LYNX - a Special Interest Network on Ecological Networks

3. Nature in Poland

4. The existence of selected plant and animal species as criteria for the mapping of core areas in EECONET-PL

5. Plant communities of Poland and their characteristics as criteria for mapping EECONET-PL

From the Publisher

Acknowledgements

Foreword

1. The European Ecological Network - EECONET

1.1. The concept

In 1992 the nations of the world, attending the UN Conference on Environment and Development (UNCED) in Rio de Janeiro, urged that efforts to protect the natural environment be integrated and intensified. The Convention on Biological Diversity, drawn up at the conference and ratified by Poland in 1995, aims to strengthen protection of species, ecosystems and gene stocks both within different countries and across continents. Industrial development, increasing emission of pollutants traversing state borders and the intensification of land usage are endangering all forms of life. Leaving aside the consequences of chemical contamination, man’s pressure on nature is leading to the depletion of natural resources, the impoverishment of fauna and flora and the fragmentation of ecosystems.

The effects of these changes are confirmed by the various Red Data Books’ ever-lengthening lists of vanishing and threatened species of plants and animals [Council Directive 92/43/EEC 1992]. In many countries during the last 10 years or so, protection strategies have changed The protection of species now generally takes second place to the protection of large areas. Only a few of the many endangered plants and animals have been taken care of; for some time now a significant loss of interest in flora and fauna research has been noticed in Poland. And all too often conservation problems have been perceived solely in national or (at best) regional terms; the panEuropean threat to natural stocks has been ignored.

The limitations resulting from this too parochial view of environmental problems take several years to correct, even when international help is forthcoming. Many Conventions and co-operative Programmes have been established: the Ramsar Wetlands Convention, the Bonn Migratory Species Convention, the Bern European Wildlife and Natural Habitats Convention, UNESCO’s Man and the Biosphere Programme, to name but a few. These oblige participating countries to protect species and habitats of international importance. As a result Europe now has many different categories of reserves with specific aims under various criteria. However these reserves are, generally speaking, too isolated and too dispersed to encourage effective animal and plant protection.

Biotic resources, both in individual countries and across continents, can only be properly safeguarded when protective systems are organizationally and spatially integrated.

The countries of the European Union, in furtherance of this aim, proposed the creation of a European Ecological Network (EECONET). Intended as a natural heritage for Europe, EECONET areas are integrated organizationally and spatially. An administrative system within the EECONET programme has been requested to ensure that EECONET principles are implemented at the national level in accordance with the objectives of the various international Conventions and Programmes - such as those already named.

Whilst the natural variation of the European continent will be clearly expressed in the context of national and regional protective systems, EECONET will form an overarching hierarchical structure. Holland [Bennett 1991] has been one of the foremost countries in fusing EECONET ideas with national policy on nature protection. Other West European countries have used Dutch experience in creating their own national networks and also - under the auspices of the European Council’s Habitat Directive - in forming up the broader EECONET concept for the countries of the European Union.

1.2. The basic principles of EECONET

1.2.1. The aim

The principal reason for creating the European Ecological Network is to integrate protected areas in individual European countries with areas to be protected in the EECONET system, according to international criteria and standards [Bischoff, Jongman 1993].

The creation of EECONET allows:

• the formation of a spatially integrated network of those areas which have been least transformed by man and which, at the same time, reflect the variety of European nature;
• better protection of species and habitats listed as particularly endangered and considered of special importance in Europe;
• the migration and spreading of species on our continent through the protection of areas which are migration routes that are vital both for the preservation of genetic variety and, in many cases, for the survival of populations;
• the development of a common European strategy for the protection of the least changed ecosystems and landscapes that would also act as an effective counter to those processes which cause plants and animals to become extinct;
• the preparation of an EECONET map that would highlight the continent’s natural amenities and the responsibility of both individual countries and the European Union as a whole to preserve them.

1.2.2. The EECONET structure

The European Ecological Network consists of the following elements:

• Core areas:
  • Biocentres;
  • Buffer Zones;
• Ecological corridors;
• Nature restoration areas.

Core areas are areas whose richness of ecological diversity differentiates them from surrounding areas and which are above the ecosystem level of organization. Their defining features fall under one of the following headings:

• almost entirely natural;
• semi-natural;
• anthropogenic, extensively used, with a multitude of plant and animal species specific to traditional, open-field farming.

Core areas are characterized by a variety of species, landscapes and habitats. They are also important sanctuaries for native and migrating species, especially those classified as endangered. While core areas will vary in size they will not be smaller than 500 hectares.

Within the core area are Biocentres which will contain a sizeable quantity of the most precious elements. These are surrounded by buffer zones which, though of lesser importance, still have distinctive values. The buffer zones also pinpoint the extent of the biotic and abiotic links with the core area. In the future, protective activities, optimal methods for the protection of existing natural resources and the restoration of those lost, will take place in the buffer zone.

In compliance with EECONET principles, each physical-geographical sub-province should contain at least one core area. It is recommended that most of the natural landscapes of a given country should be represented in that country’s EECONET system. Where it has only a small amount of a particular physical-geographical feature, it will be acceptable to have this feature represented outside the borders of the country. Some core areas will be of the transborder type.

Ecological corridors are territorially devised so as to facilitate the movement and migration of species between core and adjacent areas. They will have varied forms:

• continuous linear form distinctly different in type from the surrounding areas, not intensively used or managed;
• areas formed as the belts that link individual core areas and show the main direction of these links;
• ‘stepping stones’ that do not have structural continuity but maintain functional continuity, e.g. migratory bird sanctuaries.

Characteristics of the ecological corridors should be shared with the core areas that they link. On the local scale they should recreate the real translocation routes of examined species. On a national or continental scale, however, the purpose of the eco-corridor will be to encourage a healthy genetic mix by directing the course of the ‘stream’ that provides it.

Because EECONET has a mainly continental application, attention has been drawn to searching for long-distance migrating and translocating species - in particular, birds, fish and large mammals.

The ecological corridor is an elastic concept. Core areas on a local scale (e.g. animal sanctuaries, small forest complexes) may have corridors on a regional scale. It is advisable that corridors, especially the larger ones, should be characterized by rich habitats and ecological niches. They would thus be more diverse and so better adapted to different migration patterns.

It is assumed that size is as crucial to the functioning of corridors as it is for core areas. No corridor should be less than 500 meters wide and those on a European scale should be several kilometres wide; where narrowing occurs, there continuity is threatened. Length is another important aspect - the longer, the less effective because further from the core area where conditions for fauna and flora are optimal.

Nature restoration areas may be treated as supplementary elements of the network, being areas degraded due to contamination or overuse, although still retaining characteristics of the former natural habitat. These previous states may well be recreated - for example, drained wetland or deforested slopes of lower montane belt. Alternatively, ecological management can also restore former values: for example, timber forests or intensive farmland.

1.2.3. Establishing the principles of EECONET

The ground-rules of the European Ecological Network are to:

• enlarge existing protected areas (often too small to be effective) and to act as functional links reaching much further than the protected areas;
• retain the hierarchical structure of EECONET;
• identify the areas in need of restoration because of their substantial ecological potential;
• ensure connection between core areas via ecological corridors.

The rule that core areas should be larger than the already existing protected areas must be stressed. Nature reserves, national parks or other protected areas as classified by IUCN, usually represent a small percentage of the territory of a given country. According to Bischoff and Jongman (1993) the countries of the European Union protect between 3% and 12% of their land. And these protected areas are relatively small, being a compromise between the needs of protection and those of economic exploitation. The creation of a network of areas of international importance, established under the different conventions, is still in its infancy. As yet they are few in number. Many internationally important areas are therefore still very ill-protected.

EECONET has a hierarchical structure - meaning that its elements (core areas, eco-corridors) may be distinguished at different levels: local, regional, national and international. The function of a given element in the network depends on its level. Areas of local importance (e.g. nature reserves, areas of ecological value, plant and animal refuges) perform the function of nodal (core) areas at the lower level. This function may be changed on the national scale (local nodes may become an element of an ecological corridor) or the function may not be shown. When the elements of the network pass from local to national level, their internal structure becomes more complicated - selected core areas and corridors become increasingly more complex from a biological point of view. The EECONET hierarchical structure depends upon the size of the area, its projected biotic potential and the level of the element. The areas in the EECONET structure are large and their international importance derives from their importance in preserving biological variety at the local and regional levels.

1.2.4. The National Nature Plan

The integration of political structures in western Europe has paved the way for countries in central and Eastern Europe to integrate their own systems of nature protection with EECONET. First steps in this process were undertaken by IUCN - The World Conservation Union which initiated extensive analyses and proposals for broadening the network in Poland, the Czech Republic, the Slovak Republic and Hungary, within the framework of the National Nature Plan. It must be stressed that the NNP project will not interfere with the ecological policies of member countries nor undermine their achievements in the area of global nature conservation. The aim is to establish a panEuropean system for areas in which natural values and ecological links constitute the natural heritage of Europe.

In Poland the NNP project will be carried out in two stages:

Stage 1: mapping out the bounds of Poland’s contribution to the European Ecological Network - EECONET-PL;

Stage 2: drawing up the rules for working within this network and establishing the organizational system and the legal instruments which will enable EECONET-PL to function effectively.

2 The concept of the national ecological network EECONET-PL

2.1. Basic principles

EECONET-PL aims to form an integrated system of the areas whose natural value measures up to the highest national and international standards. Individual areas within the system should be characterized by a large percentage of well-preserved natural and semi-natural landscapes as well as by areas extensively exploited (rational exploitation by man is of great importance). Additionally they should be integrated functionally and spatially by a network of natural links (eco-corridors).

In the creation of EECONET-PL the aims and principles adopted in forming the IUCN network have been taken into account, whilst preserving and building on Polish achievements in this field. EECONET-PL will:

• strive to integrate all habitats typical of a given region in Poland into the ecological network;
• ensure the spatial and functional unity of the ecological network in order to protect the migrations and natural journeyings of different species;
• include existing protected areas (national parks, landscape parks, nature reserves and areas of protected landscape) insofar as international criteria permit;
• deem it important to include traditional agricultural and fish-farming areas and semi-natural ecosystems (man-made values) in compliance with the spirit of the Convention on Biological Diversity.

2.2. Landscape and species-oriented approach to nature conservation

There are many aspects to the aims of EECONET-PL. Initially, however, the approach is landscape-and-species oriented. As far as landscape is concerned, an important role has been played by analyses of structures and the spatial requirements of systems above the organizational level of an ecosystem. Abiotic elements of natural habitat (in particular, geomorphological and hydrological conditions along with plant-cover biotic elements) and certain types of land use have been analyzed. These analyses, together with the results of various ecosystem assessments, are of prime importance in determining which areas should be included in the network and at what level. The comprehensive value of this approach to the forming of EECONET-PL has been verified by analyses of endangered species in Poland and Europe.

2.2.1. EECONET-PL as a structure for ‘organizing’ nature

The workings of nature occur on different (imperfectly understood) levels. Of prime importance in the forming of EECONET-PL is a right assessment of ecological levels and spatial needs. On the one hand we have ecosystems (biogeocoenoses), ecological landscapes (physiocoenoses), biomes etc.; on the other hand we have populations of some given species. In the quest for ‘natural preservation’ nature has developed two main currents:

• a specific current, dealing with location, causes and degree of threat for each species;
• a landscape current, dealing with areas of natural value worth preserving.

The optimal method to adopt at this stage would be to adjust EECONET-PL to the spatial structure expressed in the hierarchical system of ecological units. However, theoretical knowledge and the practical results of spatial analysis do not allow this. It has therefore been assumed that EECONET-PL structures should deal with already recognized natural structures, especially in relation to the hierarchical, regional systems of complex geobotanical and physical-geographical units (annex, map 1 + legend). The structures will not, however, sufficiently reflect man’s transformation of natural habitat. EECONET-PL has therefore included systems which combine land use with a fairly minimal change in plant cover. Densely populated areas, urban-industrial agglomerations and the like have been excluded.

2.2.2. Typological and regional variability

Natural systems show typological variability. One should note, however, that even very similar-looking systems have their own singular features showing their individuality. EECONET principles require that both typical and individual features be considered worth preserving.

EECONET-PL’s system of core areas and eco-corridors will therefore include representative samples of outstanding and distinctive regional structures as well as more typical habitats and landscapes. The routes taken by the eco-corridors will normally be through similar habitats, thus maintaining a continuity of structure with the core area.

2.2.3. Status of species to be protected by EECONET-PL

Analysis of the status and distribution of target species is intended to identify the areas that should be included in EECONET-PL - taking into account the role these areas play in population function. The following types of species (or groups of species) have been selected on the basis of their status:

• vanishing and threatened species - species threatened world-wide and listed in Poland in the Polish Animal (1992) and Plant (1993) Red Data Books;
• species (or groups of species) whose populations have plunged over the last 50 years due to loss of biotopes;
• rare species, endemic species and relicts found in appreciable numbers in certain places;
• certain species which have spread into Poland, indicating suitable habitat and right conditions for survival and genetic mix with local populations;
• species which are not necessarily rare or threatened in Poland but whose population comprises a substantial part of the European population - for example, the white stork;
• species that migrate over long distances during their life cycles.

Before all the above-mentioned groups were finally placed on the EECONET-PL list they were also compared against the lists of species considered important to Europe and put forward for inclusion in the CORINE database, Habitat Directive and Dutch EECONET [The Nature Target Types Handbook, 1994].

The locations and sizes of refuge for the chosen species have been based on the following criteria:

• refuges necessary for the whole life cycle (e.g. fish spawning areas, feeding grounds, bird moulting grounds, bat wintering grounds);
• refuges with particularly rich fauna or flora (e.g. breeding or wintering birds, water reservoirs with rich ichtyofauna, invertebrate groups, sites with rare or endangered plants);
• potential routes for chosen invertebrate species (eco-corridors).

2.3. Criteria for selecting the areas and for EECONET-PL structure

2.3.1. Selecting the areas

Criteria used in selecting the EECONET-PL areas have formed the basis for valuing natural structures in order to indicate the areas of highest value. The criteria are:

• biological diversity;
• natural character;
• rarity of occurrence;
• degree of threat.

Biological diversity measures the heterogenic character of the area and the intensity of natural-area management. Generally speaking, there is less diversity in the vast areas with homogenic landscape structure - such as large forest plantations and areas of intensive agriculture.

Biological diversity also demonstrates the natural behavior of ecosystems. It has been assessed on the basis of the number of species, relicts and endemic plants found within the different habitats and ecosystems of a given area. Variety of habitat and forms of management have been deemed the main contributors to biological diversity.

Natural character measures the natural attributes of ecosystems, subdivided into the almost natural, the semi-natural and the anthropogenic.

The most natural ecosystems are of natural origin; their species structure, being in natural accord with their habitats, does not differ from their types of phytocoenosis. These systems are usually found in strictly protected reserves and nature refuges not easily accessible to man.

Semi-natural systems are either plant communities of anthropogenic origin often not in accord with their habitat, or communities of natural origin but partly transformed by management - e.g. harvested forests, various types of grassland (meadows, pastures, drained peat bogs). However, many plant species of forest, meadow and moor remain in these areas, creating conditions for richness of ecological niches.

Anthropogenic systems are man-formed so far as the spatial, layer and species structure is concerned. Management by man (farmland, ponds, orchards etc.) is essential in ensuring achievement of desired aims. Correct ecological management can provide vital refuges for many rare and endangered species.

Rarity of occurrence applies both to the rarity of species and habitats due to human activity and rarity stemming from the fact that certain environments are uncommon in nature.

Rarely found species and habitats, as well as their abiotic conditions (e.g. arid grassland, salt marsh, mountain vegetation, lobelia lakes) are those which occur in the country only sporadically. The current (and former) intensive exploitation might cause them to vanish entirely. Natural communities with primeval features (e.g. Bialowieza forest) are seldom found.

The existence of an exceptionally rare habitat or species or group of species may be due to a unique combination of biogeographical elements - or exceptional preservation of certain natural phenomena. Good examples include the mobile dunes in Slowiñski National Park with many sand communities and Lake Hañcza Poland’s deepest (108.5 m) lowland oligotrophic lake with unique fauna and flora.

Degree of threat applies to individual species, groups of species and plant communities under severe national or continental threat. Species included are those listed in the Polish and European Red Data Books as well as plant communities rapidly decreasing as a result of intensive (mis)management both past and present.

2.3.2. Formation of the EECONET-PL structure

It has been agreed that geomorphological structures which are to be included in EECONET-PL should:

• have many heterogenic habitats and contribute to biological diversity;
• help to preserve hydrogenic habitats;
• help to preserve fragments of natural vegetation in refuges that are not easily accessible to management (map 2 + legend). These include:
  • mountain areas with morphological and lithological diversity creating good conditions for preservation of different habitats and natural and semi-natural systems;
  • finely sculpted hillside areas enriched by eroded or karstic forms;
  • plains of rivers and water-glacial accumulation;
  • dune areas;
  • large lowland river valleys, especially marginal stream valleys;
  • bar or cliff coasts.

Hydrological conditions. Hydrographic systems, due to their natural value and great endangerment, should be included in core areas - and also in the network of eco-corridors. That is why there are international corridors on the Baltic coast and in lake districts and large river valleys (map 3 + legend).

It is especially advisable to create core areas and eco-corridors which would include the following:

• water communities along the Baltic coast including delta and estuary ecosystems. They are endangered not only by natural factors - insufficiently strong links with the sea, shallow waters, desalination - but also by man-made factors such as excessive pollution and over-fishing. They demand protection because they contain specific ecosystems characteristic of salty waters plus many migratory and other bird species;
• lowland river valleys that are connected with rich systems of hydrogenic habitats - water, river bank, flood-plain marsh and mire;
• mires of a natural or semi-natural character and, especially, rare types of peat bog such as raised bog, calcareous fen and bog heath of the Atlantic type;
• other highly hydrogenic habitats. endangered due to water-course (waste) regulations, drainage systems and intensive agriculture;
• mountain and lowland rivers with steep drops on the uplands, and lake districts with numerous strongly defined fissures;
• areas with lakes of different origin, and especially:
  • very large, shallow coastal lakes at near-sea level which are vulnerable to degradation from periodic inflows of brackish sea water;
  • delta lakes with similar characteristics to the above;
  • karstic lakes, rarely seen, connected with karstic phenomena in the shallow karstic substratum in Polesie;
  • numerous post-glacial lakes (especially oligotrophic and dystrophic) varying in size and location depending on the hydrography of the terrain;
  • lakes and old river beds, usually small, with amphibians and other fauna not found in open rivers - highly endangered by man-made changes, in particular by river regulations and drainage works;
• artificial reservoirs, dammed reservoirs, pond complexes, especially in lake-free regions outside the area of the last glaciation.

Biotic conditions. As already mentioned the EECONET-PL core areas have been drawn up in order to preserve the plant communities and plant and animal species which are, to varying degrees, threatened. Special attention has been given to the following communities:

• forest communities in fertile habitats (deciduous and mixed forests);
• forest communities in hydrogenic habitats (deciduous and coniferous forests);
• large coniferous forests in sandy habitats;
• mire vegetation;
• maritime communities (white and gray dunes);
• aquatic communities;
• mountain, subalpine and alpine communities;
• semi-natural, especially xerothermic grassland, extensively exploited meadows and heathland;
• field-weed communities strongly linked with traditional farming;
• rare communities or trans-frontier communities extending into Poland.

Landscape structure. This has been determined on the basis of land exploitation (map 4 + legend). From the standpoint of values to be protected by EECONET-PL the chosen landscapes are:

• large forest complexes;
• large green land complexes;
• large areas of water (sea, lakes, large rivers);
• mosaic systems with a large percentage of forest, permanent green land, open water (even considerably dispersed) and extensive traditional farming.

Large areas of land in the northern and western parts of the country, as well as in the southern mountain region, have excellent land-use systems, so allowing core areas and important eco-corridors to be formed there which assure east-west continuity. (Land use of this calibre seldom occurs in other areas.) Valleys, too, have a landscape structure which permit the creation of core areas plus internationally important eco-corridors.

Occasionally mosaic systems, when containing the right mix of forest, water and green land, may independently play the role of core area. These types of system are well known in the country, giving continuity to the EECONET-PL network, especially in central and southern parts.

Poorly structured systems, totally dominated by cultivated fields, are particularly prevalent in central and southern regions. In areas where these systems are most abundant, the important role is played by the network of eco-corridors with a rich landscape structure, thus preventing the formation of multisurface complexes acting as barriers within the system.

Existing protected areas. The structure of protected areas in Poland is the result of activities for the protection of nature undertaken over many years (map 5 + legend). The Act on Environmental Protection (1991) calls for a national system of protected areas. The process of forming this system is not yet complete; many important areas have as yet to be included [Denisiuk et al. 1990]. At present protected areas cover 23.7% of the country. They comprise 20 national parks (0.8%), 1031 nature reserves (0.36%), 91 landscape parks (5.5%) and 245 protected landscapes (17%) (figures for 31 December 1993). These various existing and proposed areas will nearly all become part of the EECONET-PL network. And certain protected landscapes and landscape parks and reserves will now form part of the eco-corridor structure at a European level.

2.4. EECONET-PL implementation: special points

The team preparing EECONET-PL was forced to introduce certain changes in the working methods initially agreed between the Polish, Czech, Slovak and Hungarian teams. These changes mainly referred to scale - how detailed should the various analyses be. In Poland the working scale was 1:500,000 as against 1:50,000 and 1:100,000 in the other 3 countries. The latter were thus able to analyze on a local level, then gradually pass to a synthesis at a national level on a scale of 1:500,000. This discrepancy arises from the fact that Poland is very much the largest of these 4 countries.

3. Nature in Poland

3.1. Special characteristics of Poland’s natural environment

The Polish environment is characterized by infiltration from neighbouring areas - especially from the west and east. Sandwiched between the oceanic, varied landscapes of the west and the monotonous continental landscapes of the east, Poland possesses nearly all the components of these regions in its natural environment, especially with regard to geological or climatic phenomena and, to a lesser extent those of soil and water.

Poland’s unique geological structures are the result of its position abreast the contact points of Europe’s tectonic plates: Precambrian east European, mid-European, Palaeozoic formations and the younger alpine systems (figure 3.1 + legend). Each of the plates has a different geological structure, differing depths of troughs in the ancient crystalline foundations, connected with the thickness of the sedimentary rocks [Gilewska 1991].

In the north-east of Poland, on the edge of the ancient monolithic east European plate, the crystalline foundation dips very steeply covered in places by a layer of sedimentary rocks only a few centimetres thick. However, in the south-western part of the country, a region of more varied west European Palaeozoic structures, the crystalline foundation is extremely deep, covered by sedimentary rocks several kilometres thick. Only the south-western edge of Poland’s crystalline substratum is close to the surface; forming the Sudeten massif it has many cracks and faults. Cyclical changes in the Scandinavian ice sheet in the Pleistocene affected almost the entire country, stopping only at extreme elevations in the Carpathian and Sudeten ranges, influencing and layering the parallel system of the major geomorphological units (see figure 3.2 + legend). In the parallel southern and northern regions of Poland lie the following morphological zones:

• young alpine-system mountains - the Carpathian and sub-Carpathian basins characterized by wide flysch and submontane basins not found in the Alps;
• old Sudeten mountains and uplands (plus the Sudeten foothills, Swiêtokrzyskie mountains and southern Polish uplands) which vary from other European forms of this type by having deeper fissures - a post-glacial effect;
• lowland zones of central and northern Poland (covering as much as 70% of the country), consisting of the old glacial area in the south and the young glacial area - of a fresh post-glacial appearance - in the north and extending beyond Polish borders.

East-west layers of the Polish landscape are emphasized by the positioning of large marginal stream valleys that absorbed thaw waters in the consecutive stages of ice-sheet disappearance (among others, Wroclaw-Magdeburg, Glogowo-Baruck, Warszawa-Berlin and Toruñ-Eberswalde). Part of these later made up rivers running south-north, creating the very distinctive parallel southern system of main river valleys. This system is characterized by the asymmetry of the main river basins (above all the Odra and the Vistula and, beyond Polish borders, the Niemen and the Dzwina), right-hand inflows being more numerous and longer than left-hand.

The transitional nature of Poland’s natural environment is also shown particularly clearly where humid air from the Atlantic meets dry air originating in the east. This creates a rapid movement of barometric high and low pressures and a resultant changeability in weather systems. Towards eastern Poland the climate becomes more continental: winters are severer, snow cover lasts longer, the temperature range is greater and the growing period is shorter. The mountain areas of southern Poland have an entirely different climate from the rest of the country, with climatic vertical zones caused by the drop in air temperature at high altitudes.

The specific characteristics of plant cover and the animal world are the result of Poland’s position on the contact area between western and eastern Europe in the wide belt of post-glacial relief (limited from the south by the Carpathian and Sudeten mountain ranges, but open to outside influence from both east and west - figure 3.4 + legend).

The most distinctive feature of Polish plant cover is its transitional nature as compared with neighbouring areas. There is a distinction between west and east (as the climate becomes more continental) and between north and south (corresponding with the parallel layering of the landscape zones) with vegetation varying according to whether Atlantic or continental influences dominate - with even some Pontic-Panon elements.

As you move east, lowland sub-continental mixed pine-oak and sub-boreal spruce forests become more common (with Eurasian features being especially prominent in the far north-east) while the lowland beechwoods and acidophilous oakwoods characteristic of western Poland gradually disappear. In lowland regions two basic types of habitat have emerged - deciduous forests on fertile soils and coniferous forest on poorer soils [Matuszkiewicz W. 1981, Matuszkiewicz W. et al. 1973, Matuszkiewicz W. and Matuszkiewicz A. 1985, Szafer 1972].

Demonstrating the transitional nature of Poland’s flora is the fact that over 50% of species are so-called transitory species, that is, species whose full range does not occur on Polish territory [Pawlowska 1972]. They are usually common species, representing the Holartic geographical element and the Euro-Siberian and mid-European sub-elements. Species, which reach their geographical limits within Poland, account for 40% of Poland’s flora. Arctic and Mediterranean sub-elements are relatively rare, although Atlantic and Mediterranean-Atlantic sub-elements are well represented in western and north-western regions. In the south-east Poland there is increased evidence of the Pontic-Panon elements and, to a certain degree, a Mediterranean element reaching west towards the Polish highlands. Northeast Poland is characterized by numerous boreal and boreal-continental elements and (to a small extent) Pontic, Arctic and Mediterranean-Atlantic elements.

Another characteristic of Poland’s plant cover is the clear contrast between the lowland-upland areas and the mountain areas which cover only 3% of the total. In spite of its lowland appearance Polish vegetation is much more varied in the mountains (over 20% of vascular plants and plant communities are found here) than in the lowland-upland areas. Mountainous areas show distinct altitudinal zones which depend upon climatic as well as other factors change with elevation.

The fauna, consisting of many species from all over the continent, also displays a transitional character. There are few endemic species (species unique to Poland) and preholocene relicts are confined almost exclusively to the upper parts of mountain ranges. Mountain fauna is distinct from that found in upland and lowland areas. Containing many species of vertebrates and butterflies, Polish fauna is far from monotonous.

The previously mentioned hydrological, geological and biotic factors account for the characteristics of the Polish pedosphere, The main soil types are brown-earth (brown and lessive) dominating over half the surface of the country. Podzol earth (rusty and typical podzol) covers 25% of this area. Also occurring mainly outside the climatic-vegetal zones is a black earthy soil, ‘chernozem’. West of Polish borders lie more fawn-coloured soils - to the east, yet more podzol soils. Non-zonal soils - such as peat, former peat and alluvial - play an important role in the structure of Polish soils. Salty soils are a rare curiosity.

The real differentiation of the Polish environment is evident in its division into complex physical-geographical units. On the one hand these reflect the parallel belt-like relief; on the other, the climatic, meridional changeability of the country (see figure 3.5 + legend). According to a recent regionalization account of Europe [Kondracki 1991], Poland is generally viewed as the physical-geographical area of western Europe. Only to the east and north-east is there any evidence of the units denominated as eastern Europe. This high regional differentiation is not that obvious in the physical-geographical landscape, as the Polesian landscape, not found in western Europe, may only be detected in the lowlands, valleys and extensive plains. The area of Poland designated as western Europe covers two sub-areas: non-alpine western Europe and the Carpathian and sub-Carpathian depressions. There are five provinces considered to be within western Europe: the mid-European lowlands, the Czech Massif, the Polish uplands, the western Carpathians and the eastern Carpathians. Eastern Europe has just two provinces; the west Russian lowlands and the Ukrainian uplands.

The borders of these large units, with their own climatic, geological and historical characteristics of flora and fauna, are not always clearly manifested in the physical-geographical landscape. Typological differences in the landscape of the lower-level units may be seen clearly. However, the landscape patterns of the parallel units within the area of western and eastern Europe are often quite similar. In general the landscapes of those zones formed during the same period and under the influence of the same geomorphological factors share a common and specific character.

These zones are as follows:

• The Baltic coastland - totally incorporated within the mid-European lowlands;
• The early-glacial lake districts - including the south-Baltic lake districts (a region of the mid-European lowlands) and east-Baltic lake districts (a region of the west-Russian lowlands);
• The Peryglacial lowlands - including the Saxon-Luzyce lowlands and mid-Polish lowlands (found in the mid-European lowlands) and the Podlasie-Belorussian uplands and Polesie (found in the west-Russian lowlands);
• The uplands - including the Polish uplands from the west European area and Wolyñ-Podole uplands (the western part of the Ukrainian uplands) from the east European zone; the pre-Carpathian Depression - totally within the west European area (the west Carpathian province);
• Mountain areas:
  • Sudetens and Sudeten foothills - which form part of the Czech Massif;
  • Carpathians.

Regional differences within these landscape zones are expressed first of all in different plant cover. Landscape consisting of valleys and extended plains occurs in many different regional units, illustrating the important role they play in integrating Poland’s natural habitats. The fact that the physical-geographical landscapes within the area of parallel east-west landscape zones are very similar with similar habitats is evidence of basic ecological connections which entirely justify the creation of eco-corridors.

3.2. Regional differences

The landscapes of Poland and their differences in biotope and plant cover were dealt with in the chapter discussing landscape zones (map 1 + legend).

3.2.1. The Baltic coastland

The Baltic coast is characterized by specific natural landscapes: sand-bar coastland grading into peat-lake landscape - the best representation of this landscape type in Europe. Apart from the open Baltic featuring the Pomeranian, Puck and Gdañsk bays there are further bays connected with the sea by narrow straits, e.g. the Szczecin and Vistula bays and the coastland and delta lakes uniquely characteristic of this region. Other characteristics are sandy beaches, bars, coastland lakes, white-and-gray dunes and also older forest-covered dunes. Dunes often emerge from high and transitional moorland areas. Steep and eroded coastland may be found only where these zones have ecosystems characteristic of the contiguous lake districts.

Oceanic impact is strongly marked on the Baltic coast - particularly its western part where many fairly rare Atlantic and sub-Atlantic species are found. In this region, as well as species wholly connected with the sea, occur the following plants: wax-myrtle, Myrica gale, woodbine, Lonicera periclymenum, heaths, Erica tetralis, and Swedish mountain ash, Sorbus intermedia.

The most characteristic plant communities are those of salt marsh, white-and-gray dunes vegetation, maritime crowberry moor, Atlantic wet heathland and the Atlantic-type high peatbog. On strengthened dunes occurs a special type of pine wood: Empetro nigri-Pinetum. Deciduous forests occur in places where moraine heights meet the coast. They belong to the sub-Atlantic type with predominant beech woods (both lowland-rich and poor) and acidophilous oak forests. Only in the western part of this region in poor, acidic, permeable habitats (which elsewhere are covered with pine forests) do oak-birch woods, typical of such habitats in western Europe, appear. Oak-hornbeam forest, Querco-Carpinetum sensu lato ("grond"), also occur in the region as a community with distinctive sub-Atlantic features - Stellario-Carpinetum association.

This zone contains too the big river estuaries (the Vistula and the Odra): estuary plains are the dominant landscape - a landscape that is well preserved in the Zulawy Wislane area. The whole area has deeply indented small valleys with small rivers flowing directly into the Baltic.

3.2.2. The upper glacial lake district

This vast and richly sculptured zone, which extends westward into Germany and eastwards into Lithuania, Belorussia and Russia, has a network of unimpressive surface outlets, numerous post-glacier lakes and small depressions which often take the form of peatbogs. This type of landscape, described as washboard moraine and lake-district outwash [Kondracki 1981, 1991], is characterized by a rich sculpture of undulating hummocks, kame fields, broad outwash plains, lake district plains, small peatbogs and numerous eutrophic, oligotrophic and dystrophic lakes. In the moraine landscape these conditions give rise to a large variety of habitats which favour biological diversity.

Climatically the whole zone shows a gradual continentalization as you progress east. In addition the eastern part contains a steep drop in altitude from the high point created during the Pomeranian phase of the Baltic glaciation. In this marginal area the vegetation changes greatly, from (going east) sub-Atlantic to sub-continental to sub-boreal.

Conditioned by climate and habitat variability, this zone can be divided into areas corresponding to the prevailing type of landscape brought about by age and geobotanical region [Matuszkiewicz J.M. 1993].

• moraine sub-zone of the Pomeranian phase of Baltic glaciation west of the Vistula valley (Pomeranian divide, Szczecin region, central Pomeranian lakelands);
• outwash sub-zone of the Pomeranian phase (Pomeranian divide, Sandrian forelands of central Pomeranian lakelands);
• Toruñ-Eberswalde proglacial stream valley (Brandenburg - Great Poland divide, Notec-Lubus region, Notec woodland sub-region);
• lake district sub-zone of the earlier phases of Baltic glaciation (Brandenburg - Great Poland divide, central Great Poland region, southern Great Poland - Luzyce region);
• upper glaciation lake district in the transition region (Mazovian - Polesie divide, Chelmno-Dobrzyñ region);
• Mazurian - Lithuanian lakelands (northern divide-, Mazurian region).

Baltic glaciation: moraine sub-zone of the Pomeranian phase. The most characteristic feature of this zone is the existence of young post-glacier formations, especially in the hummock zone of the terminal moraines at altitudes, in eastern parts, of above 300 m. (On smaller areas altitudes exceed 150 m in the west and 250 m in the east - the Wiezyca region.)

These formations have produced deep erosive cuts and water courses similar to mountain streams. Altitude plus closeness to the sea make for higher precipitation and lower temperatures than in neighbouring areas. As a result sub-ocean plant communities and species occur more often here than in other areas of other (even more westerly) zones. Argillaceous and sandy-argillaceous moraine subsoil mean most habitats are rich. In western parts, in particular, lowland beech forest (rich Melico-Fagetum and poor Luzulo pilosae-Fagetum) is predominant. More prominent in the east are sub-Atlantic beech-oak-hornbeam forests, Stellario-Carpinetum. Among poorer habitats, sub-Atlantic acidophilous oak and beech-oak forests (Luzulo-Quercetum and Fago-Quercetum), rare in other areas, predominate; mid-European pine-oak mixed woods, Querco roboris-Pinetum, are less common; pine forests, represented by sub-Atlantic association of Leucobryo-Pinetum are relatively rare. There are no moist pine forests, Molinio-Pinetum; their habitats have been colonized by acidophilous oak woods [W. and J.M. Matuszkiewicz 1973]. Marshy woods in the vicinity of small rivers, as well as often being found in Poland Circaeo-Alnetum association, are represented by the Carici remotae-Fraxinetum association in its lowland, sub-ocean variety.

In numerous waterlogged depressions with no outflow are found swamp alder forest, Carici elongate-Alnetum, on lowmoor peat and sub-continental bog pine forest Vaccinio uliginosi-Pinetum on highmoor peat, as well as sub-Atlantic swamp birch forest, Betuletum pubescentis, on transitional peatbog.

In this zone also occur natural end semi-natural non-forest communities, some of them rare or even endangered nation-wide. The large number of depressions with no outflow makes for a surprising plenitude (particularly in the eastern part) of small areas of transitional and highmoor peat not found in other regions. On highmoor peat, as well as mosses, Sphagnetum magellanicum, which other regions do have, occurs the Atlantic-type peatbog, Erico-Spagnetum medii. Also occurring in some places is the very rare (in Poland) calcareous fen, Caricion davalliane [Herbich 1982].

Numerous lakes are the other characteristic feature of the moraine zone. There are lakes of all types eutrophic, oligotrophic and dystrophic with typical vegetation (many lakes have stoneworts). Well preserved in this zone - and very rare in other regions - are lobelia lakes with corresponding vegetation and species, Isoetes setacea. All five Polish localities are in the south-east part of the zone. Here are found Lobelia dortmanna, Isoetes lacustris, Najas marina, Litorella uniflora etc. Reed and cyperaceous vegetation, Phragmition and Magnocaricion, are found in the vicinity of the lakes. Worth emphasizing is that here too occurs the twig rush, Cladietum marisci.

Baltic glaciation: outwash sub-zone of the Pomeranian phase. This zone adjoins to the south of the zone described above. Moraine plains from earlier periods of the Baltic glaciation are still a feature of this widespread outwash with its Pomeranian-phase dunes. In the outwash area large wood complexes are preserved. Although partly transformed by forest management, some areas still exist in a close to natural form. There are habitats similar to those in the zone described above but the proportions are different. Leafy wood habitats are not numerous. Pine woods predominantly appear in their fullest diversity - from dry lichen-rich pine wood, Cladonio-Pinetum, and mesic mid-European pine forest, Leucobryo-Pinetum to swamp pine forest, Vaccinio uliginosi-Pinetum. Starting from the terminal moraines towards the Toruñ-Eberswalde proglacial stream valley, sub-ocean features become less prominent. On poorer soils, mixed woods, Querco-Pinetum, are more common than acidophilous oak woods. On richer soils, beech woods occur less often and sub-Atlantic beech-oak-hornbeam forest rarely. Mid-European Galio silvatici-Carpinetum is dominant.

The essential element of this zone is valleys rich in rivers running from the lakeland region. Valleys still in their natural state include floodplain forests of marshy lowland willow-poplar. Prominent in some areas are the half-natural communities of inland moor, Calluno-Genistion, and, on sandy soils, dry grassland, Corynephoretalia and Festuco-Sedetalia. There are a great many lowmoor, transitional and highmoor peatbogs as well as eutrophic, oligotrophic and dystrophic lakes (including a few lobelia lakes).

The Toruñ-Eberswalde proglacial stream valley. This is a broad-valley area filled by fluvio-glacial and river sand with, on the lowest terrace, lowmoor peat and river mud which form a corridor joining the Vistula and Odra valley systems. The dominant landscape is that of valley bottoms, terraces and dunes. Chiefly found on the valley bottoms are vast area of lowmoor peat with reeds, Phragmition, and tall sedge communities, Magnocaricion, and well preserved, for the most part, low sedge communities of Caricion fuscae. The prevailing meadow vegetation includes many wet meadows, Calthion, accompanied by - increasingly rare in Poland - single-harvest moor-grass meadows, Molinion, and forb meadows, Filipendulo-Petasition, preserved due to non-intensive use.

Woods and marshy bushes are preserved in small parcels. However the area covers a whole series of marshy habitats due to different frequency of flooding - from very common willow bushes, Salicetum triandro-viminalis, and annually flooded willow-poplar wood, Salici-Populetum to occasionally flooded elm-ash forest, Fraxino-Ulmetum and swamp-marsh alder -ash forest, Circaeo-Alnetum. There are also alder swamp forest, Carici elongatae-Alnetum, on areas turned into marsh osiers, Salicetum pentandro-cinereae.

Upper terraces represent sandy and poor habitats where large forest complexes are preserved. Forestry has had a significantly transforming effect but numerous areas of phytocoenosis survive, representing full habitat diversity ranging from dry pine forest, Cladonio-Pinetum on dunes to the mesic sub-Atlantic mid-European pine forest, Leucobryo-Pinetum, to bog moss pine forest, Vaccinio uliginosi-Pinetum in depressions between dunes. Locally, highmoor peat and transitional peat occur. On monadnock hillocks, preserved in a proglacial stream valley, is a rich beech wood, Melico-Fagetum and a mid-European oak-hornbeam forest, Galio-Carpinetum.

High up and exposed to the south a proglacial stream-valley slope is the habitat of xerothermic grassland, Festuco-Brometea, and sub-xerothermophilous oak woods, Potentillo albae-Quercetum. Both types of vegetation occur on the northern fringes of the area.

Lake district: earlier phases of Baltic glaciation. This zone is characteristically rolling or hummock and is shaped by moraines. Lakes, mostly eutrophic, are not as numerous as in the moraine zone of the Pomeranian phase; the moraines are less high, the sub-ocean features less marked. The mid-European element dominates; beech woods, both rich Melico-Fagetum and poor Luzulo pilosae-Fagetum are common; oak-hornbeam forest is exclusively represented by mid-European association Galio-Carpinetum. Moderately poor habitats have beech-oak woods, Fago-Quercetum and Luzulo-Quercetum, and oak-pine, Querco-Pinetum. On poor habitats - not very common - are found mid-European pine, Leucobryo-Pinetum, dry pine, Cladonio-Pinetum, and bog pine, Vaccinio uliginosi-Pinetum forests. Molinio-Pinetum is not found. Corresponding sites are occupied by acidophilous oak woods or humid mixed woods. In hydrogenic habitats lowmoor peat is very common - as are swamp alder, Carici elongate-Alnetum, and swamp marsh, Circaeo-Alnetum. In agricultural areas forests or extensive meadows are rare; core areas are concentrated on land less transformed by man.

The upper glacier lake district in the transitional region. This region includes areas in the range of the Baltic glaciation with a significant number of lakes, reed beds and peatbogs, but dominated by central Polish or sub-continental features. Sub-Atlantic elements are few and confined to northern and western peripheries where rich beech woods, Melico-Fagetum, still exist. In most of the area, though, beech and spruce are absent. Within deciduous forests is found sub-continental Tilio-Carpinetum, while mixed woods contain mid-European Querco-Pinetum and sub-continental Serratulo-Pinetum. In mesic pine woods is found the sub-continental Peucedano-Pinetum. There is virtually no Molinio-Pinetum but Potentillo albae-Quercetum is quite common.

Mazurian - Lithuanian lakelands. These fragments of the upper glacial lake district have large and variable habitats, exposed to the east, and are distinctly sub-boreal. They continue east and north into Lithuania and Belorussia. The sub-boreal character is shown by spruce forest, Querco-Piceetum, and peatbog spruce, Sphagno-Piceetum; the only representative of mixed forest is Serratulo-Pinetum. Low birch and willow bushes, Betulo-Salicetum repentis, periodically occur, along with other communities specific to the region. Plant communities not found elsewhere in Poland, central or western Europe, occur here - for instance, Carici chordorrhizae-Pinetum [Palcz 1975], Carici globularis-Pinetum and Thelypteri-Betuletum [Czerw 1970]. Moist forest Molinio-Pinetum is common and several large complexes of ‘primeval forest’, mainly on the outwash, have survived. Other data relating to the more eastern area are not available; whether they represent borderland forms of sub-boreal communities and significantly marked regional forms of communities known in other areas of Poland or successive stages would be hard to determine. They contribute, however, to the region’s peculiarity.

Apart from its many lakes the characteristic feature of this region is its lowmoor, transitional and (less often) highmoor peat with fragments of calcareous and spring fen. There are also great numbers of waterfowl and birds of prey.

The region has a significant plenitude of species, including numerous types of flora that are very rare in Poland. There is too quite a large number of glacial relicts.

3.2.3. The periglacial plains

This zone has no lakes and is dominated by flat or rolling periglacial plains. This type of landscape - though it boasts a fine river network - militates against diversity of habitats. Only the river valleys have significant features, often with terraced dunes. Connected to proglacial streams, these valleys are highly diversified hydrogenic habitats amenable to exploitation.

Within this zone the east-west variability is less marked than in the lake district zone. (A small number of elements of sub-ocean character exist on the level of plant species rather than plant communities.) The mid-European element is dominant. In western parts there are beech woods and, in moderately poor habitats, acidophilous oak woods, Luzulo-Quercetum. In the east are found Calamagrostio-Quercetum (but without the distinctive sub-ocean Fago-Quercetum which exists in Pomerania) and mid-European Querco-Pinetum - although as you go east the latter gradually gives way to Serratulo-Pinetum, initially of the Sarmatian type and then in sub-boreal variety. Oak-hornbeam forests are less variable than in the lake district due to the absence of Stellario-Carpinetum.

On poor habitats along the Vistula occur mid-European Leucobryo-Pinetum and, towards the east, sub-continental Peucedano-Pinetum. Sub-xerothermophilous oak forests, Potentillo albae-Quercetum, are quite common here - unlike the lake district. With no natural lakes, water and mire vegetation, including waterfowl habitats, are mainly connected to the river valleys and old river beds. Locally important enrichment of habitats is shown by the existence of old fish ponds and clay ponds.

In this zone fragments of natural or semi-natural vegetation - such as are seldom now found in Europe - still survive in the big river valleys. Riverside willow bushes, Salicetum triandro-viminalis, and marsh Circaeo-Alnetum woods are common - less so are Ficario-Ulmetum (and exceptionally Salici-Populetum) and swamp alder, Carici elongatae-Alnetum. Still less common are herb meadows, Filipendulo-Petastion, one-harvest variably-humid meadows, Molinion, lowmoor peat, Caricion fuscae and cyperaceous Magnocaricion. On high terraces are found pine wood communities with swamp alder and transitional peatbog, Scheuchzerietalia palustris, plus highmoor peat, Sphagnetum magellanici and Ledo-Sphagnetum.

Close to natural vegetation favouring numerous animal species is also still found in certain forest complexes. While these are normally poor habitats unattractive to agriculture, their survival is often attributable to historical factors.

The eastern borders of this zone give onto the west Russian plains, a very specific region thanks to its genesis and geological structure. A major role (particularly in the north) is played by the Pleistocene river formations which nowadays often become marshy. In the subsoil occur Cretaceous formations formed by the karst process, creating numerous and widespread depressions covered by lakes and peatbogs. The result is a type of landscape called the Polesie plain. Extremely exposed to the west and extending onto Belorussian and Ukrainian territory, its flora has numerous sub-continental and sub-boreal elements. At the same time its spacious lakes and swamps give a relatively humid local climate, allowing certain sub-Atlantic elements to flourish some distance from their main range.

3.2.4. The uplands

The uplands differ strongly from zones so far described, so much so that their borders (defined according to different criteria - biogeographic and physical-geographic) do not greatly vary. In this zone the Quaternary formations have a smaller significance, the decisive role belonging to the old Caledonian mountains and the high uplands - often made of carbonate rocks. These rocks have a great many karst formations, including caves which serve as rare habitat for certain endangered species, such as bats. Rare types of xerothermic and saline habitats are connected to outcrops of gypsum in the Nida basin.

The upland zone is erosive with differentiation of geological structure and sculpture contributing to a significant mosaic of habitats favouring biological diversity. Most of the area is in the range of fir and beech (with the exception of the Lublin uplands which for this reason are not counted as uplands in some geobotanical regionalization - J.M.Matuszkiewicz 1992). Mountain and Pontic-Panon flora are more plentiful here. Frequently occur Festuco-Brometea arid grassland (‘steppe’), sub-termophilous oak forest, Potentillo albae-Quercetum and, in its special upland variety, oak-hornbeam Tillio-Carpinetum. In the western part are habitats of acidophilous oak woods, Calamagrostio-Quercetum, which give way in central and eastern parts to mid-European mixed woods, Querco-Pinetum. Among marsh communities, besides those inhabiting the plains, is sub-montane ash wood, Carici remotae-Fraxinetum.

Due to the differences in terrain and geological structure within the province of Wyzyny Polskie, 3 sub-provinces have been selected: the Silesian-Cracow uplands in the west, the Ma³opolska uplands in the centre and the Lublin-Lvov uplands in the east. The eastern edge of the strip is included in the Ukrainian uplands (Wolyñ-Podol) [Kondracki 1991]. The geobotanical regionalizations incorporate broadly similar divisions [Matuszkiewicz M.J. 1993, Matuszkiewicz W. 1991, Szafer 1972].

3.2.5. The Carpathian foreland depression

The Carpathian foreland depression is a sub-province of the western Carpathians. It is filled by Pleistocene glacial silts, glacial water, and Pleistocene and Holocene river mud. Soil temperatures are fairly warm. An important role is played by pulpy sand silts which often create a landscape of dune terraces at the bottom of the valleys of the Vistula and its tributaries flowing from the Carpathians. It is a land of farming and commercial forestry - with the forests occasionally damaged by industry (for instance, Puszcza Sandomierska). Large and dense forest complexes still occur to the north-east in the region of Równina Bilgorajska.

3.2.6. The Sudeten mountains and foothills

The Sudeten mountains are part of the Czech Massif and comprise an area of ancient mountains with a very varied geological structure. The range is made up of different rocks throughout - acid crystal, metamorphic, (granite, gneiss, schist), silt silicate (sandstone, greywacke), carbonate (limestone, marble) and, which is very rare in Poland, volcanic (basalt, porphyry, gabbro, serpentinites). The result is a diversity of habitats and plant communities, including rarities found only on particular kinds of rock.

The plant cover of the Sudeten range varies markedly with altitude - becoming Alpine on its highest elevation. On lower levels, at around 400 m [Kondracki 1981] are found submontane forms of mid-European oak-hornbeam forest, Galio-Carpinetum, acidophilous oak woods, Luzulo-Quercetum, and the Sudeten beech - on rich soils, Dentario enneaphyllidis-Fagetum, on poor soils, Luzulo nemorosae-Fagetum. The lower montane belt occurs at up to 1000 m. It is an area of rich and poor Sudeten beech woods and mountain spruce, Abieti-Piceetum montanum. The upper montane belt (rising to 1250-1300 m) is the habitat of spruce forest, Plagiothecio-Piceetum hercynicum. The subalpine belt is characterized by dwarf mountain pine, deciduous bushes and tall forb vegetation. The geological history of this area contributes to a great mosaic of habitats (significantly greater than in the Carpathian flysch) conducive to biological diversity. Although the impact of man has been considerable, numerous areas survive almost unaltered. The Sudeten range boosts many rare plants, some of which are found nowhere else in central Europe.

3.2.7. The Carpathians

Only the northern part of the impressive ridge of the Carpathians is on Polish territory. The geological structure, as compared with the Sudetens, is less diverse; the eastern and western extremities consist of sandstone formed between the early Cretaceous and the Oligocene. The varying sculpture of the landscape comes from the varying hardness of the rock. Formed in the late Cretaceous the west central Carpathians have a significantly different geological structure. During the forming of the outer Carpathians the western Carpathians were ‘rejuvenated’; powerful upheavals exposed earlier structures. Today the central part of the mountain chain comprises a Palaeozoic crystalline trunk - the High Tatra massif. Mesozoic structures are revealed in the limestone’s of the western Tatras, in the Tatra’ s lower regions and in the range of Jurassic limestone which has Pieniny as its highest part. On the Tatra foreland is a depression formed at the same time as the remaining central Carpathians but not subsequently elevated. Tertiary sediments now fill it.

Carpathian vegetation differs significantly from Sudeten, due, partly, to the size of its massif, higher altitude, and more eastern location. This affects the main vicariant communities of vegetation. The sub-montane belt reaches 550 m [Pawlowski 1972] and as high as 600 m in eastern parts (Bieszczady). Habitats of sub-continental oak-hornbeam forest (Tilio-Carpinetum) in a special, upland-submontane variant, predominate, accompanied by mixed wood, Querco-Pinetum (there are no acidophilous oak woods in this region), while beech woods play a supporting role [Matuszkiewicz W. l984]. Lower montane belt reach to 1100 m in Beskid Slaski and to 1220 m in Bieszczady (but in Beskid Niski only to 1000 m). At these altitudes are Carpathian beech woods, Dentario glandulosae-Fagetum, spruce and fir forest, Abieti-Piceetum montanum, mixed mountain forest, Galio-Piceetum carpaticum, and mixed beech and fir forest, Galio-Abietetum, which have no equivalent in the Sudetens. In certain mountain ranges, still other associations are found. Woodlands are accompanied by rich meadows, Gladiolo-Agrostietum and tall forbs, Arunco-Doronicetum austriaci. As well as willow-poplar, Salici-Populetum, in large river valleys, plus Carici remotae-Fraxinetum in small stream valleys, mountain gray alder, Alnetum incanae, and marshy mountain alder, Caltho-Alnetum, also occur here.

Upper montane belt do not exist in Poland’s eastern Carpathians nor in Beskid Niski; in Beskid Zachodni it reaches 1257 m, in Beskid Slaski 1360 m and in the Polish Tatras 1500 m. It consists of spruce woods, Piceetum tatricum, and, in the limestone area of the Tatras, Polysticho-Piceetum. At both montane levels the grass community, Hieracio-Nardetum, is common pasturage.

Alpine and sub-alpine pastures are found only in the Tatras and Beskid Zywiecki. The border line between the two occurs at around 1650 m. The sub-alpine level consists of bushes of dwarf mountain pine, Pinetum mughi carpaticum, and forb and fern vegetation, Adenostyletum alliarie and Athyrietum alpestris. At the Alpine level (only in the Tatras and on Babia Góra) the most common vegetation is the tall grassland, Calamagrostietum villosae tatricum, and the alpine short grassland, Caricetea curvulae. In Bieszczady, mountain pastures occur only at heights of 1220-1348 m.

Carpathian flora is richer than Sudeten. The former boasts around 500 types of mountain plants against about 200 for the latter (although 22 of these 200 are not found in the Carpathians). The Carpathians also have numerous eastern (Pontic-Panon) plants absent in the Sudetens. Only 6 sub-ocean species existing in the Sudetens do not occur in the Carpathians.

Endemism is a feature of the Carpathians. There are nearly 100 Carpathian endemics (plus nearly 20 sub-endemics), of which more than 20 occur in the west Carpathians and a substantial group in the east, although some of these do not reach Polish territory. (There is also a certain number of Tatra and Pieniny endemics.) In the eastern Carpathians Balkan flora is a prominent feature - as are certain continental species; in the western part sub-ocean species are found. The two regions are quite distinct. It is usually assumed [Kondracki 1991, Pawlowski 1972] that within the borders of Poland the eastern Carpathians include Bieszczady, Góry Slonne and Pogórze Przemyskie.

Although many Carpathian forests have, to a greater or lesser extent, been transformed by man, numerous complexes survive in their natural and even near-primeval state. While the foothill levels are significantly transformed, there has been relatively little change at upper montane, sub-alpine and alpine levels.

Core areas are considered to be best protected by making an ecological corridor of the mosaic landscape and semi-natural vegetation of the remaining parts of the Carpathians, thus safeguarding population contacts within the whole mountain chain.

4. The existence of selected plant and animal species as criteria for the mapping of core areas in EECONET-PL

4.1. Assessment of species diversity in Poland

Decreasing variety of habitats and the fragmentation of initially large forest complexes and wetland drainage are inevitably connected with the development of civilization. They have led (and are leading) to a reduction in the number of plant and animal species. The phenomenon is world-wide, Poland being no exception. Although large numbers of animal species are protected in Poland (including 99 totally protected vertebrates species - and a further 95 partially protected in line with hunting laws), the populations of many species are decreasing, and many are threatened with extinction. Out of 430 vertebrate species reproducing in the country only 44 are not endangered and as many as 41 are extremely endangered [Andrzejewski, Weigle 1993]. Then again, of some 235 species of breeding birds, 40 are down to fewer than 100 pairs, 34 have between 100 and 1000 pairs and a further 43 between 1000 and 5000 pairs - a number that is often considered to be the lowest number for a bird species to be reasonably secure.

Of the 48 invertebrate species considered extinct, 20 have died out since 1950 [Andrzejewski, Weigle 1993]. The home range of many species constantly decreases - for example the Apollo butterfly, Parnassius apollo, found formerly on many sites in the lowlands can nowadays be found only on a few sites in the mountains [Glowaciñski 1992a, b]. Mollusc skopka perloronda, Margaritifera margaritifera, is no longer found and an attempt to reintroduce it failed [Glowaciñski 1992]. The reason why so many species have disappeared and the extent to which the remaining invertebrates are endangered is not satisfactorily explained, due to great differences in habitat needs and sensitivity, and also due to the inadequately examined biology and ecology of individual species. Only 74 species are totally or partially protected.

Polish flora has over 2300 vascular plant species (some discrepancies between data here are due to differences in approach), over 600 moss species, about 250 liverworts and some 1200 species of lichen [Zarzycki, Kazmierczakowa 1993]. The threats though are very considerable. Among vascular plants, 34 species in the Polish Red Plant Book are extinct. Especially worrying is the fact that they included 3 endemic plants: Cochlearia polonica, that had survived only on a substitute site, small bloom gladiolus, Gladiolus parviflorus, that has not been seen for the last 20 years on any site (some of these sites have been totally destroyed) and Pieniny dandelion, Taraxacum pieninicum, whose only known site was destroyed by collapsing rock. Searches for other sites have drawn a blank although one cannot be absolutely sure that some specimens have not survived on inaccessible limestone. Additionally, 92 plant species are considered to be disappearing, 148 are endangered, 108 are rare and 33 are of unknown status. (Rare plant species are defined in the Polish Red Book as those found on very few or sometimes only a single site in Poland.)

One should add that disappearing and endangered species can die out rather fast. Probably over half of the sites of Luronium natans mentioned in the 19th century and first half of the 20th century are now gone while the water caltrop, Trapa natans, has disappeared since 1870 on at least 188 sites - on 57 of them during the last 20 years [Zarzycki, Kazmierczakowa 1993].

It seems that the protection of species and the protecting areas (reserves, national parks) is not sufficient to stop the negative trends in populations of rare species. It is important to draw attention to the existence of some species also outside the areas that stretch over only a small part of the country. EECONET-PL has been created for this purpose (among others) and locating endangered and/or rare species is an important part of its work.

EECONET-PL also plays an important role in protecting species that, although still often found in Poland, are gravely threatened or extinct in other parts of Europe. Poland may become a supply source for such species. The appearance of some of these species was one reason for giving EECONET-PL its present shape. The rare and/or endangered species that decrease in number when habitats shrink were taken into consideration as were those which constitute a substantial part of the European population (e.g. aquatic warbler, Acrocephalus paludicola). The list of species considered when planning EECONET-PL, was prepared on the basis of the Polish Red Book of animals [Glowaciñski 1992] and the Red list of dying and endangered animals [Glowaciñski 1992b], the Red Data Book for endangered plants [Zarzycki, Kazmierczakowa 1993], the list of endangered vascular plants [Zarzycki, Szelag 1992], the European Red list of animals [Wajda, Zurek 1992] and lists of species of the CORINE programme as well as materials in individual works prepared for the EECONET-PL project [Gromadzki, Chylarecki 1994; app. 10.4, Kowalski 1994]

The EECONET-PL list does not include invertebrates that are not certain to be found in Poland (e.g. green lizard, Lacerta viridis). The crucial criteria in making the list were the number of a given species and how often it may be found. Some endangered species are not on the list (e.g. some species of amphibians and reptiles, although all are to a lesser or greater degree endangered). When selecting species attention has been paid to migratory animals (e.g. fish traveling to spawn - such as the brown trout, Salmo trutta trutta - and bird ‘stopovers’)

The basis for mapping out the boundaries of core areas and corridors was via analysis of the appearance of selected species of plants, invertebrates, fish, birds and mammals (paying special attention to bats). The work was based on the already quoted individual works, the CORINE database and natural habitat map (map 7 + legend), the atlas of mammals appearing in Poland [Pucek, Raczyñski 1983] and works on national and landscape parks. Work was also based on the protected areas in Poland [Walczak and others 1993], the Polish Red Books of animals [Glowaciñski 1992] and plants [Zarzycki, Kazmierczakowa 1993] and other available works (see references).

Due to very evident differences in habitat needs and an uneven degree of study of individual invertebrate groups, the decision was made not to give special importance to any one group. Core areas were chosen to reflect the needs of invertebrate communities, particularly the large number of rarer species. In the less studied Polish regions, little changed habitat fragments for rare and endangered species became a criterion for differentiating core areas.

4.2. Flora diversity and character

The present delimitation of EECONET-PL considers only vascular plants because they are the best analyzed group with regard to frequency of appearance in different regions. An assessment of the individual areas could be influenced not by the richness of different plant groups but by the extent to which the area has been examined. Among the lower plants only stoneworts (Chara, Nitella, Nitellopisis), often treated as indicators of water purity have been analyzed.

Also the materials collected for the CORINE programme, which helped shape EECONET-PL, discussed only the higher plants.

The 2400 vascular plant species found in Poland are considered a moderately large number by European standards. The countries north and east of Poland have much poorer plant cover, those to the west and south much greater. The vascular flora of the whole of Fennoscandinavia embraces 1800 species (inclusive of subspecies), for the former Czechoslovakia the figure is 3100, for France and Corsica 4500 and for the Balkan peninsula over 7000 [Pawlowska 1972]. These figures are, of course, a reflection of latitude and humidity. There are only a few endemic plants in Poland. Endemism is hindered by a number of factors. One is the open character of the Polish landscape eastwards and westwards. Another is that Poland’s flora is young; the Pleistocene glaciation which covered both the lowlands and the uplands including large mountain areas, interrupted plant-cover development. As a result Poland has not too many endemic or sub-endemic plants and these are often represented by so-called small species (e.g. Galium cracoviense, Alchemilla babiogorensis, Alchemilla jasiewiczii) or taxa lower than species (e.g. Saxifraga moschata ssp. basaltica, Viola collina ssp. porphyrea, Asplenium onopteris, silesiacum form), or occasionally critical specimens that need further research in order to establish their taxonic character (e.g. Gladiolus parviflorus). The most interesting Polish endemic plants are two species in the Pieniny region (the Pieniny dandelion, Taraxacum pieninicum and Erysimum pieninicum), and the uplands Cochlearia polonica. Carpathian (or even just west Carpathian), Tatran and the few Sudeten endemic plants are not dependent on the state borders, and the areas situated within Polish borders are of prime importance for their survival. The existence of endemic and sub-endemic plants was considered when the core areas were formed, and also when giving them international status (the areas of Jura Krakowsko-Czêstochowska, Karkonosze-Izery, Snieznik massif, Zywiec Beskid, Tatras, Sadecki region, Beskid Niski, Bieszczady, Przemysl foothills).

One should also examine a group of endemic plants with sites in Poland situated far from their main area of distribution - e.g. the snow saxifrage, Saxifraga nivalis, an arctic species found in Karkonosze and then not again south of central Sweden; Dendranthema zawadzkii found in Pieniny (the Sadecki area) whose next population is found a few hundred kilometres away on the mid-Russian uplands; the yellow rhododendron, Rhododendron flavum, a Pontic species, found in Lezajsk, whose nearest island site is about 300 km away in the southern Polesie (and not occurring to any great extent before reaching the Kaukaz region); Quercus pubescens found in Bielinek in the Odra estuary area, a Mediterranean species, whose nearest usual habitat is southern Germany. An attempt has been made to include such distant sites within the EECONET-PL nodal areas and they have also influenced what status the area has been allotted.

The core of Polish flora - over 50% [Pawlowska 1972] - consists of so-called transitory species, that is, species whose full range does not occur on Polish territory. They are usually common species, representing the Holarctic geographic element, and the Eurosiberian and mid-European sub-elements. Rare elements define the specific character of Polish and regional flora, especially those species which reach their geographical limits here. Relatively rare are Arctic and Mediterranean sub-elements. In the west and north-west of Poland there are substantial numbers of Atlantic and Mediterranean-Atlantic sub-elements. This is particularly true of the Baltic coastland and the Pomorze lake districts and to a lesser extent of Great Poland and Silesia. On the other hand south-east Poland is characterized by Pontic and to a certain degree Mediterranean elements that may be found in the western part of the Polish uplands. Northeast Poland is characterized by numerous boreal and boreal-continental elements and less numerous Pontic, Atlantic and Mediterranean-Atlantic elements. In marking out EECONET-PL core areas, attempts have been made to consider the specific character of the regions with regard to species at the limits of their natural habitat and especially those species with different types of boundary limitations (e.g. the areas of Tucholski forest, west Mazury, lower Silesian forests, Wieluñ uplands, Bieszczady and Przemysl foothills). It was also one of the important criteria when establishing the national and international status to be allotted to an area. For example, the international status was allotted to the area of west Mazury because, among other factors, its border regions have many sub-Atlantic and boreal species. The sites and varying extent of habitat of some species in EECONET-PL are shown in figures 4.1 + legend, 4.2 + legend, and 4.3 + legend.

Documentation of the core areas includes the sites of endangered and even extinct species (as there is always the possibility of finding them in the region they previously inhabited). This category contains many maritime species which accounts, in part, for the network of core areas along the Baltic. Among endangered species only Ligularia sibirica is not found in a core area but its two Polish sites are secured eco-corridors. Due to the fact that the species endangered to a greater or lesser degree contain groups of species connected with particular habitats (e.g. sub-alpine species, oligotrophic-lake species, extensive hay-growing meadow species and traditionally farmed ploughfield species), the existence of these habitats was one criterion for inclusion in the EECONET-PL network.

Due to the great variety of species in Polish flora, the very existence of relict species is of great importance. Many are on the red list; EECONET-PL preparatory work considered all relicts, even those most frequently found (none of them are common); survivors from former climatic periods are all equally endangered.

Polish flora includes many species that are considered endangered on a European scale. These, together with species that are important for maintaining European species variety, are on the IUCN list for the EECONET programme and on the CORINE programme list. Most of these species are on the Polish red list, but some of them are more frequently found in Poland (e.g. cotton-grass Eriophorum gracile, common larch Larix decidua ssp., Polish polonica). However, none of them are common. All the species (84) were taken into account when planning EECONET-PL and formed one of the most crucial criteria when determining the international rank of the area.

All in all the EECONET-PL project, as it now stands, protects a large majority of the sites of endangered and rare species. In the case of many species it protects all of their sites.

4.3. Degree of endangerment for rare invertebrates and locations ^*

The fauna of invertebrates in Poland covers almost 30,000 species and is not yet fully documented. Species that were previously found in Poland are constantly being spotted. One of the difficulties of obtaining accurate information is that there are no data on species that are disappearing because hitherto specialists studied systematic groups. The data obtained were found to be more precise for groups of species connected with particular places - rare endemic plants, for example, found only on some fixed sites for Formicidae. Many invertebrates listed on the international lists (IUCN, CORINE) are found quite frequently in Poland, e.g. the wood ant Formica rufa, Formica pratensis, Formica polyctena. In most fauna studies such species are not considered particularly important; that is why there is not enough documented data on them. One can, however, assume that they are found wherever suitable habitats occur.

The huge variety of species of some invertebrate groups and the degree to which they are endangered is illustrated in a table.

The number of species considered to be endangered varies from source to source: for example, 389 according to the statistical annual publication on Environmental Protection 1994, 1171 (in four categories) according to Andrzejewski and Weigle [1993], 1182 (divided into six categories according to the degree of danger) to quote Glowaciñski [1992b], and this list does not contain many systematic groups.

It is estimated that a further 2500-3000 Coleoptera should be included - leaving aside other possible under-estimates. The species considered rare and endangered may be divided into several categories according to where they are situated, which in turn determines the way in which they should be protected.

Relict species (in Poland these are most often from glaciation periods) and endemic plants clearly demonstrate links with given locations - be they small areas or isolated sites (figure 4.4 + legend). In Poland these are mainly mountain areas, with Tatra and Pieniny as the centers for endemic plants. These relict species can also be found - although not as frequently - in different regions; for example, Formica uralensis and Formica forsslundi on the highmoor in the 34M area. Most of the locations of such species have been previously protected as reserves and they were also included within the core areas of EECONET-PL. However, due to their insular occurrence, it is difficult to give them any role in the European system.

Species typical of various sites in southern Europe (Pontic-Mediterranean elements) and found in southern and central Poland (particularly on the uplands) are usually less evenly spread, more dispersed, than the boreal and Eurosiberian species further north. European species denominated as Atlantic are rare and appear mainly in the north-western part of Poland and in individual sites in central Poland. These kind of species may play an important role in the European system, because spatial communication and preservation of good habitats may contribute to the re-emigration of species to their original territories where they are now extinct.

The transitional nature of Polish flora and fauna is particularly well exemplified by the frequent overlap of invertebrate species whose main centers of population are quite elsewhere - for example, far to the east or west (figure 4.5 + legend). This coexistence often occurs in the belt between Gdañsk Bay and the eastern Sudeten or western Carpathian fringes. In the upland belt in the south of Poland where these borders are not so marked, southern and south-eastern species can be seen more frequently. That is why this area has a relatively rich structure and a large variety of invertebrates. It is an important area due to its biological variety and to its quite high management level. It may also be an important southern and south-eastern ‘refuge’ area of the European system.

Not many species are identified as central European elements, and their sites are grouped (for example, Trichoptera) in the western part of the Carpathians, in the Sudetens and the southern part of Great Poland.

Species found in areas with a specific character show even stronger links with the character of the terrain. For example, mountain species cannot be found in the lowlands - with occasional exceptions (e.g. Pirata piccoli in Bialowieza forest; area 29M). Linking EECONET-PL with mountain areas of the network in neighbouring countries is very important for these species.

Xero- and thermophilous species are dependent on specific conditions and vegetation, and steppe xerothermic grass. These Orthopetra are grouped in southern and central Poland, reaching as far north as Bielinek (core area 1M) and in the Chelmno area (lower Vistula corridor). Boreal and Eurosiberian species of thermophilous grass reach their southern extent in Poland, embracing northern and western Poland and the submontane and mountain areas of southern Poland. This type of habitat is quite rare in Poland - it occurs only in small areas. Invertebrate species connected with xerothermic grass are rare. However, due to the specific character of their habitat, they might be important in areas with similar conditions and generally do not require a direct link between habitats.

Descriptions of individual EECONET-PL core areas have lists of rare species, with documented occurrence in the given area. The best known areas, so far as invertebrates are concerned, are the following: 1M, 9M, 13M, 29M, 30M, 40M, 42M, 43M, 45M, 12K. The exact status of these invertebrates is not known - in particular their range. Studies take years, are not often undertaken, and focus on small areas. Very inaccurate descriptions of sites and locations make finding them difficult. Different areas are not examined to the same degree - the study is usually undertaken by specialists working in different groups and with particular interests in mind. The most carefully examined are the protected areas, although information on invertebrates is not often found in the relevant documents.

Not all documented sites of rare and endangered invertebrates were included in the system. Most invertebrate species placed on the EECONET-PL list are sited within the core areas or in the corridors (figure 4.6 + legend). Data on their exact positioning is in the documentation.

At the moment documentation covers only pant of the known sites of the selected species found in the individual core areas. Work at present is based mainly on synthetic data, referring to small numbers of species and not precisely locating their sites. Precise information can mostly be found in the results of specific studies in selected points. Dispersal of data and the time needed for data collection has meant deferring making use of them until the next stage. Data from the last 30 years has been accepted (for now) as being current.

4.4. The areas important for fish and lampreys

Problems connected with ichthyofauna distribution were dealt with by Backiel and Freytag [1994]. The following text is largely an extract from their work. They claim that Polish waters contain 74 species, subspecies and forms of lampreys and fish. Due to pollution almost all of them are endangered. Especially endangered are 16 species, 2 of them still-water species (minnow, Phoxinus percnurus and powan, Coregonus lavaretus). The remaining species listed as susceptible or endangered are flowing-water fish or those dependent on them (brown trout, vimba). Over 20% of endangered and rare species are a substantial part of our sweet-water ichthyofauna

The variety of species (calculated by the number of fish species) is a function of the size and variation of the water environment (for example, isolated lakes, lake complexes, river fragments, small Pomeranian river basins, large basins). In small dystrophic lakes exist some (often only one) fish species. In a small system of the Wieprzowka river (Skawa inflow, 27 km long) 18 fish species were found [Skóra, Wlodek 1989]. In the entire Pilica basin (340 km long) 89 fish species and 2 lamprey species were found [Penczak 1989]. Ample ichthyofauna groups were found in a relatively large and morphologically varied water region; one lake is usually not rich, but a lake complex connected by isthmus (or rivers) may have rich ichthyofauna ecosystems.

The preservation of endangered species of fish and lampreys is very often a task contrary to the previous one. A good example of it is the minnow Phoximus percnurus, mainly found in small isolated reservoirs with very poor ichthyofauna. The need to protect the spawning grounds and habitats of traveling and lake trout is reduced to the protection of flowing water segments with a very poor variety of fish species. Taking into account fish species that travel regularly, it is relatively simple to point out places of greater importance (core areas and the corridors). The corridors mark migration routes, while spawning places are the core areas. The matter is complicated by artificial obstacles to migration - dams, weirs etc. As far as other species of fish are concerned, the core areas are where important rare or endangered species can be found. The presence of common species cannot be a geographical criterion for delimitating the core areas, but their variety is a critical feature of the environment. So habitats with rich ichthyofauna must be considered.

Ecological corridors have 3 roles:

• as routes for species expansion (population); the presence of Black Sea species in our waters may point to the use by fish and lampreys of long-forgotten canals (a dramatic example of expansion is a lamprey parasitizing on precious fish in large American lakes above Niagara Falls after the Welland Canal had been built);
• as a means of genetic exchange between relatively isolated populations;
• as regular migration routes.

Especially valuable fish core areas and corridors have been pointed out in this study. Two criteria were taken as a base: varied ichthyofauna and the importance of the area for endangered species. The proposed distribution of these areas is shown in figure 4.7 + legend:

Miedwie and Pelcz lakes (1M) and Drawsko lake - endangered lavaret;

• Pomeranian lakes: Bukowo, Jamno, Lebsko and Gardno - varied ichthyofauna and migration between the sea and lakes (2M);
• Pucko Bay endangered lavaret (3M);
• the lakes in the Wdzydze landscape park (Kaszuby) which contain the only lake-trout population (9M);
• the Drwêca river, its left-side tributaries and Lake Drwêckie were recognized as a Salmonidae "reservoir" (13M); trout are now once again traveling here from the Baltic to spawn. The area is also important for river lamprey; the Vistula is an important corridor for this area from the estuary up to the Wloclawek dam;
• Lake Jeziorak and the small neighbouring lakes (Olsztyn area) - varied ichthyofauna (13M);
• the so-called Big Mazurian Lakes - Sniardwy with small neighbouring lakes and Mamry - Dargin and other small lakes (14M and l5M) - diversified ichthyofauna including endangered species of trout;
• lake and rivers complexes in Wigry National Park a large variety of ichthyofauna (including trout) as well as frigidophile fish habitats (16M);
• the Biebrza and its tributaries in Biebrza National Park - a large variety of thermophile ichthyofauna (26M);
• the Lêczyn-Wlodawa lake district - specific fish diversity and phoxinus (27M);
• Poprad and Dunajec rivers (above Roznowo) - re-introduced but endangered huchen (salmonoid fish) (43M);
• Lake Slawskie in the Zielona Góra district, the most southerly habitat of the European whitefish (4K);
• the middle reaches of the Vistula (from the mouth of the San to Wyszogród) - a large variety of ichthyofauna and the north-south corridor (20M and 23M);
• the middle reaches of the San - vimba population (25K).

Especially threatening is a dam on the Vistula river in Wloclawek. During the autumn migration trout and vimba gather around the dam and, because they cannot leap it, are extensively caught.

4.5. The areas important for bird populations ^*

Data