In book: The future of Polish mires., Publisher: Wydawnictwo AR, Szczecin, Editors: L. Wołejko, J. Jasnowska, pp

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1 In book: The future of Polish mires., Publisher: Wydawnictwo AR, Szczecin, Editors: L. Wołejko, J. Jasnowska, pp Jacek Forysiak 1, Dorota Michalska-Hejduk 2 CHANGES OF THE WILCZKÓW PEAT-BOG UNDER LONG-TERM ANTHROPOPRESSURE 1 Department of Quaternary Studies, Kopcińskiego 31, University of Łódź, Łódź 2 Department of Geobotany and Plant Ecology, University of Łódź, Banacha 12/16, Łódź Abstract. The characteristics of factors and resulting changes were estimated based on archival and contemporary maps and aerial photographs. The data were supplemented by field research (drill cores, soil profiles, phytosociological relevés). Main human activity in the study area was peat exploitation, and since the beginning of the 20 th century, also wetland drainage. These factors led to the creation of aquatic communities, but also to lowering of groundwater level which resulted in stopping the development of the peat plant cover. The commencement of meadow management and grazing stopped the ecological succession to forest, but also caused eradication of peat-bog species. In the last years, as a result of abandoning grazing and mowing, the succession to alder-peat-bogforest has started. Key words: peat-bogs, anthropopressure, ecological succession, Central Poland. Introduction Peat-bogs occupy ca ha in Central Poland, or nearly 2% of the total area of the region. Over 75% of this area is under management as various forms of land use (Kucharski 1998). Small peatlands predominate in this group, while peatbogs of more that 200 ha in area are rare in Central Poland. Though human activity on peat-bogs dates back to the Neolithic period (Wiklak 1975), it is only as late as the 17 th century when enhanced anthropopressure is observed which lasts until today. The Wilczków peat-bog with an area of over 250 ha has been managed in various ways for the last ca. 150 years. Thus, it constitutes an interesting and important examples for studies on changes occurring in peat-bogs of Central Poland under long-term anthropopressure. The aim of the present study was the evaluation of changes occurring in the plant cover of the peat-bog and preliminary determination of the possibilities of further studies in depth, including analysis of peat deposits (e.g. paleobotanical and chemical analysis etc.). Methods The characteristics of changes and factors that caused them have been determined on the basis of archival and contemporary maps (Mapa , 1942, 1961, 1986) as well as an aerial photograph (1996). This data has been

2 supplemented by field research along 7 transects conducted across the peat-bog. Drill cores were collected and soil profiles were analysed along these lines, and 31 phytosociological relevés have been performed by the Braun-Blanquet method. These studies allowed us to characterise the current plant cover and geological structure of the peat-bog (Fig. 1). Study area The Wilczków peat-bog lies in the eastern part of the inactive Balin-Chropy valley which links river valleys of the Ner and the Warta (Fig. 2). Currently, this valley is drained by means of small streams into the Warta and the Ner, while a valley watershed occurs in the vicinity of the Wilczków village. Peat layer thickness in the Wilczków peat-bog varies from 1 to 6 metres. Its substrate are humus sands (with organic acid admixture). The age of peat-bog emergence has been set for the beginning of the Holocene (age years). Within the Warsaw-Berlin proglacial marginal valley, other inactive valleys occur too, but this is the only site of emergence of a major peat-bog ( ha) that has been in existence for the whole of Holocene (Forysiak 2000, Kamiński & Forysiak in press). The current vegetation of the peat-bog consists of a mosaic of meadow, pasture, low peat-bog, aquatic and scrub communities. The middle part where the valley is at its broadest and the peat layer is thickest (up to 6 m) is occupied by aquatic communities (in holes from which peat has been excavated and which have been filled with water) and reed communities. The peat substrate is also overgrown by willow thickets which consist mainly of Salix cinerea. Those fragments of the peat-bog which have never been exploited are overgrown by wet meadows from the Molinio-Arrhenatheretea class, often with a significant share of marshland meadow species from the Scheuchzerio- Caricetea class (Michalska-Hejduk & Forysiak 2002). Results and discussion Man has appeared in the Warsaw-Berlin marginal valley, including the surroundings of the described peat-bog, already in the Holocene, but he started to exert a significant influence on the environment only with the beginnings of agriculture in the Lusatian culture period. This is attested to by the presence of slope deposits the so-called tillage diamictons which arise as a consequence of soil tillage on sloping ground. The age of their substrate has been dated to 2730 years BP (Forysiak & Twardy 2002). Human activity in the peat-bog itself has started as late as the end of the 19 th century when peat exploitation began. First land

3 reclamation projects appear in the early 20 th century. In this period, wetland area in the western part of Central Poland has decreased for this reason by 40% (Majchrowska 2002). The drainage ditch network in the investigated peat-bog becomes more dense in late 1970s (Fig. 2-3, Table 1). These factors led i.a. to the appearance of aquatic communities in peat holes and in drainage ditches (Table 1). Overgrowing of these artificial water reservoirs, which can be observed on maps as significantly decreasing open water surface (Table 1), has been seen since early 1980s. The course of this overgrowing is similar to the one described by Podbielkowski (1960, 1967) from the environs of Warsaw. Drainage has also led to a decrease in groundwater level and subsequently stopped the growth of peat-bog vegetation. Introduction of meadow management and grazing to the reclaimed areas has led to appearance of meadow vegetation instead of peat-bog communities (Fig. 1b, c). Species from the Molinio-Arrhenatheretea class constitute 63.4% of the flora of non-forest communities, while peat-bog species from the Phragmitetea class account for 17.6% and from the Scheuchzerio-Caricetea class for 3.3%. Such changes were also observed in numerous other peat-bogs in Central Poland (Kucharski 1999). However, transitional peat-bog species from the Scheuchzerio- Caricetea nigrae class, such as Eriophorum vaginatum, Carex diandra and others, are still present in meadow communities. Mowing and grazing has stopped ecological succession towards forest communities. Spontaneous forest development has appeared on small areas in the 1960s, but it was not until meadow management and grazing has been stopped in late 1980s that a fast increase in forest acreage could be seen (Fig. 2-3, Table 1). It is observed in all types of geocomplexes of Central Poland (Kucharski 1999, Majchrowska 2002). Lack of palynological data and macroremnant analysis makes it impossible to determine whether this area has been forested before. Cartographic data available since the 18 th century present the described area as unforested. Conclusions The changes observed in the Wilczków peat-bog after over 150 years of anthropopressure do not differ significantly from those observed in all of Central Poland. However, peat thickness and area make this peat-bog unique. Moreover, valuable peat-bog species and small patches of peat-bog communities are still present here. Further peat exploitation and peat-bog drainage, even on an extensive scale, will quickly lead to inhibition of peat-creating processes and extinction of peat-

4 bog species. For this reason, further studies of this area and placing it under legal protection are necessary. Because of a character of described peat-bog and its localisation ecological land-use will be the most convenient form of the protection. References Forysiak J Zmiany vistuliańskiej doliny Balin Chropy w holocenie (dorzecze środkowej Warty). Materiały sympozyjne. Uniwersytet Śląski. Sosnowiec Forysiak J., Twardy J Wpływ naturalnych i antropogenicznych czynników na holoceńską ewolucję martwej doliny Balin-Chropy. Materiały konferencyjne. Uniwersytet Łódzki. Łódź Kamiński J., Forysiak J. (w druku) Szczegółowa Mapa Geologiczna Polski 1: arkusz Uniejów. PIG, Warszawa. Kucharski L Interesujące zespoły roślinne występujące na torfowiskach Polski Środkowej. Acta Univ. Lodz., Folia bot. 12: Kucharski L Szata roślinna łąk Polski Środkowej i jej zmiany w XX stuleciu. Wydaw. Uniw. Łódz. Łódź. Majchrowska A Wpływ antropopresji na przemiany środowiska przyrodniczego zachodniej części województwa łódzkiego. Acta Geogr. Lodz. 82: Mapa Mapa Zachodniej Rosji Mapa Mapa topograficzna. Wojskowy Instytut Geograficzny (przedruk z roku 1942). Mapa Mapa topograficzna obrębowa. Zarząd Topograficzny Sztabu Generalnego Mapa Mapa topograficzna. Państwowe Przedsiębiorstwo Geodezyjno- Kartograficzne Michalska-Hejduk D., Forysiak J Roślinność martwej doliny Balin-Chropy w dorzeczu środkowego Neru i jej uwarunkowania siedliskowe. Bliskie naturze kształtowanie dolin rzecznych. Materiały ogólnopolskiej konferencji naukowej Sarbinowo września Wydaw. Uczelniane Politechniki Koszalińskiej. Koszalin: Podbielkowski Z Zarastanie dołów potorfowych. Monog. Bot. 10, 1: Podbielkowski Z Zarastanie rowów melioracyjnych na torfowiskach okolic Warszawy. Monogr. Bot. 23, 1:

5 Wiklak H Neolit w Polsce środkowej. Pr. i Mat. Muzeum Archeol. i Etnograf. w Łodzi. Ser. archeol. 22. Zdjęcie lotnicze. Centralny Ośrodek Dokumentacji Geodezyjnej i Kartograficznej Głównego Urzędu Geodezji i Kartografii Table 1. Changes of land use in the Wilczków peat-bog during the last 100 years Years Forests Water areas Meadows, pastures, scrubs ha % ha % ha % * Estimations based on maps and an aerial photograph.

6 Fig. 1. Toposequence of phytocoenoses against the background of geological crosssection (transect D -Wilczków) The Holocene: 1 peat, 2 organic and mineral silt of slope origin, 3 fluvial sand with organic silt and plant debris; The Vistulian: 4 fluvial sand; The Warta glacial stage: 5 till, The Tertiary: 6 loam and silt; Vegetation: a rush communities (Phragmition), b large sedge communities (Magnocaricion), c wet meadows (Calthion), d herbaceous plant communities (Filipendulion), e initial stages of peat-alder forest (Ribeso nigri-alnetum), f fields. Fig. 2. Changes of forest and open water acreage in the years , , , ; W water areas; L forests.

7 ZMIANY TORFOWISKA WILCZKÓW POD WPŁYWEM DŁUGOTRWAŁEJ ANTROPOPRESJI Streszczenie. Torfowisko Wilczków, jedno z większych torfowisk znajdujących się w dolinie Warty (na terenie województwa łódzkiego) ma zmienną (od 1 do 6 metrów) miąższość torfu a położone jest na terenie doliny, która jest odwadniana przez niewielkie cieki do Warty i Neru. Podstawowymi formami antropopresji na omawianym terenie było eksploatowanie torfu a od początku XX wieku również melioracje. Czynniki te spowodowały z jednej strony pojawienie się zbiorowisk wodnych w dołach potorfowych, z drugiej zaś obniżenie poziomu wód gruntowych co doprowadziło do zahamowania rozwoju roślinności torfowiskowej. Wprowadzenie na zmeliorowany teren gospodarki łąkarskiej i wypasu nie dopuszczało do sukcesji w kierunku lasu ale spowodowało ustępowanie gatunków torfowiskowych. Gatunki z klasy Scheuchzerio-Caricetea nigrae, takie jak Eriophorum vaginatum, Carex diandra i inne są jednak wciąż obecne w zbiorowiskach łąkowych. W ostatnich latach w wyniku zaniechania wypasu i koszenia została zainicjowana sukcesja w kierunku zbiorowisk olsowych. Brak danych palinologicznych i analizy makroszczątków uniemożliwia stwierdzenie czy las występował tu wcześniej. Dane kartograficzne, począwszy od XVIII wieku, przedstawiają opisywany teren jako bezleśny. Biorąc pod uwagę niewielką liczbę podobnych obiektów w środkowej Polsce oraz interesujące gatunki roślin, które tu występują należy rozważyć możliwość ochrony czynnej tego obiektu w formie użytku ekologicznego. Słowa kluczowe: torfowiska, antropopresja, sukcesja ekologiczna, środkowa Polska