Ivan G a m s GEOGRAFSKO RAZISKOVANJE KRASA V SLOVENIJI Raziskave slovenskega krasa vzbujajo razm erom a precej zanim a­ n ja , ker je Slovenija zlasti v tu jin i v geografskih krogih znana kot de- jžela krasa. K ras zavzem a v okviru SR Slovenije tretjino ozemlja (okoli 7.000 km2). Večina ga je v južni Sloveniji, k je r geološko-tektonsko p r i­ p ad a D inarskem u gorstvu (t. i. Zunanjim Dinaridom ) in predstavlja večidel sredogorje. Večje zap la te zavzema v Julijskih A lpah in Kam ­ niških A lpah, k jer tvori visokogorske planote in dolinasti relief. V K aravankah in v predalpskem sredogorju zavzem a še daljše apneniške ali dolomitne gorske nize s kraško hidrografijo kot edinim kraškim po­ javom, v subpanonskem gričevju p a le še osamljene površine. A bsolut­ no je v p rev lad i karbonatn i kras. Bolj kot po razsežnosti je kras v Sloveniji znan zarad i zgodovine krasoslovja, saj iz njega izhaja m ednarodni term in karst. Povzet je po pokra jin i med Tržaškim zalivom in Vipavsko dolino, ki ji Slovenci p ra ­ vijo Kras, v avstroogrski m onarhiji p a je dobila nemško ime K arst. Ker je b ila Slovenija pred nacionalno osvoboditvijo izpod Avstroogrske in nastankom Jugoslavije 1. 1918 v veliki m eri znanstvena provinca avstrij­ ske geografije, se je preko nemške lite ra tu re uveljavil term in »karst«. Pod vplivom dunajske geografske in geološke šole (A. Penck) so ga uporabljali tudi jugoslovanski raziskovalci (Cvijič, Gavazzi, 1904). Po njihovi zaslugi je postal slovenski kras »klasični« kras, sloves, ki ga uživa še danes (glej W agner, 1954, Corbel, 1956), ustrezno pokrajino nad T ržaškim zalivom p a pogosto označujemo kot »matični« Kras. Raziskovalni dosežki slovenskih geografov (A. Melik, J. Rus) v času med obema vojnam a so doživeli m anj odzivnosti v tu jin i, ker so bili objavljeni v slovenskem jeziku in ker se je ozemlje njihovega raziskova­ n ja skrčilo na polovico. Zm agovalka iz prve vojne, Ita lija , je nam reč zasedla Prim orsko Slovenijo z m atičnim Krasom vred. V Postojni je osnovala vseitalijanski speleološki institu t. Kot plod njegovega dela je bil 1. 1926 objavljen kataste r jam — D uem ilalGrotte (Bertarelli-Boegan, 1926), dvatisoč jam , ki jih je večina na slovenskem etničnem ozemlju, mnoge s popačenim i imeni. Po drugi svetovni vojni je ostala I ta liji samo še slaba tre tjin a m atičnega Krasa, na trad ic iji ita lijanskega speleološkega K A R B O N A TN E (K R A Š K E ) K A M N IN E V S LO V E N IJ I K A R B O N A TE (K A R S T IC ) R O CK S IN S L O V E N IA . in stitu ta p a je Slovenska akadem ija znanosti in um etnosti 1. 1947 osno­ vala In stitu t za raziskovanje k rasa v Postojni. Njegov predsto jn ik A. Serko bi istega leta pričel na geografskem institu tu univerze v L jub­ ljan i redna p red av an ja o krasu kot samostojnem učnem predm etu geo­ grafije , če ga ne bi doletela sm rt (Ta p redavan ja so b ila obnovljena šele 1. 1967). In stitu t za raziskovanje k rasa objavlja svoje, pretežno speleolo- ške rezultate, v zborniku A cta carsologica, od katerih je od 1. 1955 do 1. 1971 izšlo p e t knjig. K raške študije izhajajo še v rev ijah Geografskega d ruštva, »Geografskemu vestniku« in »Geografskem obzorniku«, v izda­ jah In š titu ta za geografijo SAZU (»Geografski zbornik« in posebne k n ji­ ge iz serije »Dela«,) v glasilu D ruštva za raziskovanje jam (zdaj Jam ar­ ske zveze Slovenije) »Naše jame« (od 1. 1959), v ak tih jugoslovanskih speleoloških in geografskih kongresov itd. Pregled znanstvenih dosežkov 1922—1972 bo tu podan v dveh po­ glavjih. V prvem bodo tem atske, v drugem regionalne raziskave. P ri h i d r o g r a f s k i h r a z i s k a v a h so bila v ospredju ugotav­ ljan ja podzem eljskih vodnih zvez. R ezultate 45 barvan j izpred druge svetovne vojne je tabelarno podal Serko (1946), novejših 23 barvan j pa Gams (1965). Po drugi vojni so mnoge opravili v zvezi s pro jek tiran jem vodnih akum ulacij, do zgraditve k a terih p a v Sloveniji, v razliko z osta­ lim D inarskim krasom, ni prišlo. D robna izjem a je v p re tek lih stolet­ jih zelo znano C erkniško polje, k jer so po večstoletnih načrtih o tem elji­ tejšem osuševanju po lja in po delnih m elioracijah vodnih tokov in po­ žiraln ik jam 1. 1970 zgradili na odtočnih jam ah zapornice, da bi vsako­ letnem u periodičnem u jezeru podaljšali tra jan je . Vsa barv an ja so ugo­ tovila sicer medsebojno kom uniciranje vodnih tokov v podzem lju, ne pa tudi njihovega podzem eljskega k rižan ja. Sicer redka v rtan ja za p itno vodo, sloneča na postavki o sklenjeni vodni gladini, niso našla zadost­ nih pretočnih količin. Č eprav izkušnje p r i g radnjah na D inarskem krasu še niso dovolj teoretsko obdelane, vse kaže, da v globokem krasu, k i je visoko dvignjen nad erozijski nivo, v naspro tju z nizkim krasom v tu ji­ ni in m orebiti v obalnem krasu v Istri (Jenko, 1959), ni tolikšne sklenje- nosti vodne gladine, da bi ekonomsko opravičila v rtan ja za vodo. Na globokem slovenskem krasu tud i ni odvisnosti med strm cem pod­ zemeljskega toka (= razlika med ponorom in izvirom) in hitrostjo p re ­ tak an ja (Serko, 1946), ki je v razponu m ed 57 in 0,15cm/sek. Višji vo­ dostaj pom eni pravilom a h itre jši p re tok in domneve, da bi ob zelo viso­ kih vodostajih na k rašk ih poljih pretočnost izvirov u p ad a la (Jenko, 1959), je b ila om ajana (Gams, 1970). Velike razlike so p ri mehanizmu in terin itentnih izvirov (Habič 1970), kakor tud i glede m inim alnih spe­ cifičnih odtokov ob suši, k i mestoma zdrknejo na 2 1/sek/km2 (Gospoda- rič-H abe-H abič, 1970). Razm erom a dobro so preučene hidrofacije in tem perature k rašk ih voda (Novak, 1970, Habe, 1937). P rv a kom pleksna hidrološka delitev slovenskega k rasa je bila iz­ vedena s stališča načina vodnega odtekanja; opredeljene so bile eno­ stavne odtočne regije, pretočno-odtočne regije globokega krasa, regije z m enjavanjem površinskega in podzem eljskega p re tak an ja in regije s podzem eljskim dotokom in površinskim odtokom v plitvem krasu (Habič, 1969). K l i m a t o l o g e je kras pritegnil n a jp re j z v rtačam i v gorskem svetli z obilico snega, od katerih nekatere, zlasti na Trnovskem gozdu in Snežniku, opozarjajo nase z vegetacijskim obratom (od roba p ro ti dnu vrtače si sledijo bukov, nato iglast gozd, ruševje in ponekod še alpska, izjem om a celo snežna cona). N ajstarejšo, enostransko razlago vegeta­ cijskega obrata s tem peraturno inverzijo so novejše m eritve dopolnile in pokazale na pom en tra ja n ja snežne odeje in specifičnih ta ln ih pogojev. Udornice tip a Velika ledenica v P arad an i p a pom enijo prehod k jam ski k lim i (Gams, 1972). Bolj kot dokazan je nakazan kras kot kom pleksen ki i- m atološki fenomen, ki se izraža v svojski geoterm ični stopnji, svojskem tem peratu rnem režim u ta l in vlažnosti, svojskih ekoloških pogojih, niz­ ki m eji uspevanja k u ltu rn ih rastlin , k a r vse še čaka nada ln jih raziskav. Več raziskav obravnava jam sko klimo: v Podpeški jam i, v Postojnski jam i (C restani-Anelli, 1939, Gams, 1966, 1968), k jer je b ila m erjena rast kapnikov, in v P redjam i, k jer n asta ja v nekem dinam ičnem rovu pozimi med toplim in m rzlim ustjem razlika do 31,6° C (Habe, 1970). Ker se v Sloveniji goji g e o m o r f o l o g i j a prvenstveno v okviru geografije, je doprinos slovenske geografije k razvoju k raške geomor- fologije najvidnejši. Do nedavna je b ila v ospredju raziskovanja geo- m orfogeneza k rašk ih oblik in reliefa. P rv i slovenski geomorfologi po p rv i svetovni vojni so sledili trad ic iji avstrijsk ih geologov. Rus (1921) je p rip isoval za nastanek R ibniško-kočevskega polja največji pom en tek ­ toniki. M elik (1928, 1951) je iskal razlago za nastanek večjih oblik no­ tran jskega in dolenjskega k rasa predvsem v p red k rašk i fazi s površin­ skim rečnim odtekanjem , ki je pustila v današnjem reliefu suhe doline in podolja. N aziran je o p red k rašk i fluvialni fazi je našlo v najnovejšem času novo potrd itev v najdbah silikatnega kam ninskega drobirja na brezvodnem krasu. K ar ga je bolj ali m anj zaobljenega, ga štejejo za od- k ladnino p red k rašk ih površinskih tokov, m anj zaobljen p a bi lahko ostal po erodiranih neprepustn ih pokrovih, ki so pokrivali apnenec ali dolomit. Z najdbam i teh »prodnikov« je b ila podkrep ljena shema o pred- kraškem površinskem toku N otranjske R eke preko m atičnega Krasa, ki s svojimi zelo širokim i, domnevno suhimi dolinam i vred visi p ro ti Soški ravnini. N a an tik linorijum u, zgrajenem iz k redn ih in paleozojskih a p ­ nencev, je R eka na K rasu dobivala p ritoke z eocenskega fliša na severu, ki tvori zdaj sinklinalo V ipavske doline (Radinja, v tisku). Postopno skrajševanje površinskega toka zarad i ponikev je pustila na severovzhod­ nem K rasu nivoje, k i preidejo v slepo dolino N otranjske Reke, ki ponika v Škocjanske jam e (R adinja, 1967) te r je izvotlila vrsto votlin, k i jih do­ kazujejo številne udornice. S pomočjo silikatn ih prodnikov je b ila re ­ konstru irana tu d i površinska vodna m reža na Trnovskem gozdu (Habič, 1968). Č eprav so naz iran ja o tem, k a teri procesi so na krasu poglavitni, tud i m ed povojnim i krašk im i geomorfologi na Slovenskem zelo različna, jim je skupno, da p rip isu jejo pleistocenski dobi večji pomen za se­ danjo oblikovanost krasa, kot doslej; bolj izstopa v ospredje selektivna erozija, m anj poudarka p a dajejo tektogenezi. Najobsežnejši opis slovenskih k rašk ik polj je podal Melik (1955), ki jih je razlagal v glavnem kot fluvialne erozijske tvorbe. Zaradi po­ večanega m ehaničnega p reperevan ja v glacialnih dobah so vode na po­ ljih naplavile prod, pesek in ilovico, za trpavale lastne ponore in povzro­ čale trajnejšo ali periodično ojezeritev, kak ršn a je do danes ostala samo na C erkniškem polju. Deloma zarad i prem alega upoštevanja klim atskih n ihan j v pleistocenu in zarad i avtom atskega p riš tevan ja m odrikastih glejev k jezerskim sedimentom, M elikova razp rava, čeprav po d p rta z rezu ltati pelodnih analiz, ni doživela tolikega odziva kot bi sicer zaslu­ žila. K vartarne akum ulacijske terase so se najlepše očuvale v tistih k rašk ih poljih, na katere p ritek a reka z neprepustn ih sedimentov. Tak prim er je Postonjska kotlina, k je r je mogoče vzporejati terase z etažam i Postojnske jam e (Gospodarič-H abič, 1966). D rug prim er je Dobro polje, k jer je Š ifrer (1967) glede na preperelost in lego prodov razlikoval wiirm- ski, rišk i in m indelski (?) nasip. V Postojnski kotlini so oprli ugotav­ ljanje starosti teras in jam skih etaž na arheološke ugotovitve in ločili m indelsko-riško erozijsko fazo, riško akum ulacijsko teraso, erozijo v m edledeni dobi R/W , würm sko aluvialno teraso in holocensko erozijo (Gospodarič-H abič, 1966). T udi v jam ah na obodu Sajevškega po lja nu ­ dijo sedim enti in a rte fak ti oporo za določevanje starosti nastanka (Habe- H riber 1964). P rim erjava teras v slovenskih k rašk ih po ljih je privedla do trd i­ tve, da sta razv iti v glavnem dve uravnavi, starejša iz starejšega pleisto- cena, ki je ohranjena v robnih terasah, in m lajša v dnu iz m lajšega plei- stocena (od G/M do danes). Faze u ravnavan ja se ujem ajo s povečano akum ulacijo in ploskovnim uravnavanjem živoskalne osnove pod n a­ plavino. V tem je razlika s fluvialnim erozijskim reliefom, k jer se zni­ ževanje ujem a z globinsko erozijo. Njeno vlogo na dnu kraškega polja ali slepe doline vrši pod talna korozija (Gams, 1972). R azlična m nenja v povojni svetovni geomorfologiji o tem, ali je korozija najin tenzivnejša v h ladni subark tičn i (J. Corbel) ali v vlažni topli tropsk i klimi (H. Lehm ann), so našla svoj odziv tud i v Sloveniji v kvantitativnem določevanju korozijskega procesa. Prvi izračuni koro­ zije s pomočjo trdo t rečnih voda in specifičnega odtoka, ki ga na večjih k rašk ih rekah že vrsto let ugotavlja hidrom eterološka služba, so po k a­ zali, da je neupravičeno istovetiti površinsko vodno dreniran je in pred- kraško fluvialno fazo s fazo erozije (in adekvatno k raške faze izključno s korozijsko fazo). Izven Alp je v Sloveniji na vodoneprepustnih, bolj ali m anj karbonatn ih kam ninah (karbonatnih laporjih , skrilavcih in po­ dobno) korozija kot proces odnašanja gmote dom ala tako intenzivna kot erozija (Gams, 1962). H itrejše zniževanje reliefa v neprepustn ih kam ninah, ki je značilno za kvarta rno dobo, je prvenstvena posledica selektivne erozije v h ladnih pleistocenskih razdobjih, ki je na krasu bistveno m anjša. Zato je k rašk i relief sredi neprepustn ih sedimentov pridobival na re lativni višini. Za porečja, k jer na krasu delujejo vodo- m erske postaje, znaša korozijska intenzivnost med 30 in 90 cm3/CaCC>3/ km2. Zaradi perhum idne klim e je korozija razm erom a visoka in zato so fosilne forme tropskega k rasa iz terc iarne dobe težko razpoznavne. Re­ ducirajo se v glavnem na tip t. i. kopastega k rasa (Habič, 1968). Že pred razčiščenjem problem a o intenzivnosti korozije v razn ih klim ah, ki ga izpričuje sodobna svetovna lite ra tu ra , je bilo za slovenski kras ugotovljeno, da im a prim arno vlogo specifični vodni odtok (Gams, 1966). V endar ti izračuni niso n ičesar prispevali k d irek tn i pojasnitv i n a ­ stanka k rašk ih depresijskih oblik. Le-te nastaja jo večidel zarad i lokalno pospešene korozije (pod pokrovom naplav ine — pod talna korozija, kot robna korozija, korozija poplavišč, nadalje na stiku golega in poraslega sveta vzdolž odtokov z ledenikov in večjih snežišč- Gams, 1964) K van tita tivn ih metod določevanja korozije se je oprijela večina m lajših raziskovalcev kraškega površja (Radinja, H abič, K unaver). V kljub tem u je p ri n jih ostala še živa dilem a, v koliko so vrtače po ­ sledica udorov in v koliko lokalno pospešene korozije. N a Slovenskem sta bila p rv a protagonista obeh skrajnosti. T. G ruber in B. H acquet s svojimi deli iz konca 18. stoletja. Večja enotnost je dosežena v naziran jn , da je na slovenskem krasu v ladala še ob koncu te rc ia ra pretežno p o v r­ šinska, v k v a rta rju pa pretežno k ra šk a hidrografska mreža. Razm erom a malo raziskav je n a jti v slovenski k rašk i lite ra tu ri o posam eznih k rašk ih oblikah. Č eprav so poleg k rašk ih polj v rtače najbolj tip ična k rašk a oblika slovenskega krasa, geneza v rtač ni p ritegnila po­ sebnih raziskovalcev. Zbranega je precej g radiva o po jav ljan ju tako im e­ novanih ugrezov (Horvat, 1953), k i nastaja jo največk rat n a ravn ih km e­ tijsk ih površinah z debelejšo naplav ljeno prstjo . Le krajevno je bila obdelana m orfom etrija v rtač (Radinja, 1969). Sistem atske preučitve skal­ nih visokogorskih oblik in višinske conalnosti so le delno objavljene (Ku­ naver, I960 . M elik (1962-63) in R ad in ja (1969) sta poskušala izdvojiti tako im enovani »dol« ali »kraški dol« kot posebno kraško obliko, p o ­ dobno podolgovati v rtač i oziroma suhi dolini, nastali pretežno kot rečni dolini, potem p a je reka p restav ila svoj tek v podzemje. N ajbolj znam e­ n iti tak dol. v katerem leži k ra j Čepovan, je bil doslej vedno preskusni kam en kraške teorije. P rim erjalno so bile štud irane slepe doline, p ri k a ­ terih je b ila dokazana odvisnost velikosti slepe doline in zlasti njenega končnega dela v apnencu od trdo te reke in njene vodnatosti. Cim nižja je trdo ta in čim več vode ponira, tem večja je pravilom a slepa dolina (Gams, 1962). Tektonsko grezanje kot vzporedni vzrok nastanka kraškega polja na Slovenskem ni našlo toliko privržencev kot drugod, ker za to geološki p rofili ne dajejo osnove. V m išljenju, da so k rašk a polja heterogena po nastanku in sedanji hidrološki funkciji, je b ila m odificirana H. Lehm an- nova shema. Po n je j se po lja ločijo na: perife rna po lja (na stiku ne­ p repustn ih kam nin, ki so znotra j polja, in k ra šk ih kam nin), robna polja (z vododržnim i se^dim enti na robu po lja ali izven), p retočna ali p re livna po lja (z izviri na enem in ponori na drugem k ra ­ ju), polja v nivoju Forfluierja te r razne vrste netip ičn ih polj, k i jih lahko označujem o kot »psevdopolje« ali »parapolje« (piedm ontska v gorah, po lja na p lanotah in polja v sistemu podolja (Gams, 1972). L. 1962 je Geografsko društvo Slovenije v sodelovanju z Geološkim društvom prired ilo simpozij o slovenski k rašk i term inologiji te r rezultate tud i objavilo v Geografskem vestniku 1962. L. 1971 so slovenski geografi p rired ili jugoslovanski sim pozij z namenom, vsk lad iti in objaviti kom­ parativno term inologijo jugoslovanskih narodov. Spričo razm erom a številnih krasoslovnih razp rav in drobnih opi­ sov je presenetljivo malo p r e g l e d o v č e z v e s s l o v e n s k i k r a s . Največ strokovnega gradiva je zbranega v obliki strokovnega potopisa1, izdanega v francoskem in angleškem jeziku ob p rilik i 4. m ed­ narodnega speleološkega kongresa, k i je bil od 12.—26. IX. 1965 v Slo­ veniji in D alm aciji. Ob tej p rilik i je izšel tud i v svetovnih jezik ih n a­ p isan i zvezek revije Naše jam e (1965, 1—2) s preglednim i članki o ju ­ goslovanskem krasu in o krasu v posam eznih republikah. Razsežnejše m onografske opise najdem o za nekatere jam e (Postojnsko, Logarček, Predjam a-H abe, 1970). Uspelo morfološko in morfogenetsko obdelavo je doživelo planotasto sredogorje Trnovski gozd-Hrušica-Nanos med V ipav­ sko dolino in Idrijco (Habič, 1968). Ko bo za opisom slepe doline — Vremske doline, Dobrdobskega krasa in Senožeškega podolja (Radinja, 1967, 1969,) izšel še opis preostalega dela m atičnega K rasa, bo za­ okrožena podoba njegovega razvoja - modela kraške morfogeneze neke pokrajine. V p rip rav i je obsežnejša š tud ija o delu Julijsk ih Alp —• K a­ ninu, (Ju rij Kunaver) in v tisk je p redana p rim erja lna m orfogenetska š tud ija o vsem slovenskem krasu (Radinja, v tisku). N avedene m onografije so geomorfološke, redke pa so, ki bi obravna­ vale vsestransko fizično geografijo. Splošne geografske opise krašk ih pokra jin obsegata ustrezni M elikovi knjig i »Posavska Slovenija« (Ljub­ ljana 1959) in »Slovensko Prim orje« (L jubljana I960). Toda kom pleksnih znanstvenih analiz določenega kraškega p redela skoraj še ni. Eden p rv ih poskusov, oprt na moderne metode, je proučitev prirodnih pogojev in agrarnega izkoriščanja k rašk ih ta l v eni od vasi na m atičnem Krasu (Gam s-Lovrenčak-Ingolič, 1970). O dprla je nove dim enzije kraškega raziskovanja. Pokazala je, kako bistveno se je površje v svoji drobni oblikovanosti sprem enilo pod vplivom km etijskega izkoriščanja v zgo­ dovinski dobi. Ko je km etovalec otrebil površinsko kam enje, na travnik ih do nivoja zemlje, na ornih površinah do globine lemeža, je sprem enil na razsežnili površinah polgoli kras v pokritega, obdelovanje p a je po drugi stran i znižalo nivo p rsti in izzvalo erozijo. Š tudij podtaln ih k rašk ih oblik (Gams, 1971) je odprl metodo, ki omogoča, po drobni oblikovanosti kam ­ nitega površja določevati erozijo prsti. T rebljenje kam enja na površju v pre tek lih stoletjih in intenzivno ozelenjevanje in ogozdovanje zadnjih sto let je spremenilo tip ičn i videz prim orskega slovenskega krasa, k i je po p rv ih opisih v tu ji lite ra tu ri zaslovel kot sinonim za kam nito polpu- stinjo s krašk im i pojavi. Kmetovalci so sprem enili tud i obliko številnih v rtač: zemljo, ki so jo nastrgali po obodu vrtače, so nasuli in dvignili dno Guide de l’excursion ä travers le Karst Dinarique-Guide - Book of the Coigress Excursion through Dinaric Karst. Ljubljana 1965 za širšo njivo. Bolj lijakaste vrtače so postale tako bolj skledaste in p lit­ ve. V kljub ogromnemu vloženemu delu je na krasu orne zemlje malo in teže jo je strojno obdelovati K tem u se p ridružujejo še težave s pitno in industrijsko vodo. T udi to je vzrok, da spadajo v najnovejši dobi kra- ške pokrajine med tiste predele Slovenije, ki gospodarsko kom aj ali le počasi napredujejo , pač p a doživljajo intenzivno preslojevanje p reb i­ valstva in depopulacijo. Zadnja leta narašča število raziskovalcev krasa, ki tildi vedno bolj uporab lja jo m odernejše raziskovalne metode. Ko bodo izšle nekatere že navedene raziskave v tisku, bo dokončno ob veljavo trd itev , ki je bila izrečena o razvoju kraške morfologije v Jugoslaviji v p rv i polovici tega stoletja, označujoča ta rzvoj kot epigonstvo (Blanc, 1958). Ivan G a m s GEOGRAPHICAL RESEARCH OF KARST IN SLOVENIA Considerable atten tion has been pa id to the research of karst phe­ nomena in Slovenia since the country is know n abroad to geographers as the classical k a rs t area. A bout one th ird of the surface of the Socialist Republic of Slovenia is indeed a karst landscape (some 7.000 square k i­ lometres). Most of it is to be found in the southern p a r t of the country and is, w ith regard to the structu ra l geology, p a r t of the D inaric moun­ ta in system (viz. of the so called O uter D inarids). Most of the k ars t area of Slovenia is a t m oderate heights above sea-level. There are also large patches of the karst in the Julian A lps and the K am nik Alps, in high p lateaus between valleys. In the K aravanke m ountains k ars t is found on the limestone and dolomite ridges only as a hydrological phe­ nomenon. K arst is lim ited, however, only to a few spots in the sub-pan- nonian h ill-country in the east. The carbonate ty p e of karst is absolu­ tely predom inant in Slovenia. The karst of Slovenia is better known for the history of karst explo­ ration and research than for the area affected by karst phenom ena. This exploration has, in fact, introduced the in ternational term of k ars t info general use. I t refers to the area betw een the G ulf of Trieste and the \ ip a v a valley w hich is called » K r a s « by the Slovenian population living there and w hich appeared in the germ anized form as »karst«. As the area was explored largely by A ustrian geographers and geologists p rio r to W orld W ar I the la tte r term became w idely used in Germ an lite ra tu re and, following A. Penck, also b y some Yugoslav researchers (Cvijic, Gavazzi, 1904). Owing to their w ritings the Slovenian region Kras above the G ulf of Trieste has become and has rem ained the »clas­ sical« k ars t area (see: W agner, 1945; Corbel, 1956). The research conducted a fte r the liberation in 1918 by Slovenian geographers (A. Melik, J. Rus) is less well known abroad since the find ­ ings were published in the Slovenian language. Also about h a lf of the area m entioned above has become unaccessible to them because of the in ter-w ar in ternational boundary. The w estern half of the Slovenian karst area — including the K ras region — came under the Ita lian rule. In Postojna (renam ed then Postum ia) an Ita lian central speleological in ­ stitu te was set up. A cave inventory, published on this basis a few years later, illustrates the w ork done until 1926 (See: Bertarelli-Boegan, Duem ila Grotte). Most of the caves mentoined — often under distorted names — are located w ith in the Slovenian speaking territo ry . A fter the W orld W ar II only one th ird of the classical K ras region rem ained un ­ der Ita ly . In 1947 the Slovenian Academ y of A rts and Sciences (SAZU) established a t Postojna a new Institu te for K arst Research th a t has con­ tinued the trad ition of its predecessor. In the same year the director of the institu te, A lfred Šerko, had to s ta rt also a regular course in karst 5 G eografsk i vostn ik 65 studies a t the D epartm ent of geography at the university of L jubljana. In the same year, however, Serko suddenly died and the course was not reassum ed before 1967. The results of research done by the institu te (most­ ly in speleology) are published since 1955 in a new serial »Acta carsolo- gica«. F ive volumes are out by 1971. K ars studies are also published in the two rewievs (»Geografski vestnik« and »Geografski obzornik« ed i­ ted by the G eographical Society of Slovenia) and in »Geografski zbor­ nik« and »Dela« (monographs) published by the Institu te of G eography of the Slovenian A cadem y of Sciences and Arts. The periodical »Naše jame« published by the Speleological Society also brings articles re la ­ ted to karst research since 1959. Some studies w ere also published in the Proceedings of the Yugoslav geographical or speleological congres­ ses or in other publications. A survey of the scientific findings during the 1922—1972 period and concerning research on k ars t w ill be presented in two sections. The first deals w ith them atic research and the second w ith regional studies of k arst areas. The h y d r o l o g i c a l r e s e a r c h was focused on the u nder­ ground courses of w ater in the k ars t areas. The results of the 45 tracings m ade before W orld W ar II are sum m arized in a table by Serko (1946) and of the 23 tests perform ed later, by Gams (1965). M any specific explo­ rations were undertaken a fte r W orld W ar II in connection w ith the p ro ­ jects for w ater reservoirs for pow er-plants w hich, however, w ere n e ­ ver carried out in Slovenia, in contrast to other p a rts of the Dinaric, karst. A sm all exception is the once famous polje of C erknica. A fter centuries of p lans for the dra in ing of the periodic lake and a fte r more recent reclam ation efforts concerned w ith w ater courses and sink-holes, the sluices were bu ilt a t the m ain sink-holes a fte r 1970 in order to prolong the duration of th a t seasonal lake. A ll tracings perform ed until now have proved th a t the in terference of underground w ater courses are in te rre­ lated, bu t have not established any unconnected crossings of the chan­ nels used b y the w ater. Following the assum ption of a contiguous u nder­ ground w ater-tab le a few borings for d rinking w ate r were m ade bu t no sufficient am ounts were discovered. A lthough the experience gained in the construction of dam s and reservoirs in the D inaric k ars t areas have not yet been evaluated from a theoretical viewT-point, a ll bits of evidence suggest th a t there are no areas of contiguous underground w ater-tab le large enough to ju stify the costly search for w^ater in the deep karst areas w hich are a t high elevation above the erosion base-level. This is in con­ tra s t to findings in the low k ars t areas abroad and, possibly, in the coastal zone of Is tria (Jenko, 1959). There is, in the deep k ars t of Slovenia, also no relation between the grad ien t of the underground w ater-flow channels (i. e. the d ifference in height between the source and the swallow-hole) and its velocity (Serko, 1946). The la tte r is w ith in a range of 57 and 0,15 cm/second. A higher w ater-level means, as a rule, a sw ifter cu rren t and the assum ption th a t the flow capacity m ight be decreased w hen high w aters occur in the poljes (Jenko, 1959), lias been shaken (Gams, 1970). D ifferences in the mechanisms affecting in term itten t sources w ere noted (Habič, 1970) as well as in the m inim al specific run-offs in d ry seasons w hen they can be as low as 2 seconds/1 per square kilom etre (G ospodarič-H abe-Habič, 1970). The tem peratu re and hydrofacies are ra ther well established (Ha­ be, 1937, Novak, 1970). The first com prehensive hydrographical classification of the karst areas of Slovenia was m ade on the basis of d iffe ren t modes of the w ater circulation and run-off. The first hydrographical ty p e includes the areas ol the deep karst w ith no surface stream s and an en tirely under­ ground run-off; the nex t type is represented by areas w ith predom inant underground circulation bu t w ith some surface tribu taries; the interm e­ d iate ty p e includes areas w ith short in term itten t stream s on the surface and w ith an underground out-flow of w aters. The last ty p e includes areas of surface in-flow and surface run-off in the shallow karst a t low altitudes near sea-level (Habič, 1969). The sm all k a rs t depressions, — dolines in the highland areas w ith abundan t snow-cover during the w in ter a ttrac ted the c l i m a ­ t o l o g i s t s ’ a ttention to the k ars t regions. Some of these dolines — in the Trnovski gozd and the Snežnik m ountains ■— are rem arkable for the m arked vegetation inversion (beech, conifers’ scrubs, the alp ine and eventually even the nival zones follow in suc­ cession). The original sim ple explanation of the vegetation inversion supposedly due to the tem peratu re inversion has been expanded and m odified as a result of new m easurem ents w hich have revealed the im ­ portance of the long snow cover and of the specific soil conditions. Large collapsed »dolines« like Velika Ledenica near P arad an a indicate a transition to the true cave clim ate (Gams, 1972). The karst as a com plex clim atic phenom enon — th a t is expressed in a peculiar geothermic degree, in specific tem perature in the soil and its m oisture variations, in specific ecological conditions, low altitude lim its for cultivation etc. — is ra th e r indicated th an fu lly proved and still aw aits fu rth e r research. Several studies are concerned w ith the cave clim ate in Podpeška jam a (Podpeč cave) in Dobro polje and in the Postojna caves (Crestani-Annelli, 1959; Gams, 1966, 1968) where the growth of stalagm ites and stalactites was m easured; and in P redjam a, w here tem peratu re fluctuations in a dynam ic vertical cavern are as m uch as 31.0°C during the w in ter (Habe, 1970) Because in Slovenia g e o m o r p h o l o g i c a l research was carried out by geographers their share in karst geomorphology is also most no­ table. U ntil recently the research was focused on the origin of karst to­ pography and land-form s. F irs t research done by Slovenian geomorpholo- gists was on the lines established already by A ustrian geologists before W orld W ar. I. Rus (1925) considered th a t the R ibnica - Kočevje polje was formed largely due to structu ra l geology of the area. M elik (1928, 1931), however, came to the conclusion th a t the larger karst landform s in the Lower and Inner C arniola are to be a ttribu ted to the processes in the p re­ karst stage of evolution, when surface drainage was still effective, as in ­ dicated by d ry valleys of various size left in the present relief. The as­ sum ption of a p rek ärst fluvial stage were recently confirm ed by the d i­ scoveries of flints in the w ater-less k a rs t areas. The more rounded pieces are explained as surface deposits of the p re -karst stream s, w hile an­ gu lar and unw orm pieces m ay be considered as rem ainings of the erod­ ed im pervious rocks once covering the exposed limestones and dolomites. The discovery of this »river gravel« has strengthend the concept of the p re -karst course of N otran jska R eka (called Tim avo by Ita lian explorers) across the classical K ras region w ith its broad f la t stretches of assumed dry valleys w hich are on the whole oriented tow ard the Soča p lain . The river (Reka) in its course on this syclinorium consisting of cretaceous and old te rtia ry rocks was fed by tribu taries from a belt of the eocene flyscli to the north w hich now forms p a r t of the V ipava valley (R adinja, in p rin t). The surface w ate r courses th a t were getting shorter because of emerging sink-holes left terraces a t the eastern rim of the K ras region; they are continued in the blind valley of the N otran jska R eka w hich now d isappears underground a t Škocjan caves (R adinja, 1967) w here m any caverns were formed (which are also indicated on the surface by subsided portions of the roof above them). The flints found on the high k ars t area of Trnovski gozd and discovered only recently also helped to trace the courses of the form er river net-w ork there (Habič, 1968). A lthough the views of the karst geomorfologists in Slovenia about the dom inance of p a rticu la r processes in k ars t areas vary , they agree th a t the pleistocene period is more im portan t for contem porary land- forms in carst areas th an i t wTas considered earlier; they single out the role of the selective erosion and p u t less stress on th a t of the structu ra l geology. The most exhaustive account of karst poljes in Slovenia was given by M elik (1955). In his view, they were largely formed by fluvial erosion. Because of the increased m echanical w eathering during glacial periods the rivers deposited clay, sand and gravel on the floor of the poljes, thus filling in the sinkholes and causing lasting or periodical form ation of the lakes; the last of them rem ained until the presen t time only in the C erknica polje. Because too little a ttention was paid to clim atic fluctu ­ ations during the pleistocene period M elik’s statem ents, although sup ­ ported by pollen analysis, did not m eet the reponse th a t they deserved. The aggraded terraces formed during the pleistocene period are best p re ­ served in those k ars t poljes w hich are transversed b y rivers originating in im pervious sediments, as it is the case in the basin of Postojna w here terraces can be correlated w ith d ifferen t levels of channels in the Postojna caves (G ospodarič-H abič 1966). In another case (Dobro polje) Š ifrer (1967), tak ing into consideration the position as well as the am ount of the w eathering of gravels, could discern three layers related to the W ürm , Riss and M indel stages. In the basin of Postojna, the age of the terraces was ascertained by (paleo) archeological evidence. The succesi- ve stages are: Mindel-Riss erosion period, Riss aggraded terrace, Riss- W ürm erosion period, W ürm alluvial terrace and tlie holocene erosion period (Gospodarič-H abič, 1966). The sediments and arte fac ts in the caves along the edge of Sajevško polje also provide evidence for dating their origin (Habe, H ribar, 1964). The com parison of the terraces in the (karst) poljes of Slovenia led to the conclusion th a t there arc two m ain levels to be found. The older dates back to the early pleistocene period and is preserved in the la te ­ ra l terraces w hile th a t found on the bottom of the k ars t depressions da­ tes from the younger pleistocene period (from the Günz-M indel period onwards). The stages of levelling coincide w ith increased aggradation and w ith the app lanation of the solid rock under the m antel of alluvial de­ posits. This is the contrast w ith th e fluvial erosion relief w here the lo­ wering coincides w ith dow nw ard erosion. This role is taken, on the b o t­ tom of (karst) poljes or d ry valleys, by the subsoil corrosion (Gams, 1972). The differences of opinion among geomorphologists in the world as to w hether corrosion is most intensive in the cold sub-arctic clim ate (J. Corbel) or in the hum id tropical clim ate (H. Lehmann) triggered of quan tita tive m easurem ents in Slovenia in order to determ ine the cor­ rosion process. The first calculations concerning the am ount of corrosion on the basis of the hardness of river w ater and of the specific run-off (that is regularily m easured by the W eather Bureau) have shown th a t it is not justified to draw paralels between the surface w ater drainage and the erosion stage, and between karst drainage and an exclusively corrosion stage. O utside the high A lps the corrosion in im pervious rocks of more or less carbonate ty p e (marls, shales and sim ilar rocks) is almost ju st as effective in the removal of rock mass (bed-rock) as the (normal) erosion (Gams, 1962). Q uicker lowering of the relief consisting of im per­ vious rocks th a t is the characteristic of the q u arte rn ary period is p r i­ m arily the result of the selective erosion in cold pleistocene periods which in k ars t areas is m uch less effective. As a consequence, the karst relief am idst areas of im pervious sediments was relatively gaining in height. In those karst drainage areas w here regular observations are m ade the cor­ rosion in tensity is between 30 and 90 m3 of C a Q 0 3 p er year on a square kilometer. D ue to the perhum id clim ate, corrosion is com paratively strong and therefore the fossil forms of the trop ical karst th a t have re ­ mained from the tropical period are hard ly discernible. They are mostly reduced to the type of the so called rounded m ountain tops karst (Habič, 1968). Even before the problem of the in tensity of corrosion in d ifferen t clim ates was settled, as reported in recent lite ra tu re obroad, it was esta­ blished th a t in the karst areas of Slovenia the m ajor role is p layed by the specific run-off of the w aters (Gams, 1966). The m easurem ents, however, did not d irectly throw any new light on the origin of specific forms of karst depressions. These came into existance largely because of local accelerated corrosion (corrosion under the m antle of deposits — subsoil erosion; la tera l corrosion; corrosion in often flooded sectors; also corrosion on the contact between the open and tlie wooded terra in , on the tree-line along the w ater courses from glaciers and snow-fields (Gams, 1964). Most younger researchers of the karst phenom enon adopted the quan tita tive methods for assessing the am ount of corrosion (R adinja, H abič, K unaver). Even among them the, old dilem m a w hether the dolines are p rim arily the result of rock-col- lapse above caves or of locally accelerated corrosion is still open. The two students w hich in their w ritings dealt w ith the problem as early as in the late 18th century, F. G ruber and B. H acquet were protagonist of both extrem e views. By now the researchers generally agree th a t a t the close of the te rtia ry age there was a predom inantely norm al fluvial ri­ ver netw ork in the k ars t areas of Slovenia w hile karst hydrography took u p p er hand in the pleistocene period. C om paratively few studies are published in Slovenian karst lite ra­ ture on p articu la r k a rs t landform s. A p art from (karst) poljes the doli­ nes are most ty p ica l forms to be found in Slovenia, bu t only a few re­ searchers pa id more atten tion to their origin. A lot of evidence was as­ sembled about the recently subsided dolines (Horvat 1953) w hich are m ostly found on fla t ag ricu ltu ral land consisting of th ick layers of inun­ dation alluv ial soil. The m orphom etric m easurem ents of the dolines were carried out only here and there (R adinja 1969). System atic research was done on karst landform s and zonal differences in the rocky areas of the high m ountains results have been published only p a rtia lly (Kunaver, 1961). Melik (1962/63) and R ad in ja (1969) tried to single out »dol« (or »karst dol«) as a special k a rs t landform , sim ilar to an elongated »dolina« or a d ry valley th a t could come into existance basically as a (normal) valley of a small river w hich has la te r d isappeared underground. The most out­ standing exam ple of such a »dol« is to the north of G orica a t Cepovan and was all the times one of the testing stones for karst theory. A com pa­ rative study was m ade of the blind valleys and it has been proved th a t their size, in p articu la r a t the end in the limestones, depends on the am ount of w ater and of its hardness. The lover the hardness is and the greater is the am ount of w ater th a t filters down the larger is — as a rule •— the blind valley (Gams 1962). The notion of the tectonic origin of (karst) poljes was generally not held by so m any researchers in Slovenia as elsewere, as the geological p roliles in Slovenia do not provide sufficient evidence. The w idely held view th a t (karst) poljes are heterogenous w ith regard to their origin and to their p resent hydrological function has led to a m odification of the concept developed by H. Lehmann- According to tha t concept the (karst) poljes m ay be classified as: periphera l poljes (formed on the con­ tac t betw een im pervious rocks w ith in poljes and karst rocks), b o r­ der poljes (w ith w ater-tigh t sedim ents a t the edge of poljes or a t the rim outside); over-flow poljes (w ith w ater sources a t one end and sink-holes on the other end); poljes a t the level of the »Vorfluter« and d iffe ren t kinds of a ty p ica l poljes w hich m ay be described as »pseudo- poljes« or »para-poljes« (e. g. peidm ont poljes in the m ountains, poljes on p la teaus and poljes w ith in large valley-like depressions (Gams, 1972). In the year 1962 a jo in t symposium about the k ars t term inology was organized by the G eographical and Geological Societies in L jub­ ljana; the proceeding were published in G e o g r a f s k i v e s t n i k (1962). In the year 1971 the Slovenian geographers organized a Yugoslav sym posium w ith the same objective to coordinate and publish a com pa­ rative term inology used in the Yugoslav languages. O nly a few overviews of the karst phenom enon in Slovenia were published inspite ob the ra th e r num erous carstological studies and minor descriptions. Most of the pertinen t inform ation is collected in a guide­ book pub lished— in English and French — a t the occasion of the 4th In te r­ national speleological Congress held between 12—26 Septem ber 1965 in Slovenia and D alm atia. The m agazine N a š e j a m e (1965 vol., No. 1—2) also published a series of general articles on the karst phenomenon in Yugoslavia viz. about karst areas in p articu la r republics. Several si­ zeable m onographs exist on some caves (that of Postojna, of Logarček, of P red jam a; Habe, 1971). A good morphological and morphogenetic m onograph was published on Ihe p lateau-like m ountainous area of T r­ novski gozd — H rušica — Nanos, lying between the Y ipava and Id rijca valley (Habič, 1968). As soon as the regional studies in karst topography- now published for the area of blind valley of Yreme, for the Doberdob and Senožeče areas — w ill be com pleted by studies on the rem aining p a r t of the K ras region (Radinja, 1967, 1969), we shall have a rounded-off p ic tu ­ re of its evolution; a model of the karst m orphogenesis of th a t region. A study on K anin area in the Ju lian A lps is in p rep ara tio n (J. Kunaver) and a com parative m orphogenetical study about the entire karst area of Slovenia (Radinja, is in p rin t). The m onographs ju st m entioned m ain ly focus on geomorpliology and are only seldom concerned w ith w ider aspects of physical geography. The general geographical characteristics of the karst areas of Slovenia are described in two books by A nton M elik »Posavska Slovenija«, »Slovensko Prim orje« (L jubljana 1959, 1960). B ut there are few com plex regional analyses of the k ars t areas. Using contem porary methods a small village in the »classical« K ras region has recently been studied in such a w ay from the point of view of the n a tu ra l conditions and the land use and has opened new dimensions in karst research (Gams-Lovrenčak-Ingolič, 1970). The study has shown how basic were changes in the m icrorelief due to the agricu ltu ral land-use during the historical period. A fter the cultivators have removed the rocks sticking out of soil, w hich did to the dep th of the plough-share for arab le land and to the surface level for meadows, the half-barren karst surfaces have turned into the covered patches; b u t the cultivation has, on the other hand, reduced the soil- level and started erosion. The research on subsoil k a rs t topography (Gams, 1971) introduced a m ethod th a t enables to determ ine soil-erosion by the consideration of the tin y surface landform s. The removal of rocks on the surface w hich w ent on for centuries and intensive afforestation of the K ras region has produced a rem arkable change in the typ ical k arst landscape in the sub-m editerranean p a r t of Slovenia, wliich be­ came famous, ever since the firs t descriptions in the foreign lite ra tu re as a synonym for barren sem i-desert area w ith k ars t features. Also, the shape of m any »doline« was changed: the soil th a t was scratched from the rim was accum ulated a t the bottom which thus has been raised to m ake possible a larger field. The funnel shaped »doline« took ra th e r the form of m ore shallow bowls. Insp ite of the trem endous am ount of w ork perform ed there is still very little arable land in karst areas and can h ard ly be worked by machines. An additional handicap is the lack of w ater for d rinking and industrial use. This is another reason for most intensive depopulation, social transform ation and slow economic growth of karst areas in Slovenia. The im pact of the recent increase in the num ber of researchers on karst phenom ena and of the use of more and more sophisticated methods of research, is more and more evident. W hen the studies now in p rin t and m entioned earlier w ill be available the statem ent m ade some years ago about the lagging evolution of karst m orphology in Yugoslavia du­ ring the first h a lf of the cen tu ry (Blanc, 1958) w ill finally be refuted. Literatura — Bibliography Blanc, A., 1958, R eperto ire b ib liog raph ique critique des etudes de re lief kars tiquc en Yougoslavie depuis Jovan C vijič. M em oires e t docum ents, T. VT. C en tre national de la recherche scientifique, P aris. C orbel, J., 1956, Le K arst p rop rem en t d it. E tude m orphologique. Revue de G eographie de Lyon, No 4. Lyon C restan i, J., A nelli, F., 1939, R icherche di m eteorologia ipogea ne lla G ro tte di Postum ia. M inistero di lavori publiei, Uff. idrogr., No 143, Roma. Gams, I., 1962, S lepe doline v S loveniji (Sum m ary: B lind V alleys in Slovenia). G eografski zborn ik — A cta geographica VII, Acad, scient. a rt. slovenica, L ju b lja n a — 1962, Meritve korozijske intenzitete v Sloveniji in njihov pomen za geo- morfologijo (Summary: Measurements of Corrosion Intensity in Slovenia and tlieir geomorfological signification). Geografski vestnik XXXIV, Ljub­ ljana — 1964, Types of Accelerated Corrosion. Problems of Speleological Research. Czechoslovak Acad, of Seien. Brno — 1965, Apercu sur l ’hydrologie du Karst Slovene et sur ses communications souterraines. Naše jame VII, No 1—2, Ljubljana —• 1966, Faktorji in dinamika korozije na karbonatnih kameninah slovenskega dinarskega in alpskega krasa. (Summary: Factors and Dynamics of Cor­ rosion of the Carbonatic Rocks in the Dinaric and Alpine Karst of Slove­ nia (Yugoslavia). Geografski vestnik XXXVIII, Ljubljana — 1968, Über die Faktoren, die die Intensität der Sintersedimentation bestim­ m en. P roceedings of the 4th In tern . Cong. Speleology in Y ugoslavia 12—26. IX. Vol. I ll, L ju b lja n a — 1970, M aksim iranost k ra šk ih podzem eljsk ih pretokov n a p rim eru ozem lja med Cerkniškim in Planinskim poljem. (Summary: Maximisation of the karstic underground Water Flow in Example of the area among the Karst Poljes of Cerknica and Planina.) Poročila — Acta carsologica V/4, Acad, scient art. slov., Ljubljana. — 1971, Podtalne kraške oblike (Summary: Subsoil karst forms). Geografski vestn ik XLIII, L ju b lja n a — 1972, Die zweiphasige quartärzeitliche Flächenbildung in den Poljen und B lind tä lern des nordw estlichen D inarischen K arstes. G edächtn isschrift H e rb e rt Lehm ann. F ran k fu rt. — 1972, Physisch-geographische Faktoren, die das Klima der Dolinen und P o ljen beeinflussen (aufgrund der neueren M essungen in Slovenien). F estsch rift fü r I lan n s Tollner. Salzburg. Gavazzi, A., 1904, D ie Seen des K arstes. I. Teil Abh. Geogr. Ges. W ien, Bd V, No 2 Gam s I., L ovrenčak, F., Ingolič, B., 1971, K ra jn a vas — štu d ija o p rirodn ih pogojih in ag ra rnem izko riščan ju k rasa . (Sum m ary: K ra jn a vas — A S tudy of the N a tu ra l C onditions and of ag ra rian Land U tilization on the K arst). G eografsk i zborn ik — A cta geograpica XII, Acad, scient. art. slovenica, L ju b ljan a . Gospodaric, R., Habič, P., 1966, Črni potok in Lekinka v sistemu podzemeljske­ ga odtoka iz Pivške kotline (Summary: The Crni potok and the Lekinka cave within the system of the underground drain from the Pivka Basin. Naše jame VIII. No 1—2, Ljubljana Gospodarič, R., Habe, F., Habič, P., 1970, Orehovški kras in izvir Korentana. (Summary The Karst of Orehek and the Source of the Korentan). Poročila — Acta carsologica V/2 Habe, F., 1956—1937, Toplinski odnošaji na izvirih Ljubljanice. (Zusammen­ fassung: Temperaturverhältnisse an den Karstquellen der Ljubljanica). Geografski vestnik XII—XIII, Ljubljana Habe, F., 1970, Predjamski podzemeljski svet (Zusammenfassung: Die Höhlen­ welt von Predjama). Poročila — Acta carsologica VII/1, Acad. scient, art. slovenica, Ljubljana Habe, F., Hribar, F., 1964, Sajevško polje (Zusammenfassung: Das Polje von Sajevče). Geografski vestnik XXXVI. Ljubljana Habič, P., 1968, Kraški svet med Idrijco in Vipavo. (Summary: The karstic re­ gion between the Idrijca and Vipava Rivers). Dela-Opera 21, Acad. scient. art. slovenica, Ljubljana Habič, P., 1969, Hidrografska rajonizacija krasa v Sloveniji. (Summary: Hydro- graphic Regionalisation of the Slovene Karst. Krš Jugoslavije, 6. Habič, P., 1970, Intermitentni kraški izvir Lintvern pri Vrhniki. (Summary: The intermitent karstic Source Lintvern near Vrhnika). Poročila - - Acta carsologica, V/5 Acad. scient. art. slovenica, Ljubljana Horvat, A., 1953, Kraška ilovica (Summary-Zusammenfassung: Karst clay — Karstlehme). Ljubljana. Jenko, F., 1959, Hidrogeologija in vodno gospodarstvo krasa (Summary: The Hydrogeology and Water Economy of karst). Ljubljana. K unaver, J., 1961, V isokogorski k ra s vzhodnih Ju lijsk ih in K am niških Alp (Sum m ary: H igh m outain k a rs t in the E astern p a r t of the Ju lian A lps and in the K am nik Alps. G eografski vestn ik XXXIII, L ju b ljan a M elik, A., 1928, Plicensko po reč je L ju b ljan ice (Resume: Bassin pliocene de la L jub ljan ica). G eografski vestn ik IV, 1—4, L ju b ljan a . Melik, A., 1931, Hidrografski in morfološki razvoj na srednjem Dolenjskem. (Resume: Evolution hydrographique et morphologique dans les bassins des Mirna, Temenica et Krka superieure). Geografski vestnik VII. 1—4, Ljubljana Melik, A., 1955, Kraška polja Slovenije v pleistocenu (Resume: Les Polje kar- stiques de la Slovenie au pleistocene). Dela-Opera 7, Acad. scient. art. slovenica, Ljubljana Melik, A., 1962-63, O dolih na krasu. (Resume: Sur les dols (vallons) du karst). A rheološki vestn ik XII—XIV, L ju b ljan a Novak, D., 1970, K lasifikac ija podzem eljsk ih voda n a slovenskem k rasu po n jih fizikalno-kem ičnih lastnostih . P eti jugoslovansk i speleološki kongres, Skopje. Radinja, D., 1967, Vremska dolina in Divaški kras (Summary: The Valley of Vreme and the Karst of Divača). Geografski zbornik — Acta geographica XI, Acad, scient. artium Slovenica, Ljubljana Radinja, D., 1969, Doberdobslci Kras (Summary: Le karst de Doberdob). Geo­ grafski zbornik — Acta geographica XI, Acad, scient. art. Slovenica. Ljub­ ljana. Radinja, D., (v tisku), Zakrasevanje v Sloveniji v luči celotnega morfogenetske- ga razvoja. Geografski zbornik — Acta geographica, XIII Rus, J., 1921, Ribnica in Kočevje (Resume: Ribnica et Kočevje). Glasnik Georg, dr. V. Beograd Šerko, A., 1946, Barvanje ponikalnic v Sloveniji (Resume: Les colorations des rivieres karstiques cn Slovenie). Geografski vestnik XVII, 1—4, Ljubljana. Šifrer. M., 1967, Kvartarni razvoj doline Rašice in Dobrega polja (Summary: The Quaternary Development in the valley of Rašica and Dobro polje.) Geografski zbornik — Acta geographica X, Acad, scient. art. slovenica, Ljubljana Wagner, G., 1954, Der Karst als Musterbeispiel der Verkarstung. Aus der Heimat-Naturw. Monatschr. 62 Jg., H. 9—10, Tübingen.