Synanthropic Flora and Vegetation

The synanthropic flora of the Lviv city was studied. It includes 663 species of vascular
plants which belong to 382 genera and 103 families of four divisions. The families which
are the most saturated of synanthropic species: Аsteraceae (15.2 %), Rosaceae (7.4 %),
Poaceae (7.2 %), Fabaceae (6.8 %), Brassicaceae (6.5 %), Lamiaceae (4.8 %), Scrophulariaceae
(3.8 %), Polygonaceae (3.2 %), Caryophyllaceae (3 %), Chenopodiaceae (3 %).
Prevailing genera of synanthropic flora are: Bromus Scop. (1.7 % видів), Vicia L., Geranium
L. (по 1.5 %), Amaranthus L., Trifolium L. (по 1.4 %), Chenopodium L., Potentilla L.
і Veronica L. (по 1. 2 %), Aster L., Atriplex L., Epilobium L. і Rumex L. (по 1 %). 31
families are represented exclusively in apophytes, and 37 – are only in adventitious species.
The apophytes fraction is larger – it accounts for 334 species. The adventitious fraction includes
329 species (archeophytes – 102 and kenophytes – 227 species). The largest number
of adventitious species occurs along roads, railways, near garbage, on abandoned sites, on
private plots. The degree of naturalization is dominated by a group of epecophytes (49.8 %),
by the way of penetration – ergasiophytes – 40.4 %.

Plant macro remains from archaeological situations were studied in order to trace the history of gradual formation of today’s synanthropic vegetation. Synanthropic plants represent a heterogeneous group of species with various qualities and strategies, as well as with various immigration histories. In general, the synanthropic flora is rich in aliens, so it is important to know, when exactly these species immigrated to our territory (to know their residence time).
Besides the determination of the residence time of alien plants, also the dynamics of formation of urban flora and vegetation was studied. Special attention was paid to the Medieval Period, when the urbanisation process started. The emergence of urban agglomeration may have been the cause of the emergence of new habitats, followed by formation of new plant associations - the predecessors of the today’s ones. In general, towns represent a special case of anthropogenic environment with many various synanthropic habitats, causing their species richness.
Questions
1. When exactly the synanthropic flora of medieval towns emerged? Was the transition from the Prehistory to the Medieval Period rather gradual or sudden?
2. What particular species took place in the medieval change of synanthropic vegetation? Where did these species come from? Was the emergence of medieval towns right the main cause of the observed change in species composition?
3. In which way was the local diversity of synanthropic flora influenced by medieval urbanisation? Did rather the new species emerge or, contrarily, the previously common ones extinct?
4. What factors influenced the spread of new species during the Medieval Period?
Materials and Methods
The data were based on the analyses of plant macroremains, sometimes in combination with other methods (mainly the pollen analysis). The case studies were focused on particular localities in Central Bohemia, tracing gradual changes taking place in each locality.
To trace general trends and to answer the questions, the Archaeobotanical Database of the CR was used, covering the time span since the Neolithic to the High Middle Ages.
Results and Discussion
218 archaeophytes were found in macro-remain material from high medieval towns, representing ca. 90% of unintentionally introduced alien plants. The majority of them have been present in our territory since the Prehistory; forty new aliens immigrated during the Early Medieval Period (EM). On the contrary, only several new aliens were introduced in High Medieval (HM). It means that the main wave of immigration took place in EM, which implies that the medieval immigration couldn’t be connected with the urbanisation process.
Medieval urbanisation influenced plant diversity in the similar way as present processes connected with urban enlargement. The diversity of semi-natural vegetation in the suburbs drops as a result of vanishing of suitable habitats, whereas the abundance of common ruderal species increases. The increase of diversity via immigration of new alien species is connected mainly with the intensity of long-distance trade (mediated by increased propagule preasure).
The frequency of alien species in medieval towns was also influenced by their residence time. The comparison of the OLD (present since the Prehistory) and NEW (since the Middle Ages) alien plants shows similar pattern as today’s comparison of archaeophytes vs. neophytes.

The aim of this article is to outline our recent knowledge of the history of anthropogenic flora based on data from archaeobotanical investigations of prehistoric sites. It is based on 207 archaeological sites (301 settlement phases) investigated in the Czech Republic. We aimed at tracing both successive changes of anthropo-genic flora, as well as the spreading history of alien plants (using computation of the immigration rate of archaeophytes). Moreover, our data reflect the origin of anthropogenic non-forest vegetation (segetal and ruderal plant communities, and also semi-natural communities such as pastures, meadows, and wet meadows). Above all, we depict the specific features of archaeobotanical analysis, and emphasise some limitations of this method when used for botanical interpretations.

The class Parietarietea judaicae Oberd. 1977 in Italy. On the basis of literature and unpublished data, a synthesis on the synanthropic chasmophilous perennial vegetation occurring in the Italian territories has been carried out. These plant communities are linked to masonry walls and rocky faces heavily disturbed by man, and are dominated by hemicryptophytes, chamaephytes and bryophytes. From the syntaxonomical point of view, in accordance with the majority of the authors who studied the matter, the wall vegetation should be ascribed to a well-distinguished class, Parietarietea judaicae Oberd. 1977, rather than to the Asplenietea trichomanis class, as proposed by other authors. Within the class, one order, Tortulo-Cymbalarietalia Segal 1969, and two alliances are represented in Italy: Parietarion judaicae Segal 1969 and Cymbalario-Asplenion Segal 1969. The first alliance, chiefly linked to the Mediterranean bioclimate, is mostly characterized by thermophilous chamaephytes, while cryptogams are nearly absent; the second one, distributed in the territories having a temperate bioclimate, is differentiated by an high abundance of small ferns and mosses. For each syntaxon the nomenclatural type and synonims are reported, as well as the indication of the main ecological, floristic and chorological characteristics. Besides, some unpublished relevés from NE-Sicily, Tuscany (Volterra) and Garda lake are presented, and a new association, Asplenio trichomanis-Umbilicetum horizontalis, is described.