GIS can be closely connected to tools for planning and management of woodland and so it may be considered as a bridge between natural resources databases and management choices (Nresset, 1997). The actual GIS are not only able to draw thematic maps overlaying several sources but also to analyse, manage and model database coming from different inventories.
The GIS we have been trying to improve started using the various resources already present in the Province ofTrento. Luckily, the existence of a quite complete cover ofwoodland plans assures the basic data for each work of investigation, as well as the continuous care of forests warranted by the provincial Forest Service organisation. The Forest Trees Damages
Monitoring was made possible by these combinations of basic data and personnel, while its evolution towards a GIS seems a natural consequence of the trend in forest planning. In these years, the FTDM proved to be not only a very good way to recover data on pests and
pathogens incidence, like the other forest damages inventory (Stergulc et al. 1999), but also a practical instrument to monitor the forestry choices of the pasts, by means the presence of several bio-indicators (Ambrosi and Salvadori, 1998). The most important and effective agents of damages are in fact related to the presence of woods which can be considered too artificial for the environment. Besides, both pest and pathogens show the influence of climatic stress and of ageing in natural woods, suggesting the need of appropriate silvicultural
treatment. The link between damage diagnosis and silvicultural choice is enhanced by the testing of the management control treatment suggested in each observed case. In this way, the Forest Health GIS can become a decision support system for forest planner.
The continuous monitoring of woods can also permit the observation ofthe insurgence of new outbreaks, allowing the control of their evolution. The statistical examination ofthe collected data inserted in the GIS management program would make possible in the future to arrive at forecasting model and, on this point, a better link with climatic data, expressly managed, is desirable to obtain a reliable tool. In this contest, a very interesting attempt was appointed by the ARF (regional forest agency) ofLombardy for its property (Tagliaferri et al., 1999). At the moment, the use of remote sensing methods, which proved to be very effective in many forest GIS applications and in some diseases studies (Ambrosini et al., 1997) seems not fundamental in our system, because of the real control of all the woodland executed by the Forest Service personnel. But in the future, the use of aerial or satellite photos and of Global Positioning System (GPS) could be implemented in the system to evaluate the evolution of local outbreaks.
Summarising, the proposed Forest health GIS could work as:
1. A historical record of the pest and pathogens attacks;
2. A scientific tool to understand better the role of biotic agents in the natural evolution of woods by means of the comparison of geo-referenced series of data;
3. A managing tool, helping the forester to operate choices towards a better naturalistic woodland management;
4. A forecasting tool, following the pairing and the interpretation of data.
5. An economic tool for planning the woods management cost, able to show figures of the values both of damages in woods and of needed treatments.
Of course, several practical problem have still to be solved before all the things work in the
References
Ambrosi P. and Salvadori C., 1998. Monitoraggio fitopatologico delle foreste quale strumento per la gestione selvicolturale: otto anni di applicazione in Trentino. Monti e Boschi 5, 9-12.
Ambrosi P. and Salvadori C.,1997. Monitoring of forest tree damages- Trentino model: an instrument to better woodland management. Extended Abstracts in Proceedings of
International Meeting for Specialists in Forest Ecosystems (29-31 oct. 1997, Bolzano-Bozen, Italy), Ed. Prov. Aut. di Bolzano, 1997.
Ambrosi P., Salvadori C., George E. and Marchetti F.,1998. Monitoring of tree damages in the pine stands as a tool to better woodland management. In print in Proocedings of "Research and monitoring askey elements for sustainable development in the limestone alps", Bled (Slovenia), 11-13 ottobre 1998.
Ambrosini I., Gherardi L., Maresi G., Turchetti T. and Viti M. L., 1997. Monitoring diseases of chestnut stands by small format aerial photography. Geocarto International12 (3), 41-48.
Biraghi A.,1955. Finalita della patologia forestale. Atti del Congresso Nazionale di
Selvicoltura per il miglioramento e la conservazione dei boschi italiani, Firenze 14-18 marzo 1954, Accademia Italiana di Scienze Forestali ed., vol. I, 501-512.
Ciolli M. 1996. Ipotesi di una struttura ideale di un GIS per un Ufficio Assestamento.
Dendronatura 2, 83-87.
Ciolli M., Tabarelli S. and Zatelli P., 1998. 3d spatial data integration for avalanche risk management. In print in the proceedings oflnternational symposium on "GIS-between vision and applications", September 7-10 Stuttgart, Germany, 1998.
Liebhold A., Luzader E., Reardon R., Roberts A., Ravlin F. W., Sharow A. and Zhou G., 1998. Forecasting gypsy moth (Lepidoptera: Lymantriidae) defoliation with a geographical information system. Journal of Economic Entomology 91 (2), 464-472.
Maresi G., Ambrosi P., Confalonieri M., and Capretti P. 1999. Disseccamenti da Cenangium ferruginosum e Sphaeropsis sapinea nelle pinete trentine. Monti e Boschi 2, 35-41.
Nresset E., 1997. Geographical information systems in long-term forest management and planning with special reference to preservation of biological diversity: a review. Forest Ecology and Management 93, 121-136.
Nelson M. R., Orum T.V., Jaime-Garcia R. and Nadeem A. 1999. Application of Geographic Information System and Geostatistics in plant disease epidemiology and management. Plant Disease, 83 (4), 308-319.
Ripple W. J. 1996. The GIS applications book examples in Natural resources: a compendium.
American Society for Photogrammetry and remote sensing. Bethesda, USA.
Stergulc F., Frigimelica G., Bartoli P. L., Corradini L. and Gottardo E. 1999. Inventario fitopatologico forestale del Fiuli- Venezia Giulia, cos'e, a cosa serve, come funziona.
Sherwood- foreste ed alberi oggi, 43, 29-35.
Tagliaferri A., Frigerio G., Giglio A., Di Girolamo F., Berizzi D. and Boriani M., 1999.
Progetto Carta Fitosanitaria delle FF.DD.RR. Internal report, pp.47.
Taylor P. J., Walker G.R., Hodgson G., Hatton T. J. and Correll R. L. 1996. Testing of a GIS model of Eucalyptus largijlorens health on a semiarid saline floodplain. Environmental Management, 20 (4), 553-564.
Wilds S. P., 1997. Analysis ofthe distribution of a fungal disease ofCornusjlorida in the southern Appalachian Mountains, Tennesse. Journal ofVegetation Science, 8 (6), 811-818.
Forster, B.; Knizek, M.; Grodzki, W. (eds.) 1999: Methodology of Forest Insect and Disease Survey in Central Europe.
Proceedings ofthe Second Workshop ofthe IUFRO WP 7.03.10, April20-23, 1999, Siort-Chateauneuf, Switzerland.
Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) 187-188.
INVESTIGATIONS IN THE DISTRIBUTION OF PHYTOPHTHORA SPECIES IN GERMAN ALDER SITES
Sabine WERRES, Federal Biological Research Center for Agriculture and Forestry, Institute for Plant Protection in Horticulture, Messeweg 11/12, D- 38104 Braunschweig
INTRODUCTION
During the last years alder decline has become a serious problem in many european countries. (GIBBS 1995, BRASIER, ROSE and J.N. GIBBS 1995, GIBBS and LONSDALE 1996, MATHIEU 1996, TIDNGGAARD 1996, CECH 1997). Characterstic symptoms of the disease are crown thinning and tarry or rusty spots on the stems, starting at the ground level, which can develop into a bleeding cancer. Under the bark the tissue is dark brown to reddish brown and can be clearly distingished from the healthy tissue.
From diseased alders species of the fungal like microorganisms of the genus Phytophthora could be isolated. The most important species seem to be a homothallic variation of Phytophthora cambivora. In Germany P. cambivora and other Phytophthora species could also be isolated from dieseased alder trees (HARTMANN 1995, WERRES 1997, 1998). But up to now there has been only little information on the distribution of these pathogens in German alder sites and on the intensitivity of the decline. Therefore in 1998 a project was started to collect data on diseased alder stands and to screen soil samples of these stands for Phytophthora spp ..
MATERIAL AND METHODS
With the help of a questionnaire data such as the occurance of characteristic symptoms, water profile and soil typ were collected. Those foresters who had problems with diseased or dying alders was asked to send soil samples according to a detailed guideline. At the laboratory the soil samples were screened for Phytophthora with the Rhododendron leaf test (WERRES et al. 1997;
THEMANN & WERRES 1998, www.bba.de/phytoph/diagnose.htm). In this test Rhododendron leaves are used as a bait to detect Phytophthora propagules. The test had been developed for routine screening of a high number of water, soil and root samples for Phytophthora spp. and for large samples. The test system baits a wide range of Phytophthora species and is highly sensitive. Furthermore it is very easy to handle.
RESULTS
As the project has not yet been finished only the first results can be presented.
a - Character of the alder sites, the soil samples had been sent from Soil samples from 45 different sites from all over Germany were sent.
In most of the alder sites:
- the size is below 5 hectars
- the alder trees are of the same age
- the alder trees are aged between 31 and 50 - the alder trees are cultivated (planted) - Alnus glutinosa is the main alder species
- water is close by
-there is temporary stagnant moisture or flooding (mainly winter/spring) -the pH value in the soil samples ranged from 3.3 to 7.9
-between 1-50% ofthe alder trees were diseased - there were only low numbers of dead trees
b - Presence of Phytophthora spp.
In 60 % of the soil samples one or more Phytophthora species could be detected. The taxonomical work to determine the species has not yet been finished.
c - Correlation between the presence of Phytophthora spp. and factors like soil pH
There was a strong correlation between the pH-value of the soil samples and the occurance of Phytophthora spp.
REFERENCES
BRASIER C.M., ROSE J. and J.N. GffiBS (1995): An unusual Phytophthora associated with widespread alder mortality in Britain. Plant Pathology 44: 999-1007.
CECH Th.L. (1997): Phytophthora- Krankheit der Erie in Osterreich. Forstschutz Aktuel119/20:14-16 GffiBS J.N. (1994): Phytophthora root disease of Common alder. Research Information Note 258.
Forestry Authority, Research Division, Alice Halt Lodge, Wrecclesham, Farnham, Surrey: 4 S.
GffiBS J.N. (1995): Phytophthora root disease of alder in Britain. EP PO Bulletin 25: 661-664.
GffiBS J.N. & LONSDALE D. (1996): Phytophthora disease of alder: The situation in 1995. Research Information Note 277. Forestry Commission, EdinbUrgh: 1-4.
HARTMANN G. (1995): Wurzelhalsfaule der Schwarzerle (Alnus glutinosa)- eine bisher unbekannte Pilzkrankheit durch Phytophthora cambivora. Forst und Holz. 18: 555-557.
MATHIEU D. (1996): Resultats de l'enquete ,deperissement de l'aune" de l'automne 1996. La sante des Forets, Bilan 1996: 13.
THINGGAARD K. (1996): Svampen Phytophthora I Elletraeer. Skoven 3: 132-133.
WERRES S. (1996): Phytophthora spp. an Erie, Eiche, Kastanie und anderen Baumen-aktueller Stand in der Bundesrepublik Deutschland. Nachrichtenblatt des Deutschen Pjlanzenschutzdienstes 48(7), 160 WERRES S., HAHN, R. und THEMANN K. (1997): Application of different techniques to detect
Phytophthora spp. in roots of commercial produced Chamaecyparis lawsoniana. Zeitschrift for Pjlanzenkrankheiten und Pjlanzenschutz 104(5), 474-482.
WERRES S. (1998): Mikroorganismen aus der Gattung Phytophthora - Erlensterben. Allgemeine Deutsche Forstzeitschrift 10, 548-549
THEMANN K. und WERRES S. (1998): Verwendung von Rhododendronblattern zum Nachweis van Phytophthora-Arten in Wurzel- und Bodenproben (Use of Rhododendron leaves to detect Phytophthora. species in root and soil samples). Nachrichtenblatt. des Deutschen Pjlanzenschutzdienstes 50(2), 37-45.
Guidlines for the handling of the Rhododendron leaf test to detect Phytophthora spp. in root, soil and water samples (www.bba.de/phytophldiagnose.htm).
Forster, B.; Knizek, M.; Grodzki, W. (eds.) 1999: Methodology of Forest Insect and Disease Survey in Central Europe.
Proceedings ofthe Second Workshop ofthe IUFRO WP 7.03.10, April20-23, 1999, Sion-Chateauneuf, Switzerland.
Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) 189-193.
Introduction
THE PRESENCE OF FUNGUS SPHAEROPSIS SAPINEA ON PINES IN CROATIA
DankoDIMINIC
Faculty of Forestry University of Zagreb Svetosimunska 25, 10000 Zagreb, Croatia
Sphaeropsis sapinea (Fr.) Dyko et Sutton causes different types of diseases on conifers: stunting of a new growth, browning of needles, shoot blight, twig and branch dieback, crown wilt, bark cankers, root disease, damping-off, root rot, and as saprophyte blue stain of sapwood of fallen or freshly cut timbers. The fungus is wide spread in the temperate and tropical regions all over the world (Browne 1968, Punithalingam & Waterston 1970, Swart & al. 1985, Chou & MacKenzie 1988). Among different hosts Pinus nigra Arnold, P.
radiata Don. and P. sylvestris L. have been found as the most susceptible to the fungus attack (Punithalingam & Waterston 1970).
First report of fungus presence in Croatia as causal agent of pines dieback was by Bohm (1959). He reported one-year-old diseased Austrian pines in nursery near Karlovac. Till than there haven't been reports on damaging impact of S. sapinea. In 1992 it turned out as causal agent of pines dieback in Istria (Diminic 1994). In the December 1991 the local foresters noticed dieback symptoms in pine crowns in plantation on the eastern coast of the peninsula. First observation in that plantation and neighbour one have been made in April
1992 (Figure 1, research area No. 6). The observed symptoms were die back of young and older shoots, branches and hole crowns of pine trees, mainly of P. nigra. Analyses showed that S. sapinea was the most frequent fungus on collected samples.
Since 1992 health condition inventory of pine plantations have been carried out, and further on observations revealed pines dieback on other localities in Croatia. To investigate where and with what influence S. sapinea is present on pines in Croatia, not only locations with die back symptoms were observed, but also sites with no reports of die back.
Materials and Methods
Pine plantations and pine trees in urban areas were randomly selected. Research localities are shown in Figure 1. In each plantation 3 to 10 pine trees were evaluated according to health condition. Dieback needles, shoots, and branches from crowns, fallen needles and branches from the ground were collected. Cones from the crowns as well as on the ground were collected too. Pines in urban areas as ornamental trees were observed also, and collection of samples were done.
In the laboratory collected samples were analyses as follows. Needles, shoots, parts of branches and cone scales were kept in humid conditions in petri dishes for day or two.
Analyses of prepared samples were done under the stereomicroscope (illuminations 4-16 x).
Observed fungus fruit bodies and host tissue were used to make cross section slides, and analysed under the light microscope (illuminations 100 - 400 x). A few isolations from the necrotic tissues under the bark of die back shoots and branches have been done. Malt Extract Agar (CM 59) "Oxoid" was used as media to obtain and purify fungus isolates.
Results
Field observations and laboratory analyses carried out from April 1992 to November 1998 revealed following data. On some localities pines were in relatively good condition. On the other hand on some localities dibeck symptoms on Austrian pine were noticed: Buje stanica, Kanegra, Fazana, Puntera, Marina, Prtlog, Krsan, Plomin, Rabac, Klenovica and Lopar (Figure 1). In the area ofZagreb city dieback was noticed onPinus heldreichii var.
leucodermis (Ant.) Markgraf and P. nigra as well. It was generally established that the crown die back intensity vary form 5 to 100 %. On some localities Marina and Prtlog, Figure 1, research area No.: 2 and 6) up to 30% of all observed trees were attacked.
Analyses of collected samples (needles, shoots, branches and cones) from pine trees with dieback symptoms showed that among different fungi foundS. sapinea (Fr.) Dyko et Sutton was the most frequent. Other fungi found:
on needles: Cyclaneusma niveum (Fr.) DiCosmo, Peredo et Minter, Lophodermium seditiosum Minter, Staley et Millar, Lophodermium pinastri (Schard. ex Hook.) Chev., Leptostroma seditiosum Fr., Leptostroma pinastri Desm., Truncate/la hartigii (Tub.) Stay.;
on shoots: Truncate/la hartigii (Tub.) Stay.;
on branches: Cenangium ferruginosum Fr.
Isolations from the necrotic tissues under the bark of die back shoots and branches of P. nigra (Prtlog locality) and P. heldreichii var. leucodermis (Zagreb locality) confirmed the fungus presence.
S.sapinea was also found on samples of P. brutia Ten., P. halepensis Mill., and P.
sylvestris L. trees, but with no significant dieback symptoms.
Discussion
Research revealed the differences in S. sapinea impact on different pine species and in its occurrence on research localities in Croatia. On some of them it has been established just a presence of the fungus (Figure 1, research area No.: 1, 3, 4, 9, 11, 12) and on the other
localities its outbreak (Figure 1, research area No.: 2, 5, 6, 7, 8, 10).
The symptoms observed in the field were dieback of young and older shoots, branches and hole crowns of pine trees. The same symptoms were notified in parks and gardens. P.
nigra turned out as the most susceptible pine species in plantations, parks and gardens, although dieback was also strongly observed on P. heldreicii var. leucodermis in parks and gardens in the city ofZagreb.
According to research on fungus isolates (Diminic 1997), obtained from pycnidia on necrotic needles from different localities, it was established that all belong to the group of virulent morphotype A described by Palmer et al. (1987). Isolates significantly differ among each other in growth rate, but in inoculation experiment they showed, with no significant difference, capability to attack pine seedlings through wounds on the bark, and cause the tissue necrosis, which led to seedlings dieback.
Based on aforementioned results on S. sapinea occurrence and the presence of only virulent morphotype A on pines in Croatia, it has been concluded that the reason for fungus outbreak on some localities should be targeted to predisposing factors . Drought, poor site conditions, increased air born nitrogen deposition, wounds caused by hail, frost, insects and pruning, are considered to be the pines predisposing factors to fungus attack by many authors
(Haddow & Newman 1942, Punithalingam & Waterston 1970, Torres-Juan 1971, Chou 1984, Bachi & Peterson 1985, De Kam & al. 1991, Nicholls & Ostry 1990, Stanosz 1994).
The following factors have been analysed according to available data.
Drought. During the period March- September 1991 approximately 30% precipitation deficit occurred in Istria region (Figure 1, research area No.: 1 to 6). In the December 1991 the local foresters noticed first dieback symptoms in pine crowns on locality No. 6. Research area No. 6 (with pines dieback) had 559 mm and research area No. 1 (with no dieback symptoms) had 871 mm of total precipitation in that period.
Drought. During the period March- September 1991 approximately 30% precipitation deficit occurred in Istria region (Figure 1, research area No.: 1 to 6). In the December 1991 the local foresters noticed first dieback symptoms in pine crowns on locality No. 6. Research area No. 6 (with pines dieback) had 559 mm and research area No. 1 (with no dieback symptoms) had 871 mm of total precipitation in that period.