DE VEL OP MENT OF THE KUB£OWO PALAEOLAKE, CEN TRAL
PO LAND, DUR ING THE EEMIAN INTER GLA CIAL AS AGAINST
SUBFOSSIL CLADOCERA ANAL Y SIS – PRE LIM I NARY RE SULTS
Monika Niska1, Ma³gorzata Roman2
1 In sti tute of Ge og ra phy and Re gional Stud ies, Pom er a nian Uni ver sity in S³upsk, Partyzantów 27, 76-200 S³upsk, Po land, e-mail: monikaniska@wp.pl
2
De part ment of Geo mor phol ogy and Palaeo ge ogra phy, Fac ulty of Geo graph ical Sci ences, Uni ver sity of £ódŸ, Narutowicza 88, 90-139 £ódŸ, Po land , e-mail: mroman@geo.uni.lodz.pl
Ab stract
The re sults of anal y sis of Cladocera oc cur rence in lac us trine sed i ments from the Kub³owo site have been pre sented. Lac us trine and peat de pos its found there have been pre vi ously an a lyzed for pol len con tent (depth of 11.1–3.8 m) and rep re sent a lon gest con tin u ous Eemian–Vistulian suc ces sion in cen tral Po land (Ro man and Balwierz, 2010). Cladocera anal y sis was car ried out on 25 sam ples from the depth of 9.20–10.5 m of an Eemian age sec tion. The sec tion con -sists of fine or ganic sand, silt with or ganic mat ter and gyttja. Iden ti fied were 19 spe cies of subfossil Cladocera and five zones of fauna de vel op ment were dis tin guished. In the early and mid-Eemian low fre quency zoo plank ton in the palaeolake has been found. Best con di tions for zoo plank ton de vel op ment oc curred in the late Eemian (R PAZ E6, E7). At the end of the Eemian a sig nif i cant change of cli mate in a de te ri o ra tion of en vi ron men tal con di tions and de creased pres ence of zoo plank ton has been noted. Cladocera re sults and the pol len data en able a re con struc tion of the cli ma tic and en vi ron men tal changes in the Kub³owo palaeolake.
Key words: Cladocera anal y sis, Eemian Inter gla cial, palaeoenvironment, cen tral Po land.
Mansuscript re ceived 15 September 2013, ac cepted 23 May 2014
IN TRO DUC TION
Nu mer ous lo cal i ties with lac us trine de pos its of Eemian Inter gla cial age have been found in cen tral Po land, par tic u -larly in the P³ock Lobe area and its sur round ings (Fig. 1). The area, was a wide lakeland dur ing the Eemian. Lake sed i ments of that age have well been doc u mented in palynology. At some sites (Ruszkówek, Kaliska and Studzieniec) a suc ces -sion of Cladocera has also been re corded (Miros³aw-Gra-bowska and Niska, 2007a; Miros³aw-Gra(Miros³aw-Gra-bowska and Niska, 2007b; Miros³aw-Grabowska et al., 2009; Niska, 2008).
Gen er ally, Cladocera an or gan isms group dom i nant within zoo plank ton and their subfossil re mains are well pre -served in sed i ments (cf. Szeroczyñska, 2002). Small size of Cladocera, their ap ti tude to pro duce ephippia which may be trans ported by birds to col o nize new wa ter bod ies, and abil ity to re pro duce by par the no gen e sis, caused Cladocera much more ex pan sive and mo bile than larger aquatic fauna. Thus, their re sponse to cli ma tic and en vi ron men tal changes may be faster and more rad i cal than in the case of larger or gan isms.
Subfossil Cladocera have been stud ied for al most 90 years. In Po land, first stud ies were con ducted in the 1980s and 1990s (Czeczuga et al. 1970, Mikulski, 1976, Szero-czyñska, 1984, 1985, 1991, 1998; Biñka et al. 1991). The high use ful ness of Cladocera in re con struc tion of en vi ron men tal con di tions has led to a con sid er able in ter est in its po
-ten tial ap pli ca bil ity in stud ies of older sed i ments pre ced ing the last gla ci ation. Frey (1962) ini ti ated in ves ti ga tions of Cladocera from Eemian de pos its. Since 2001 sim i lar stud ies have been taken up in Po land by Niska (Kupryjanowicz, 2005; Miros³aw-Grabowska and Niska, 2005; Niska, 2002, 2003). Cladocera subfossils de pos ited dur ing the Eemian Inter gla cial, com pared to those from the Ho lo cene sed i -ments, are thin ner, have a more dam aged struc ture and of ten lack char ac ter is tic fea tures en abling spe cies de ter mi na tion. subfossil Cladocera re mains ex am ined in the Eemian sed i -ments did not ex hibit sub stan tial dif fer ences in ap pear ance and size com pared to the pres ent-day re mains. De spite the sub stan tial de struc tion of the Cladocera re mains, the ob tained re sults are fully cred i ble and may be used in the re con -struc tion of en vi ron men tal con di tions from the pe riod prece-ding the last gla ci ation
The aim of the ar ti cle is to pres ent re sults of Cladocera anal y sis and zoo plank ton suc ces sion, em pha siz ing the palaeolake en vi ron men tal changes dur ing the Eemian Inter gla -cial at Kub³owo.
STUDY SITE
The Kub³owo site is lo cated in the north ern part of the K³odawa Pla teau within the area of the Warta Stadial, the fi nal stadial of the Odranian (Late Saalian) Gla ci ation (for
-merly Wartanian Gla ci ation) (Lindner, 2005; Ber et al., 2007) and slightly to the south of the max i mum limit of the Vistulian (Weichselian) Gla ci ation ice sheet (Fig. 1). The K³odawa Pla teau is a mo not o nous morainic plain at 120–130 m a.s.l., mainly com posed of till. There are no postglacial lakes, how ever, in fos sil de pres sions at Kub³owo can be found biogenic de pos its which ac cu mu lated through out the Eemian Inter gla cial and the older part of the Vistulian, and were sub se quently cov ered by glaciofluvial sed i ments dur -ing the last ice sheet ad vance (Ro man and Balwierz, 2010). The or ganic de pos its at Kub³owo have been found to be as so -ci ated with mar ginal forms of the max i mum ex tend of the Vistulian Gla ci ation ice sheet in the P³ock ice lobe (Ro man 2007, 2010). Lac us trine and peat de pos its found there have been an a lyzed for their pol len con tent (depth of 11,1 – 3,8 m) and rep re sent a lon gest con tin u ous Eemian–Vistulian suc -ces sion in cen tral Po land (Ro man and Balwierz, 2010). The pres ently examinated de pos its from 10.50 to 9.20 m do not con tain car bon ates and their li thol ogy is shown be low: Depth (m)
9.20–9.40 lam i nated silt and silty clay, gray to brown -ish-gray,–HCl
9.40–10.10 gyttja, highly com pressed, dark gray, –HCl 10.10–10.35 silt with or ganic mat ter, dark gray, –HCl 10.35–10.50 very fine or ganic sand, light gray, –HCl
METH ODS
The Cladocera anal y sis was car ried out on 25 sam ples from the depth of 9.20 to 10.50 m. The sam ples of 1cm3 were pre pared ac cord ing to the stan dard pro ce dure (Frey, 1986), slightly mod i fied. Af ter re moval of car bon ates us ing 10% HCl, each sam ple was heated to 80°C in 10% KOH for 20 min utes. Af ter wash ing with dis tilled wa ter, the res i due was sieved through a 40µm mesh. The fine ma te rial was trans ferred into a polycarbone testtube. Be fore count ing, the re -mains were col oured with safranine. A min i mum num ber of 200 re mains of Cladocera (3–5 slides) were ex am ined in each sam ple. All the re mains from each slide were counted (head-shield, shell, postabdomen, postabdominal claws, an ten nules and other), and next, the cladoceran spec i mens were as sem -bled. Iden ti fi ca tion and eco log i cal in ter pre ta tion of the Cla-docera re mains were car ried out ac cord ing to Duigan (1992), Frey (1958, 1962), Goulden (1964), Hofmann (1986, 2000), Korhola (1990), Flössner (2000) Szeroczyñska (1985), and Szeroczyñska and Sarmaja-Korjonen (2007). Re sults of the quan ti ta tive and qual i ta tive anal y sis are shown in the con cen tra tion di a gram, and the to tal num ber of Cladocera spec i -mens in 1cm3 of de pos its and the spe cies di ver sity was as sessed ac cord ing to the Shan nonWiener Biodiversity In -dex to see on Fig ure 2, 3 (PolPal com puter pro gram, Walanus and Nalepka, 1999) .
32
M. NISKA & M. RO MAN. 2 . gi F .e li f or p o w o³ b u K f o st ne m i de s e ht ni sl a u di vi d ni ar ec o da l C f o re b m u n et u l o s ba e ht f o ma r g a i D
RE SULTS
Subfossil cladoceran fauna from the Kub³owo palaeo-lake is rep re sented by 19 spe cies be long ing to four fam i lies: Bosminidae, Chydoridae, Sididae, Daphnidae. Most of the re mains are of the Chydoridae and Bosminidae fam i lies. Dom i nant were two spe cies of Chydoridae – Alona affinis and Camptocercus rectirostris be long ing to a group in hab it -ing the lit to ral zone in clear and calm wa ter, de pend -ing on the pres ence of aquatic plants (Flössner, 1972). Con sid er ing the age of the re mains from over 100 ka BP (128,000–118,000 years BP, Shackle ton, Opdyke 1976), they are well pre served and came in large num bers. The quan ti ta tive and qual i ta tive com po si tion of fauna has en abled to dis tin guish five phases of the Cladocera de vel op ment (Fig. 2).
Phase I (10.50 m – 10.42 m): at that phase only one spe
-cies has been iden ti fied, namely, Eurycercus lamellatus which was tol er ant to low wa ter tem per a tures (Poulsen, 1944) and inhabs the lit to ral zone in clear wa ters. E.
lamella-tus sug gests the ex is tence of macrophytes (Flössner, 1972).
Phase II (10.42 m – 10.17 m): at that phase oc curred spe
cies pre fer ring wa ter with low con tent of nu tri ents and tol er -ant of cold wa ter, such as Acroperus harpae, Eurycercus
lamellatus, Sida crystalina, Alona affinis, (White side, 1970)
and eurybiont – Chydorus sphaericus (Alhonen, 1970). Through out this phase the pres ence of eight spe cies of Cla-docera was noted (above 400 spec i mens/1 cm3 in the sed i -ments, Fig. 3). Within the du ra tion of this phase oc curred
Monospilus dispar, a spe cies con nected with sand in the bot
tom. The oc cur rence of the Camptocercus rectirostris sug -gested a lit tle warmer wa ter con di tions (Poulsen, 1944). At that phase there are spe cies char ac ter is tic for a lit to ral zone and the ab sence of spe cies from the open wa ter was noted.
Phase III (10.17 m – 9.80 m): at that phase spe cies tol er
ant to cooler wa ter (Eurycercus lamellatus) give way to spe -cies pre fer ring wa ter of higher tem per a ture. In the lake found were Camptocercus rectirostris – pre fer ring warmer, clean and calm wa ter, dwell ing in the macrophyte zone, and
Pleu-roxus uncinatus and PleuPleu-roxus trigonellus – pre fer ring wa ter
that is warmer and richer in nu tri ents (Frey, 1958). This may in di cate a rise in wa ter tem per a ture and an in crease in nu tri -ents in the lake. Im prove ment of liv ing con di tions in the lake caused a greater biodiversity, 14 spe cies oc curred (above 1500 spec i mens/1cm3 of sed i ments, Fig. 3).
Phase IV (9.80 m – 9.30 m): the be gin ning of phase IV
was ex pressed by an in crease of both di ver sity of taxa (18 spe cies) and fre quency of Cladocera re mains up to 8000 spec i mens/cm3 of a de posit. It in di cates an im prove ment of the en vi ron men tal con di tions (warmer wa ter, more nu tri ents) in the lake. The con vic tion of the warm con di tions in this palaeolake is sup ported by the pres ence of Camptocercus
rectirostris, Pleuroxus trigonellus, Pleuroxus uncinatus and Graptoleberis testudinaria. Higher at ten dance of the Leydi-gia acanthocercoides, Alona rectangula, Pleuroxus uncina-tus spe cies sug gests a higher con tent of nu tri ents in the wa ter
(Korhola, 1990). The ap pear ance of Graptoleberis
testudi-naria may in di cate nu tri ent-rich wa ter (Duigan, 1992). In the
mid dle of that phase there was an in creased pres ence of spe -cies pre fer ring open wa ter: Bosmina coregoni, Bosmina
longirostris and Daph nia pulex-group. This may sug gest a
rise of the wa ter level in the lake. In the mid dle of that phase (9.50 m) Alonella excisa have been re ported, spe cies that can be re lated to the de crease of pH of the wa ter in the lake (KrauseDellin and Steinberg, 1986). That phase ends the pe -riod of fa vor able con di tions for the de vel op ment of Clado-cera. Dur ing that phase, two short pe ri ods of lower Cladocera fre quency were re corded (9,65 m and 9.40 m). This could be due to the fluc tu a tions in ther mal con di tions in the res er voir and the oc cur rence of short cold cli mate pe ri ods.
Phase V (9.30 m – 9.20 m): at the be gin ning of that phase
12 spe cies of Cladocera were iden ti fied in sed i ments. The sig nif i cant de crease in the pres ence of Cladocera in di vid u als of all spe cies (max 3000 in di vid u als/1cm3) along with low er -ing num ber of spe cies was ob served. In the palaeolake
Acroperus harpae spe cies re ap peared. In that phase pre
-sented were spe cies with di verse con di tion pref er ences but a de crease in con cen tra tion of re mains in the sed i ment may in -di cate de te ri o rat ing liv ing con -di tions in the lake prob a bly con nected with wa ter low er ing and cli mate cool ing.
DE VEL OP MENT OF THE KUB£OWO PALAEOLAKE
The stra tig ra phy of the sed i ments of the Kub³owo pa-laeolake was de ter mined on the ba sis of the dis tin guished pol len zones. Ac cord ing to the pol len data, the lac us trine de -pos its from 11.00m to 9.20m were ac cu mu lated dur ing the Eemian Inter gla cial (Ro man and Balwierz, 2010).
Early Eemian, Pol len zone K1 – Pinus-Ar te mi
sia-Juni-perus; K2 – Pinus–Betula-Quercus
Sed i men ta tion of or ganic de pos its at Kub³owo com -menced when in the neigh bor hood were open pine for ests with a dis tinct birch share (L PAZ K1), while scarce open ter rains were grassy (Ro man and Balwierz, 2010). The ame lio -ra tion of the cli mate led to a vis i ble re duc tion in heliothytes, re placed by dense birch-pine for ests (L PAZ K2) (Ro man and Balwierz, 2010). At the begining of the pe riod cor re lated with L PAZ K2 in the lake ap peared cladocerans rep re sented by a sin gle spe cies tol er at ing cold wa ter (Cladocera Phase I). The wa ter level was prob a bly low. At the bot tom of the lake sand was de pos ited. The con di tions in the lake were not fa -vor able for the de vel op ment of zoo plank ton.
Eemian op ti mum, Pol len zone K3 – Quercus, K4 –
Corylus-Tilia-Almus, K5 – Carpinus-Alnus-Corylus-Tilia
The inter gla cial cli ma tic op ti mum be gan with oak for -ests and some elm and ash (L PAZ K3). At that time in the lake dom i nated spe cies pre fer ring wa ter with a low con tent of nu tri ents and tol er ant to cold wa ter. In the zone the Cladocera spe cies pre fer ring warmer wa ter ap peared for the first time, which sug gested slightly warmer wa ter con di tions (Cladocera phases II). At that zone pre dom i nated spe cies from the lit to ral zone. The pro gress ing warm ing re sulted in changes in the dom i nant tree stands. The dom i nant spe cies – oak, elm and ash trees were re placed by multispe cies de cid -u o-us for ests with ha zel and lin den trees, as well as al ders (L PAZ K4), pre vail ing in wet hab i tats. With time, horn beams be gan to spread and at the end of L PAZ K5 they be came
dom i nant (Ro man and Balwierz, 2010). In the lake from L PAZ E4 (Cladocera Phase III) there was an in creased fre quency of spe cies pre fer ring warmer wa ter richer in nu tri -ents. Im prove ment of liv ing con di tions in the lake caused a greater di ver sity of spe cies. From the be gin ning of the K5 zone the wa ter level in the res er voir be came slightly higher.
Eemian post-op ti mum, Pol len zone K6 –
Picea-Abies-Carpinus, K7 – Pinus-Picea
The de cline of the cli ma tic op ti mum was marked by the pre-em i nence of horn beam for est. The grad ual cool ing of the cli mate led to a re ces sion of thermophilous trees and the ap pear ance of spruce, fir and yew (L PAZ K6). De spite the pro -gress ing cool ing, the fauna in hab it ing the lake reached its max i mum de vel op ment. The cli ma tic con di tions oc cur ring in the L PAZ K6 and at the be gin ning of the K7 zone were op -ti mal for the de vel op ment of zoo plank ton, which re sulted in the in crease of the Cladocera spe cies and re spec tive in di vid -u als, in cl-ud ing thermophilic spe cies (Cladocera phase IV). A larger num ber of spe cies pre fer ring more fer tile wa ter as well as a pres ence of or ganic mat ter were noted. At the be gin ning of L PAZ K7 the in creased num ber of spe cies pre fer ring open wa ter sug gests ris ing of the wa ter level in the lake. Then,
Alonella ex cise was re ported. This may in di cate the de crease
of pH. The sed i ments changed into silt. At the end of L PAZ K7 there was a dec re ment in both the num ber of the Cladocera spe cies and the num ber of spec i mens of par tic u lar spe
-cies (Cladocera phase V). At that time the spread of pine trees with some spruce and ini tially also fir (L PAZ K7) marked the de cline of the Eemian Inter gla cial (Ro man and Balwierz, 2010). In the lake the most un fa vor able con di tions for the de vel op ment of zoo plank ton oc curred prob a bly due to the pro -gress ing cool ing of the cli mate.
Dur ing the late Eemian Inter gla cial there were re corded short pe ri ods of lower fre quency of Cladocera (9.65m, 9.40m – Cladocera phase IV), which could have been due to fluc tu a -tions in the ther mal con di -tions in the lake and the oc cur rence of short cool ing pe ri ods.
DIS CUS SION
The re con struc tion of the Cladocera suc ces sion dur ing the Eemian Inter gla cial at Kub³owo is com pa ra ble with the re cords from the ad ja cent Eemian sites: Ruszkówek (Jan-czyk-Kopikowa, 1997; Miros³aw-Grabowska and Niska, 2007b) and Kaliska (Janczyk-Kopikowa, 1965, Miros³awGrabowska and Niska, 2007b). These palaeolakes are lo -cated no fur ther than 40 km from each other. The clos est to Kub³owo is the Kaliska palaeolake. The Cladocera suc ces -sion in the Kaliska palaeolake be gan with the outstart of the ha zel zone (R PAZ E4). How ever, in the Ruszkówek palaeo-lake an in di vid ual Cladocera spe cies ap peared at the turn of R PAZ E2/E3 like in the Kub³owo palaeolake. The Cladocera spe cies oc cur ring dur ing the early Eemian Inter gla cial be -long to the so-called arc tic spe cies (Alona affinis, Acroperus
harpae), tol er ant of cold wa ter with a low con tent of or ganic
mat ter (Eurycercus lamellatus).
Dur ing the pe riod cor re lat ing with R PAZ E4 (Corylus) in the palaeolakes of Ruszkówek and Kub³owo fauna de vel -op ment and in creased amount of therm-ophilic spe cies were re corded. How ever, at the end of the ha zel zone (E4) and in the horn beam zone (E5) at two sites – Kaliska and Ruszkówek an ab sence of fau nal re mains was ob served. The ex -pla na tion of that phe nom e non is dif fi cult. One rea son could have been the high con tent of CaCO3 in those sed i ments. The
car bon ate might have ac cel er ated the de cay of chitin shells, which have not pre served till now. The sec ond rea son could have been a short age in nu tri ents and/or un fa vour able con di -tions in the res er voir con nected with a higher wa ter level (Miros³awGrabowska and Niska, 2007b). There is no sig -nif i cant drop in Cladocera fauna fre quency in the pro file of Kub³owo prob a bly due to lack of cal cium car bon ate in the sed i ments. This re sulted in a con tin u ous suc ces sion of Cladocera in the mid dle of the Eemian. In the palaeolakes the be gin ning of the late Eemian was as so ci ated with the de vel op -ment of the Cladocera fauna. Es pe cially clearly marked was the increase in the frequency of fauna in the profiles of Kaliska and Kub³owo.
In the palaeolakes spe cies from the lit to ral zone dom i -nated. Bosmina longirostris was a com mon mi grant spe cies which, with in creas ing tro phy, could move be tween open wa ter and the lit to ral zone (Frey, 1986). Only from Kub³owo the pres ence of the Bosmina coregoni, the spe cies con nected with open wa ter zone was repoted, which may in di cate greater depth in the Kub³owo palaeolake than in the others lakes.
The end of the Eemian Inter gla cial is con nected with a strong drop in fre quency of Cladocera in the stud ied palaeo-lakes. The grad ual cool ing re sulted in an in hi bi tion of life in all the lakes.
In the neigh bor ing palaeolakes, there was a sim i lar de vel op ment of the Cladocera suc ces sion re sult ing from re -gional cli mate changes tak ing place in the Eemian Intergla cial. The dif fer ences in the de vel op ment of the fauna be tween lakes are the re sult of dif fer ences in the lo cal con di -tions un der which lakes ex isted and of their or i gin, cha-racteristics and the location of the lake basin.
The stud ies of the Kub³owo palaeolake will be con tin ued for the pur pose of trac ing the Cladocera suc ces sion and lake de vel op ment through out the Vistulian. The re search will also be sup ple mented by de ter mi na tion of sta ble iso topes in the sediments.
CON CLU SION
1. In the Kub³owo palaeolake most dom i nant and most di verse group of spe cies was the lit to ral group – the Chydo-ridae fam ily.
2. The de vel op ment of zoo plank ton in the res er voir be -gan as in other res er voirs in the re gion be fore the L PAZ K3 (R PAZ E3).
3. The en vi ron men tal con di tions in the palaeolake dur -ing the early Eemian Inter gla cial have not pro vided fa vor able con di tions for the de vel op ment of zoo plank ton, which could be as so ci ated with a low con tent of nu tri ents in the water.
4. In crease wa ter fer til ity oc curred in the mid dle of Eemian Inter gla cial (Cladocera Phase III).
5. Based on the in crease in the num ber of Cladocera found that the most fa vor able en vi ron men tal con di tions for the fauna de vel op ment pres ent in the end of the mid dle Eemian Inter gla cial and the be gin ning of the late Eemian Interglacjal.
6. The high est fre quency of the Cladocera re mains in the sed i ments oc curred at the end of the Eemian Inter gla cial (K6 and K7 L PAZ) sim i larly to other sites, the Kaliska and the Ruszkówek.
7. The Cladocera spe cies found in the ex am ined palaeo-lake cor re spond to the pres ent-day spe cies in hab it ing the area of Po land and Europe.
8. Cladocera subfossils de pos ited dur ing the Eemian Inter gla cial, com pared to those from the Ho lo cene sed i -ments, were thin ner, had a more dam aged struc ture and they of ten lacked char ac ter is tic fea tures en abling spe cies de ter-mination.
9. Cladocera phases show a good cor re la tion with the lo cal pol len as sem blages zones dis tin guished by Balwierz (Ro -man and Balwierz, 2010).
The re search pro ject was sup ported by the Foun da tion for Pol ish Sci ence, Bridge Pro gram 2012 – pro ject: “Re con -struc tion of the de vel op ment of lake en vi ron men tal in the Eemian inter gla cial based on subfossil Cladocera (Crusta-cea) analysis”.
REF ER ENCES
Alhonen, P., 1970. The paleolimnology of four lakes in southwest -ern Fin land. Ann. Acad. Sci. Fenn. A. III, 105: 1–39. Biñka, K., Cieœla A., £¹cka, B., Madeyska, T., Marciniak, B.,
Szeroczyñska, K., Wiêckowski, K., 1991. The de vel op ment of B³êdowo Lake (Cen tral Po land) Stud. Geol. Polon, 100: 1–86. Ber, A., Lindner L., Marks, L., 2007. Propozycja podzia³u
straty-graficznego czwartorzêdu Polski. Prz. Geol., 55(2): 115–119. Bruj, M., Ro man M., 2007. The Eemian Lakeland ex tent in Po land
ver sus strati graphi cal po si tion of the Mid dle Pol ish Glacia-tions (in Pol ish with Eng lish sum mary). Biul. Pañstw. Inst. Geol., 425: 27–34.
Cheddadi, R., Mamakowa, K., Guiot, J., de Beaulieu J. L., Reille, M., Andrieu, V., Granoszewski, W., Peyron, O., 1998. Was the cli mate of the Eemian sta ble? A quantitive cli mate re con struc -tion from seven Eu ro pean pol len re cords. Paleogeogr., Paleo-climat., Paleoecol., 143: 73–85.
Czeczuga, B., Go³êbiewski, Z., Kossacka, W., 1970. The his tory of Lake Wi¿ajny in the ligth of chem i cal in ves ti ga tions of the sed -i ments and Cladocera fos sils. Schweiz. Z. Hydrobiol. 25: 75–86.
Duigan, C.A., 1992. The ecol ogy and dis tri bu tion of the litoral fresh wa ter Chydoridae (Branchiopoda, Anomopoda) of Ire -land with tax o nomic com ments on some spe cies. Hydrobio-logia 241: 1–70.
Flössner, D., 1972. Branchipoda, Branchiura. Tierwelt Deutschl., 60: 1 – 501.
Flössner, D., 2000. Die Haplopoda und Cladocera (ohne Bosmi-nidae) Mitteleuropas. Backhuys Pub lish ers, Leiden: 1–428. Frey, D.G., 1958. The Late Gla cial cladoceran fauna of a small lake.
Ar chives of Hydrobiology 54: 209–275.
Frey, D.G., 1962. Cladocera from the Eemian Inter gla cial of Den -mark. Jour nal of Pa le on tol ogy 36: 1133–1154.
Frey, D.G., 1986. Cladocera anal y sis. In Berglund B. E. (ed.),
Hand book of Ho lo cene Palaeo ec ol ogy and Palaeohydrology. Wiley, Chichester, UK 667–692.
Goulden, C.E., 1964. The his tory of the cladoceran fauna of Esthwaite Wa ter (Eng land) and its lim no logi cal sig nif i cance. Ar -chives of Hydrobiology 60: 1–53.
Hofmann, W., 1986. De vel op men tal his tory of the Grosser Plöner See and the Schöhsee (north Ger many): cladoceran anal y sis, with spe cial ref er ence to eutrophication. Ar chives of Hy dro-bi ology. Stuttgart. Suppl., 74, 259–287.
Hofmann, W., 2000. Re sponse of the chydorid fau nas to rapid cli -ma tic changes in four al pine lakes at dif fer ent al ti tudes. Pala-eogeography, Palaeoclimatology, Palaeo ec ol ogy 159(3–4): 281–292.
Janczyk-Kopikowa, A. Z., 1965. Eemian Inter gla cial flora at Kaliska near Chodecz in Kujawy (in Pol ish with Eng lish sum -mary). Biul. Inst. Geol., 187: 107–118.
Janczyk-Kopikowa, A. Z., 1997. Analiza py³kowa osadów intergla- cja³u eemskiego w Ruszkówku na Pojezierzu Kujawskim. Prz.Geol., 45(1): 101–104.
Korhola, A., 1990. Paleolimnology and hydroseral de vel op ment of the Katasuo Bog, South ern Finlad, with spe cial ref er ence to the Cladocera. Ann. Acad. Sci. Fenn., 155: 5–40.
KrauseDellin, D., Steinberg, C., 1986. Cladoceran re mains as in di -ca tors of lake acid i fi -ca tion. Hydrobiologia 143, 129–134. Kupryjanowicz, M., 2005. Roœlinnoœæ i klimat Podlasiaw czasie
interglacja³u eemskiego oraz wczesnego i œrodkowego vistu-lianu. Prace Komisji Paleogeografii Czwartorzêdu P AU, 3: 73–80.
Lindner, L., 2005. A new look at the num ber, age and ex tent of the Mid dle Pol ish Gla ci ation in the south ern part of cen tral–east -ern Po land (in Pol ish with Eng lish sum mary). Prz. Geol., 53(2): 145–150.
Mamakowa, K., 1986. Lower bound ary of the Vistulian and the Early Vistulian pol len stra tig ra phy in con tin u ous Eemian– Early Vistulian pol len se quence in Po land. Quatern. Stud., 7: 51–63.
Mikulski, J.S. 1976. Fur ther in ves ti ga tions upon Ho lo cene his tory of Lake Jeziorak. Part I. The Boy Moty. Acta Univ. Nicol. Copernici. Limnol. Pa pers 9: 65–73.
Miros³aw-Grabowska, J., Niska M., 2005. Iso to pic and Cladocera re cords of cli mate changes of Early Eemian at Besiekierz (Cen tral Po land). Geo log i cal Quar terly 49: 67–74.
Miros³aw-Grabowska, J., Niska, M., 2007a. Iso tope and Cladocera data and in ter pre ta tion from the Eemian op ti mum and postoptimum de pos its, Kaliska palaeolake (Cen tral Po land). Qua ter -nary In ter na tional 175: 155–167.
Miros³awGrabowska, J., Niska, M., 2007b. Re con struc tion of en -vi ron men tal con di tions of Eemian palaeolake at Studzieniec (Cen tral Po land) on the ba sis of sta ble iso tope and Cladocera anal y ses. Qua ter nary In ter na tional 162–163: 195–204. Miros³awGrabowska, J., Niska M., Sienkiewicz, E., 2009. Evo lu
-tion of the palaeolake at Ruszkówek (cen tral Po land) dur ing the Eemian Inter gla cial based on iso to pic, cladoceran and di a -tom data. Jour nal of Paleolimnology 42: 467–481.
Niska, M., 2002. Pres er va tion of Chydoridae (Cladocera) re mains in the Ho lo cene and Eemian lake sed i ments. Book of Ab stracts VIth ISC Po land, Wierzba.
Niska, M., 2003. Cladocera w osadach interglacja³u eemskiego na przyk³adzie stanowiska Kuców C. W: Badania paleobota-niczne jako podstawa rekonstrukcji zmian klimatu w czwarto-rzêdzie Polski. I Polska Konferencja Paleobotaniki Czwar-torzêdu, 22-25 maja 2003, Materia³y konferencyjne, Bia³o-wie¿a: 31
Niska, M., 2008. Interpretacja zmian œrodowiska jeziornego w interglacjale eemskim na podstawie analizy kopalnych Clado-cera. Akademia Pomorska w S³upsku, s 128.
Poulsen, E., 1944. Entomostraca from a lategla cial lac us trine de -posit at Næstved, Den mark. Meddelelser fra Dansk Geologisk Forening 10, 405–416.
Ro man, M., 2007. Zasiêg i formy glacimarginalne lobu Wis³y w ob- szarze Pojezierza Kujawskiego i Kotliny P³ockiej. In: Plejs-tocen Kujaw i dynamika lobu Wis³y w czasie ostatniego zlodowacenia (eds. W. Wysota et al.): 23–31. XIV Konfe-rencja “Stratygrafia Plejstocenu Polski, Ciechocinek”. Pañstw. Inst. Geol.
Ro man, M., 2010. Rekonstrukcja lobu p³ockiego w czasie ostatniego zlodowacenia (Re con struc tion of the P³ock ice lobe dur -ing the last gla ci ation). Acta Geographica Lodziensia, 96: 1 – 171.
Ro man, M. Balwierz, Z., 2010. Eemian and Vistulian pol len se -quence at Kub³owo (Cen tral Po land): im pli ca tions for the limit of the Last Gla cial Max i mum. Geo log i cal Quar terly, 54, 1, 55–68.
Shackle ton, N.J., Opdyke N.D. 1976. Ox y gen-iso tope and paleomag netic stra tig ra phy of Pa cific core V., 28239. Late Plio -cene to Lat est Pleis to -cene. Geo log i cal So ci ety of Amer ica Mem oirs 145, 449–464.
Szeroczyñska, K., 1984. Analiza Cladocera w osadach niektórych jezior tatrzañskich (Re sults of ex am i na tion of Cladocera re -mains in lac us trine sed i ments of Dol ina Piêciu Stawów Pols-kich). Pr. i Stud. Geogr., 5: 93–102.
Szeroczyñska, K., 1985. Cladocera jako wskaŸnik ekologiczny w póŸnoczwartorzêdowych osadach jeziornych Polski Pó³nocnej (Cladocera as ecologic in di ca tor in late Qua ter nary lac us -trine sed i ments in North ern Po land). Acta Palaeontologica Polonica 30(1–2): 3–69.
Szeroczyñska, K., 1991. Im pact of pre his toric set tle ments on the Cladocera in the sed i ments of Lakes Suszek, B³êdowo and Skrzetuszewskie. Hydrobiologia, 225: 105–114.
Szeroczyñska, K., 1998. Palaeolimnological in ves ti ga tions in Po -land based on Cladocera (Crustacea). Palaeo ge ogra phy, Pala-eoclimatology, Palaeo ec ol ogy, 140: 335–345.
Szeroczyñska, K., 2002. Hu man im pact on lakes re corded in the re -mains of Cladocera (Crustacea). Qua ter nary In ter na tional 95– 96: 165–174.
Szeroczyñska, K., Sarmaja-Korjonen, K., 2007. At las of Subfossil Cladocera from Cen tral and North ern Eu rope. Towarzystwo Przyjació³ Dolnej Wis³y, Œwiecie: 1–84.
Walanus, A., Nalepka, D., 1999. POLPAL. Pro gram for count ing pol len grains, di a gram plot ting and nu mer i cal anal y sis. Pro -ceed ings 5th EPPC. Acta. Paleobot. Suppl., 2: 659–661. White side, M.C., 1970. Dan ish chydorid Cladocera: mod ern ecol
