NATURAL AND FODDER VALUES OF COMMUNITY WITH Carex nigra IN THE BYDGOSZCZ CANAL VALLEY

Acta Sci. Pol., Agricultura 13(4) 2014, 77-91 NATURAL AND FODDER VALUES OF COMMUNITY WITH Carex nigra IN THE BYDGOSZCZ CANAL VALLEY Ewa Krasicka-Korczyńska, Romuald Dembek, Maciej Korczyński, Tomasz Stosik University of Science and Technology in Bydgoszcz 1 Abstract. Carex nigra Reichard is a relatively constant species typical of damp and inundated habitats. One of the species that gain the highest cover in meadow communities with common sedge is Ostericum palustre Besser. This work presented comparison of communities with predomination of C.nigra or O. palustre in phytocenotic and yieldforming aspects. In floristic terms, Pratocenoses with C. nigra or O. palustre refer to meadows from the alliance Molinion. Their sward contains small proportion of valuable meadow plants. Habitat differences of both variants determined based on the Ellenberg indices indicate more alkaline character of the subsoil of patches with O. palustre. Yields obtained from the studied areas dominated by C. nigra were on average by about 1 Mg ha -1 lower and by C. nigra and O. palustre by about 1.5 Mg ha -1 lower than the mean national meadow productivity. Phosphorus and potassium content was lower than that required in feeding standards. Phosphorus and potassium occurred in larger amounts in sward with O. palustre. Proportion of O. palustre improved calcium balance particularly in the second regrowth. In general agricultural evaluation studied communities should be regarded as low-value. Consequently the main reason for their maintenance is their natural values connected with protection of plant communities and natural habitats. Key words: biological diversity, Bydgoszcz Canal Valley, Carex nigra, Ostericum palustre, sward quality, yields INTRODUCTION Production of fodders deriving directly from grasslands arises less interest in modern agriculture. In the Kuyavian-Pomeranian region this thesis is confirmed by differentiation of areas with the highest cattle stock from those with a relatively large proportion of meadows in the landscape [Krasicka-Korczyńska et al. 2008]. Meadows with a high level of ground waters are first of all left out of use. Such a tendency can be Corresponding author Adres do korespondencji: dr inż. Ewa Krasicka-Korczyńska, Department of Botany and Ecology of University of Science and Technology in Bydgoszcz, S. Kaliskiego 7, 85-796 Bydgoszcz, e-mail: kra-kor@utp.edu.pl

78 E. Krasicka-Korczyńska, R. Dembek, M. Korczyński, T. Stosik observed in many regions [Prach 2008, Krause et al. 2011]. From the other hand, once utilized damp habitats constituted a place of living for many plant and animal species, whereas intensification of pratotechnique results in simplification of the sward botanical composition [Grzywna and Szajda 2008]. Damp and boggy habitats at the same time stimulate water retention and processes leading to its self-purification. These factors became a motive for actions aiming at reconstruction of damp meadows in conditions of their agricultural reuse. The legal and economic mechanism supporting maintenance of meadows on damp habitats involves agri-environmental programs. Variants of the packet protection of endangered bird species and natural habitats such as mosses, tall sedge reeds, seminatural damp meadows, are referred particularly to them. Meadows qualified to this group make living sites of many protected plants [Krasicka-Korczyńska et al. 2008, Grzelak et al. 2011]. Apart from maintenance of the biological diversity of meadows utilized agriculturally, attempts are made to reconstruct abandoned meadow habitats connected with wet and damp areas. The factor limiting the effectiveness of those actions is impoverished soil seed bank. In the case of long discontinuation of use, lack of depositing diaspores during flooding or due to very early cutting, diaspores of many plants typical of those habitats are not preserved [Klimkowska et al. 2007]. A relatively constant species typical of damp and inundated habitats is common sedge C. nigra Reichard. Its diaspores are preserved for the longest time in the soil seed bank [Schrautzer et al. 1996]. The species has a wide ecological spectrum, since it is found in tall sedge reeds, meadows of the alliances Molinion and Calthion, and its reaches the optimum on lowland bogs [Nowiński 1967, Sotek 2010]. It occurs more copiously in cut meadows than in those which are not utilized [Kamiński and Chrzanowski 2007]. It appears in sward as a result of secondary bogginess [Podlaska 2012]. The yield-formation potential and value of hay obtained from grasslands with predomination of C. nigra are regarded as low [Grzelak et al. 2011, Klarzyńska and Strychalska 2011]. Nevertheless, with the use of bacterial-enzymatic addition, fodders from boggy meadows with a large proportion of C. nigra have fodder value suitable for young cattle [Żurek et al. 2006]. One of species achieving the highest cover in meadow communities with common sedge is marsh angelica O. palustre Besser, which is quite often found in meadows of the Bydgoszcz Canal Valley and the Noteć River Valley [Krasicka-Korczyńska et al. 2008, Krasicka-Korczyńska 2009], which is of importance in creating their productive potential. The aim of this study was to compare communities with predomination of common sedge C. nigra and phytocenoses of common sedge with a considerable proportion of O. palustre in respect of phytocenosis and agricultural value. At the same time, the zero hypothesis about the lack of differences between the analysed phytocenoses was verified. MATERIAL AND METHODS The field study was carried out in meadows of the Agricultural Experimental Station in Minikowo owned by the University of Technology and Life Sciences in Bydgoszcz. These are situated in the Bydgoszcz Canal Valley, being the west part of the Toruń Valley mesoregion [Kondracki 2000]. Grasslands predominate in the landscape. They Acta Sci Pol.

Natural and fodder values... 79 form on the peat subsoil with a density reaching up to 6-9 m thickness. It usually has the character of moss and sedge-moss, less often of sedge or sedge-reed [Roguski 1961]. Characteristic of communities with C. nigra was based on 20 phytosociological releves made in 2006-2010, the half of which was releves with O. palustre. Phytosociological releves were subjected to the analysis of ordination with the principal component analysis (PCA), in order to determine the factors that affect their different character, using the MVSP packet [Kovach 2007]. The 0-1 scale of quantity was adopted in order to eliminate the effect of dominant species. Characterizing the patches of communities, there were compared the mean number of species in the releve, their cover coefficients, value of the Shannon-Wiener diversity index [Krebs 1996] as well as average values of F, R, N indices acc. to Ellenberg et al. [1992]. Significance of mean differences was evaluated with the t-student test [Oktaba 1980]. Also the group participation of species characteristic of syntaxa of higher rank was compared [Matuszkiewicz 2005]. In the years 2006-2008 the assessment of yield of 10 plant patches predominated by C. nigra and 4 with C. nigra variant with O. palustre was carried out. All of them were used in accordance with the Agri-environmental Program (PO1b). The control treatments were two areas with C. nigra that were not involved in this program. The studied meadows were cut after 1 st July (usually on 2 nd or 3 rd of July), and the control meadows two weeks earlier about 15 June. The yields were determined based on sward samples collected each time from four frames with an area of 0.5 m 2 (a total of 2 m 2 ) from each analysed area at times preceding determined harvest periods. Collected sward served also for chemical analyses made in UTP laboratories. The amount and value of the yield was presented on the background of the weather conditions, based on the data from the meteorological point of the Agricultural Advisory Centre in Minikowo. RESULTS Flora of the examined meadows of community with C. nigra was composed by a total of 94 species of vascular plants, whereas in patches with common sedge there were 79 of them and in patches with O. palustre 68. Apart from O. palustre and C. nigra, which occurred in the highest constancy class, considerable constancy and cover index values were obtained by: Achillea millefolium L., Cirsium oleraceum (L.), Ranunculus acris L. and Ranunculus repens L. Festuca rubra L. had the highest constancy and cover index (Table 1). The mean number of species recorded in phytosociological releves was almost identical. A total of 31 taxons occurring only in one of the phytocenoses were found and they occurred sporadically, with low cover. From that number, Molinia caerulea (L.) Moench s. str., Plantago major L. and Centaurea jacea L. were recorded only in patches predominated by C. nigra. Of fodder plants, Trifolium repens L., Poa pratensis L. s. str., Festuca pratensis L. s. str and Trifolium pratense L. were of greater importance. Of valuable meadow species, only F. rubra was co-dominant in the variant with O. palustre. Small floristic differentiation and qualitative proportion of individual species is confirmed by values of biological diversity coefficients. Differences between their means for both phytocenoses were non- -significant (Table 2). Agricultura 13(4) 2014

80 E. Krasicka-Korczyńska, R. Dembek, M. Korczyński, T. Stosik Table 1. Comparison of Carex nigra Reichard community variants Tabela 1. Porównanie wariantów zbiorowiska z Carex nigra Reichard Variant Wariant C. nigra + O. palustre C. nigra Number of relevés Liczba zdjęć 10 10 Number of species Liczba gatunków 68 79 class of constancy klasa stałości cover index współczynnik pokrycia class of constancy klasa stałości cover index współczynnik pokrycia 1 2 3 4 5 SENECIONI-TUSSILAGINETUM Sonchus arvensis I 55 I 5 Silene vulgaris I 10 Polygonum lapathifolium pallidum I 5 ARTEMISIETEA VULGARIS Geum rivalec II 15 I 10 Glechoma hederacea I 10 I 10 Urtica dioica I 5 I 5 Anthriscus sylvestris II 15 Carduus crispus I 5 Epilobium parviflorum I 10 Eupatorium cannabinum I 5 PHRAGMITETEA Carex acutiformis II 110 I 5 Carex disticha II 355 I 5 Phalaris arundinacea I 380 II 15 Galium palustre I 5 I 5 Carex gracilis I 10 Eleocharis palustris I 10 Scutellaria galericulata I 5 Carex vesicaria I 5 Veronica anagallis-aquatica I 5 Schoenoplectus tabernaemontani I 5 Glyceria maxima I 0 CALTHION Cirsium oleraceum V 215 V 90 Epilobium palustre II 20 I 50 Polygonum bistorta II 20 Caltha palustris 1 Trifolium hybridum I 5 Scirpus sylvaticus I 5 MOLINION Carex panicea I 5 Molinia caerulea I 630 Linum catharticum I 5 FILIPENDULION Lythrum salicaria III 25 II 20 Hypericum tetrapterum II 15 I 5 Filipendula ulmaria I 5 I 5 Valeriana officinalis II 15 Lysimachia vulgaris I 5 MOLINIETALIA Ostericum palustre V 6250 IV 130 Deschampsia caespitosa III 30 III 200 Lychnis flos-cuculi III 25 II 15 Angelica sylvestris I 10 II 65 Equisetum palustre I 100 I 55 Cirsium palustre II 20 Lotus uliginosus I 5 Acta Sci Pol.

Natural and fodder values... 81 Table 1 continue cd. tabeli 1 1 2 3 4 5 ARRHENATHERETALIA Achillea millefolium V 135 V 135 Galium mollugo IV 220 III 25 Trifolium repens III 70 II 605 Taraxacum officinale II 15 II 15 Heracleum sibiricum I 10 I 10 Rumex thyrsiflorus I 5 I 5 Arrhenatherum elatius I 5 Dactylis glomerata I 5 TRIFOLIO FRAGIFERAE-AGROSTIETA Festuca arundinacea IV 40 II 190 Ranunculus repens IV 125 V 270 Agrostis stolonifera III 70 I 55 Potentilla anserina II 20 IV 85 Carex hirta II 60 III 30 Rumex crispus I 10 Potentilla reptans I 5 I 5 Inula britannica I 5 PLANTAGINETALIA MAJORIS Plantago major III 30 Poa annua I 5 MOLINIO-ARRHENATHERETEA Festuca rubra V 2925 IV 915 Ranunculus acris IV 130 V 395 Rumex acetosa III 25 II 110 Holcus lanatus II 390 III 580 Poa pratensis II 110 III 380 Cerastium holosteoides II 20 I 10 Poa trivialis II 20 I 10 Festuca pratensis II 15 III 395 Plantago lanceolata II 105 II 65 Vicia cracca I 55 II 190 Trifolium pratense I 10 I 175 Agrostis gigantea I 10 I 5 Phleum pratense I 5 I 5 Centaurea jacea II 555 Prunella vulgaris I 50 SCHEUZERIO-CARICETEA NIGRAE Carex nigra V 3735 V 6500 Juncus articulatus I 10 II 110 Carex lepidocarpa I 5 I 5 Triglochin palustre I 5 II 60 Hydrocotyle vulgaris I 50 Eriophorum angustifolium I 5 NARDO-CALLUNETEA Potentilla erecta I 5 TRIFOLIO-GERANIETEA SANGUINEI Galium verum II 20 TOWARZYSZACE Medicago lupulina II 20 II 15 Polygonum amphibium f. terrestre II 15 II 15 Mentha arvensis II 15 II 60 Cardaminopsis arenosa II 15 II 15 Mentha xverticillata I 375 I 5 Odontites serotina I 5 I 55 Plantago intermedia I 55 Sagina nodosa I 10 Salix cinerea (c) I 10 Mentha aquatica I 50 Dactylorhiza incarnata I 5 Agricultura 13(4) 2014

82 E. Krasicka-Korczyńska, R. Dembek, M. Korczyński, T. Stosik Table 2. Carex nigra Reichard community diversification Tabela 2. Zróżnicowanie zbiorowiska z Carex nigra Reichard Number of species Coefficient of in the relevé variation Liczba gatunków Współczynnik F R N w zdjęciu różnorodności C. nigra 23.2 4.01 6.95 4.35 3.92 C. nigra + O. palustre 23.0 3.91 6.73 5.28 4.09 t-studenta 0.05 0.37 1.37* 2.34** 0.50 * p = 0.2; ** p = 0.05 F, R, N Ellenberg indices wskaźniki Ellenberga In respect of syntaxonomy, patches of both variants of the community with C. nigra is characterized by a considerable proportion of species from the order Molinietalia and class Molinio-Arrhenatheretea. Differences of the group proportion of individual syntaxa do not exceed 5%. The largest refers to species characteristic of Molinietalia, which is of greater importance in patches of the variant with O. palustre. In the studied patches, only C. nigra is a constant species and at the same time, characteristic of the class Scheuzerio-Caricetea. Meadow species predominate, with a hardly noticeable proportion of reed bed plants (Fig. 1). Fig. 1. Characteristic species group share in Carex nigra Reichard community variants; dominates Carex nigra Reichard (Cn), dominates Ostericum palustre Besser (Cn+Op) Rys. 1. Udział grupowy gatunków charakterystycznych w wariantach zbiorowiska z Carex nigra Reichard; dominuje Carex nigra Reichard (Cn), dominuje Ostericum palustre Besser (Cn+Op) Habitat differences of both variants determined based on indices of Ellenberg et al. [1992] indicate more alkaline character of the substratum of patches with O. palustre. Abundance in nitrogen compounds may be regarded as similar. Difference in the soil moisture level is small (Table 2). Acta Sci Pol.

Natural and fodder values... 83 Ordering of releves confirmed low differentiation of the studied phytocenoses. Their arrangement along the first axis made it possible to confirm the substratum reaction as the habitat factor affecting the floristic structure of both variants of communities with C. nigra. At the same time the releves with the predomination of C. nigra were partially separated from those of C. nigra with O. palustre (Fig. 2). Fig. 2. Rys. 2. R reaction odczyn, F moisture wilgotność, N nitrogen zasobność w azot Canonical correspondence analysis for the Carex nigra Reichard community relevés Kanoniczna analiza zgodności CCA zdjęć zbiorowiska z Carex nigra Reichard The meteorological conditions presented in Table 3 indicate that in the studied region, on average in the growing season, there is rainfall deficit of about 110 mm in comparison with the optimal rainfall reported by Grabarczyk [1975]. The first two years of the study were characterized by a relatively small rainfall deficit. Air temperatures higher than the average for the region, especially at the beginning of the second regrowth in July, combined with heavy rainfalls in the period from 24 July to 10 September 2006, resulted in the highest yields of the second regrowth noted in the three-year period (Table 4). Heavy rainfalls and a favourable temperature distribution in the first half of the growing season also favoured the yield of the 1st regrowth in 2007. The second regrowth was weakened due to moisture deficit lasting from the 10th of August. The lowest yields were obtained in all the treatments in the last year of the study, characterized by the largest rainfall deficit. Yields obtained from the studied areas dominated by C. nigra were on average by about 1Mg ha -1 lower, and by C. nigra and O. palustre by about 1.5 Mg ha -1 lower, than the means from domestic meadows. The first cut accounted for 58.5% the annual yield in communities with C. nigra and 59.8% in communities with C. nigra and O. palustre. Even the earlier harvest of the 1 st cut used in the control treatments did not introduce significant changes in the annual yields. It only leveled proportions between the yields Agricultura 13(4) 2014

84 E. Krasicka-Korczyńska, R. Dembek, M. Korczyński, T. Stosik of both cuts. There was, however, a tendency to a lower yields of communities with a high proportion of O. palustre in drought periods commonly occurring in this region. Table 3. Weather conditions in years of study according to the meteorological point ODR in Minikowo Tabela 3. Warunki pogodowe w latach badań według punktu meteorologicznego ODR w Minikowie Year Rok April kwiecień May maj June czerwiec July lipiec Month Miesiąc August sierpień Temperature Temperatura, ºC September wrzesień April- September kwiecień wrzesień January- December styczeń grudzień 2006 7.7 12.4 17.1 21.0 17.0 16.3 15.3 8.7 2007 8.7 14.2 18.0 17.5 17.9 13.1 14.9 9.2 2008 7.8 12.8 16.3 17.9 17.3 12.9 14.2 9.1 1949-2009 7.4 12.7 16.2 17.7 17.3 13.4 14.1 7.9 Precipitation Opady, mm 2006 66.0 58.8 22.7 46.1 112.9 50.5 357.0 496.3 2007 18.7 70.4 99.8 105.9 45.5 31.0 371.3 603.1 2008 27.3 11.4 21.0 59.7 95.5 22.2 237.1 467.0 1949-2009 29.5 47.5 55.2 77.2 57.1 43.1 309.5 506.8 Deficiency (-) or an excess of precipitation in relation to the optimal precipitation Niedobór (-) lub nadmiar opadów w stosunku do opadów optymalnych 2006 16.0-6.2-57.3-43.9 32.9-4.5-63.0 2007-31.3 5.4 19.8 15.9-34.5-24.0-48.7 2008-22.7-53.6-59.0-30.3 15.5-32.8-182.9 1949-2009 -20.5-17.5-24.8-12.8-22.9-11.9-110.4 Table 4. Dry matter yields, Mg ha -1 Tabela 4. Plony suchej masy, Mg ha -1 Cut Pokos Year Rok 2006 2007 2008 Mean Średnia Caricetum nigrae average with 10 treatments Caricetum nigrae średnia z 10 obiektów I 2.30 2.31 1.98 2.20 II 2.16 1.27 1.24 1.56 Total Suma 4.46 3.58 3.22 3.76 Caricetum nigrae + Ostericum palustre average with 4 treatments Caricetum nigrae + Ostericum palustre średnia z 4 obiektów I 1.95 2.38 1.79 2.04 II 2.06 1.11 1.00 1.59 Total Suma 4.01 3.48 2.79 3.43 Control treatments Caricetum nigrae average with 2 treatments Caricetum nigrae średnia z 2obiektów I 1.69 1.74 1.72 1.72 II 2.01 2.02 1.25 1.76 Total Suma 3.70 3.76 2.97 3.48 Delayed time of harvest of the 1 st cut, rarely applied in agricultural practice before introduction of agri-environmental programs, resulted in a very low concentration of Acta Sci Pol.

Natural and fodder values... 85 total protein and high concentration of raw fibre in sward, especially in the first two years of the study (Table 5). High temperatures in the period of yield growth were an additional factor modifying this sward component. They accelerated the plant growth, and consequently, they unfavourably changed proportions between these components. The protein level in sward noted in both years, slightly exceeding 80 g kg -1, is characteristic of hay with low feeding value. Temperature distribution in 2008 was similar to the long-term means. This caused a slower development of sward components, and thus higher content of protein and lower content of fibre than in the previous years. These, however, are still typical values of poor hay. The sward of the second regrowth, characterized by a more favourable concentration of both fundamental components, also did not meet requirements of good hay. Table 5. Content of nutrients in sward, g kg -1 Tabela 5. Zawartość składników pokarmowych w runi, g kg -1 Specification Wyszczególnienie Crude protein Białko surowe Crude fiber Włókno surowe P K Ca Mg Cn Cn+Op Cn Cn+Op Cn Cn+Op Cn Cn+Op Cn Cn+Op Cn Cn+Op Cut Pokos Cn C. nigra Cn+Op C. nigra + O. palustre Year Rok 2006 2007 2008 Mean Średnia I 81.3 82.3 107.4 90.3 II 126.1 126.0 125.6 125.9 I 94.8 98.3 101.3 98.1 II 105.0 131.2 144.3 126.9 I 307 309 302 306 II 318 280 277 292 I 294 304 307 301 II 297 297 300 298 I 1.62 2.05 1.98 1.88 II 2.02 2.23 2.21 2.15 I 1.69 1.84 2.26 1.93 II 2.05 2.01 2.90 2.32 I 4.94 5.09 5.21 5.08 II 5.21 8.39 4.64 6.08 I 6.13 5.69 4.54 5.45 II 5.90 7.19 4.62 5.90 I 4.36 4.02 5.77 4.71 II 4.51 4.01 5.67 4.73 I 5.82 6.02 6.09 5.98 II 6.28 7.38 7.02 6.89 I 3.55 3.56 3.99 3.70 II 4.15 3.58 3.97 3.90 I 2.64 3.90 4.58 3.71 II 4.10 3.96 4.91 4.32 Standards for good hay Normy dla dobrego siana 130 300 3.00 17.0 10,0 7.00 2.00 Phosphorus content was lower than that required in nutritional standards. Moreover, the studied sward was characterized by extremely low concentration of potassium. Deficiency of this element may be one of the main reasons for development of C. nigra. Phosphorus and potassium occurred in larger amounts in sward with O. palustre. Agricultura 13(4) 2014

86 E. Krasicka-Korczyńska, R. Dembek, M. Korczyński, T. Stosik Calcium concentration in sward of patches dominated by C. nigra was considerably smaller than that currently required for a good feed. A higher level of this macroelement was found in sward patches with O. palustre, particularly in the second regrowth. Among the studied mineral elements, only magnesium content exceeded the level of 2 g kg -1 required by nutritional standards and completely covered nutritional needs of even most demanding high-milk cows and young animals in the period of growth and development. The highest magnesium level was observed in the sward of the second regrowth of communities with O. palustre. Proportions of nutrients are important indicator of quality of feeds from grasslands (Table 6). The Ca:P ratio is higher than that regarded as appropriate. As a result of longterm feeding with fodders with improper proportion of these macroelements, animals develop tendency to osteomalacia. The very narrow K:(Ca+Mg) ratio shown in the study eliminates a possibility of occurrence grass tetany, but at so high deficiency of potassium, the intensity of photosynthesis decreases, and consequently, also the effectiveness of generating carbohydrates and proteins. Table 6. Proportion of nutrients in sward Tabela 6. Proporcje składników pokarmowych w runi Cut Pokos I II Cn C. nigra Cn+Op C. nigra + O. palustre Specification Wyszczególnienie Ca:P 2:1 K:(Ca+Mg) 2,2 Cn 2.51 0.60 Cn+Op 2.20 0.70 Cn 3.10 0.56 Cn+Op 2.68 0.56 DISCUSSION Despite hydrogenous origin of the soils covering the bottom of the Bydgoszcz Canal valley and a small distance from both the canal and the nearby Kardynalski Pond, according to Łyszczarz and Suś [2009], the amount of precipitation in the growing season is an essential factor, determining the groundwater level in the studied meadows. Dynamic changes in moisture of the top layer of organogenic soils have an effect on the growth and development of shallow-rooted species, including mainly grasses and sedges. Patches of C. nirga are formed here under conditions that differ from the optimum for this species. Common sedge is usually accompanied by brown mosses, and the water level remains close to the ground surface [Nowiński 1967]. It occurs in once-cut or uncut meadows accompanying complexes of peat bogs [Stosik 2009]. Neither the weather conditions that prevail in the Bydgoszcz Canal Valley, nor the technical infrastructure favour maintaining systems creating the ecological optimum for this sedge. Hence in patches of phytocenoses there are few species of the class Scheuchzerio-Caricetea nigrae, of which the species is characteristic [Matuszkiewicz 2005]. Neglect of pratotechnique or meadow degradation result in its vanishing [Kamiński and Chrzanowski 2007, Prach 2008]. Meadow utilization resulting in transformations of habitats with C. nigra allows the sedge species to maintain in Acta Sci Pol.

Natural and fodder values... 87 meadows in meadows classified as Calthion or Molinion [Botta-Dukát et al. 2005]. The studied patches of vegetation confirmed that opinion through a considerable share of species of the order Molinietalia in the sward with a considerable proportion of C. nigra. Thus the mere domination of the common sedge cannot be the sufficient criterion for distinguishing the association Caricetum nigrae [Podlaska 2012]. In conditions of one-cut utilization of meliorated meadows C. nigra is accompanied by two times more species in relations to its typical once-cut patches. At a slightly higher mean number of plants in the releve they have two times higher value of the biological index [Klarzyńska and Strychalska 2011]. Yielding of the studied areas was lower than the average national meadow yields at that time given by GUS and similar to the natural productivity of those meadows on the level of about 4 Mg ha -1 determined by Roguski [1961], and currently, by Łyszczarz and Dembek [2006]. Because of low profitability of feed production in such conditions, suitably addressed subventions seem to be necessary, which at the same time will force the proper pratotechnique preventing the degradation of these habitats. The protein content in the sward recorded particularly in the first two years of the study was lower than the concentration in grasses at the final phase of flowering given by Antoniewicz and Żebrowska [1997] and Zarudzki et al. [1999]. Choromański et al. [1991] classify such sward in the lower limits of the range for weak hay. Bulky feeds produced from those meadows can be applied only in small amounts in feeding dairy and fattening cattle. The find application to a larger extent in feeding of extensive races. Despite a large time interval between the studies by Roguski [1961] and by Łyszczarz and Dembek [2006], they indicate that the soils of the studied meadow complex are characterized by a considerable variability of phosphorus content, from low to high, and a low content of potassium. Moreover, phosphorus availability for plants is limited by the large content of calcium carbonate and alkaline reaction of the top soil layers. Under such conditions there occurs apparent deficit of phosphorus. The problem of deficiency of elements results also from long-term abandoning of fertilization balancing the amount of elements taken out with yield. Quoting Falkowski et al. [2000], it may be stated that the reason for different contents of this element between communities differentiated by the proportion of O. palustre is commonly observed higher P level in dicotyledonous plants in comparison with monocotyledonous. From the study by Łyszczarz et al. [2006] it follows that in grass-herb sward collected from these meadows the level of phosphorus exceeded the 3 g kg -1 wrewuired by the nutritional standards. In sward dominated by C. nigra the content of this macroelement was definitely lower. Phosphorus concentration decreases along with the processes of plant ageing, therefore in the second regrowth harvested at younger development phases, a higher level of this element was found each time. Pisulewski et al. [2009] report that phosphorus is one of the fundamental macroelements, particularly in feeding high-milk yielding cows. Potassium deficiency in feeds, according to Falkowski et al. [2000], become the cause of aphosphorosis. The optimal content of potassium in plants is regarded as 17 g kg -1, but already 10 g kg -1 covers the needs of plants and animals. The lower concentration observed in the studied sward decreases the effectiveness of photosynthesis, and consequently, affects the sward yield. This may also be the cause of hypokalemia in animals [Falkowski et al. 2000]. When assessing the calcium content in the sward of C. nigra, communities, in comparison with the changing but usually high content of carbonates and alkaline soil Agricultura 13(4) 2014

88 E. Krasicka-Korczyńska, R. Dembek, M. Korczyński, T. Stosik reaction found by Roguski [1961] and by Łyszczarz et al. [2006], its level in the present study should be regarded as very low. The proportion of O. palustre improved the balance of this macroelement, particularly in the second cut, where according to the study by Krasicka-Korczyńska [2008], apart from the leaf rosette, also generative shoots appeared. Similar to the habitat assessment based on the indices of Ellenberg et al. [1992], also chemical analyses indicate that the proportion of O. palustre in the sward can be regarded as the indicator of higher Ca concentration in the fodder. Therefore relationships between the occurrence of O. palustre and soil reaction and Ca content in sward should be more precisely determined. Falkowski et al. [2000] stress that calcium concentration increases along with the growth and development of plants. In all nutritional recommendations this element, together with phosphorus, is mentioned as the fundamental, determining the effects of feeding cattle, especially cows in the period of the highest lactation. Considerable deficit in nutrition results in hypocalcaemia, which is manifested among other things with demineralization of bone tissue. Magnesium concentration in sward exceeded the necessary minimum determined by Choromański et al. [1991] and the authors of current nutritional standards. This may result from the high and stable abundance of the soils in Mg observed by Łyszczarz et al. [2010]. Dirturbances in relation to proper proportions of macroelements in sward given by Falkowski et al. [2000] expressed with Ca:P i K:(Ca+Mg) rations are the synthetic indicator of poor fodder value of sward obtained from the studied plant communities. In the general agricultural assessment, the studied communities should be regarded as of little worth. The slight economic usefulness of the assessed reed beds is shown by comparison with the effects reported by Grygierzec [2012] obtained from extensive used ryegrass meadow covered with the Agri-Environmental Program. On this basis it is difficult now to find another justification of maintaining these meadows than that connected with protection of natural plant associations and protected plants. CONCLUSIONS 1. Meadow community with C. nigra is the evidence of past cenotic systems which vanished after regulation of water relations and introduction of regular cutting use. 2. Pratocenoses with predomination of C. nigra or O. palustre in respect of floristic richness refer to meadows of the Alliance Molinion. The proportion of valuable meadow plants in their sward is small. 3. Yields of communities with C. nigra were considerably above the mean national meadow productivity. The first cut (with poor fodder value) accounted for 59% of the annual yield. Protein and fibre content in the second cuts classified the sward in the lower limits of nutritional standards. 4. Sward with O. palustre was characterized by a more favourable proportion of protein and fibre and higher contents of phosphorus, potassium, calcium and magnesium. 5. Due to the content of phosphorus, potassium and calcium lower than normal and high content of magnesium the K:(Ca+Mg) ratio was too narrow and Ca:P ratio too wide. Acta Sci Pol.

Natural and fodder values... 89 6. Due to a slight agricultural value of communities with C. nigra the basic reason for their utilization is protection of plant communities, including also localities of O. palustre. REFERENCES Antoniewicz A., Żebrowska T., 1997. Tabele wartości pokarmowej pasz. [W:] Normy żywienia bydła, owiec i kóz, Instytut Zootechniki Kraków, 121-213. Botta-Dukát Z, Chytrý M., Hájková P. Havlová M., 2005. Vegetation of lowland wet meadows along a climatic continentality gradient in Central Europe. Preslia, Praha 77, 89-111. Choromański K., Choromańska D., Sapek A., 1991. Jakość siana pierwszego pokosu w latach 1985-1987 na tle terminu zbioru. Wiad. Mel. i Łąk. 1, 17-19. Ellenberg H., Weber H.E., Düll R., Wirth V., Werner W., Paulissen D., 1992. Zeigerwerte von Pflanzen in Mitteleuropa. Scr. Geobot. 18. Falkowski M., Kukułka I., Kozłowski S., 2000. Właściwości chemiczne roślin łąkowych. Wyd. AR Poznań. Grabarczyk S., 1975. Melioracje rolne. [W:] Podstawy agrotechniki, PWRiL Warszawa, 77-135. Grygierzec B., 2012. Fodder value of hay from extensively used Arrhenatherum elatioris typicum community. Fragm. Agron. 29(3), 37-44. Grzelak M., Waliszewska B., Sieradzka A., Speak-Dźwigała A., 2011. Ekologiczne zbiorowiska łąkowe z udziałem gatunków z rodziny turzyc (Carex). J. Res. Appl. Agric. Engng 56(3), 122-126. Grzywna A., Szajda J., 2008. Functioning of meadow ecosystems in river Piwonia valley 40 years after its melioration. Teka Kom. Ochr. Kszt. Środ. Przyr., OL PAN, 5 A, 38-46. Kamiński J., Chrzanowski S., 2007. Wpływ użytkowania kośnego i pastwiskowego na właściwości fizyczne gleb oraz skład florystyczny zbiorowisk roślinnych na zmeliorowanym torfowisku. Woda-Środowisko-Obszary Wiejskie 7, 2b(21), 75-86. Klarzyńska A. Strychalska A., 2011. Bioróżnorodność zbiorowisk łąkowych w dolinie Bogdanki. PTPN, Wydział Nauk Rolniczych i Leśnych, Pr. Kom. Nauk Rol. Kom. Nauk Leś. 102, 133-145. Klimkowska A., van Diggelena R., Bakkera J.P., Grootjans A.P., 2007. Wet meadow restoration in Western Europe: A quantitative assessment of the effectiveness of several techniques. Biol. Conserv. 140, 318-328. Kondracki J., 2000. Geografia regionalna Polski. WN PWN Warszawa. Kovach, W.L., 2007. MVSP A MultiVariate Statistical Package for Windows, ver. 3.1. Kovach Computing Services, Pentraeth, Wales, U.K. Krasicka-Korczyńska E., 2009. Swamp angelica Ostericum palustre Besser. in grassland complexes of The Noteć River Valley and The Bydgoszcz Canal. [In:] Understanding the Requirements for Development of Agricultural Production and of Rural Areas in the Kuyavian-Pomeranian Province as a Result of Scientific Research, (ed.) E. Śliwińska, E. Spychaj-Fabisiak. University of Technology and Life Sciences Press, 199-209. Krasicka-Korczyńska E., 2008. Effect of the cutting date on blooming and fruit-bearing of Ostericum palustre Besser. Acta Agrob. 61(1), 129-136. Krasicka-Korczyńska E., Załuski T., Ratyńska H., Korczyński M., 2008. Roślinność siedlisk łąkowych i użytków przyrodniczych w regionie kujawsko-pomorskim. Podręcznik dla doradców rolnośrodowiskowych, K-PODR Minikowo. Krause B., Culmsee H., Wesche K., Erwin Bergmeier E., Leuschner Ch., 2011. Habitat loss of floodplain meadows in north Germany since the 1950s. Biodivers. Conserv. 20, 2347-2364. Krebs Ch.J., 1996. Ekologia. Eksperymentalna analiza rozmieszczenia i liczebności. WN PWN Warszawa. Łyszczarz R., Dembek R., 2006. Skład botaniczny i potencjał produkcyjny ekstensywnie użytkowanych łąk w Dolinie Kanału Bydgoskiego. [W:] Człowiek i środowisko przyrodnicze Agricultura 13(4) 2014

90 E. Krasicka-Korczyńska, R. Dembek, M. Korczyński, T. Stosik Pomorza Zachodniego, I. Środowisko biotyczne biologia środowiskowa, eksperymentalna i stosowana, Wydział Nauk Przyrodniczych, Uniwersytet Szczeciński, 183-189. Łyszczarz R., Miatkowski Z., Dembek R., 2006. Persistent green grounds in the Bydgoszcz Canal Valley the status and future use from the perspective of the Minikowo advising centre. Polish J. Env. St. 15(5DP.1), 215-219. Łyszczarz R., Suś R., 2009. Dynamika wód gruntowych i osiadania powierzchni gleb hydrogenicznych w dolinie Kanału Bydgoskiego. Woda-Środowisko-Obszary Wiejskie 9(4), 163-175. Łyszczarz R., Dembek R., Suś R., Zimmer-Grajewska M., Kornacki P., 2010. Renowacja łąk trwałych położonych na glebach torfowo-murszowych. Woda-Środowisko-Obszary Wiejskie 10(4), 129-148. Matuszkiewicz W., 2005. Przewodnik do oznaczania zbiorowisk roślinnych. WN PWN, Warszawa. Nowiński M., 1967. Polskie zbiorowiska trawiaste i turzycowe. Szkic fitosocjologiczny. PWRiL Warszawa. Oktaba W., 1980. Elementy statystyki matematycznej i metodyka doświadczalnictwa. PWN Warszawa. Pisulewski P., Strzetelski J., Antoniewicz A., 2009. Podstawowe założenia IZ PIB INRA norm żywienia przeżuwaczy. [W:] J. Strzetelski (red.), IZ PIB-INRA. Normy żywienia przeżuwaczy. Wartość pokarmowa francuskich i krajowych pasz dla przeżuwaczy, Wyd. IZ PIB Kraków, 11-20. Podlaska M., 2012. Walory przyrodnicze nieużytkowanych łąk pobagiennych Dolnego Śląska. Inż. Ekol. 29, 130-140. Prach K., 2008. Vegetation Changes in a Wet Meadow Complex during the Past Half-Century. Folia Geobot. 43, 119-130. Roguski W., 1961. Zagospodarowanie łąk w dolinie Kanału Bydgoskiego w świetle badań i doświadczeń przeprowadzonych w latach 1948-1952. Rocz. Nauk Rol. F 74, 581-672. Schrautzer J., Asshoff M., Müller F., 1996. Restoration strategies for wet grasslands in Northern Germany. Ecological Engineering 7, 255-278. Sotek Z., 2010. Disrtibution patterns, history, and dynamics of peatland vasculat plants in Pomarania (NW Poland). Biodiv. Res. Corserv. 18, 1-82. Stosik T., 2009. Możliwości ochrony walorów przyrodniczych łąk na przykładzie gminy Śliwice w Borach Tucholskich. PAN, Oddział w Krakowie, Komisja Technicznej Infrastruktury Wsi, Infrastruktura i Ekologia Terenów Wiejskich 6, 161-170. Zarudzki R., Traczykowski A., Mroczko L., 1999. DLG tabele wartości pokarmowej pasz i norm żywienia przeżuwaczy. Przedsiębiorstwo Produkcyjno-Handlowe VIT-TRA Kusowo. Żurek H., Wróbel B., Zastawny J., 2006. Ocena wartości żywieniowej sianokiszonek z łąk bagiennych. Ann. Univ. Mariae Curie-Skłodowska, Sect. E, Agricultura 61, 405-411. WALORY PRZYRODNICZE I PASZOWE ZBIOROWISKA Z Carex nigra W DOLINIE KANAŁU BYDGOSKIEGO Streszczenie. Stosunkowo trwałym gatunkiem właściwym dla siedlisk wilgotnych i podtapianych jest C. nigra. Jednym z gatunków osiągających najwyższe pokrycie w zbiorowiskach łąkowych z turzycą pospolitą jest O. palustre. W pracy przedstawiono porównanie pod względem fitocenotycznym i plonotwórczym zbiorowisk z dominacją C. nigra lub O. palustre. Pratocenozy z C. nigra lub O. palustre pod względem florystycznym nawiązują do łąk ze związku Molinion. W ich runi niewielki jest udział wartościowych roślin łąkowych. Różnice siedliskowe obu wariantów określone na podstawie wskaźników Ellenberga wskazują na bardziej alkaliczny charakter podłoża płatów z O. palustre. Plony uzyskiwane z badanych powierzchni zdomi-nowanych przez Acta Sci Pol.

Natural and fodder values... 91 C. nigra były średnio o około 1 Mg ha -1, a C. nigra i O. palustre o około 1,5 Mg ha -1 mniejsze od średniej krajowej wydajności łąk. Zawartość fosforu i potasu była niższa od wymaganej w normach żywieniowych. Fosfor i potas w większych ilościach występowały w runi z O. palustre. Udział O. palustre poprawiał bilans wapnia zwłaszcza w drugim odroście. W ogólnej ocenie rolniczej badane zbiorowiska należy uznać za mało wartościowe. Tym samym głównym motywem ich utrzymywania są wartości przyrodnicze związane z ochroną zbiorowisk roślinnych i siedlisk przyrodniczych. Słowa kluczowe: Carex nigra, Dolina Kanału Bydgoskiego, jakość runi, Ostericum palustre, plony, różnorodność biologiczna Accepted for print Zaakceptowano do druku: 28.10.2014 For citation Do cytowania: Krasicka-Korczyńska E., Dembek R., Korczyński M., Stosik T., 2014. Natural and fodder values of community with Carex nigra Reichard in the Bydgoszcz canal valley. Acta Sci. Pol., Agricultura 13(4), 77-91. Agricultura 13(4) 2014