Itinera Adriatica

Information retrieved from: Nimis, P. L. & Tretiach, M. (1999): Itinera Adriatica - Lichens from the eastern part of the Italian peninsula. Studia Geobotanica, Vol. 18: 51-106
More information about this study are available here.

Introduction

Italy is one of the lichenologically best investigated countries in the World. Most of the records derive from the "Golden Age" of Italian lichenology, between 1846 and 1880, and from the recent, somehow surprising resurrection of Italian lichenology which started in 1987, with the foundation of the Società Lichenologica Italiana (Nimis 1988). The most important earlier studies concerned, in northern Italy, the regions of Liguria, Piemonte, Lombardia, Trentino-Alto Adige and Veneto; in southern-central Italy those of Toscana, Sardegna, and Sicilia (Nimis 1993). More recently, the lichen flora of Sardegna was studied by Nimis & Poelt (1997), and that of Calabria has been the object of a thorough monograph by Puntillo (1996), which transformed this formerly very poorly known region into the best known one of southern Italy, and probably of most of the Mediterranean area. The Adriatic, eastern part of the Italian Peninsula, stretching from the Marche to the Puglia regions, remained almost unexplored by lichenologists. Nimis (1993) reported only 187 species from Marche, 47 from Umbria, 335 from Abruzzo and Molise (all records were from Abruzzo), 383 from Puglia and 216 species from Basilicata. Such figures, when compared with those presently available for other Italian regions (e.g. more than 800 species known from Friuli, Veneto, Trentino-Alto Adige, Lombardia, Piemonte, Toscana, Calabria, Sicilia, and Sardegna), show how much the eastern side of the Italian Peninsula was neglected by lichenologists, both in the past and in more recent times. After 1993 there were only a few contributions dealing with these regions: Ravera 1998 (Umbria), Recchia et al. 1993, Recchia & Villa 1996, Olivieri & Pacioni 1996, Olivieri et al. 1997a,b, and Loppi et al. 1999 (Abruzzo), Bartoli & Puntillo 1996, 1998 (western Basilicata). This state of things has two main reasons: a) the eastern side of the Peninsula lied outside the most fashionable "Italian Tour" of the last century where most universities were located (Firenze, Pisa, Roma, Napoli); b) the eastern side of the Peninsula is, admittedly, lichenologically less interesting than its western side, due to its more "continental" climate, and to the absolute prevalence of calcareous and alluvial substrata. In order to contribute to a more even exploration of the country, we decided to dedicate much time and work to the lichenological exploration of the eastern part of the Peninsula, the least promising and probably the least interesting part of Italy. The present paper reports the results of several field surveys carried out between 1996 and 1999 in Marche, Umbria, Abruzzo, Molise, Puglia and Basilicata.


Survey Area, Data and Methods

The survey area (see map) includes the eastern side of the Italian Peninsula, from the region of Marche in the north to that of Puglia in southern Italy; the region of Basilicata, which partly belongs to Tyrrhenian Italy, and especially its eastern part, was also included. Most of the collections were gathered in the course of four field surveys:

  1. Nimis& Tretiach: April 4-13, 1996;
  2. Nimis& Tretiach: August 6-20, 1996;
  3. Nimis & Tretiach, with H. Hertel (München): April 1-6, 1997;
  4. Nimis & Tretiach, with L. Malyshev (Novosibirsk): April 13-17, 1998.
Just short before going to press, seven further stations were added thanks to two short collecting trips of M. Tretiach and P.L. Nimis, five of them in the Marche, one in Abruzzo and one in Umbria. The latter region was not included in the original plan of our Iter. However, since this is the lichenologically least known part of Italy, we decided to include it at the last moment, adding also a further small collection on the walls of the village of Castelluccio, taken during the first field trip, and originally excluded from our plan: the two collections from Umbria added 64 species to its lichen flora. The seven collections by Tretiach and Nimis, plus the earlier one in Castelluccio, will be indicated by letters (A-H), and not by numbers, in the list of localities. Altogether, 130 collecting sites were explored, 35 in the Marche, 2 in Umbria, 23 in Abruzzo, 11 in Molise, 38 in Puglia, and 21 in Basilicata. A few records only derive from more or less sporadic collections carried out ouside the main field trips. A map of the collecting sites is provided in Fig. 1. The sampling sites were selected in such a way as to cover a broad spectrum of altitudinal and ecological situations. The number of samples taken in each site, and the time devoted to its exploration, were very variable. Sometimes several hours were devoted to the investigation of natural habitats, in other cases only a few minutes were spent in sampling special habitats, such as wayside trees, roofing tiles, cement and mortar walls. No effort was made for obtaining reasonably complete floristic lists at each site and no selection of species was carried out: both trivial and rare species were collected, to obtain an estimate of their frequency in the survey area. Nomenclature mainly follows Nimis (1993) with some later updating and corrections available on the WWW (see Grube & Nimis 1997, Nimis 1999a). Authors' abbreviations are according to Brummitt & Powell (1992).


Discussion

The list reports 805 infrageneric taxa, including 777 lichenized fungi, 23 lichenicolous fungi and 5 non-lichenized fungi belonging to genera with lichenized species; the taxa are distributed among regions as follows: Marche: 417, Umbria: 106; Abruzzo: 459, Molise: 305, Puglia: 423, and Basilicata: 337. Fourteen taxa (Anema moedligense, Arthonia anombrophila, Aspicilia desertorum, Caloplaca veneris, Cresporhaphis wienkampii, Dirina cretacea, Immersaria uzbekica, Lecanora congesta, Lecanora graeca, Lecidea albohyalina, Peccania salevensis, P. tiruncula, Thelidium dionantense, and T. impressum) are new to the Italian lichen flora. In spite of these figures, the Adriatic part of the Peninsula still remains the less well-known region of the country. However, the new data substantially increase its lichen floras, and permit to test a hypothesis formulated by Nimis & Tretiach (1995) on the basis of a much poorer set of records, that of a fundamental subdivision between the western (Tyrrhenian) and eastern (Adriatic) side of the peninsula. According to these authors, Tyrrhenian Italy is characterized by a much higher incidence of suboceanic species, many of which have a subtropical character. In the following, we report the percents of suboceanic species, and of species with Trentepohlia (an indicator of tropical-subtropical affinities) in some regions of Tyrrhenian and Adriatic Italy. Tyrrhenian Italy: Liguria (22.1; 10.1), Toscana (27.0; 11.6), Lazio (27.5; 12.2), Campania (21.2; 10), Calabria (25.2; 12.3), Sicilia (23.7;10.5). Adriatic Italy (incl. regions of the north): Venezia Giulia (16.6; 8.9), Friuli (13.4; 6.3), Veneto (14.0; 8.6), Emilia-Romagna (15.2; 5.9), Marche (15.2; 8.2), Abruzzo (14.7; 7.3), Molise (11.1; 5.2), Puglia (23.8; 14.6). The differences are such as to confirm the hypothesis by Nimis & Tretiach (1995). The values relative to Puglia would be much lower if the flora of the Gargano Peninsula would be excluded: this area, with an exceptionally humid climate, gives to the lichen flora of Puglia a suboceanic flavour which does not reflect the climatic conditions prevailing in most of the region, one of the driest of Italy. The truly oceanic element, which is anyway extremely rare in Italy, is practically absent along the eastern side of the Peninsula, with the only exception of Lobaria virens in the Gargano Peninsula. Several more or less suboceanic species are much less common in Adriatic than in Tyrrhenian Peninsular Italy; among them we can cite: Acrocordia cavata, Arthonia cinnabarina, Bactrospora patellarioides, Blastodesmia nitida, Cetrelia olivetorum, Collema multipunctatum, Collema nigrescens, Collema subnigrescens, Dendriscocaulon umhausense, Diploicia canescens, Enterographa crassa, Fuscopannaria ignobilis, Fuscopannaria mediterranea, Heterodermia speciosa, Ingaderia troglodytica, Lecanographa lyncea, Lecanora lividocinerea, Lecanora pruinosa, Normandina pulchella, Opegrapha celtidicola, Opegrapha herbarum, Opegrapha ochrocincta, Opegrapha subelevata, Parmotrema chinense, Parmotrema reticulatum, Peltigera neckeri, Pertusaria hymenea, Pertusaria velata, Physconia enteroxantha, Physconia servitii, Pyrenula chlorospila, Pyrrhospora quernea, Ramalina lacera, Ramalina subgeniculata, Ramalina thrausta, Roccella fuciformis, Roccella phycopsis, Schismatomma decolorans, Thelenella modesta, Thelopsis isiaca, Usnea articulata. Species like Normandina pulchella and Parmotrema chinense which are locally almost trivial in other parts of Italy (northeastern plains, Tyrrhenian Italy) are practically absent in the survey area. Also some widespread temperate species, otherwise very common in the deciduous oak belt throughout Italy, are much less abundant along the Adriatic side of the peninsula; examples are: Candelaria concolor, Cladonia furcata, Candelariella reflexa, Parmelia caperata, and Parmelia subrudecta. Despite the scarcity of oceanic and suboceanic species, the survey area, however, has only a few, slightly subcontinental lichens which are more common in Adriatic than in Tyrrhenian Italy. Examples are: Acarospora cervina, Caloplaca decipiens, Parmelia acetabulum, and Parmelia glabra. Other more or less subcontinental species, very rare or absent in Tyrrhenian Italy, and occurring - albeit rarely - in Adriatic Italy are: Acarospora heppii, Acarospora insolata, Acarospora laqueata, Aspicilia desertorum, Caloplaca lobulata, Diploschistes diacapsis, Heppia solorinoides, Parmelia subargentifera, Psora vallesiaca, Squamarina lentigera, Teloschistes contortuplicatus, Toninia philippaea, Toninia physaroides, Toninia lutosa, Xanthoria elegans, Xanthoria fulva, Xanthoria candelaria. Some of them are just bound to dry climates, which are common anyway in the eu-Mediterranean belt. The most interesting records from Adriatic peninsular Italy are those of the non-strictly Mediterranean Acarospora laqueata and Aspicilia desertorum, and the abundance of Teloschistes contortuplicatus along the eastern slopes of the Apennines. The climates of Adriatic penisular Italy are not enough humid for allowing an abundant presence of suboceanic lichens, but also not dry-continental enough as to permit the presence of a consistent set of truly continental species. Absent from Adriatic peninsular Italy are many silicicolous species, due to the absolute prevalence of calcareous substrata. Three times we tried in vain to visit the Monti della Laga in Abruzzo, the only extensive siliceous outcrops (sandstone) of the survey area, always dissuaded by an extremely bad wheather: a future exploration of this area will be likely to increase considerably the lichen flora of Abruzzo. A very peculiar phenomenon is the frequent occurrence of some more or less silicicolous species on limestone, especially at low altitudes. Among them are: Diploschistes actinostomus, Lecanora campestris, Lecanora sulphurea, Lecidella asema, Lecidella carpathica, Lecidella stigmatea, Ochrolechia parella, Placopyrenium buceckii, Sarcogyne privigna, and Tephromela atra. This phenomenon is usually explained by a "superficial decalcification" of the calcareous rocks; however, all of the rock samples which we examined showed a clear reaction to HCl; the occurrence of silicicolous species on limestone in Adriatic Italy is probably a more complex phenomenon, where climatic conditions could play an important role, and which still awaits a more satisfactory explanation.


References