THE ANTHROPOGENIC REFUGE AREAS FOR BEE FLORA IN AGRICULTURAL LANDSCAPE

The investigations were carried out in 2002 2006 in two municipalities of Konopnica and Jastków close to the western part of Lublin, Poland. The aim of the study was to identify the con dition of bee flora and determine the floristic richness depending on the biotops in agricultural landscape. Flora of the anthropoge nic refuge areas consists of 214 species, among them 80% were flow taxons. Apophytes (162 species 78%) predominated on all types of biotops under consideration. Perennials predominated in flora of boundary strips and bush communities. Mainly annual (40%) and biennial (15%) species comprise the flora of fallows. A great number of bee taxons represent meadow, segetal or rude ral communities. Most of flow plants compose loose patches, but their successive blooming ensures a source of food for Apoidea from early spring till the end of summer. The flora of boundary strips, bush communities and fallows significantly increases the biodiversity in agricultural landscape. The treatments including sowing, mainly on fallows with nectariferous and polleniferous species, would enrich generally weak flows in highly agricultural landscape.


INTRODUCTION
The opinion about pollution of agricultural landscape is generally accepted (van O p s t a l , 2000).Rapid changes of agricultural technologies encouraged farmers to abandon traditional husbandry methods and mixed farming systems in favour of intensive enterprises with pesticides, herbicides, fungicides and other chemicals.New technologies influenced both segetal and ruderal flora.The advantages of synantropic taxons in agroecosystems are widely discussed.The benefits include soil enrichment with nutrients, positive alleopathic effects.A great number of weeds are known as bee plants and can be important from two main points

THE ANTHROPOGENIC REFUGE AREAS FOR BEE FLORA IN AGRICULTURAL LANDSCAPE
1 Bożena Denisow, 2 Małgorzata Wrzesień are characteristic to Arrhenatherion elatioris.The most valuable as a source of bee flora is Cirsietum rivularis with the predominance of Cirsium rivulare (70%) and Polygonum bistorta (30%).Small surface areas are occupied by phytocenoses from Scheuchzerio-Caricetea fuscae.The fragments of Ribo nigri-Alnetum are present mainly in the eastern part of the Jastków municipality.Some other natural woodland complexes of varied size occur as isolated areas in different parts of the studied area.Usually, the forests represent fragmented forms of Querco-Fagetea and are reduced in species.Rapid economic changes after the transformation in 1989 caused strong anthropogenic pressure and are partly responsible for an increase of fallows to approx.18% of arable lands.The cultivated area includes 7500 ha, the farming is still intensive and the mosaic structure of landscape characteristic for the eastern part of Poland is maintained (Figs. 2, 3).Most of the cultivated area is under cereals (63-68%) and about 18-22% is occupied by root crops (potato fields and sugar beet).An abundant nectar and pollen flow was observed only in May, during the blooming of both orchards and meadows.Entomophilous crops such as rape plantations and perennial papilionaceous were very rare.

Methods
Observations of the entire flora were made up separately on field margins, bush communities and fallows, every two-three weeks during vegetation to take seasonal blooming aspects and to assign the time and length of blooming.The list of nectariferous and polleniferous taxons was established on the basis of data from literature (Wa r a k o m s k a , 1995,1997; W r ó b l e w s k a , 2002) and according to own observations.The record provides taxonomic nomenclature by M i r e k et al. (2002) and the description of each taxon including its life span, geographic -historical status (Z a j ą c 1979;Zając et. al. 1998), sinecological group (M a t u s z k i e w i c z , 2001), and average time of blooming.The intensity of Apoidea foraging was estimated as averages on the basis of 30 min observations concerning each species, during sunny weather in the most intense foraging hours (10.00--14.00EET) in full blooming period.The following range for bee visits was applied: weak -0-1•m -2 ; medium 2-4• m -2 ; good >5•m -2 .

RESULTS
The data concerning the diversity and distribution of bee flora in different agricultural biotops are given in Tab. 1.
Presently, the flora of the anthropogenic refuge areas consists of 214 species belonging to 39 families of which the most abundant are Asteraceae, Fabaceae, Rosaceae, Caryophyllaceae, Brassicaceae and Lamiaceae (Fig. 5).The great majority of taxons occurred on fal-lows -153 species, among them 73% were identified as good bee plants.Then, 124 different vascular plants were present on boundary strips, including 103 nectariferous and polleniferous.In the flora of margins, a high grass participation (2%) was observed which is probably connected with a high level of fertilisation on adjacent fields.The least abundant and most floristically stable were bush communities with only 34 species recorded and recognised as flow species.
Apophytes (162 species -78%) predominated on all types of biotops under consideration (Fig. 5).Alien species occurred less frequently and were represented by archeophytes (36 species -17%), epecophytes (7 species -3,3%), and of short duration agriophytes (only 4 species -2%).The complete absence of efemerophytes indicates a very low coefficient of synantropisation in the analyzed biotops.Interestingly, a considerable increase of development in the last 15 years and the transformation of arable lands into fallows did not cause the inflow of alien species.
Perennials predominated among species recorded on different refuge areas in the studied agricultural landscape (Fig. 6).Annuals were most frequently recorded among species registered on fallows (approx.40%) and biennials compose 15% of its flora.The spontaneously growing bush communities include only 15% of annual species.The changes in abundance of species during the successive five years of study on most of the studied biotops were insignificant.Only on fallows, the number of segetal flora decreases.Coincidentally, an increase of ruderal species and the occurrence of a bigger number of perennials were recorded.Unfortunately, the changes in the structure of fallow flora were associated with a decline in the number of flow species.
The spontaneously growing bushes most frequently develop on the edges of arable fields, the sunny slopes of loess ravines and were frequently covered by patches, different in size, predominated by Prunus fruticosa which is very important in the early spring aspect.Other shrubs often present and intensely foraged were Rosa canina, R.   Taking into consideration the sinecological group, a considerable participation of species from Stelarietea--medie and Molinio-Arrhenatheretea classes on fallows was proved (Fig. 7).On boundary strips, a decrease of segetal species from Stelarietea-medie was recorded.The share of meadow and ruderal taxons on both fallows and boundary strips was comparable.Whereas in the flora of bushes ruderal (Artemisietea vulgaris class) and thermophilous species (Rhamno-Prunetea class) predominated.
Season-long succession of bloom was observed on boundary strips and fallows.The species in bush communities bloom mainly in early spring and provide the first and rather abundant nectar and pollen flow.Our observations have shown that the blooming plants on boundary strips and fallows create favourable conditions both for feeding and nesting for different Apoidea.Apart from Apis mellifera, bumblebees and solitary bees (mainly representatives of Andrena) were present.Generally, the density of Apoidea changed during the vegetation season and correlated with the blooming spectrum on the observed biotops.The largest density in bush communities occurred in April, whereas on field margins and fallows in summer.
The presently recorded flora of anthropogenic biotops is composed of some rare species: Centaurium erythraea, Dianthus cartusianorum, Helichrysum arenarium, Lavanthera turingiaca, Ononis arvensis, Potentilla alba, Trifolium alpestre, or Viburnum opulus.That is the confirmation of great importance of such habitats as essential areas retaining floristic biodiversity.

CONCLUSIONS
1.The flora of anthropogenic refuge areas in the studied landscape comprises 214 species of which 80% were classified as nectariferous or polleniferous.Fallows and boundary strips were the most abundant in species.The majority of taxons are apophytes which predominate over antropophytes.The complete absence of efemerophytes was associated with the character of the area.
2. The great majority of flow taxons are meadow, segetal or ruderal plants.Most of nectariferous or polleniferous taxons create loose patches, a small number forms dense areas, but the time and period of their blooming ensure a continuous, unbroken feeding band for Apoidea from early spring till late summer.
3. Boundary strips, fallows and bush communities form in agricultural landscape refuge areas for bee plants as well as for valuable, rare elements of flora, hence they positively influence the biodiversity.
4. The dynamic succession observed on fallows caused a decrease in bee flora in the successive years of study.The treatments including sowing fallows with nectariferous and polleniferous species would enrich generally weak flows in highly agricultural landscape.

Table 1
Alphabetical list and characterization of species (averages from 2002 2006).