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PRELIMINARY ANALYSIS OF THE VASCULAR FLORA OF EXTENSIVELY GRAZED SKOSZEWSKIE MEADOWS

ANNOTATION

biotope beef cattle floristic

The results of research of the effect of extensive grazing of the Polish Koniks, Scottish Highland cattle and Limousine beef cattle, on the floristic changes are presented. The largest number of vascular plant species was found in areas grazed by Scottish Highland cattle, while the smallest one in those grazed by Limousine cattle. In respect of life-forms, the species of the group of hemicryptophytes prevailed in all locations. On horse pastures, the percentage of species with high light index was the largest. The areas grazed by Scottish Highland cattle proved to be most humid. The species that indicate a higher eutrophication degree of biotope occurred more abundantly on horse and Scottish Highland pastures. Pastures for horses and beef cattle were classifying to site of low natural values, while those grazed by Scottish Highland cattle to lands of medium-moderate values.

Keywords: vascular plants, extensive grazing, horse, cattle, ecological indicator values

INTRODUCTION

One of the methods of protecting and renaturising naturally valuable grassland communities is to introduce extensive forms of mowing and grazing use. Management of this type is aimed, among others, at restoration of floristic diversity as well as prevention of unfavourable transformations within pratocenoses. Attempts of this type have come into larger and larger prominence in recent years, in particular with respect to areas being under such protection actions as Natura 2000 [1,6,9]. The Skoszewskie Meadows, situated by the Szczecin Lagoon, belong to such a grassland. This derelict land has been subject to renaturisation for several years [10]. One of the methods of restoring their natural and economic values is extensive grazing of Polish Koniks, Scottish Highland cattle and Limousine beef cattle applied for four years. Evaluation of the effect of this activity on selected floristic and ecological indicators of these pratocenoses is the objective of the presented study.

MATERIAL AND METHODS

Geobotanical examinations currently carried out within the Skoszewskie Meadows, a fragment of which are the results obtained in 2007 and presented in this paper, have been started in 2002 [9,10]. In the first stage, areas for a year-long and day-long grazing of Polish Koniks (stocking rate 0.3-0.5 LU) and Scottish Highland cattle (stocking rate 0.3-0.6 LU/ha) and a seasonal grazing (from spring to autumn) of Limousine beef cattle (stocking rate 0.5-0.6 LU/ha) were separated. Within the marked out permanent transects which included the areas grazed by aforesaid animal species and breeds, floristic examination were carried out systematically, consisting in evaluation of the botanical composition of sward. In order to do this, a phytosociological method and an estimation one were applied [8]. On this ground, the analysis of vascular flora was made. It included, as follows:

- species abundance and biodiversity [15];

- natural evaluation [11];

- selected ecological indicator figures [16];

- life forms according to Raunkiaer [14,16].

RESULTS AND DISCUSSION

Within the whole examined area of about 200 ha, 100 taxa of vascular plants were recorded, out of 25 families. Most numerously represented were grasses, compositae plants and knotweed plants. The largest number of species, i.e. 87 out of 24 families, was found on areas grazed by Scottish Highland cattle, as opposed to pasture sward for Limousine cattle with over a half smaller number of species out of 14 families. An intermediate number of species and families represented the plant cover of grassland grazed by horses (Tab. 1). Changes in the botanical composition of extensively used or derelict meadows have become recently the subject of a number of researches [2,3,4,5]. On the other hand, the influence of grazing as a method of active protection of naturally valuable areas has been relatively poorly recognised while paying more attention to intensive forms of grazing connected with the effect of animal production [12,13].

Species abundance did not significantly affect the degree of floristic biodiversity. This is evidenced by calculated Shannon indices, ranging from 1,3 to 1,9 (Fig. 1). Basing on this, all examined pastures were classified into a group of low diversity [15]. Worth emphasising is the fact that pasture for Scottish Highland cattle was characterised by a higher index, while that for Limousine cattle by the lowest. As a rule, biodiversity increased to a small extent as the vegetation season was elapsing.

The accomplished natural evaluation of examined meadow objects (Tab. 2) allowed classification of areas grazed by Polish Koniks as well as of pastures for beef cattle into lands of small natural amenities (A III), while of those used by Scottish Highland cattle into lands of average moderate ones (B V). Generally, the whole grazed area can be regarded as a land with moderate natural amenities [11].

From among a number of ecological indicators, the examined flora was evaluated in respect of light, moisture and trophic requirements. Within all examined objects, a very large participation of species with moderate (4) and full light (5) requirements was found. They constituted about 90% of recorded vascular plants and no significant differences between respective pastures were found in this respect (Fig. 2). High and moderate light requirements of the pasture vegetation are a characteristic feature for grazed areas, contrary to mowed grassland [7].

In respect of moisture requirements, the areas grazed by Scottish Highland cattle proved to be most moist. On this grassland, taxa of wet and moist biotopes constituted 52 % of the flora. Higher participation of species from fresh biotopes, reaching 50%, was found on pastures for horses and beef cattle (Fig. 3). Worth emphasising is the fact that a main reason for importing a herd of Scottish Highland cattle into the Skoszewskie Meadows was a good adaptation of these animals to utilise a low-value meadow forage from wet and moist biotopes [9].

Species indicating to a higher degree of biotope eutrophication occurred in a higher percent proportion (64-66.5%) on pastures for horses and Scottish Highland cattle. Within the areas grazed by beef cattle, eutrophic taxa occurred with a lower intensity (Fig. 4).

In respect of life forms, irrespective of the type of grazed animals, species of the group of hemicryptophytes prevailed everywhere, i.e. the plants forming growth buds at the ground level. Annual species (terophytes) constituted from 19.5 to 24.5% of vascular flora, with their higher percentage being found within pastures for horses (Fig. 5). High participation of hemicryptophytes and terophytes is evidence of a considerable heterogeneity of the grazed areas and a small density of sward. This should be also treated as an effect of strong and frequently excessive over-grazing of certain parts of pasture [12].

CONCLUSION

- Species and breed of grazing animals affected the species abundance of vascular plants. In respect of the number of taxa, the grazing of Scottish Highland cattle proved to be most favourable.

- Analysis of vascular flora biodiversity as well as evaluation of natural amenities and ecological bioindication of the sward of extensive pastures did not show any significant effect of animal species and breed on these indicators. It seems however that trends observed in plant cover changes will become deeper within next years of applying this form of active protection in the Skoszewskie Meadows.

LITERATURE

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2. Baryіa R. & Urban D., 1999. Kierunki zmian w zbiorowiskach trawiastych w wyniku ograniczenia i zaniechania uїytkowania rolniczego na przykіadzie і№k Poleskiego Parku Narodowego. Folia Univ. Agric. Stetin. 197, Agricultura 75: 25-30.

3. Czyї H., Kitczak T. & Stelmaszyk A., 2007. Wartoњж paszowa, przyrodnicza i energetyczna polderowych uїytkуw zielonych wyі№czonych z dziaіalnoњci rolniczej. Ј№karstwo w Polsce, 10: 21-28.

4. Grzegorczyk S., Grabowski K. & Benedycki S., 1999. Wpіyw braku uїytkowania na ksztaіtowanie siк roњlinnoњci і№kowej obiektu Siуdmak. Univ. Agric. Stetin. 197, Agricultura 75: 107-112.

5. Grzegorczyk S., Grabowski K. & Benedycki S., 2001. Zmiany roњlinnoњci і№kowej w zaleїnoњci od uїytkowania. Zesz. Probl. Post. Nauk Roln., 478: 35-40.

6. Kochanowska R., Rogalski M., Trzaskoњ M. & Wieczorek A., 2007. Zmiany zbiorowisk і№kowych na polderze Zaіom koіo jeziora D№bie. Acta Botanica Warmiae et Masuriae, 4: 163-172.

7. Kryszak A., Kryszak J. & Grynia M., 2007. Zmiany degradacyjne na і№kach i pastwiskach wyі№czonych z uїytkowania. Acta Botanica Warmiae et Masuriae, 4: 205-214.

8. Mannetje L., 2001. Methods for estimating botanical composition, species diversity and dry matter yields. Grassland Science in Europe, 6: 311-323.

9.Musielak D., 2006. Wpіyw ekstensywnych form wypasu na zrуїnicowanie przestrzenne runi wybranych zbiorowisk і№kowych. W: Czіowiek i њrodowisko przyrodnicze Pomorza Zachodniego. I. Њrodowisko biotyczne - biologia њrodowiskowa, eksperymentalna i stosowana. Ed. J.Tarasiuk i J.Kкpczyсski. Wyd. Uniwersytetu Szczeciсskiego, 205-208.

10. Musielak D. & Rogalski M., 2006. The impact of extensive grazing of Polish Koniks on changes in vegetation cover of selected lant communities of coastal meadows. In. Salt grasslands and coastal meadows. Ed. H.Czyї, Wyd. AR w Szczecinie, 39-44.

11. Oњwit J., 2000. Metoda przyrodniczej waloryzacji mokradeі i wyniki jej zastosowania na wybranych obiektach. Wiadomoњci IMUZ, 79, 3-32.

12. Rogalski M., 1996. Rola czynnikуw zoogenicznych w ksztaіtowaniu trwaіoњci i skіadu florystycznego zbiorowisk pastwiskowych, Rocz. AR Poznaс. CCLXXXIV, Roln., 47: 53-63.

13. Rogalski M., Wieczorek A. & Kardyсska S. 1999. Pas№ce siк zwierzкta jako czynnik reguluj№cy skіad botaniczny runi. Fol. Univ. Agric. Stetin, 197 Agricultura 75: 267-270.

14. Rothmaler W., 1990.Exkursionsflora von Deutschland. Band 4, Kritischer Band, Volk und Wissen Verlag GmbH, Berlin. 754.

15. Szoszkiewicz K. & Szoszkiewicz J. 1998. Ocena rуїnorodnoњci gatunkowej pratocenoz na przykіadzie wybranych zbiorowisk. Pr. Kom. Nauk Roln. I Kom. Nauk Leњn. PTPN 85: 47-52.

16. Zarzycki K., Trzciсska-Tacik H., Rуїaсski W., Szel№g Z., Woіek J. & Korzeniak U., 2002. Ecological indicator values of vascular plants of Poland. Wyd. Instytutu Botaniki PAN, Krakуw.

Table 1

Checklist of families and number of vascular plants on examined pastures

Table 2

Natural value of examined pastures

Figure 1 Values of biodiversity index of pastures for: Scottish Highland cattle (1), Polish Koniks (2) and Limousine beef cattle (3)

Figure 2 Share of plant species of different light value (%): total (1), on pastures for: horses (2), scottish cattle (3) and limousine cattle (4) Light value: 5 - full light, 4 - moderate light, 3 - half-shade, 2 - moderate shade

Figure 3 Share of plant species of different soil moisture value (%): total (1), on pastures for: horses (2), scottish cattle (3) and limousine cattle (4). Soil moisture value: 6 -aquatic, 5 - wet, 4 - moist, 3 - fresh, 2 - dry

Figure 4 Share of plant species of different trophy value (%): total (1), on pastures for: horses (2), scottish cattle (3) and limousine cattle (4). Trophy value: 5 - soil very rich (extremely fertile), 4 - soil rich (eutrophic), 3 - soil moderately poor (mesotrophic)

Figure 5 Share of plant species of different life-forms (%): total (1), on pastures for horses (2), scottish cattle (3) and limousine cattle (4).

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