PLANT COMMUNITIES AND ASSOCIATIONS OF ROOT CROPS OF THE KAŁUSZYŃSKA UPLAND

A phytosociological classifi cation and the characteristics of weed communities developing in root crops of the Kałuszyńska Upland are given in this paper. The presence of three associations: Digitarietum ischaemi, Echinochloo-Setarietum and Lamio-Veronicetum politae, as well as of two communities: Setaria pumila–Setaria viridis and Panico-Setarion alliance, has been found. The differentiation in trophic and soil moisture conditions of habitats results in the fl oristic diversity of communities, divided into lower phytosociological units. Two variants have been distinguished within the association Digitarietum ischaemi, whereas Echinochloo-Setarietum has been divided into 2 subassociations and 6 variants.


INTRODUCTION
Plant communities accompanying root crops are characterised by a specifi c botanical composition which is formed primarily from the time of the completion of culturing until the harvest of the crop plant (K a p e l u s z n y , 1979; W n u k , 1989).The composition and structure of these phytocenoses depend on many natural, agricultural practice and economic factors (D o m a ń s k a and W ó j c i k , 1974; R o l a et al. 1989).Species-poor communities, devoid of characteristic species and diffi cult to classify, develop more and more frequently (S z o t k o w s k i , 1981; W n u k , 1989; W ę g r z y n e k , 2005).
The current state and dynamics of root crop agrocenoses have been the subject of numerous fl oristic and phytosociological studies (W a r c h o l i ń s k a , 1988; K o r n i a k , 1992; S k r z y c z y ń s k a , 1994; K u ź n i e w s k i , 1996; Wójcik, 2000; S i c i ń s k i , 2003; W ę g r z y n e k , 2005).
This publication is a continuation of the characteristics of segetal vegetation of the Kałuszyńska

MATERIALS AND METHODS
This paper is devoted to phytocenoses accompanying root crops.Root crop communities are described based on 157 phytosociological relevés made using the Braun-Blanquet method (P a w ł o w s k i , 1972) at the end of August and in September in the years 1995-2000.The classifi cation system and nomenclature of distinguished root crop communities follow M at u s z k i e w i c z (2001), and species nomenclature follows M i r e k et al. (2002).

Systematics of distinguished root crop communities and associations
Class: Stellarietea mediae R.Tx., Lohm. et Prsg, 1950Order: Polygono-Chenopodietalia (R.Tx. et Lohm. 1950)  In potato crops on sandy soils belonging to the very weak and weak rye complex and the weak cereal-fodder complex, Digitarietum ischaemi patches developed.
This association is described by 43 phytocenoses, out of which 28 represent the typical variant and 15 are characterised by the variant with Bidens tripartita (Tab. 1,col. 2,3).Patches of the typical variant with Digitarietum ischaemi often occurred in the Kałuszyńska Upland area, whereas phytocenoses of the variant with Bidens tripartita rarely grew on potato plantations.In all the investigated patches, the dominant species was Digitaria ischaemum.Permanent components of this association, with large cover, comprised weeds specifi c to poor and acid habitats, such as: Rumex acetosella, Spergula arvensis, Scleranthus annuus, Anthemis arvensis and Raphanus raphanistrum.The structure of patches of the moist variant was distinguished by the presence of hygrophilous species, with Bidens tripartita, Juncus bufonius and Polygonum hydropiper occurring most abundantly among them.
Digitarietum ischaemi was fl oristically poor.In all the patches, a total of 75 species occurred (55 in the typical variant and 57 in the variant with Bidens tripartita).The average number of species in a relevé ranged between 14 in the typical variant patches and 19 in phytocenoses of the variant with Bidens tripartita.

The community Setaria pumila -Setaria viridis
This community developed on sandy soils classifi ed as the weak rye and good rye complex (Tab. 1, col. 4).Patches of the community in question are rarely met in the Upland.They are described based on 13 phytosociological relevés in which there was a total of 59 weed species, and the number of species in a relevé ranged between 19 and 28 (on the average, it was 23).Phytocenoses of the community concerned were characterised by a large share of differential species Setaria viridis and Setaria pumila.In addition to foxtails, aci-dophilous species Spergula arvensis, Raphanus raphanistrum, Rumex acetosella and Anthemis arvensis were noted in great numbers and with large cover.Locally, patches developed which were dominated by the mass occurrence of permanent species, such as Elymus repens, Cirsium arvense and Equisetum arvense, indicating neglect in agricultural practice.Furthermore, Chenopodium album, Stellaria media, Fallopia convolvulus, Polygonum aviculare, Viola arvensis, Centaurea cyanus and Galeopsis tetrahit were found frequently and with large cover.

A species-poor community from the alliance Panico-Setarion Siss. 1946
On sandy soils belonging to the weak, good rye complex as well as on sandy enclaves of the very good rye complex and the weak cereal-fodder complex, species-poor patches of this community developed, devoid of characteristic species of known root crop associations (Tab. 1 col.5).This community is described based on 23 phytosociological relevés.It was made up of 60 species; the number of species in a relevé ranged from 14 up to 29 (on the average, 20).
The characteristic feature of the community was the numerous occurrences of acidophilous species, characteristic and distinguishing for the alliance Panico -Setarion, such as: Rumex acetosella, Spergula arvensis and Raphanus raphanistrum, as well as the absence of species characteristic for associations of this alliance.Out of species characteristic for the order Polygono-Chenopodietalia, only Chenopodium album and Stellaria media occurred more frequently and in greater numbers.Common weeds characteristic for the class Stallarietea mediae, such as: Anthemis arvensis, Fallopia convolvulus, Polygonum aviculare and Viola arvensis, comprised a large group, and from companion species, Elymus repens and Equisetum arvense occurred in great numbers.
Patches of the community in question were also found in excessively moist habitats, locally with a large share of Equisetum sylvaticum, Polygonum hydropiper and Gnaphalium uliginosum.

Echinochloo-Setarietum Krusem. et Vlieg. (1939) 1940
Echinochloo-Setarietum was a commonly occurring association of root crops in the Kałuszyńska Upland.Patches of this association developed in different trophic and soil moisture conditions.These soils were most frequently formed from sands of different origin (rarely from clays) belonging to all soil complexes occurring in the Kałuszyńska Upland, except for the weak rye complex.The wide amplitude of occupied habitats was refl ected in the species composition and the structure of phytocenoses of the association.Out of the species characteristic for this association, Echinochloa crus-galli was noted in great numbers, Raphanus raphanistrum occurred frequently, but less numerously.In addition, species characteristic for the alliance Panico-Setarion and common fi eld weeds from higher syntaxonomic units made up a large group.The fl oristic diversity of phytocenoses of this association fi nds its refl ection in subassociations and variants.On sandy soils most frequently classifi ed as the weak rye, good rye and weak cereal-fodder complexes, patches of Echinochloo-Setarietum sperguletosum developed (Tab. 2,col. 2,3,4).Acidophilous species occurring in great numbers, such as: Spergula arvensis, Rumex acetosella, Anthemis arvensis, as well as frequently noted Scleranthus annuus, Setaria pumila and Setaria viridis were the species which distinguished this subassociation.In addition, Chenopodium album, Fallopia convolvulus and Viola arvensis occurred frequently and with large cover.Locally, patches dominated by Equisetum arvense developed.
The subassociation in question is described by 67 phytocenoses, out of which 21 represent the variant with Digitaria ischaemum, 10 the typical variant, and 36 patches are characterised by the variant with Juncus bufonius.
Echinochloo-Setarietum typicum phytocenoses were found on soils more cohesive than the previously mentioned subassociation, since they were formed from light and strong loamy sands and clays, most frequently classifi ed as the very good rye, good wheat and strong cereal-fodder complexes (Tab.2, col.5, 6, 7).They developed in potato and sugar beet crops.Out of species characteristic for this association, Echinochloa crus-galli occurred in great numbers, whereas the acidophilous species Raphanus raphanistrum and other species characteristic for Panico -Setarion were noted with small cover.Soil fertility and water availability in these habitats affected the fl oristic composition of the communities.The occurrence of species with higher trophic requirements was found in them, among others: Galinsoga parvifl ora, Matricaria maritima subsp.inodora, Stellaria media, Polygonum lapathifolium subsp.lapathifolium, Chenopodium album, Sonchus arvensis, Anagallis arvensis and Thlaspi arvense.Locally, in the vicinity of buildings, patches with a very large share of Galinsoga parvifl ora and Galinsoga ciliata occurred.
The subassociation in question is demonstrated by 72 plant patches, out of which 19 represent the typical variant, 33 the variant with Juncus bufonius, and 20 the variant with Fumaria offi cinalis.

Lamio -Veronicetum politae Kornaś 1950
Lamio -Veronicetum politae phytocenoses developed in potato and sugar beet crops, primarily on strong loamy sands and light clays belonging to the good wheat and very good rye complexes (Tab. 2,col. 8).The extent of the occurrence of this association was restricted to the most fertile soils which occur in small areas within the Upland.It is described by 19 plant patches from the Upland area.
Veronica polita and Veronica opaca are its characteristic species which show exclusive attachment to this association.Other characteristic species, Lamium amplexicaule and Veronica agrestis, though they occur frequently and may have large cover, do not belong to the most faithful of its components, as they are also found in other communities, but their optimal occurrence in the study area is in the association in question.
It is the fl oristically richest association of root crops within the study area.In its patches, as many as 102 species were found, on the average, 27 in one relevé.
The association in question is characterised by specifi c physiognomy that is determined by species occurring frequently and in great numbers which have high trophic requirements: Chenopodium polyspermum, Euphorbia helioscopia, Matricaria maritima subsp.inodora, Stellaria media, Chenopodium album, Anagallis arvensis and others.It its patches, a numerous groups of hygrophilous species was noted, with low constancy and cover.

DISCUSSION
The fl oristic richness of agrocenoses developing in root crops of the Kałuszyńska Upland was determined by trophic and moisture conditions of habitats as well as by diverse agricultural practices.Communities of species with a narrow range of tolerance are characterised by great sensitivity.Digitarietum ischaemi, which is marked by low persistence, can be included in such associations.The intensifi cation of chemical protection and increased fertilisation (D o m a ń s k a and W ó j c i k , 1974) as well as changes in land use methods (fallowing or afforestation) result in the impoverishment of the fl oristic composition and the limitation in the occurrence of this association (W ę g r z y n e k , 2005).
In the study area, on the poorest soils, in trophic terms, and on dry soils, potato crops were often colonised by the fl oristically poorest patches of Digitarietum ischaemi, but on small areas.Slightly richer phytocenoses with a share of hygrophilous species developed on light loamy sands.This Subatlantic association has better development conditions in western and northern Poland (K o r n a ś , 1950), as reported by B o r o w i e c and K u t y n a (1989).It is also often found in certain regions of the central (S i c i ń s k i Setaria pumila -Setaria viridis communities are met in similarly poor habitats (rarely in the study area).R z y m o w s k a (1999) reported from the Podlaski Przełom Bugu mesoregion phytocenoses with a fl oristic composition similar to that presented in this paper.
Patches devoid of characteristic species, classifi ed as species-poor communities from the alliance Panico-Setarion, were also rarely found in root crops of the study area.Such impoverished communities have been described by Szotkowski (1981) and Kuźniewski (1974)  The fl oristically richest patches of Lamio-Veronicetum politae were found very rarely in the study area.The reason for this is the small acreage of proper habitats.This association reaches the optimum of its development on alkaline pH soils, on loess, rendzina and black-earth soils.Judging from literature data, a conclusion can be drawn that this association occurs widely across the country.From other regions, its has been reported by: Kornaś ( 1972
et al. 1978; W a r c h o l i ń s k a , 1987,1998) and eastern (S k r z y c z y ń s k a , 1994; S k r a j n a and S k r z y c z y ń s k a , 2004) parts of the country.In many regions, Digitarietum ischaemi phytocenoses occur rarely and they signifi cantly reduce their extent of occurrence.It applies, inter alia, to Poland's southern regions (K u ź n i e w s k i , 1974; S z o t k o w s k i , 1989; Wnuk, 1989; A n i o ł -K w i a t k o w s k a , 1990; K o z a k , 2002; W ę g r z y n e k , 2005).
in Lower Silesia, by W n u k (1989) in the Częstochowa Upland (Wyżyna Częstochowska), by W n u k et al. (1989) in the Rzeszów area, and by W ę g r z y n e k (2005) in the Silesian Upland (Wyżyna Śląska).Likewise across the country (W n u k , 1976, 1989; K a p e l u s z n y , 1979; W ó j c i k , 1980; K ut y n a , 1988; A n i o ł -K w i a t k o w s k a , 1990; Skrzyczyńska, 1994; W a r c h o l i ń s k a , 1998; K o z a k , 2002; S i c i ń s k i 2003; W ę g r z y n e k , 2005), Echinochloo-Setarietum was the association commonly occurring in the Kałuszyńska Upland.This is a result of broad-scale ecological requirements of species characteristic for this association and nowadays of the wide occurrence of Echinochloa crus-galli biotypes resistant to the effect of herbicides (R o l a et al. 1989; J ę d r u s z c z a k and A n t o s z e k , 2002).
), K a p e l u s z n y (1979), W ó j c i k (1980), S z o t k o w s k i (1981), K u t y n a (1988), W n u k (1989), A n i o ł -K w i a tk o w s k a (1990), H o ł d y ń s k i (1991), T r ąb a and Z i e m i ń s k a (1994), W a r c h o l i ń s k a (1994), K o z a k (2002), S i c i ń s k i (2003).

. Ch. D. Echinochloo- Setarietum Panico-Setarion
Explanatory notes: numbers after species inform about numbers of columns in the table: S -phytosociological constancy, D -cover factor * -species constancy with little cover.cd.table2