Tadeusz Prus and Kajetan Perzanowski, International Centre of Ecology, Polish Academy of Sciences, Dziekanów Leśny.
Introduction
Initial contacts between ILTER and Poland took place in 1996 when two Polish representatives were invited to attend an ILTER meeting in Central America. Their experience has provided grounds for a nation-wide discussion about the conditions for and the benefits to Polish scientific institutions joining the ILTER network.
Prior to the meeting, an initial inquiry for potential participants of the country network gathered together 10 institutions including units of the Polish Academy of Sciences (PAS), various research institutes, and a university. That meeting provided the basis for the first country report describing the background of ecological research in Poland and potential LTER sites. The second stage in mutual contacts involved a visit by Dr. James Gosz and Dr. John Vande Castle to Poland in June 1997, which provided them with first-hand knowledge on selected sites, including the Bieszczady Mountains, Solina Dam Reservoir, Kampinos Forest, and Białowieża Forest. All four sites were regarded as excellent potential LTER sites and Białowieża, with its extraordinary long, meticulously maintained biological records, already met all standards of an ILTER site. Both guests presented the concept and framework of LTER to PAS authorities and the directors of institutions potentially interested in joining LTER network.
At the ILTER meeting in Taiwan, in November 1997, a report on the advances in organisation of potential ILTER sites in Poland was presented, including a detailed description of a site in the Bieszczady Mountains where long-term ecological studies have been initiated by the International Centre of Ecology (ICE), Polish Academy of Sciences. The report also included a description of two other sites in east (Białowieża Forest) and central (Kampinos National Park) areas of Poland.
Since 1996 further efforts have been made to spread the idea of ILTER in Poland and fulfil all formal conditions necessary for Polish sites to be accepted into the ILTER network. Besides the sites described earlier in the 1997 National Report, two aquatic sites in the Masurian Lakeland with long-term ecological data were incorporated. The present list of sites is by no means complete. The Committee of Ecology, of PAS is considering further proposals, which will be incorporated into an electronic edition of this book as soon as they are ready.
Description of sites and research opportunities
Site: East Carpathian Mountains (Bieszczady)
Terrestrial communities
The Bieszczady Mountains stretch 2000 sq. km between the Uocka Pass in the east, the upkowska Pass in the west, the Polish state border with Slovakia and Ukraine in the south, and the valley of the San River in the north. The geology is typical of the Carpathian Range, with sandstone and shale being the dominating base rocks.
;Elevations vary from about 500 m above sea level in main valleys and 1346 m above sea level at the highest peak (Tarnica). The climate has a strong continental influence from Ukraine and western Russia. Average air temperature is +5.1 C, and annual precipitation is 1200-1300 mm. Snow cover lasts from 110 to 160 days. The area is over 60 percent forested with native beech-fir (Fagetum-Carpaticum) as the dominant association. Large areas of former agricultural land remain in various stages of secondary succession. The number of vascular plant species is estimated to be about 700. A rich fauna of 284 vertebrate species includes all large European predators (wolf, brown bear, lynx, wildcat), and a number of herbivorous species such as European bison, red and roe deer, elk, and wild boar.
;The highest and best preserved part of Bieszczady is inside the National Park boundary, which in 1992 became a part of the Eastern Carpathians International Biosphere Reserve, with more than 1000 km2 in Poland. This is the least populated the region in the country, with human density ranging from five to 10 people per km2.
The long-term series of biological data concerning the structure, composition, and the area of local forests, as well as the numbers, harvest, and natural mortality of the main game species are available from the State Forest Administration. Data on plant communities, including occurrence and distributions of rare and protected species are collected by the scientific unit of the National Park. The Carpathian Branch of International Centre of Ecology, PAS, located in Ustrzyki Dolne, coordinates research projects that cover not only the Polish part of the range but also adjoining areas of Slovakia and Ukraine, allowing access to biological data from both countries. Collaborating institutions in Slovakia and Ukraine are the Forest Research Institute in Zvolen and the Institute of the Ecology of Carpathians in Lvov.
The Bieszczady Mountains, due to their high biodiversity, offer a great range of possibilities for long-term ecological research varying from natural mountain forest and alpine meadows to human-altered forest and agricultural ecosystems. The central part of the region is a 35-year-old cascade of two dam reservoirs on the San River, with a well-documented history. Intensive and experimental studies of soils, plant communities or animal populations can be conducted in the area commercially managed by State Forests. Observational and low-impact studies can be done within the part protected as the Park.
Especially interesting is the potential for interdisciplinary studies based on historical records of land-use patterns and trends of the local economy, reflected in the present status and condition of local habitats. Such projects are conducted by the Historical-Ethnographic Unit of the ICE PAS in Ustrzyki Dolne.
Plans for the near future include an international Polish–Ukrainian project involving an early warning system of disturbances in terrestrial and aquatic mountain ecosystems based on wide array of biological indicators.
Aquatic communities (Solina and Myczkowce Dam Reservoirs)
In the Bieszczady Mountain region, the aquatic site consists of two dam reservoirs, Solina and Myczkowce, situated one after another forming a two-threshold cascade. The reservoirs differ in size: at around 2100 ha, Solina is over ten times larger than Myczkowce. It is the largest dam reservoir in Poland. The difference in water level between the two reservoirs is about 60m. Maximum depths are 65m and 12m, respectively. Water volume turnover is twice per year in the larger body and 12 times per month in smaller one.
The littoral zone is affected by a large range of water level changes (up to 10 m) weekly or monthly in Solina, and 1-2 m daily in the Myczkowce reservoir. One part of Solina Lake is strongly affected by tourist activity; the other is more natural. The entire system holds almost 20 percent of total water storage in Poland, and the goals for constructing the cascade in 1968 were power generation, flood control, and tourist and recreational functions. As the outflow of water from upper reservoir emanates from the level of hypolimnion, the water in lower reservoir is approximately 10°C cooler than in the upper reservoir during the vegetation growth season. Both reservoirs freeze over in winter.
The temperature difference creates an excellent opportunity for research, affording a natural in situ experiment in terms of temperature gradients. Another topic of research begun by the International Centre of Ecology is the biodiversity of atypical littoral as influenced by fluvial fauna brought with the two large affluents from the San and Solinka. The site presents an excellent opportunity for large teams of international investigators.
Site: Primeval Deciduous Forest (Białowieża)
Plant communities
Białowieża Primeval Forest (Puszcza Białowieska) today covers some 1300 km2 on the Poland/Belarus border. The forest is representative of the boreo-nemoral zone and grows on formations from the Riss glaciation. The short growing season (mean 185 days according to synphenological criteria) together with the long duration of snow cover (mean 92 days a year) favors the occurrence of boreal elements in the flora and fauna. However, the high degree of climatic variability from year to year allows for transitional biogeographic characteristics in the Białowieża Forest. The transitory biogeographical nature of the forest is manifested in the dominance of geophyte-rich, essentially central European, multi-species deciduous forests (Tilio-Carpinetum of the Carpinion betuli alliance), along with some mixed and coniferous forests (of the Dicrano-Pinion and Vaccinio-Piceion alliances). The unique regional characteristics of the Białowieża forests are emphasised by the co-occurrence in the landscape of thermophilous oak forests (Potentillo albae-Quercetum of the order Quercetalia pubescentis) and spruce bog forests (Sphagno girgensohnii-Piceetum of the Vaccinio-Piceion alliance). Of the greatest significance here are three phenomena resulting from the occurrence of spruce—the universal presence of the species in almost all forest communities, the ease with which it dominates in favorable circumstances in all habitats, and the influence it has on the course of the most important ecological processes.
The transitory biogeographical nature of the forest complex is also clear from the considerable role played in the flora and fauna by species with a boreal-mountainous or boreal range. This is most clear in spruce forest communities, irrespective of the participation of sub-oceanic or central European elements, which dominate in deciduous forest complexes. The best-preserved forest communities with tree stands of primary origin have been protected in the Białowieża National Park since 1921 (47 km2), augmented in 1996 (to 105 km2).
Long-term studies on permanent plots in northeastern Poland (mainly in Białowieża Forest) are supplemented with comparative studies in southern Italy (Promontorio del Gargano) and Russia (southern-western Siberia). These studies include: seasonality of forest communities (since 1952); ecotones between forest communities; the role of tree windfall in forest dynamics; geophytes/hemicryptophyte relationships under the influence of wild boar rooting (1975-1982; since 1991); modification of plant populations in forest and meadow communities; plant demography in vegetation succession (since 1972); vegetation fluctuation, regeneration and succession; phenomena related to secondary succession on abandoned farmland (since 1971); species turn-over; the role of dioecious species; return of native species; differentiation and integration of community structure; course of succession; fire impact, and stochastic processes during succession; the role of cryptogamous species in the structure and function of forest communities; invasion of foreign species upon native plant communities (neophytism); and the formation of anthropogenic communities and synanthropic flora in the compact forest complex (synanthropisation of plant cover).
Animal communities
Since 1959, three times per year (in spring, summer, autumn) small rodents and shrews have been trapped on a small grid and two transects located in an oak-lime-hornbeam forest of the strict reserve of Białowieża National Park. The results show a dependence of rodent population dynamics on the fruiting pattern of the main deciduous trees: oak, hornbeam, and maple. Outbreaks of rodents (followed by deep crashes) occur regularly every six to nine years. Other years are characterised by moderate densities and strongly seasonal population dynamics of rodents. Since 1985, a community of carnivores and raptors that exploit forest rodents has been studied, and their predatory impact estimated.
Data on numbers of five species of ungulates (in the form of game inventories and hunting statistics) are available, dating from the 19th century. Since 1969, The Mammal Researches Institute of the Polish Academy of Sciences has sporadically participated in the inventories and, since 1991, it has conducted annual censuses of ungulates and large predators. Predatory impact of wolf and lynx and the other factors affecting ungulate population dynamics have been estimated. In co-operation with Białowieża National Park, numbers of wild European bison have been censused annually.
Site: Kampinos Forest
The Kampinos National Park is situated in the largest water junction created by valleys of the Vistula, Bug and Narew rivers. It is connected by a system of ecological corridors with natural areas significant to conservation and restoration of rare species of plants and animals. The Park and the valley of the Vistula River with its unregulated banks are extremely important biotopes, including old riverbeds, sand dunes, isles, marsh meadows and shrub areas. About 1,100 vascular plant species and more than 200 species of moss, lichens and liverworts have been identified. The species diversity of fauna was estimated as at least 50 percent of Poland’s total species (i.e. 16,500 species with only about 3,000 identified).
A precious element of the Park is a mosaic of habitats and the resultant large number of ecotones. A large area of the Kampinos Forest consists of inland dunes, unique in Europe, formed within the pre-valley of the Vistula River. Up to 30 meters high, the dunes give the area an undulated configuration with a variegated landscape.
The forest in the Kampinos National Park covers about 28,000 ha or 80 percent of the total surface area. The most important forest-making species include common pine (72 percent), black alder (13 percent), oak (eight percent), verrucose birch (six percent of the total area). Dominant habitats are temperate forest followed by temperate mixed coniferous forest, temperate mixed forest, humid forest and ash swamp. The average age of tree-stands is about 60 years, and for about 200 years the Kampinos forests have been intensely managed. The Park has a potential to become one of major centres of specialised tourism in Poland with an international range of influence.
A plan for protection of the Kampinos National Park was established in 1997. The law of nature conservation made it mandatory to prepare protection plans for national and landscape parks, their buffer zones and nature reserves (a novelty in nature conservation in Poland). The Kampinos National Park was selected for the development of the first, experimental and exemplary plan of protection in Poland. The essence of the 20-year plan involves protecting, recultivating, restituting and renaturalising actions for particular types of ecotones and natural landscapes.
The Kampinos forest, and especially the Kampinos National Park, have served as a site for ecological studies for the last 50 years by various scientific institutions: the Institute of Ecology PAS, Warsaw University, the Institute of Forest Research and others. It also has been used for education by secondary schools and universities located in Warsaw.
Site: Masurian Lakeland
A. River Jorka Catchment
The Masurian Lakeland is characterised by severe climatic conditions, an abundance of lakes and swamps and a considerable area of coniferous forests. The climate of this region is more severe than in other regions of Poland. The main hydrographic web of the area is a chain of lakes in the eastern part of the watershed connected by the sections of the Jorka River. The lake area (296 km2) constitutes 8.8 percent of the watershed area. In this watershed, small lakes and bogs occur, varying in size and water surface stability. Many of them are periodic. These lakes and swamps retain considerable amounts of nutrients washed out from the watershed. Due to the high nutrient level, this site area is overgrown with hydrophilous vegetation.
The waters in the Jorka River watershed are both permanent and periodic; Swamps bordering lakes and rivers are periodically flooded. The vegetation is highly diversified, represented by groups of benthic and littoral communities, meadows, pastures, forests and synantropic communities. Within these communities, 20 associations and two communities were found. The structural and functional diversity of the landscape compels research integrating particular elements and processes so as to form a functional entity. One of these processes is cycling and translocation of matter in landscape.
B. Great Masurian Lakes
Lake Śniardwy (the largest lake in Poland–over 11, 000 ha) together with Bełdany and Mikołajskie and also lakes located on the Krutynia River course (e.g. Lake Mokre) form the south part of the Great Masurian Lakes. The Krutynia River is the longest river in this Lakeland. The lakes originated from the last glacial period (i.e. Baltic glaciation), and are characterized by diverse terrain, a high number of void-of-runoff inundations, and considerable moraine ridges.
The landscape is one of the most significant recreational regions in the whole Masurian Lakeland. Tourists number about 80, 000 per year (one and a half million person-days). The lakes are also used for fishing: bream inhabit 76 percent of total lake area, vendace–13 percent, pike and tench–seven percent and perch-pike inhabit two percent of total lake area. Some lakes are permanently stocked with vendace and eel fry.
The study focuses mainly on 24 larger lakes. Descriptions of 35 smaller lakes are generalized, on the basis of the recognition of their catchement basins. Accelerated eutrophication of the lakes has been estimated by a comparison of annual loading of phosphorus from the external sources with critical values calculated according to Vollenweider’s criteria. Other factors include total catchment to lake-area ratio, lake water residency time, percentage of areas in the basin with no surface outlet, average slope, density of the stream network, and infiltration conditions. Ecological monitoring, trophic state of lakes, water chemistry, macrophytes, phytoplankton, and zooplankton studies have also been performed. Five hundred and seventy six publications on hydrobiology, hydrology, and ornithology have been published.