2011
Letnik 13 • Volume 13

Izvleček. Namen naše raziskave je bil ugotoviti vpliv odvzema vode za potrebe hidroelektrarn Oljarica in Niko na reki Kokri in Selški Sori na združbo fitobentosa. Skupno smo v reki Kokri in Selški Sori določili 52 taksonov iz šestih razredov alg. Po številu določenih taksonov so prevladovale kremenaste alge. Primerjava vrstnih sestavov fitobentosa obeh rek na odvzemnih mestih pred in po odvzemu vode za hidroelektrarni je pokazala, da je prišlo v reki Selški Sori do znižanja biodiverzitete na odvzemnem mestu pod jezom, v obeh rekah pa so izginili nekateri taksoni, značilni za neonesnažene vodotoke, hkrati pa je bilo zaznati več taksonov, značilnih za vodotoke s povišanim organskim onesnaženjem. Na obeh rekah so bile vrednosti saprobnega indeksa na odvzemnih mestih pod odvzemom vode višje, kar je lahko posledica povečane organske obremenitve ali pa znižanega pretoka. Biomasa fitobentosa na reki Kokri je bila najvišja v predelih struge z nizko vodno gladino in upočasnjenim tokom.

Ključne besede: Alpe, fitobentos, hidroelektrarne, odvzem vode, reke, Slovenija

Abstract. The objective of our research was to determine the impact of water abstraction for hydroelectric power plant purposes Oljarica (River Kokra) and Niko (River Selška Sora) on phytobenthos community. Altogether, 52 taxa from six algal classes were determined in both rivers. According to the number of identified taxa, diatoms prevailed. Comparison of phytobenthos species compositions on both rivers before and after water abstraction showed that in the Selška Sora River phytobenthos biodiversity was lower below the dam while in both rivers decrease of algal taxa typical for unpolluted waters and increase of algal taxa typical for organically polluted waters were noticed. On both rivers, the values of Saprobic index were higher on the sites with water abstraction, which could be the result of increased organic load or reduced flow. Phytobenthos biomass in the Kokra River was the highest in the areas with low water level and low water velocity.

Key words: Alps, phytobenthos, hydroelectric power plants, water abstraction, rivers, Slovenia

Abstract We studied spatio-temporal distribution of hyporheic invertebrate community at the stream-reach scale in the River Bača on three sampling occasions (January, March, May) in 2005. On each sampling occasion, invertebrates were collected from the shallow hyporheic zone (RB1; depth 30-60 cm, 3 replicates), and deeper hyporheic zone (RB2; depth 60-90 cm, 2 replicates) in the river bed, and adjacent gravel bar (GB; depth 60-90 cm, 3 replicates) using Bou-Rouch piston pump. Concurrently, temperature, conductivity and oxygen were measured in the surface water and in hyporheic water at each sampling station. Differences in hyporheic community between dates and habitats were analysed by using two-way ANOVA (dates and habitats as fixed factors) and explored by principal component analysis (PCA). Altogether, 21,657 specimens from 63 taxa were collected. Cyclopoida juveniles, Leuctra sp. (Plecoptera), Chironomidae (Diptera), Acanthocyclops vernalis (Fischer, 1853) and Diacyclops languidus (G. O. Sars, 1863) were the most abundant in the samples. Two-way ANOVA showed significant differences between habitats (RB1 and GB), but no differences between dates when using taxonomic richness as dependent variable. No differences between habitats and dates were calculated when invertebrate densities were applied. PCA of hyporheic invertebrate data showed a gradient in community composition from shallow hyporheic zone (RB1) to deeper hyporheic zone (RB2) and gravel bar (GB). The differences were most probably due to different sediment composition in the studied habitats and less frequent disturbances due to floods in deeper layers and lateral gravel bars.

Key words: stream reach, hyporheic zone, invertebrates, distribution, community composition, spatial and temporal distribution

Izvleček. V letu 2005 je bila opravljena raziskava združbe nevretenčarjev v hiporeiku reke Bače, kjer smo opazovali prostorsko-časovno spremenljivost združbe nevretenčarjev v 3 vrstah habitatov. Nevretenčarje smo vzorčili iz globine 30 – 60 cm (RB1; 3 podvzorci) in iz globine 60 – 90 cm (RB2; 2 podvzorca) v rečni strugi ter v obrežnem prodišču iz globine 60-90 cm (GB; 3 podvzorci) v januarju, marcu in maju 2005. Merili smo tudi temperaturo vode, prevodnost in vsebnost kisika. Za testiranje razlik v številčnosti nevretenčarjev in številu taksonov med habitatoma (RB1, GB) in datumi smo uporabili dvosmerno analizo variance z vrsto habitata in datumom kot glavnima faktorjema. Sestavo združb med posameznimi habitati in datumi smo primerjali s pomočjo multivariatne analize glavnih komponent (PCA). V hiporeiku reke Bače smo nabrali 21.657 osebkov iz 63 taksonov. Najbolj številčni so bili predstavniki zgodnjih razvojnih stadijev rakov ceponožcev (Cyclopoida, Copepoda), ličinke vrbnic (Leuctra sp.) in trzač (Chironomidae) ter 2 vrsti ceponožnih rakov, Acanthocyclops vernalis (Fischer, 1853) in Diacyclops languidus (G. O. Sars, 1863). Dvosmerna analiza variance je pokazala razlike med RB1 in GB v številu taksonov, medtem ko razlik med datumi ni bilo. Številčnost nevretenčarjev ni bila značilno različna ne med habitati in ne med datumi. Analiza glavnih komponent (PCA) je pokazala gradient v sestavi združbe od plitvega hiporeika (RB1) do globljega hiporeika (RB2) in obrežnega prodišča (GB), najverjetneje zaradi različne strukture sedimenta v izbranih habitatih in bolj pogostih motenj (mešanje sedimenta) zaradi visokih voda v plitvejših slojih hiporeika.

Ključne besede: rečni odsek, hiporeik, nevretenčarji, porazdelitev, sestava združbe, prostorska spremenljivost, časovna spremenljivost

Abstract. Spreading of the invasive mosquito species Aedes albopictus in the southwestern part of Slovenia was studied in 2007 and 2010. The study was based on larval and adults search. Mosquito larvae were sampled with a dipper or a net from various artificial containers and the adults caught by human bait catches for 15 minutes. In 2007, the research was carried out in 64 municipalities, where 327 larval habitats were examined. Ae. albopictus was observed in 52 municipalities. Mosquito larvae were most often collected in small containers placed in shady areas. All the adults were caught near breeding sites. The species was found in most of the studied areas in south-western Slovenia, especially in its coastal part and near Nova Gorica. In 2010, a research was implemented in 12 municipalities that had proved negative for Ae. albopictus in 2007. The incidence of Ae. albopictus was surveyed in 100 larval habitats. The presence of Ae. albopictus was confirmed in almost all of the municipalities, which is an indicator of its firm establishment in the studied area.

Key words: Aedes albopictus, distribution, southwestern Slovenia

Izvleček. Razširjenost tigrastega komarja Aedes albopictus v JZ delu Slovenije smo preučevali v letih 2007 in 2010 na podlagi pojavljanja ličink ter odraslih osebkov. Ličinke smo vzorčili po različnih habitatih s posodico ali mrežico, odrasle komarje pa smo lovili z metodo človek – aspirator 15 minut. V letu 2007 smo pregledali 327 različnih habitatov ličink v 64 naseljih. Tigrastega komarja smo zabeležili v 52 naseljih. Komarjeve ličinke smo najpogosteje našli v manjših, osenčenih habitatih, odrasle osebke pa ob le-teh. Kot smo pričakovali, je bila gostota komarja v priobalnem pasu velika, a se je v velikem številu pojavljal tudi v preostalem delu JZ Slovenije, predvsem na Goriškem. Leta 2010 smo v raziskavo vključili 12 naselij, v katerih leta 2007 tigrasti komar ni bil potrjen. Skupno smo v letu 2010 pregledali 101 habitat ličink. Tigrastega komarja smo potrdili v skoraj vseh preiskanih naseljih, kar kaže na vzpostavitev stabilne populacije vrste na preiskovanem območju.

Ključne besede: Aedes albopictus, razširjenost, jugozahodna Slovenija

Abstract. The article presents new records of ten specimens (one juvenile, one subadult and eight snake sheddings) of four-lined snake (Elaphe quatuorlineata) recorded in a period between May 2002 and March 2011 on seven locations in Natura 2000 site Slovenska Istra (SI3000212). In some locations, the species was observed several times. Data show successful reproduction within the abovementioned Natura 2000 site.

Key words: reptiles, snakes, colubrid snakes, Colubridae, four-lined snake, Elaphe quatuorlineata, distribution, reproduction, Natura 2000, Slovenia

Izvleček. V članku so opisane nove najdbe desetih osebkov (juvenilni in subadultni osebek ter osem kačjih levov) progastega goža (Elaphe quatuorlineata) s sedmih lokacij v območju Natura 2000 Slovenska Istra (SI3000212), zabeležene med majem 2002 in marcem 2011. Na nekaterih lokacijah je bila vrsta večkrat opažena. Podatki potrjujejo uspešno razmnoževanje vrste v omenjenem območju Nature 2000.

Ključne besede: plazilci, kače, goži, Colubridae, progasti gož, Elaphe quatuorlineata, razširjenost, razmnoževanje, Natura 2000, Slovenija

Abstract. Adoption of the Water Framework Directive (Directive 2000/60/EC) includes ecological assessment of water bodies with biological communities. A WFD compliant ecological assessment includes ecological typology of water bodies, definition of reference conditions and classification system with five ecological classes. In this paper, an overview is given on the development of the ecological assessment system for Slovenian rivers. A special emphasis is laid on ecological river typology. 74 ecological river types were defined using bioregions or large rivers, and nine natural environmental descriptors recognised in literature as being important for river community composition in Slovenia. The rivers' ecological status is assessed based on two biological elements, phytobenthos and macrophytes, and on benthic invertebrates, whereas an assessment system for fish is still under development. Phytoplankton rarely occurs in Slovenian rivers; therefore phytoplankton-based assessment systems were not developed. The Slovenian river classification system consists of three modules with pressure-specific assessment methods. The impact of three groups of pressures is assessed: organic pollution (saprobity), nutrient load (eutrophication) and hydromorphological alterations/general degradation. Phytobenthos and macrophytes are used to assess river saprobic and trophic status, whereas benthic invertebrates are used to assess saprobity and impact of hydromorphological alteration/general degradation. In our study, the impact of hydromorphological alterations of the Drava River was assessed using benthic invertebrates. A Slovenian multimetric index SMEIH was calculated at fifteen sampling sites. Good to bad ecological status was assessed. Moreover, at most sites within the Heavily Modified Water Bodies of the Drava River, good ecological potential was not achieved. In conclusion, mitigation measures are needed on the Drava River in order to achieve objectives of the Water Framework Directive.

Key words: WFD, ecological status, benthic invertebrates, hydromorphology, heavily modified water bodies, ecological potential, Drava River

Izvleček. Sprejetje Vodne direktive (Direktiva 2000/60/ES) vključuje tudi ekološko vrednotenje stanja vodnih teles z združbami vodnih organizmov. Vrednotenje v skladu z vodno direktivo vključuje ekološko tipologijo vodnih teles, določitev referenčnih razmer in razvrščanje v pet razredov ekološkega stanja. V tem članku je podan pregled razvoja metodologij vrednotenja ekološkega stanja za reke v Sloveniji. Poseben poudarek je dan ekološki tipologiji rek. 74 ekoloških tipov rek je bilo določenih z uporabo bioregij oz. velikih rek in devet naravnih deskriptorjev, ki so bili v literaturi prepoznani kot pomembni za združbe vodnih organizmov v Sloveniji. Ekološko stanje voda vrednotimo z uporabo dveh bioloških elementov fitobentosa in makrofitov ter bentoških nevretenčarjev, medtem ko sistem na podlagi rib še razvijamo. Fitoplankton se v rekah v Sloveniji redko pojavlja, zato sistemi vrednotenja na podlagi fitoplanktona niso bili razviti. Slovenski sistem razvrščanja sestavljajo trije moduli sistemi vrednotenja, občutljivimi za stres. Vrednotimo vpliv treh skupin obremenitev: obremenitve z organskimi snovmi (saprobnost), obremenitve s hranili (trofičnost) in vpliv hidromorfološke spremenjenosti/splošne degradiranosti. Vpliv hidromorfološke spremenjenosti reke Drave smo ovrednotili z bentoškimi nevretenčarji. Slovenski multimetrijski indeks SMEIH je bil izračunan na 15 mestih vzorčenja. Ugotovili smo dobro do zelo slabo stanje. Za večino mest vzorčenja močno preoblikovanih vodnih teles reke Drave smo ugotovili, da ne dosegajo dobrega ekološkega potenciala. Na reki Dravi je treba izpeljati omilitvene ukrepe, če želimo doseči okoljske cilje vodne direktive.

Ključne besede: Vodna direktiva, ekološko stanje, bentoški nevretenčarji, hidromorfologija, močno preoblikovana vodna telesa, ekološki potencial, reka Drava

Abstract. The Mlake military area in Vipava Valley has been recognized as possibly the most prominent 'hot spot' of butterfly diversity in Slovenia. An area of less than one square kilometre hosts 102 butterfly species or almost 57% of the total species confirmed for Slovenia. Among these, 23 species have been recognized as nationally or continentally threatened. Due to recent urbanization, the total area suitable for butterflies has been reduced to less than half, however, the effects on butterfly diversity of the area are not yet visible. The loss of several habitat specialist butterfly species and declines visible from transect monitoring in the last five years do, however, indicate the ongoing process of habitat degradation in Mlake military area. A focused management of the remaining habitats will be required to reverse this process.

Key words: biodiversity, military area, threatened species, nature conservation, Lepidoptera

Izvleček. Vojaško območje Mlake v Vipavski dolini je verjetno ena izmed najbolj 'vročih točk' pestrosti dnevnih metuljev v Sloveniji. Na območju, manjšem od enega kvadratnega kilometra, sta bili namreč najdeni kar 102 vrsti dnevnih metuljev, ali skoraj 57 % vseh za Slovenijo potrjenih vrst. Med njimi je tudi 23 vrst s statusom ogroženosti bodisi na nivoju Slovenije ali Evrope. Zaradi nedavnih gradbenih posegov se je območje ustreznih habitatov za dnevne metulje skrčilo za več kot polovico, vendar učinek tega neposredno na pestrost vrst vsaj za zdaj še ni opazen. O degradaciji habitatov pričata izguba nekaterih specializiranih vrst dnevnih metuljev v zadnjem obdobju in zmanjševanje pestrosti in številčnosti metuljev na transektu v zadnjih petih letih. Nadaljnji degradaciji bi se lahko izognili le z načrtnim upravljanjem še ohranjenih habitatov.

Ključne besede: biodiverziteta, vojaško območje, ogrožene vrste, varstvo narave, Lepidoptera

Abstract. At the high-altitude Donje Bare and Gornje Bare Lakes in the surroundings of Tjentište village, Zelengora Mts., Sutjeska National Park, SE Bosnia and Herzegovina, Coenagrion hastulatum was recorded on 26 June 2011. The occurrence of the species on the southern border of its European range is outlined and discussed. Faunistic records on a total of 22 spp. observed at 11 localities in the southeastern part of the country between 26 and 29 June 2011 are appended.

Key words: dragonflies, distribution, disjunction, Bosnia and Herzegovina, the Balkans

Izvleček. Na visokogorskih jezerih Donje Bare in Gornje Bare v okolici vasi Tjentište, Zelengora, Nacionalni park Sutjeska, JV Bosna in Hercegovina, je bil 26.6.2011 zabeležen barjanski škratec Coenagrion hastulatum. Opisano in prediskutirano je pojavljanje vrste na južnem robu njenega območja razširjenosti v Evropi. Dodani so favnistični podatki za skupno 22 vrst, ki so bile zabeležene med 26.6. in 29.6.2011 na 11 lokalitetah v jugovzhodnem delu države.

Ključne besede: kačji pastirji, razširjenost, disjunkcija, Bosna in Hercegovina, Balkan

Izvleček. Vrsta je bila 15.7.2011 ugotovljena na rokavu reke Mure vzhodno od Petišovcev, SV Slovenija. Prikazana je njena trenutno znana razširjenost v Sloveniji in sosednjih državah. Zaradi statusa zavarovane vrste z Dodatka IV Direktive o habitatih EU ter doslej tudi statusa domnevno izumrle in zavarovane vrste po slovenski zakonodaji avtorja poudarjata, da je treba nujno ohranjati njena bivališča in opraviti nadaljnje terenske raziskave na izbranih območjih v Sloveniji.

Ključne besede: kačji pastirji, reka Mura, ogrožene vrste, Direktiva o habitatih

Abstract. The species was recorded on 15 July 2011 along the Mura River side arm channel east of Petišovci, NE Slovenia. Its currently known distribution in Slovenia and neighbouring countries is presented. Due to its status as a protected species according to Annex IV of the EU Habitat Directive and up to now also the status of probably extinct and protected species according to Slovene legislation, the need for preservation of its habitats as well as need for further field studies in Slovenia are exposed.

Key words: dragonflies, Mura River, endangered species, Habitat Directive

Abstract. There are only a few historical records of the Osiris Blue from Slovenia, and two are plausible based on the species habitat requirements. The record from gravel banks of the Sava River north of Ljubljana has been confirmed by a single female preserved in the collection of the Slovenian Museum of Natural History. Additionally, several collected specimens from Potoče village in the Vipava Valley indicate its wider distribution in the past. Currently, the species is confined to a narrow belt of the Kraški rob between Predloka and Mt. Lipnik. The habitat requirements of the species and its threat status in Slovenia are discussed.

Key words: distribution, historical records, threat status, habitat requirements

Izvleček. Znanih je zgolj nekaj zgodovinskih najdb modrega kupida v Sloveniji in od teh sta glede na prisotnost ustreznega življenjskega prostora verjetni le dve. Podatek s prodišč reke Save pri Črnučah potrjuje samica, hranjena v muzerjski zbirki (PMS). Poleg tega je med materialom tudi serija osebkov iz vasi Potoče v Vipavski dolini, kar dokazuje širšo razširjenost te vrste v Slovenji v prejšnjem stoletju. Glede na recentne podatke je vrsta pri nas razširjena le v ozkem pasu ob Kraškem robu od Predloke do gore Lipnik. Podane so glavne značilnosti habitata vrste in njena ogroženost v Sloveniji.

Ključne besede: razširjenost, zgodovinski podatki, ogroženost, habitat vrste

Abstract. This article presents the first documented records of brown coloured adults of Hierophis viridiflavus carbonarius in Slovenia, and overviews some of the historical notes on unconfirmed sightings of Hierophis gemonensis in the same area of distribution.

Key words: reptiles, snakes, colubrids, western whip snake, Hierophis viridiflavus, Slovenia

Izvleček. V članku so opisane nove potrjene najdbe rjavo obarvanih odraslih osebkov črnice (Hierophis viridiflavus) v Sloveniji. Te najdbe na območju več nepotrjenih najdb belice (Hierophis gemonensis) nakazujejo na možnost, da se slednja v Sloveniji sploh ne pojavlja.

Ključne besede: plazilci, kače, črnica, belica, Slovenija, Hierophis viridiflavus, Hierophis gemonensis