Experimental Ecology and Geobotany -...
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Scientifica Acta 2, No. 2, 93 – 96 (2008) Experimental Ecology and Geobotany Lichens and monuments: searching for the balance between the necessity of restoration and preservation, and the im- provement of the naturalistic-environmental aspects of the historical-architectural heritage Mauro Rigamonti Dipartimento di Ecologia del Territorio, Università di Pavia, Via S. Epifanio 14, 27100 Pavia, Italy [email protected] This paper presents the results of an investigation on lichen presence on some works in stone in 4 historical sites in the Pavia area (NW Italy). Releves were carried out on different types of substrata both natural, and artificial such as concrete. The floristic study recorded a total of 54 lichen taxa, some of which are of definite interest in that they had not yet been reported in Lombardy and/or defined as being extremely rare in the Po Valley phytoclimatic region. Preliminary data indicates that the majority of the species are neutro-basiphytic and nitrophytic, rather than xerophytic or photophytic. Finally, the study underlines that lichens also act as a useful indicator as to the conditions of the place. 1 Introduction All over the world people are paying increasing attention to the problem of the preservation, and of the pre- vention against the deterioration of artistic heritage; in particular the biodeterioration, i.e. the mechanical- physical processes and/or chemicals induced by the activities of organisms that determine deteriorating actions of the substratum. Diverse factors, such as climate and type of substrata, regulate the colonization of monuments and artefacts by live organisms [1]. This work has as its object the study of the lichen communities that grow on stone artefacts in some localities in the Pavia area. The study concerns two historical gardens, the Botanical Gardens of Pavia University and those of Belgioioso Castle (Pavia), and two cemeteries, Parasacco and Torre d’Isola (Figure 1 and Figure 2). Scopes of the research were: 1. to evaluate the biodiversity of the lichens that colonize monuments and artefacts 2. to individualize eventual indicative species of the state of conservation of the artefact, useful when planning interventions of preservation 3. to increment knowledge of the lichens that colonize the monuments in the NW of the country. 2 Survey area The areas of study are in the province of Pavia: the first, the Botanical Gardens of Pavia University, in an urban environment, the second, the Belgioioso Castle park, in an almost country environment, and lastly the cemeteries of Parasacco (hamlet of Zerbolò) and Torre d’Isola which are in rural areas. The climate is continental similar to that of the Po Valley type, characterized by hot humid summers, and harsh foggy winters with little rain. The areas are also characterized by high humidity and extremely variable rates of pollution. © 2008 Università degli Studi di Pavia
Transcript of Experimental Ecology and Geobotany -...
Scientifica Acta 2, No. 2, 93 – 96 (2008)
Experimental Ecology and Geobotany
Lichens and monuments: searching for the balance betweenthe necessity of restoration and preservation, and the im-provement of the naturalistic-environmental aspects of thehistorical-architectural heritage
Mauro RigamontiDipartimento di Ecologia del Territorio, Università di Pavia, Via S. Epifanio 14, 27100 Pavia, [email protected]
This paper presents the results of an investigation on lichen presence on some works in stone in 4 historicalsites in the Pavia area (NW Italy). Releves were carried out on different types of substrata both natural,and artificial such as concrete. The floristic study recorded a total of 54 lichen taxa, some of which areof definite interest in that they had not yet been reported in Lombardy and/or defined as being extremelyrare in the Po Valley phytoclimatic region. Preliminary data indicates that the majority of the species areneutro-basiphytic and nitrophytic, rather than xerophytic or photophytic. Finally, the study underlines thatlichens also act as a useful indicator as to the conditions of the place.
1 Introduction
All over the world people are paying increasing attention to the problem of the preservation, and of the pre-vention against the deterioration of artistic heritage; in particular the biodeterioration, i.e. the mechanical-physical processes and/or chemicals induced by the activities of organisms that determine deterioratingactions of the substratum.
Diverse factors, such as climate and type of substrata, regulate the colonization of monuments andartefacts by live organisms [1].
This work has as its object the study of the lichen communities that grow on stone artefacts in somelocalities in the Pavia area.
The study concerns two historical gardens, the Botanical Gardens of Pavia University and those ofBelgioioso Castle (Pavia), and two cemeteries, Parasacco and Torre d’Isola (Figure 1 and Figure 2).
Scopes of the research were:
1. to evaluate the biodiversity of the lichens that colonize monuments and artefacts
2. to individualize eventual indicative species of the state of conservation of the artefact, useful whenplanning interventions of preservation
3. to increment knowledge of the lichens that colonize the monuments in the NW of the country.
2 Survey area
The areas of study are in the province of Pavia: the first, the Botanical Gardens of Pavia University, in anurban environment, the second, the Belgioioso Castle park, in an almost country environment, and lastlythe cemeteries of Parasacco (hamlet of Zerbolò) and Torre d’Isola which are in rural areas.
The climate is continental similar to that of the Po Valley type, characterized by hot humid summers,and harsh foggy winters with little rain. The areas are also characterized by high humidity and extremelyvariable rates of pollution.
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a) b)
Fig. 1: a) The main entrance of the Botanical Gardens of Pavia with fountain and stone stairway. b) Nitrophilouslichen communities growing on a tombstone in the Parasacco cemetery.
At Belgioioso the monuments date from the 18th Century, the time the castle was enlarged when DonAntonio, first Prince of Belgioioso, on the occasion of Belgioioso becoming a principality (1769) adornedthe palace and the gardens with statues and fountains.
The statues, the balustrades of the stairway, etc., in the Botanical Gardens of Pavia, are more recent:they date from the renovations of 1933-35 by the Botanical Institute, and the Gardens soon after the SecondWorld War, in 1957 [2].
In the two cemeteries the artefacts can be dated from the end of the 19th Century and right throughthe 20th Century. The substrata are of different kinds of stone, most of it is of a limestone nature: inthe Botanical Gardens we find statues in Vicenza Stone, while sandstone and white marble prevail atBelgioioso Castle. We also find artefacts in marble and concrete in the Parasacco cemetery, while thelithologies in that of Torre d’Isola are more heterogeneous, with a prevalence of granite and concrete.
3 Materials and methods
The study of the flora involved the identification of the species of lichens both in the field and in thelaboratory. We used analytical keys [3-4-5-6-7-8-9], optical instruments (stereomicroscope and micro-scope) and chemical tests with reagents applied on the upper cortex of the thallus and on the medulla. Acomparison was then made with the information available in the Italic database [10] relative to the Ital-ian lichens. Subsequently the lichen communities were studied, by means of phytosociological relevès,according to the method suggested by Braun-Blanquet (1964)[11], and the types of vegetation were de-fined through the multivariate analysis of the data using the SYN-TAX 2000 [12] programme. Finally, theecological indexes were elaborated and a comparison of the results obtained from the various sites wasmade.
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a) b)
Fig. 2: a) Protoparmeliopsis muralis (green) and Candelariella vitellina (yellow) growing on a tombstone in Torred’Isola cemetery. b) The Neptune fountain in Belgioioso Castle Park.
4 Results
The floristic study enabled us to identify a total of 54 lichen taxa, some of which are of definite interestin that they had not yet been reported in Lombardy and/or defined in any of the literature [10] as beingextremely rare in the Po Valley phytoclimatic region. Further species are indicated, moreover, as being ofparticular floristic and ecologic interest.
Although the area does not extend very far, the lichen biodiversity is rather high both in Parasacco andin Torre d’Isola, while the floristic wealth of Belgioioso Castle is average.
Finally, in the Botanical Gardens the number of species found is decidedly lower and confirms the factthat lichens suffer greatly from city pollution and, above all, from atmospheric pollution.
The results have made is possible to distinguish some lichen communities growing on the various sub-strata.
5 Conclusions
Lichens can supply information even on the degree of naturalness of the environment because they areexcellent atmospheric pollution bioindicators.
The study has brought us to qualitative and quantitative evaluations of the florula and of the lichencommunities present on the lithologic artefacts on the survey sites.
Considering the data obtained, we advise against removing the lichens from the artifacts.In conclusion we would like to underline the cultural importance of biodiversity, a concept that has only
recently been taken into account in Italy but, without doubt, should be encouraged.In fact, if on one hand lichens can be considered as being a disturbance that must be eliminated because
of chemical-physical deterioration and because of the chromatic alteration that some species cause, on theother hand, following a naturalistic approach, they can act as a useful indicator as to the conditions of theplace.
6 Further information
For additional information please write to [email protected]
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Acknowledgements I would like to thank the following people for their precious help: Mariagrazia Valcuvia Pas-sadore, Daniela Chiappetta, Maura Brusoni, Marco Calvi, Debora Di Silvestro and Sunil Morgan Costanza. I’m alsograteful to my parents, Angela and Giuseppe, and to my brothers, Luca and Davide, for their support.
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and Protection of Cultural Heritage (Plenum, New York, 2000) pp. 250.[2] AA. VV., Storia e Immagini dell’Orto Botanico di Pavia (Antares, Pavia, 2002) pp.187.[3] P. Ozenda, G. Clauzade, Les lichens. Étude Biologique et Flore Illustrèe (Masson et C.ie Éditeurs, 1970) pp. 801.[4] G. Clauzade, C. Roux, Likenoj de Okcidenta Europo. Ilustrita Determinlibro. Bulletin de la Società Botanique
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[10] P. L. Nimis ,S. Martellos, ITALIC - The Information System on Italian Lichens. Version 4.0. University of Trieste,Dept. of Biology, IN4.0/1 (http://dbiodbs.univ.trieste.it/) (2008).
[11] J. Braun-Blanquet, Pflanzensoziologie. Grundzüge der Vegetationskunde (Springer, Wien, 1964) pp. 864 .[12] J. Podani, Syn-tax 2000 - Computer program for multivariate data analysis in ecology and systematic (Scientia
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