The original Palava Protected Landscape Area was proclaimed in 1976. In 1986, this territory was included in the world-wide network of biosphere reserves of UNESCO. Within the Pálava B.R. (its extended concept) there are two wetlands of international importance protected as Ramsar Sites according to the "Convention on Wetlands of International Importance especially as Waterfowl Habitats": R.s. "Lednice fishponds" since 1990 and nearly the whole R.S. "Floodplain of Lower Dyje River" since 1993 (MATUSKA 1994, J. CHYTIL, pers. comm.).

General characteristics of the Palava B.R. (geology and geomorphology, hydrology and climatology, soils, flora, vegetation, fauna, archeology, landscape use and human impact, tourism, nature conservation, landscape management, research and international cooperation) are reviewed by MATUSKA (1994) and the natural conditions are briefly summarized below.

Geographical characteristics. The present Palava Biosphere Reserve covers 83 sq.km and lies in the southern part of the historical territory of Moravia. It comprises the unique, small area (11 x 3 km) of the Pavlovske vrchy Hills and their immediate proximity (also comprising the woodland complex nr. Milovice and the floodplain National Nature Reserve Krive jezero Lake). The planned extended concept of the protected area should cover about three times that area (see Map) (MATUSKA 1991, 1992, 1994). Its territory will be defined by the coordinates 16^o36´-16^o59´E and 48^o36´-48^o53´N. The proposed extended concept of the Palava B.R. will contain, in addition to the present protected area, two further main parts: the first one is the landscape complex artificially built for centuries and containing large fishponds between Lednice and Valtice. The second part of the proposed area is the floodplain area on the lower reaches of the Dyje and Morava Rivers including their confluence. The whole area (the present and the proposed one) could join, in future, the multilateral "Middle Danubian National Park" (Austria, Czech Republic, Hungary, Slovak Republic), as a part of the floodplain forests along the lower stretch of the Morava River in Slovakia and Austria, and the lowland forests along the Danube between Vienna and Komarno (WWF 1990; MATUSKA 1992, 1994; BINOVA et al. 1992).

Geology. The Pavlovske vrchy Hills are the westernmost projection of the Carpathian Arch. Together with several other limestone islets in central and north-eastern Moravia, the hills form an incoherent outer clippen zone of the Carpathians. The cliffs of the Pavlovske vrchy Hills are of Mesozoic age. They are vertically divided into the older underground called the Klentnice layers, 80-100 m thick, and the younger superposed mantle consisting of Ernstbrunn limestone 120-150 m thick. In places, the limestone shows typical karstic phenomena. The hills were shifted in connection with the Alpine folding. The different resistance of the two geological layers allowed erosion activity to model the present typical appearance of this youngest Moravian mountain range (HORAK 1967, VASATKO 1979, MATUSKA 1994). The floodplains along the Morava and Dyje Rivers were influenced by erosion processes in the highlands. An accumulation of flood sediments formed large valley gravel terraces. The underlying strata are accumulated by Tertiary sediments about 5-8 m deep. The overlying deposits of Holocene sediments are up to several meters (1-2 m) deep (PELISEK 1976, KLIMO & PRAX 1985).

Pedology. The soil conditions of the Pavlovske vrchy Hills are complicated. Rendzines, typical soils of limestone areas, are the most frequent soil types in the area. The soils on hillsides are very shallow, usually 15-30 cm deep. The foothills of the Pavlovske vrchy Hills consist of deep layers of loess on which layers of black soils up to 200 cm deep developed under steppe vegetation (HORAK 1967, VASATKO 1979, MATUSKA 1994)). The southern Moravian floodplains developed through long-term action of rivers. When the rivers overflowed, the floods deposited sediments containing, besides clayey or coarser particles, also varying amounts of nutrients and humus. This gave rise to alluvial soils which overlaid original uneven relief of gravel-sands and dunes of aeolian sands.

Hydrology. The moisture regime in the floodplain was dependent, to a considerable extent, upon the water discharge dynamics in the rivers. Almost every year, sometimes even several times in a year, the rivers overflowed, the floods lasting up to several weeks long. In the past two decades, numerous water management modifications were carried out in the area. The Morava River was canalized between Lanzhot and Hodonin, the Dyje River between Breclav and Nove Mlyny. Both river beds were straightened and an arm of the Dyje River bypassing the town of Breclav was built. A series of three reservoirs was constructed at Nove Mlyny (on the Dyje), over 3000 ha in continuous water surface. The confluence of the Morava and Dyje Rivers was modified, shortening both streams (over 20 km) through breaking of its meanders (PAVLIK et al. 1983). All this has led to virtual elimination of the floods. As a result, the soil moisture regime has been fundamentally altered, the same as nutrient circulation and the specific pedogenetic process of formation of surface humus layer. The water regime in the floodplain ecosystem has changed from the floodplain one (natural floods) to the evaporation one (rainfall being lower than evaporation). The dynamics of variation in water table has been preserved in the soil profile but the water table has dropped markedly below the surface of the terrain (by ca 90 cm at Lednice, PRAX 1983). After 1989 some revitalization activities in several localities (Krive jezero Lake, the part of the Horni les Forest, the confluence of the Morava and Dyje Rivers) have been started. The main effort has been concentrated on improving the bad health condition of the hardwood forests through returning the water back into floodplain ecosystems.

Climate. According to QUITT (1971) the territory of southern Moravia, classified as arid and subhumid, is among the warmest places in the Czech Republic (daily mean air temperature 9^oC), but also among its driest regions, due to precipitation shade of the Ceskomoravska vrchovina Highlands (average annual total precipitation 524 mm; all data from the period 1901-1950, Lednice). There are more than 300 days with a mean temperature above freezing point and, on average, more than 20 tropical days with maximum temperature over 30^oC.

Paleoecology. The steppe and forest-steppe communities occurring in the area of the Pavlovske vrchy Hills developed during the prehistoric periods of the Subboreal. In the floodplains, important floods occurred, accompanied by extensive sedimentation, as a result of the first man-made deforestation (ROZKOSNY & TRNKA 1992). Probably the most marked changes took place in the flooded areas of southern Moravia in connection with the colonization of that region in the Middle Ages. Subsequent deforestation, proceeding at a higher rate, affected the discharge dynamics and occurrence of more extensive floods that caused huge amounts of materials being transported, which are now preserved in the form of sand and loess deposits along the lower reaches of the two rivers.

Botany. The flora that developed on the limestone substrate of the Pavlovske vrchy Hills is very remarkable from the phytogeographic point of view. Their north-facing slopes are grown with montane elements with important glacial relicts of Alpine origin. The other slopes are grown with forest-steppe vegetation, consisting of primary and secondary steppe plant communities. Besides the typical grassy steppe, there are important rocky steppe habitats. In some cases close relationship to the flora of limestone Alps can be found here. Many plant species growing in these habitats reach here the northernmost limit of their ranges (JATIOVA & LAPACEK 1978, GRULICH 1995a). A brief survey of botanical researches is newly summarized by UNAR et al. (1991). The woodland communities correspond to the first three vegetation tiers (HORAK 1969). The floodplain area has at all times been affected by the water regime of the landscape and by the composition of the soil-forming material. These two factors caused the development of typical floodplain ecosystems. The floodplain forest is not a phytocoenological term. It includes four forest types, of which the Querci-Fraxineta and Ulmi- Fraxineta carpini (ZLATNIK 1956) account for 90% of southern Moravian floodplain forests. At present, most of the woodland complex along the Dyje River is affected by the consequences of water management modifications (see above). In the last time, GRULICH (1995b) published a brief history of the floristic research in the southernmost Moravia, DANIHELKA et al. (1995) compiled the distribution of some vascular plants in the same area, BALATOVA-TULACKOVA (1995) launched phytocoenological and synecological characteristics of the Lanzhot meadows, and DANIHELKA & HANUSOVA (1995) added notes to the present state of the halophytic vegetation in the vicinity of the Nesyd pond.

Zoology. Data concerning invertebrates of the Palava B.R., scattered in several hundreds of partial studies, are mentioned and classified within separate groups with this prodromus. LASTUVKA (1994) presents an example of a modern revision concerning the order Lepidoptera in the study area. Vertebrates of the Palava B.R. were studied by MIKATOVA et al. (1989) who summarized all accessible data mentioning the occurrence of autochthonous amphibians and reptiles of southern Moravia including the study area. BARUS & OLIVA (1992a, 1992b) refer to general data concerning distribution of both these groups, including a survey of significant localities. Detailed data concerning birds are included in a monumental compendium of birds of the former Czechoslovakia (HUDEC & CERNY 1972, 1977, HUDEC 1983, 1994). A detailed survey of the known localities of bats in southern moravia is pointed out by VLASIN & ELEDER (1991) and VLASIN et al. (1993). ZEJDA (1995, 1991) studied the composition of the small mammals community in a floodplain forest. GAISLER & NESVADBOVA (1994) and GAISLER et al. (1995) studied the diversity of Insectivora, Chiroptera and Rodentia in the Palava B.R. UNAR et al. (1991) evaluated the extent of devastation of the environment in NNR Devin-Kotel-Souteska caused by Capra aegagrus and mouflon kept in an enclosure.

Biogeography. According to SKALICKY (1988), the Palava B.R. in its proposed extended concept belongs to the phytogeographic territory Pannonian thermophyticum (Pannonicum) and to two phytogeographic districts: (17) the Mikulovska pahorkatina Hills, with the subdistricts (b) Pavlovske kopce Hills and (c) Milovicko-valticka pahorkatina Hills, and (18) the Jihomoravsky uval Depression with the subdistricts (a) Dyjsko-svratecky uval Depression and (b) Dolnomoravsky uval Depression. A subdivision of the former Czechoslovakia for the purpose of faunistic investigations (ZELENY 1972) is essentially based on the phytogeographic districts as well.