Volume 17 (2018): Edition 2 (December 2018)

New approach for the classification of the Black Pine forest communities in Bulgaria was made in the paper. The analysis of forest pytocoenoses from Vlahina, East and West Rhodopi and Balkan Range Mountains confirmed their separation into two classes – Quercetea pubescentis (low-altitudinal) and Erico-Pinetea (high-altitudinal). The second class is represented from one polymorphic association Seslerio latifoliae-Pinetum nigrae whereas the other group is represented from two new associations. The association Junipero deltoidi-Pineteum pallasianae is more related to the surrounding thermophilous oak forests as well as the association Lathyro laxiflori-Pinetum pallasianae is more similar to the hornbeam and beech forests.

Replacing native forests by alien tree plantations can lead to changes in the species composition of the understory. However, differences in the understory species spectrum can also be a part of the natural variability of forest stands. We have tested the suitability of the twin plots method for an evaluation of the impact of alien trees on the species composition of the understory. This research was conducted on an alluvial plain (SW Slovakia) that was originally covered by a hardwood floodplain forest. The study was based on 7 twin plots of black locust (Robinia pseudoacacia) and native forest plots, with a maximum distance of 100 meters between the members of the twins. The dissimilarity of the plots within the black locust forest was significantly lower than the dissimilarity between the twin plots. In addition, the dissimilarity of the plots within the hardwood floodplain forest was also significantly lower than the dissimilarity between the twin plots. Under the same environmental conditions, the higher dissimilarity of the twin plots was caused by major edificators and their impact on the understory vegetation. The twin plots method proved to be a suitable tool for analyses of the impact of alien trees on understory vegetation.

This study reports the results of the evaluation of changes in the species diversity and composition of ruderal vegetation of three Slovak and one Czech city over the time. The dataset of 1489 relevés from five ruderal syntaxa from the cities Bratislava, Malacky, Trnava and Brno was used. Data were from two different time periods, the older dataset from the years 1960–1982, the more recent dataset from the years 2005–2016. The statistical analysis revealed the decrease of Shannon–Wiener diversity index of all (native + alien) species in the majority of classes of ruderal vegetation of cities. The analysis of the changes in the Pielou’s measure of species evenness showed that in some of the classes and cities, the species evenness remained unchanged, in the other ones it decreased. The percentage of native species in the ruderal vegetation did not change over the time, but the percentage of invasive alien species in the majority of syntaxa and cities increased significantly. In total, 38 invasive taxa were recorded in the ruderal vegetation of cities. Most of them are neophytes, therophytes and belong to the family Asteraceae. The majority of invasive taxa were recorded in both time periods. Some of the invasive species, e.g. Fallopia japonica and Juncus tenuis were recorded only in the more recent time period. Our results contribute to the knowledge about biological invasions in the cities.

The vegetation of the European Natura 2000 protected area of Spercheios river and Maliakos gulf, that includes Mediterranean sclerophyllous shrublands, as well as riverine and coastal habitats, was studied during 2000 and 2014–2015. The vegetation was analysed following the Braun-Blanquet method. Twenty six plant communities were recorded, one of which (Pistacio terebinthi-Quercetum cocciferae) described for the first time. The communities belong to fifteen alliances, fourteen orders and eleven phytosociological classes. The distinguished vegetation units are described, presented in phytosociological tables and compared with similar communities from other Mediterranean countries. Eleven different habitat types were identified. Two of them (“Quercus coccifera woods” and “Reed beds”) are Greek habitat types, while the rest are included in Annex I of the Directive 92/43/EEC. Three of the latter (1420, 2110, 3170) have a scattered presence in the Natura 2000 network in Greece, while one (3170) is a priority habitat type.

Between 2011 and 2016 we surveyed 42 sites of coastal salt marshes of Croatia. We confirmed the occurrence of several rare and endangered plant species. Ten of them are included in the Red List of Croatia; critically endangered (CR) Eleocharis uniglumis, Triglochin barrelieri and T. maritima, endangered (EN) Carex divisa and C. extensa, vulnerable (VU) Parapholis incurva, Salsola soda and Suaeda maritima and category data deficient (DD) Limonium virgatum and Puccinellia festuciformis. We also report localities of other rare taxa of salt marshes like Allium telmatum, Tripolium pannonicum subsp. tripolium, Juncus gerardii, Parapholis filiformis, Plantago cornuti, Samolus valerandi and Scorzonera parviflora. Several plant species are endangered. Their habitats, salt marshes were converted into fields or destructed by construction for developing tourist infrastructure. Today only a part of the remained areas are under protection.

Species identification is fundamentally important within the fields of biology, biogeography, ecology and conservation. The genus Geranium L. (Geraniaceae) comprises about 430 species distributed throughout most parts of the world. According to the most recent treatments, subg. Geranium is the largest subgenus with over 370 species classified in ten sections. The subg. Geranium is represented in Iran by 13 species. These species are grouped 3 sections. In spite vast distribution of many Geranium species that grow in Iran, there are not any available report on their genetic diversity, mode of divergence and patterns of dispersal.

Therefore, we performed molecular (ISSR markers) and morphological studies of 102 accessions from 13 species of Geranium (subg. Geranium) that were collected from different habitats in Iran. The aims of present study are: 1) can ISSR markers identify Geranium species, 2) what is the genetic structure of these taxa in Iran, and 3) to investigate the species inter-relationship? The present study revealed that combination of morphological and ISSR data can identify the species.

Using the (unweighted) average linkage clustering (UPGMA) method we classified 458 phytosociological relevés of Larix decidua forests in the Southeastern Alps into 25 clusters. Based on their analysis we described the following new subassociations: Rhodothamno-Laricetum deciduae geetosum rivalis, sorbetosum chamaemespili, piceetosum abietis, adoxetosum moschatellinae, cystopteridetosum fragilis, cyclaminetosum purpurascentis, dryadetosum octopetalae and sorbetosum ariae. The selected method proved adequate in identifying the differences between larch stands on potential subalpine spruce and beech sites, and larch forests on the upper forest line, as well as the differences between initial larch stages on the upper forest line and more stable development stages on better developed soils on promontories and ledges above the upper beech forest line. Larch forests occur mainly in the altitudinal belt between (1,500) 1,600 and 1,800 (1,900) m, on shady aspects and slopes that are steeper than 30°. They are some of the best preserved forest types in the Southeastern Alps, on smaller surface areas (Macesnje above the Beli Potok valley in the Julian Alps) even virgin forests, and their role as biotopes is exceptional.