Branko Vreš

Determinants of within-patch microdistribution and movements of endangered butterfly Coenonympha oedippus (Fabricius, 1787) (Nymphalidae: Satyrinae).

Determinants of Within-Patch Microdistribution and Movements of Endangered Butterfly Coenonympha Oedippus (Fabricius, 1787) (Nymphalidae: Satyrinae) The within-patch microdistribution and movements of adults of the critically endangered butterfly, Coenonympha oedippus, were studied using mark-recapture data from an isolated patch network, which consisted of 8 patches in central Slovenia. The impact of patch characteristics on both parameters was analyzed. Males fly longer distances and spend more time flying than females. The distances and seasonal pattern of male movements were dependent on the patch size, and on the microdistribution and density of freshly emerged (receptive) females. The spatial and temporal pattern of female microdistribution was influenced by vegetation height, the homogeneity of host plant stands and the shading of the ground and/or the lowest parts of herb layer. In the case of near continuous distribution of host plants within a patch, the structure of herb vegetation appears to be the major determinant of adult microdistribution. It affects the dynamics of butterfly emergence and the selection of oviposition sites. The per cent cover of the nectar plant, Potentilla erecta, does not play an important role in butterfly microdistribution. V izoliranem omrežju osmih habitatnih krp v osrednji Sloveniji smo z metodo markiranja, izpusta in ponovnega ulova raziskovali prostorsko razporeditev in gibanja imagov kritično ogrožene vrste Coenonympha oedippus v habitatni krpi in vpliv značilnosti krpe na oba proučevana parametra. Samci preletavajo daljše razdalje in v dnevni aktivnosti več časa porabijo za let kot samice. Preletne razdalje in vzorci preletavanja samcev v sezoni so odvisni od velikosti krpe ter prostorske razporeditve in populacijske gostote sveže izleglih (receptivnih) samic. Na prostorske in časovne vzorce disperzije samic vplivajo višina vegetacije, homogenost sestoja hranilnih rastlin gosenic in osončenost spodnje plasti zeliščne vegetacije. Če je razporeditev larvalnih hranilnih rastlin v krpi enakomerna in kontinuirana, je struktura zeliščne vegetacije najpomembnejši dejavnik, ki določa disperzijo imagov, saj vpliva na dinamiko izleganja iz bub in izbiro mest za ovipozicijo. Pokrovnost vrste Potentilla erecta, ki je hranilna rastlina odraslih osebkov, ne vpliva na razporeditev odraslih osebkov v krpi.

The Association Drepanoclado Uncinati-Heliospermetum Pusilli (Arabidetalia Caeruleae, Thlaspietea Rotundifolii) in the Trnovski Gozd Plateau (Slovenia, NW Dinaric Mts)

The Association Drepanoclado Uncinati-Heliospermetum Pusilli (Arabidetalia Caeruleae, Thlaspietea Rotundifolii) in the Trnovski Gozd Plateau (Slovenia, NW Dinaric Mts) The phytosociology and ecology of Heliosperma pusillum in freezing ravines of the Trnovski gozd plateau (Slovenia, NW Dinaric Mts) are discussed. The species thrive on shadowy, moist, cold and stable screes of boulders with long-lasting snow cover. The stands belonged to the association Drepanoclado uncinati-Heliospermetum pusilli (Salicion retusae, Arabidetalia caeruleae, Thlaspietea rotundifolii). Due to close proximity to the Julian Alps, the stands host a significant number of SE - Alpine and N-Illyrian species. Therefore, a new geographical variant Paederota lutea is described. Differential species for the geographical variant are Phyteuma scheuchzeri ssp. columnae, Valeriana saxatilis, Rhodothamnus chamaecistus, and Saxifraga cuneifolia. For less stable screes with smaller rocky particles a new subassociation salicetosum retusae is described, and the differential species for the subassociation are Salix retusa and Poa alpina. Stands of the association Drepanoclado-Heliospermetum var. geogr. Paederota lutea from the Trnovski gozd plateau are on the north-westernmost part of the distribution area of the Dinaric alliance Salicion retusae. Asociacija Drepanoclado uncinati-Heliospermetum pusilli (Arabidetalia caeruleae, Thlaspietea rotundifolii) v Trnovskem gozdu (Slovenije, SZ Dinarsko gorstvo) Preučili smo fitocenološke in okoljske razmere vrste Heliosperma pusillum v mraziščih v Trnovskem gozdu (Slovenija, SZ Dinaridi). Vrsta uspeva na senčnih, vlažnih in hladnih ustaljenih meliščih in skalnatih blokih z dolgotrajno snežno odejo. Sestoji, v katerih uspeva vrsta Heliosperma pusillum, pripadajo združbi Drepanoclado uncinati-Heliosperetum pusilli (Salicion retusae, Arabidetalia caeruleae, Thlaspietea rotundifolii). Zaradi bližine Julijskih Alp je v sestojih prisotnih precej jugovzhodno-alpskih in severno-ilirskih vrst. Zato smo opisali novo geografsko varianto in jo poimenovali po vrsti Paederota lutea var. geogr. nova. Razlikovalne vrste za geografsko varianto so Paederota lutea, Phyteuma scheuchzeri ssp. columnae, Rhodothamnus chamaecistus, Saxifraga cuneifolia, and Valeriana saxatilis. Na manj umirjenih meliščih z drobnejšim kamenjem smo opisali novo subasociacijo salicetosum retusae subass. nova. Za razlikovalnici smo določili vrsti Salix retusa in Poa alpina. Sestoji asociacije Drepanoclado-Heliospermetum var. geogr. Paederota lutea iz Trnovskega gozda so na skrajnem severozahodnem robu areala vegetacije snežnih dolinic iz dinarske zveze Salicion retusae.

Seed and Root Endophytic Fungi in a Range Expanding and a Related Plant Species

Climate change is accelerating the spread of plants and their associated species to new ranges. The differences in range shift capacity of the various types of species may disrupt long-term co-evolved relationships especially those belowground, however, this may be less so for seed-borne endophytic microbes. We collected seeds and soil of the range-expanding Centaurea stoebe and the congeneric Centaurea jacea from three populations growing in Slovenia (native range of both Centaurea species) and the Netherlands (expanded range of C. stoebe, native range of C. jacea). We isolated and identified endophytic fungi directly from seeds, as well as from roots of the plants grown in Slovenian, Dutch or sterilized soil to compare fungal endophyte composition. Furthermore, we investigated whether C. stoebe hosts a reduced community composition of endophytes in the expanded range due to release from plant-species specific fungi while endophyte communities in C. jacea in both ranges are similar. We cultivated 46 unique and phylogenetically diverse endophytes. A majority of the seed endophytes resembled potential pathogens, while most root endophytes were not likely to be pathogenic. Only one endophyte was found in both roots and seeds, but was isolated from different plant species. Unexpectedly, seed endophyte diversity of southern C. stoebe populations was lower than of populations from the north, while the seed endophyte community composition of northern C. stoebe populations was significantly different southern C. stoebe as well as northern and southern C. jacea populations. Root endophyte diversity was considerably lower in C. stoebe than in C. jacea independent of plant and soil origin, but this difference disappeared when plants were grown in sterile soils. We conclude that the community composition of fungal endophytes not only differs between related plant species but also between populations of plants that expand their range compared to their native habitat. Our results suggest that fungal endophytes of two Centaurea species are not able to systemically infect plants. We highlight that endophytes remain poorly studied and further work should investigate the functional importance of endophytes.

Orobanche Pancicii Beck, a New Species to the Flora of Slovenia

Orobanche Pancicii Beck, a New Species to the Flora of Slovenia We describe localities and sites of Orobanche pancicii, a new species of the Slovenian flora. It was recorded in the subalpine belt (1500 to 2000 m a.s.l.) on forest edges, clearings and on stony grasslands in the Julian Alps and the eastern Karavanke mountains, on the hosts Knautia drymeia, K. longifolia and Scabiosa lucida. V članku opisujemo nahajališča in rastišča nove vrste slovenske flore, Orobanche pancicii. Našli smo jo v subalpinskem pasu (1500 do 2000 m nm. v.) na gozdnih robovih, jasah in na kamnitih traviščih v Julijskih Alpah in v vzhodnih Karavankah, na gostiteljih Knautia drymeia, K. longifolia in Scabiosa lucida. Uvajamo tudi slovensko ime Pančičev pojalnik.

Cyperus eragrostis Lam. - a new adventitious species in the flora of Slovenia.

Cyperus Eragrostis Lam. - A New Adventitious Species in the Flora of Slovenia About ten years ago Cyperus eragrostis, a species originating in the tropical parts of South America, settled in a trench near the house at Podsabotin 49 in the Goriška Brda. From there the plant spread to similar neighbouring ruderal sites with hydromorphic soil, to roadside ditches and gravelly banks of the Pevmica, a stream on the border between Slovenia and Italy. Applying the standard Central-European phytosociological method we studied the stands in which this species grows together with other hygrophilous and ruderal species. These stands are dominated by character species of the classes Bidentetea tripartitae, Filipendulo-Convolvuletea, Molinio-Arrhenatheretea, Stellarietea mediae and Galio-Urticetea. Cyperus eragrostis is a new adventitious species in the Slovenian flora. Its ephemeral occurrence in Slovenia was first noted in Istria in 2003 (near Portorož, probably in the Sečovlje salt-pans) and later in 2006 (Gračišče). Its presence in Podsabotin and along the Pevmica, however, is not merely transitional (ephemeral); here, this alien species is likely to have already naturalized in the environment with warm and relatively moist sub-Mediterranean climate. Cyperus eragrostis Lam. - nova adventivna vrsta v flori Slovenije Cyperus eragrostis, vrsta, ki je doma v tropskih predelih Južne Amerike, se je pred približno desetimi leti naselila v izkop pri hiši Podsabotin 49 v Goriških Brdih. Od tam se je razširila na podobna okoliška ruderalna rastišča s hidromorfnimi tlemi, v obcestne jarke in na prodnate bregove Pevmice, ki je mejni potok med Slovenijo in Italijo. Po standardni srednjeevropski fitocenološki metodi smo preučili sestoje, v katerih uspeva skupaj z drugimi vlagoljubnimi in ruderalnimi vrstami. V njih prevladujejo značilnice razredov Bidentetea tripartitae, Filipendulo-Convolvuletea, Molinio-Arrhenatheretea, Stellarietea mediae in Galio-Urticetea. Cyperus eragrostis je nova adventivna vrsta v flori Slovenije. Prvič je bilo v Sloveniji zabeleženo njeno efemerno pojavljanje v Istri leta 2003 (pri Portorožu, verjetno v Sečoveljskih solinah) in kasneje še leta 2006 (Gračišče). Njena prisotnost v Podsabotinu in ob Pevmici ni zgolj prehodna (efemerna), temveč se je v okolju s toplim in razmeroma vlažnim submediteranskim podnebjem ta tujerodna vrsta že udomačila (naturalizirala).

Stellaria nemorum L. andS. montana Pierrat (Caryophyllaceae) in the Forest Communities of Slovenia

Morphological and coenological differences between closely related speciesStellaria nemorum L. andS. montanaPierrat are described.Stellaria montana is frequent in Slovenia and occurs mostly in the montane belt (altitude 600–1200 m). It has been recorded in thirty two forest communities (associations or lower syntaxa). Although widely distributed in EuropeS. nemorum is more rare in Slovenia. It occurs mostly in upper-montane (altimontane) and subalpine belt (altitude 1200–1600 m) in ten forest or shrubby communities. Both,S. nemorum andS. montana are valuable diagnostic species for certain associations. They characterize sites with fresh soil, rich in nitrogen. As an example we present two syntaxa of beech forests of Slovenia, in which the species of theS. nemorum group have high constancy and cover value.

Microtopography determines the habitat quality of a threatened peatland butterfly at its southern range margin

Knowledge of the ecology of pre-adult stages of an organism at its species’ range margins is a prerequisite for conserving species, especially for understanding its responses to future climate changes. Largely sedentary premature life stages require specific living conditions within a relatively small area. Such conditions are created by vegetation structure heterogeneity and a microclimate gradient, generated by varying microtopography. We investigated the microhabitat selection patterns of egg-laying females and overwintering caterpillars of peatland butterfly Coenonympha tullia relative to vegetation composition, water quantity and microclimatic conditions across microtopographic zones of transition mire at the species’ southern range margin. We showed that (1) small-scale variability in mire microtopography determines oviposition site selection and larval presence; (2) microhabitats of pre-adult stages were largely confined to the intermediate microtopographic zone of the transition mire (flats); (3) egg-laying females and overwintered larvae preferred microsites with high coverage of main hostplants (Trichophorum alpinum, Carex lasiocarpa, C. limosa, C. panicea), and those with more humid and cooler summertime conditions than on hummocks; (4) females and larvae avoided shallow hollows permanently filled with water. The vegetation structure of flats enables the females to select spots with sufficient humidity for egg development, and allows the larvae to change their location according to suitable thermal and moisture conditions. We also discuss poor prospects for species in view of impacts of future climate changes on mire ecosystems.