KRZYSZTOF KASPRZAK COM M UNITIES IN U R BA N G REEN AREAS OF W ARSAW ABSTRACT

PO LISH A C A D E M Y OF SC IE N C E S IN S T IT U T E OF Z O O L O G Y M E M O R А В I L I A z MEMORABILIA ZOOL. 41 О о о с О G I C A о1986 KRZYSZTOF KASPRZAK STRUCTURE OF ENCHYTRAEID {O LIG O CH AETA, ENCH YTRAEIDAE) COM M UNITIES IN U R BA N G REEN AREAS OF W ARSAW ABSTRACT Enchytraeis occurring in soils of green habitats in parks, housing estates, an streetsie greens in Warsaw comprise 22 species. Their mean ensity was about 8000 iniviuals x m 2. A particularly high ensity was recore in green areas of locsely builtup housing estates (about 1 0 iniviuals x m~2, on the average). The genus Friericia reache the highest proportion in the community. Large fluctuations in enchytraei ensity over the year were cause by ifferent cultivation treatments on the lawns an by heavy seasonal overrying. Intense traffic i not effect much the occurrence an ensity of this group. The important factors were soil type, moisture, content of organic matter, age of vegetation, also the type an intensity of cultivation treatments. INTRODUCTION Enchytraeis are common saprophages humifying organic matter in soils of ifferent types. They belong to most important biocoenotic regulatory factors in soil, since they usually occur in high ensities, have a high feeing rate, an largely stimulate microbiological ecomposition of soil organic matter. They play an important part in many soilforming processes, particularly in structuring the soil an increasing its fertility, this being of great importance to heavily egrae urban soils. The enchytraeis of urban areas of Warsaw are relatively well known (Kasprzak 1981a, b, Kasprzak et al. 1979). But so far no quantitative ata were available, particularly on the ensity of enchytraei worms in ifferent types of urban habitats on the structure of their communities an species iversity. ' These issues are iscusse in the present paper. STUDY AREAS AND METHODS Soil samples were taken from three types of urban green habitats: parks, green areas of housing estates (closely an loosely builtup), an

72 KRZYSZTOF KASPRZAK streetsie green areas (ajacent to large parks an isolate). The following urban parks were uner stuy: the Łazienki Park (plots I, II, an IV1. the park at the Cemetery of Soviet Soliers (plots I an II), the Saxon Garen (plot II), an the Praski Park (plots I, II an III). Green habitats of loosely builtup areas were examine on two plots (I, II) of Wierzbno housing estate, an those of closely builtup areas were examine at Wilcza Street, M.D.M. (plots I, II), an Hoża Street. The streetsie green areas ajacent to parks were represente by Ujazowskie Avenue, Żwirki i Wigury Avenue (plot I). Marszałkowska Street, Woronicza Street, an Niepoległości Avenue. An isolate streetsie plot was examine at Grójecka Street. Also some ata were use on suburban habitats (the quarter Białołęka Dworska in Warsaw an the palace park in Ursynów). All these stuy sites, like most of the Warsaw area, are locate on the site of a potential linenoakhornbeam (TilioCarpinetum) community. Their etaile escription is given by Kubicka, Chuzicka, an Wysocki in this volume. All the plots were sample on the following ates: September 3 10 an October 22, 1974, April 15 22 an June 20 24, 1975 (leg. et et. M. Górny), an September 15, 1976, May 24 an September 23, 1977 (leg. et et. K. Kasprzak). In 1974 1975 the samples were 20cm2 in surface area, 5cm eep, an loocm3 in volume, while in 1975 1977 the respective imensions were 8.6cm2, 9.5cm. an 81cm3. The samples were taken by means of a evice which i not isturb the natural soil layering. A series of ten samples was taken each time from each plot. In the two stuy perios, a total of 1070 samples was taken from all the plots containing 8600 iniviuals. Enchytraei worms were extracte from soil at 40CC for 3 hours using O Connor s (1955, 1971) metho. They were ientifie to species in vivo an from preparations accoring to the metho evelope by Nielsen an Christensen (1959) an moifie by Kasprzak (1975a, in print). Also unpublishe ata of Górny (1974, 1975) are use here. SPECIES RICHNESS AND DENSITY Enchytraei worms occurring in urban green areas of Warsaw consiste of 22 species representing 8 genera (Tab. 1). They accounte for about 25% of all the enchytraei species recore in Polan so far (Kasprzak 1981a). It shoul be note that the number of species occurring in Warsaw is high as compare with other habitats. A similary high number of species was recore, for example, in the soil of miforest meaows 1 The symbols of plots accoring to Kubicka et al. (1986).

Table 1. Species composition an ensity o f enchytraeis in ifferent habitats an particular' stuy plots in Warsaw ( ensity ; iniviuals x m 2) FBiałołęka Dworska No. Species > Friericia bisetosa (Lev.) Friericia bulboies Niel. et Christ. Friericia bulbosa (Rosa) Friericia paroniarta Issel Friericia galba (Hoffm.) Friericia leyigi (Vej.) Friericia alata Niel. et Christ. Friericia perrieri Vej. Friericia connata Bret. Friericia gracilis Bfflow Friericia ratzeli (Eis.) Buchholzia appeniculata (Buchh.) Enchytraeus buchholzi Vej. Achaeta bulbosa Rosa AcHaeta eiseni Vej. Achaeta affinis Niel. et Christ. Achaeta camerani (Cog.) Marionina argentea Mich. Henlea similis Niel. et' Christ. Henlea ventriculosa ( Uek.) Henlea perpusilla Frien Mesenchytraeus pelicensis Issel Friericia sp. juv. Marionina sp. juv. Achaeta sp. juv. Henlea sp. juv. Enchytraeus sp. juv. Cognettia sp. juv. Enchytraeiae non et. 1 Total г 581 : Ursynów meaow of Arrhenatheretum type TilioCarpinetum 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 U rban green habitats Suburbs 1 /О % Łazienki I park 0 / У /0 13.0 233 15.4, 78 78 5.2 i 1 г 1 675 225 ' 2331 15.4 183 3333 233 78 1 4457 74.8 ' 1! 78 1 1 i Г 'r 5.2 775 1.8 r 1513 13.9 4.6 5.2 700 15 267 Łazienki II V /О Saxon Garen II 6 4 7.1 3 2.2 4.9 325. 18.0 3.9 1.6 67 0.6 у «2 3.4 4.2 3 125 1.7 3256 698! 0743 Cemetery of Soviet Soliers II 2.9 12.2 1.4 0.3 1.2 0.6 5.6 2.8 167 79.4 4088 38 2.1 1400 t 888 1 7.7 ' /О Łazienki IV Cemetery of Soviet Soliers I 6.5 524 14.4 2209 1.9 2 2.5 213 0.5 465 600 300 5 48 Housing estate green Parks 1.6 38.0 13.0 8.2 1.9 1.4 7 4937 1967 0 5 8 0.3 2.2 29.0 1233 3.0 1.4 /0 21.0 617 125 383 25 6.1 1.2 3.8 25.2 383 2 Praski Park II Praski Park III Praski Park I /О V 1.9 3.5 1.2 2.1 8.4 31.0 6.4 7.0 1.0 % 55.0 2.4 17.6 1.6 8.1 825 ' 51.0 3133. 6 13.6 700 1.7 ' 5.1 52.7 3000 13.3 800 300 % 5638 1425 2.7 1.6 400 3863 738 1900 ' 349 0.9 6.1 1.7 2.2 2.2 0.9 349 3.7 291 3.1 0.9 2 125 167 1.8 25 19.2 : 54.7 5930 44.4 517 68.9 5. r. : ; 7.7 0.9 2288 24.5 7 5.6 1225 : 0.6 ' ' 5.1 0.6 49.7 2 46.5 5388 ; 9.5 600 7.0 24.5 333 '. 7.8 6.1 0.7 3.9 275 4.1 2 27.3 67 10.9 225 5.5 1617 3.0 4.7 : 117 756 M D M II 3.5. ; 8.5 10.7 3.2 1.9 3.5 ч MDM I Wilcza St. 1.2 10471 8.1 814 524. 814 0.5 1.2 ; 1.2 400 : 838 2 275 4.9 3.2 0.6 21.5 1013 400 8.5 3.2 ; 125 V Wierzbno I Wierzbno II Streetsie green f 1318 10.5 388 ' 5.7 3.6 6.3 2 29.7 407 21.6 2035. : 1.7 ' 51.2 10 15.3 1.7 969 14.1 ' 10705 00.0 5883 10138 7784 4271 7826 9366 13351 00.0 2392 6832 756 0.8 0.9 0.5 233 ' 6 25.1 % 4.0 1.3 0.8 233 3 67 Marszałkow Woronicza Niepolegr Grójecka St. ska Street Street łości Avenue 5.1 17.0 ' Żwirki i Wigury Avenue I 15.6 ;! 30.9 ' 4302 349 3 Ujazowskie: Avenue 814. ; 1 i ; 82.2 698 20 1.3 8.1 28.8 53.8 15.3 225 2.2 2588 1033 275 698 29.9 1438 11.9 3.2 3 8.1 5232 8666 2588 i 18085 2909 Hoża Street 5.4 0.6 79,9 196 55.6 533 1900 13.5 400. 5.8 24600 2.2 7.7 1.6 0.4 % 5.3 5 5.8 283 0 5 16 1863 3633 9 9429 3.0 /o 29.5 1 % 581. 83.4 2.7 17.5 19.8 3 38.5 10.1 62.4 5.4 16.6 1863 697

STRUCTURE OF ENCHYTRAE1D COMMUNITIES 73 ( K a i r e s a l o 1978) an beech forests ( D o z s a F a r k a s 1973). Soil, ecaying logs, an litter o f a natural oakhornbeam (QuercetoCarpinetum) forest were inhabite by 26 species ( K a s p r z a k 1975b). The ensity o f most enchytraei species, incluing m ost abunant species occurring in Warsaw, in m any habitats o f Polan is unknown. The observations mae so far in both anthropogenic an alm ost natural habitats show that som e species (e.g., Cognettia sphagnetorum, Henlea ventriculosa, Buchholzia appeniculata, Friericia bisetosa, F. paroniana, F. galba, F. ratzeli, Enchytrateus buchholzi) are o f mass occurrence in Polan. A lso in urban green areas o f Warsaw there is a group of species abunant in m ost habitats uner stuy. First o f all, these are all species o f the genus Friericia (F. bisetosa, F. bulboies, F. galba, an F. ratzeli), an to a lesser extent Henlea ventriculosa, Buchholzia appeniculata, an Enchytraeus buchholzi. The co n tribution o f the genus Friericia to the total enchytraei ensity was particularly high in soils o f parks (70%) an isolate streetsie green areas (83%) (Tab. 2). Such a high om inance o f the genus Friericia was characteristic, for example, o f northeuropean miforest meaows ( N u r m i n e n 1967). N o correlation was foun between the species richness an ensity o f enchytraei worms on any o f the plots. In soils of suburban habitats o f Białołęka D w orska 9 species were recore, accounting for about 10% o f all the enchytraei species recore from Polan so far an for 40% o f all the species occurring in soils o f green habitats o f Warsaw ( K a s p r z a k 1981b). In soil o f the linenoakhornbeam forest at Białołęka Dworska, the ominant species was Buchholzia appeniculata (75% of the 'total abunance o f the com m unity), while the soil o f a m eaow on the linenoakhornbeam forest site was ominate by young iniviuals o f Friericia sp. an F. bisetosa (jointly 66% o f all iniviuals). The mean ensity o f enchytraeis in soils o f green areas o f Warsaw was about 8000 i n i v i u a l s x m 2. The highest mean ensity was recore in soils o f green in loosely builtup areas, parks, an streetsie zones ajacent to vast green areas. In this last habitat type the highest ensity o f iniviuals x m ~ 2 was note for Warsaw. A s compare with other anthropogenic habitats, e.g., soils o f agroecosystems, all stuy habitats o f Warsaw were characterize by markely lower ensities o f enchytraeis. For instance, a mean ensity o f enchytraeis in soils o f m eaows an pastures range from to 80000 iniviuals x m ~ 2, an their mean ensity in soils o f potato fiels was up to 23000 iniviuals x m 2 ( K a s p r z a k 1980, 1982, K a s p r z a k, R y l 1978). M ean ensities o f enchytra eis in soils o f an linenoakhornbeam forest ( TilioCarpinetum), pine forest (PeuceanoPine turn), an m eaows on the site o f an linenoakhornbeam forest an alerash carr (CircaeoAlnetum) in Białołęka Dworska,

Table 2. Characteristics of enchytraei communities in ifferent urban green habitats of Warsaw Density (iniviuals x m2) Proportion of ifferent genera in (per cent) total ensity Habitat Number of species mm, max. Average Friericia Mich. Henlea Mich. Achaeta Vej. Enchytraeus Henie Buchhohia Mich. 'П JZ 2 ü c g.ü z Mesenchytraeus Eis. Species with highest proportion Parks Green of housing estates in closely builtup areas in loosely builtup areas Streetsie green areas ajacent to other green areas 17 472118085 9456 70.1 13.2 8.4 2.8 3.9 1.5 0.1 Friericia bisetosa, F. bulboies, F. leyigi, F. rotzeli, F. galba. Achaeta eiseni, Buchholzia appeniculata, Henlea ventriculosa 9 7566852 3716 31.9 23.2 1.6 39.2 4.1 Friericia bisetosa, F. bulboies, F. gracilis, 13 936613351 11359 67.7 28.7 2.1 1.0 0.5 Henlea similis, H. perpusilla, H. ventriculosa. Friericia bulboies, F. galba, Henlea ventriculosa, H. perpusilla, Enchytraeus buchholzi, Buchhohia appeniculata 8 186324600 9429 2 14.1 53.2 6.8 3.0 0.3 Achaeta eiseni, Enchytraeus buchholzi, Henlea ventriculosa, Friericia bisetosa, F. galba isolate 2 697 83.4 16.6 I 1 Friericia bisetosa KRZYSZTOF KASPRZAK

STRUCTURE OF ENCHYTRAEID COMMUNITIES 75 where the species com position an om inance structure are similar from one year to another ( K a s p r z a k 1981b), were generally much lower than in soils o f urban green areas o f Warsaw. Large seasonal fluctuations o f enchytraei ensities were observe in all the stuy plots in Warsaw. Their ensities were relatively high in soils o f streetsie an interlane green areas ajacent to large green habitats with a relative soil moisture o f about 15% an containing much litter (about g x m 2). Low ensities o f enchytraeis were note mostly in soils o f streetsie an interlane green locate far from large green habitats, generally characterize by a low content o f litter (less than g x m 2 ), an soil moisure less than 15. They were also low in soils o f isolate green o f housing estates. In these habitats enchytraeis were perioically lacking. This was m ostly the case o f newestablishe lawns (e.g., at Hoża an Grójecka Streets), frequently on rubble soil with poor structure. DESCRIPTION OF C OM M UNITIES A lthough thefe were ifferences in the om inance structure o f enchytraei com m unities from one urban habitat to another ( K a s p r z a k 1981a), they all showe som e specific features (Tab. 2). P a r k s. The number o f species was the highest in parks but it largely varie from one stuy area to another (from 3 to 12 species). A particularly high number o f species an high enchytraei ensities were recore in soils o f the Saxon Garen an the Łazienki Park. The ensity o f enchytra eis was also high in the park at the Cemetery o f Soviet Soliers an the Praski Park, but the number o f inentifie species was markely lower there. Buchholzia appeniculata reache relatively high ensities in the Łazienki Park, while it was infrequently note an sparce on all the other plots. Instea, it was om inant in soils o f the linenoakhornbeam forest an in a m eaow on the site o f an linenoakhornbeam forest in suburban areas ( K a s p r z a k 1981b). A m on g the m ost abunant representa tives o f the genus Friericia, particularly abunant an frequent in parks were F. bisetosa an F. galba. In the soil o f the park in Ursynów, the numbers o f enchytraei species an their ensity were low as compare with those in m ost parks o f Warsaw. G r e e n a r e a s o f h o u s i n g e s t a t e s. Both the number o f species an the total ensity o f enchytraeis in this habitat epene on the character o f builtup areas. Enchytraei com m unities o f green areas in loosely builtup areas were characterize by a higher number o f species an very high mean ensities, as compare with those occurring in green habitats o f closely builtup areas. The ensity o f enchytraeis was higher there than in all the other habitats uner stuy. Green habitats o f loosely builtup

76 K RZYSZTOF KASPRZAK areas were rather unevenly occupie by enchytraeis. A markely higher ensity o f these anim als was recore in the soil covere with shrubs. The ensities o f Friericia bisetosa, F. bulboies, Henlea ventriculosa, an H. perpusilla were particularly high. S t r e e t s i e g r e e n a r e a s. In the soil o f isolate streetsie green habitats, the species richness an ensity o f enchytraeis were the lowest o f all the stuy plots. In the plots ajacent to vast green areas, the ensity an species com position o f enchytraeis were largely iversifie. D om inant species varie from one plot to another. These were Achaeta eiseni (U jazowskie Avenue, M arszałkow ska Street), Friericia bisetosa (Żwirki i Wigury Avenue), Henlea ventriculosa (W oronicza Street), an F. galba (N iepoległości Avenue). THE EFFEC T O F URBAN PRESSURE The present ata show that am ong m any factors o f urban pressure aversely affecting urban fauna, the etrimental effect o f arteries o f traffic on enchytraei com m unities can be put in question. The observations m ae so far suggest that this effect is not irect an may be totally lacking. It has been foun that the ensity o f enchytraei in the soil o f green habitats ajacent to streets with m uch traffic can be even higher than in soils o f green habitats more istant from streets. In the soil o f streetsie green at M arszałkowska Street close to the Saxon Garen, locate between tw o lanes with much traffic, the ensity o f enchytraeis (24600 iniviuals x m " 2I was m ore than tw o times as high as in the soil within the Saxon Garen (10138 inivi u alsx m 2). But the number o f species w as higher in the park; enchytraeis contributing m ost to the total ensity inclue representatives o f the genus Friericia (74%) an a hyrophilous (am phibiotic) species, Henlea ventriculosa (15%). In the soil o f streetsie green, the highest contribution to the total enchytraei ensity was ue to Achaeta eiseni (88%), a species m ore resistant to soil overrying; representa tives o f the genus Henlea were lacking from this area. In other stuy areas locate at streets with much traffic (Żwirki i Wigury Avenue, U jazowskie Avenue), the ensity o f enchytraeis was markely lower. N o correlation w as foun between enchytraei ensity an the concentration o f heavy metals (lea) in soil. C ONCLUSIONS 1. In soil o f parks, housing estates, an streetssie green areas, enchy traei com m unities relatively rich in species but less ense than in agroeco systems were recore. The highest proportion in the total ensity was reache by representatives o f the genus Friericia, which showe the greatest aaptability to changing habitat conitions. Only the com m unity o f the

STRUCTURE OF ENCHYTRAEID COMMUNITIES 77 Łazienki Park was preominate by Buchholzia appeniculata, a species associate with humus o f the mor type, an characteristic o f the soil an litter o f linenoakhornbeam forests. The proportion o f this species, occurring mainly in the surface soil layer was low or null in the other parks an other habitats uner stuy. This was relate to low an variable soil moisture, an to estruction o f the surface soil layer, for example, as a result o f litter removing. 2. D om inance structure o f the com m unity iffere from one stuy area to another, an no correlation was foun between species richness an ensity. Such a correlation is com m on in natural habitats, but it oes not seem to be always clearly seen in anthropogenic habitats, where high ensities nee not be couple with species richness. 3. Both high ensities an high number o f enchytraei species are mainly characteristic o f permanent green areas, with a high content o f soil organic matter an litter, an m ost o f all with a high relative soil moisture (m ore than 15%). High enchytraei ensities in the soil o f loosely builtup areas inicate particularly suitable habitat conitions there. This is mainly ue to the fact that shrub cover prevents soil overrying, an soil surface is not so heavily estroye by trampling as in closely builtup areas. 4. The ensity o f respective species an the species com position of enchytraei com m unities vary largely over the year. This may result from the application o f various cultivation treatments on lawns an, in particular, from mechanical treatment o f soil an its temporal heavy overrying. This accounts for large eclines in enchytraei ensities. 5. Intense traffic is not an important factor reucing the istribution an ensity o f enchytraeis. Important factors inclue soil type an moisture, content o f organic matter in soil, age o f the green area also types an intensity o f cultivation treatments. Urzą Wojewózki Wyział Ochrony Śroowiska, Gospoarki Wonej i Geologii Al. Stalingrazka 16/18, 60967 Poznań REFERENCES D ó z s a F a r k a s, K. 1973. Saisonynamische Untersuchungen es Enchytraei es Besatzes im Boen eines ungarischen Quercetum petraeae cerris. Peobiologia. 13: 361 367. G ó r n y, M. 1974. Ocena skłau gatunkowego i zagęszczenia wazonkowców w glebach trawników Warszawy. Pol. Tow. Gleb., Warszawa (MS.). G ó r n y. M. 1975. Ocena skłau gatunkowego i zagęszczenia wazonkowców w glebie trawników Warszawy. Pol. Tow. Gleb., Warszawa (MS.). K a i r e s a l o, P. 1978. Ecology of Enchytraeis in meaow forest soil in southern Finlan. Ann. Zool. Fennici, 15: 210 220.

78 KRZYSZTOF KASPRZAK K asprzak, K. 1979. Metoyka utrwalania, przechowywania i preparowania skąposzczetów (Oligochaeta, Annelia). Pr. Kom. Biol. Gleby PTG, Warszawa, 3/15: 2751. K asprzak, K. 1979b. Wazonkowce {Oligochaeta, Enchvtraciàe) zespołu grąowego (Querceto Carpinetum meioeuropeum Tx. 1936) w Wielkopolskim Parku Naroowym. Fragm. Faun. (Warsaw), 20: 115 128. K asprzak, K. 1980. Oligochaeta Community Structure an Function in Agricultural Lanscapes, In: Aquatic Oligochaete Biology (e. by R. O. Brinkhurst, D. G. Cook). Plenum Publishing Corporation: 411 431. K asprzak. К. 1981a. Enchytraeis (Oligochaeta, Enchytraeiae) of Warsaw an Mazovia. In: Species composition an origin of the fauna of Warsaw. Part 1 (e. by W. Czechowski, В. Pisarski). Memorabilia Zool.. 34: 5967. K asprzak, К. 1981b. Wazonkowce (Enchytraeiae, Oligochaeta). In: Zoocenologiczne postawy kształtowania śroowiska przyroniczego osiela mieszkaniowego Białołęka Dworska w Warszawie. Część I. Skła gatunkowy i struktura fauny terenu projektowanego osiela mieszkaniowego. Fragm. Faun. (Warsaw), 26: 6576. K asprzak, K. 1982. Review of enchytraei (Oligochaeta, Enchytraeiae) community structure an function in agricultural ecosystems. Peobiologia, 23: 217232. K asprzak. К. (in print). Skąposzczety wone i glebowe, II. Rozina: Wazonkowce (Enchytraeiae). Klucze o Oznaczania Bezkręgowców Polski, Warszawa, 5. K asprzak K., Ryl, B. 1978. Wpływ gospoarki rolnej na występowanie skąposzczetów (Oligochaeta) w glebach pól uprawnych. Wia. Ekol., 24: 333366. K asprzak. K.. N iebała. W., S terzyńska, M. 1979. Stan i struktura zgrupowań fauny glebowej w ekosystemie miasta. In: Warunki rozwoju rzew i ich fauny w Warszawie. Ossolineum. Wrocław, pp. 6173. K ubicka, A., C huzicka, E., W ysocki. Cz. (1986). Structure of the fauna of Warsaw; effects of the urban pressure on animal communities. The stuy area. Memorabilia Zool., 41: 9., N ielsen, С. O., C hristen sen, B. 1959. The Enchytraeiae, critical revision an taxonomy of European species. Nat. Jutlanica, 89, 1 160. N urm inen, M. 1967. Faunistic notes on NorthEuropean Enchytraeis (Oligochaeta). Ann. Zool. Fennici, 4: 567587. O 'C onnor. F. B. 1955. Extraction of Enchytraei worms from a coniferous forest soil. Nature, 175: 815816. O C onnor, F. B. 1971. Wazonkowce. In: Biologia gleby (e. by A. Burges an F. Raw). PWRiL, Warszawa: 215257. STRUKTURA ZGRUPOWAŃ WAZONKOWCÓW (OLIGOCHAETA, ENCHYTRAEIDAE) W ZIELENI MIEJSKIEJ WARSZAWY STRESZCZENIE W glebach zieleńców parkowych, osielowych i przyjezniowych Warszawy stwierzono występowanie bogatej po wzglęem liczby gatunków fauny Enchytraeiae (22 gatunki), której śrenie zagęszczenie wynosi około 8000 osobników x m 2. Szczególnie wysokie zagęszczenie Enchytraeiae wystęuje w glebie zieleńców osielowych o zabuowie luźnej (śrenio około 11.000 osobnikôwx m2 (Tab. 1 i 2) Zarówno wysokie zagęszczenie, jak i największa liczba gatunków występują głównie na zieleńcach wieloletnich, charakteryzujących się użą zawartością w glebie substancji organicznej i ściółki, a przee wszystkim stosunkowo wysoką wilgotnością gleby (powyżej 15%). Największy uział w zagęszczeniu mają przestawiciele rozaju Friericia Mich., wykazujące spośró wszystkich Enchytraeiae największe zolności

STRUCTURE OF ENCHYTRAE1D COMMUNITIES 79 aaptacyjne o zmieniających się warunków śroowiskowych. Nie stwierzono występowania w żanym ze śroowisk zgrupowań gatunków o powtarzającej się strukturze ominacyjnej. Duże zmiany zagęszczenia w ciągu roku spowoowane są stosowaniem różnych zabiegów pielęgnacyjnych na trawnikach oraz silnym okresowym przesuszeniem. Wzmożony ruch uliczny nie jest ecyującym czynnikiem ograniczającym występowanie i zagęszczenie Enchytraeiae. Postawowe znaczenie ma głównie rozaj gleby, jej wilgotność, zawartość substancji organicznych, wiek zieleńca oraz rozaj i intensywność stosowanych zabiegów pielęgnacyjnych. СТРУКТУРА СООБЩЕСТВ ЭНХИТРЕИД (OLIGOCHAETA, ENCHYTRAEIDAE) ГОРОДСКИХ ЗЕЛЕННЫХ НАСАЖДЕНИЙ ВАРШАВЫ РЕЗЮМЕ В почве городских парков, зелени жилых районов и уличных насаждений Варшавы констатировали 22 вида Entchytraeiae. Плотность Enchytraeiae составляет в среднем около 8000 особей/м2. Особенно высокая плотность наблюдалась в почве зеленхы насаждений жилых районов в среди свободной застройки (в среднем около 11 ООО особей/м2). Наиболее высоким содержанием в сообществах характеризовались представители рода Friericia Mich. Значительные изменения плотности Enchytraeiae на протяжении года связаны с работами по уходу за газонами и сильным временным иссушением субстрата. Интенсивное уличное движение не является решающим фактором, ограничивающим встречаемость и плотность Enchytraeiae. Основную роль играет род почвы, ее влажность, содержание органических веществ, возраст насаждений и характер, а также интенисивность ухода за ними.