Nejc Jogan

Genetic diversity in widespread species is not congruent with species richness in alpine plant communities

The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies.

Determination key for Central European Epilobium species based on trichome morphology

Abstract.Strgulc Krajšek S., Dermastia M. and Jogan N. 2006. Determination key for Central European Epilobium species based on trichome morphology. Bot. Helv. 116: 169 – 178.The distribution and morphology of trichomes was investigated for 14 European Epilobium species (section synstigma) to evaluate their taxonomic relevance. Three kinds of trichomes were detected. Tapering trichomes without glandular activity occurred in all examined species but differed in their distribution on the plant. Blunt trichomes with a rounded tip were only present in some of the species. They were of two types, one of which possessed glandular activity. Together, trichomes characteristics allowed a clear distinction of the 14 species and were included in a determination key.Zusammenfassung.Die Anordnung und Morphologie der Haare von 14 europäischen Epilobium Arten wurde untersucht, um ihre taxonomische Bedeutung und Eignung als Bestimmungsmerkmale zu beurteilen. Drei verschiedene Haarformen wurden ermittelt. Spitze Haare ohne glanduläre Aktivität kamen bei allen überprüften Arten vor, aber es gab offensichtliche Unterschiede bezüglich ihrer Verteilung auf der Pflanze. Die abgerundeten Haare waren entweder gerade abstehend oder an der Basis gekrümmt. Nur die abstehenden Haare hatten eine Drüsenfunktion. Die abgerundeten Haare waren nicht bei allen überprüften Epilobium-Arten vorhanden. Die beobachteten Merkmale ermöglichten eine eindeutige Unterscheidung der meisten untersuchten Epilobium-Arten und wurden in einem Bestimmungsschlüssel zusammengefasst.

Morphology and glandular activity of unicellular trichomes of Epilobium hirsutum

The unusual glandular trichomes of willow-herbs (Epilobium hirsutum L.) were investigated. They are unicellular, without a specialized basal cell at the layer of the epidermis. They have a cutinized cell wall, a prominent and heavily cutinized wall thickening at the base, and a protruding pore on the top. Among other compounds they contain several flavonoids, e.g. quercitrin and myricitrin. Flavonoids were localized inside the upper part of the trichome cell and most likely were not excreted through the trichome pore.

Luzula sect. Luzula (Juncaceae) in the South-Eastern Alps: morphology, determination and geographic distribution

Bačič T., Dolenc Koce J. and Jogan N. 2007. Luzula sect. Luzula (Juncaceae) in the South-Eastern Alps: morphology, determination and geographic distribution. Bot. Helv. 117: 75 – 88.Within the genus Luzula, the type section (Luzula sect. Luzula) is particularly variable and taxonomically diverse. Eight taxa of Luzula sect. Luzula occur in the Alps. While these taxa have distinct caryotypes, their identification based on morphological traits has remained problematic, and their geographic distribution is insufficiently known. A morphometric study was performed on herbarium material from Slovenia and neighbouring regions to identify additional discriminative characters and to establish the distribution of taxa within the territory of Slovenia. We measured 52 plant traits on 233 herbarium sheets and analysed the data with multivariate statistical techniques. Results showed a clear differentiation between L. campestris and the seven other taxa, which were only discriminated by combinations of several quantitative characters. In general, ripe fruits are required for a reliable determination. Four of the eight taxa are widespread in Slovenia: L. campestris and L. divulgatiformis in the lowlands (mostly < 800 m), L. exspectata at higher altitude (> 900 m), and L. multiflora across a broad altitudinal range (200–1900 m). Two taxa (L. divulgata and L. alpina) proved to be rare in Slovenia, and two taxa (L. sudetica and L. pallescens), previously reported for the area, were not confirmed. Distribution maps are presented for the six Slovenian taxa, and a new determination key is proposed for the eight Alpine taxa.

Myosotis refracta Boiss. (Boraginaceae), an unexpected forget-me-not in the Slovene flora

Abstract Myosotis refracta Boiss. is reported as a new and unexpected finding for the Slovene flora. The species was found in three collections stored in the Herbarium LJU from south-east Slovenia, in the Kolpa river valley bordering Croatia. All plants thrived under overhanging dolomite rocks. On account of an earlier misidentification, the respective plant community had been described as the association Arabido alpinae-Myosotidetum strictae Accetto 2008, which is here corrected to Arabido alpinae-Myosotidetum refractae Accetto 2008 corr. Strgulc Krajšek, Accetto & Jogan 2016. Myosotis refracta has a disjunct Mediterranean-southwest Asian distribution. The reported new localities extend its known range more than 500 km in north-west direction, from its nearest known occurrences on the southern Balkan peninsula.

Synecology of Cutandia maritima (L.) Barbey, a rare psammophytic species along the Montenegrin Coast (East Adriatic Coast)

Abstract Cutandia maritima is a circum-Mediterranean species that inhabits sandy dunes along the coast line. It is fairly frequent on the western Adriatic coast but fairly rare and possibly even non-native in the east. In Croatia, it was discovered in 1990 in Crnika Bay on the island of Rab, which was considered until 2005 to be the only site on the eastern Adriatic coast from the Gulf of Trieste in the north to Corfu in the south. In 2009, the species was briefly reported for Velika plaža (Long Beach) in Ulcinj (Montenegro) but without details about the habitat type and synecology. The aim of this paper is thus to provide a deeper insight into the ecology and synecology of C. maritima in the eastern Adriatic part of the distribution area. On Velika plaža in Ulcinj, the species was found along the whole sea-inland gradient of sand dunes, in various types of vegetation: [1210] - annual vegetation of drift lines, [2110] - embryonic shifting dunes, [2120] - shifting dunes with Ammophila arenaria (white dunes), [2220] - dunes with Euphorbia terracina, [2130*] - fixed coastal dunes with herbaceous vegetation (grey dunes), and also [2190] - humid dune slacks.

Muhlenbergia Schreberi J. F. Gmel (Poaceae), a New Naturalized Species in Croatia

Abstract Muhlenbergia schreberi, nimblewill, is a widespread North American perennial grass species, slowly spreading in European countries, where it has been recorded in Spain, Switzerland, Italy, and Slovenia. In addition, a well naturalized population was discovered in Opatija (Northwestern Croatia, Croatian Littoral) in 2011 as described herein. It has been recognized as a persistent weed in some North American states, and in the last few decades its secondary European distribution range has been slowly increasing. Thus most probably it will also spread in Croatia and become classified as invasive.