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  • Author: Małgorzata Wrzesień x
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Open access

Małgorzata Wrzesień and Bożena Denisow

Abstract

Plant species diversity is threatened in many agricultural landscapes due to the changes it has to undergo. Although the modification of the agricultural landscape pattern is observed across Europe, both extensive and intensive agricultural landscapes still co-exist in Poland. The objective of the study was to examine the flora in field margins in intensively and extensively managed agricultural landscapes, located across three regions in SE Poland. The flora was compared with respect to species richness, diversity, and evenness indices. Detrended correspondence analysis was employed to characterise variation in species composition. Agricultural landscape type made a higher contribution than the topography or geology to species richness and composition in field margins. Field margins function as important habitats for general vascular plant species diversity and are useful for the conservation of rare, threatened, endangered or bee plants. A significant decline in species diversity was observed over a distance of 1000 m from the habitat elements. Plants growing on field margins are mainly perennials; however participation of annuals clearly increases in intensive landscapes. The participation of wind-dispersed species decreased in an open-spaced intensive landscape. Animal-dispersed plants predominated in an extensive landscape with forest islands. Irrespective of landscape type, native species predominated. However, these habitats create the biota and corridors for alien-invasive species as well.

Open access

Bożena Denisow and Małgorzata Wrzesień

Abstract

Understanding the factors that have an impact on the diversity of forage flora in the agricultural landscape is a key issue in the maintenance and control of food niches for pollinators. Field margins are common linear structures in the agricultural landscape. In the present study, we evaluated the factors that exert an impact on the forage flora composition and on the diversity in field margins. The study was conducted in the 2010 - 2011 time period across the agricultural landscape on the Lublin Upland of SE Poland. Data on the forage flora were obtained while making floristic charts along 45 transect plots x 300 m; the total length being 13500 m. Multivariate ordination techniques (PCA and RDA) were employed to analyse forage-flora characteristics. Field margins represent valuable refuge areas for forage-species richness, but not for the abundance of forage species. On field margins, forage-species diversity benefits from the location of natural habitats (forests or meadows), primarily if the distance from these habitats is <1000 m or the field acreage is <10 ha. The shift from heterogeneous habitats to a more homogeneous landscape causes a reduction of forage floral diversity. Due to lack of dense forage-species patches, the promotion of sowing nectariferous and/or polleniferous species seems to be a reasonable management method to enhance the quantitative food niche on field margins and to support the conservation of pollinators in the areas surrounding farms.

Open access

Małgorzata Wrzesień, Jacek Jachuła and Bożena Denisow

Abstract

In a modern agricultural landscape the assurance of food resources is a key issue in the maintaince and control of food niche for pollinators. In the present study we evaluated bee forage flora composition and diversity within railway embankments located in the agricultural landscape, SE Poland. We also analysed the abundance of pollinators that use food resources along railway embankments and recognized insect visitors preference for selected plant species. Railway embankments represent valuable refuge areas for bee forage flora (307 species, i.e. 76.1% of total flora) and pollinators (in total 4172 insect visits from 9 taxonomic groups). However, the richness and abundance of bee forage flora significantly differed between types of the railway distinguished by traffic volume. The highest diversity of bee forage flora is noted along the railway with intermediate traffic volume. Approx. 25% and 40% less bee forage species was identified along railways with low and high traffic volume. Likewise, bee forage flora differed considerably between microhabitat types, i.e. top vs. slope vs. bottom of the embankment. Providing support (e.g. mowing) seems to be an important management type in order to strengthen the native bee forage flora particularly on railway embankments along low and high traffic volume tracks. Such activity is crucial to counteract the spread of aggressive non-forage species (e.g. Calamagrostis epigejos, Artemisia vulgaris, Phragmites communis) and invasive species (e.g. Bunias orientalis, Solidago gigantea).

Open access

Jacek Jachuła, Małgorzata Wrzesień, Monika Strzałkowska-Abramek and Bożena Denisow

Abstract

There is growing evidence that food, in particular pollen, limitation is the strongest factor in pollinator decline. We have considered the potential effects of diversity in plant-community attributes as well as variations in the pollen and energy amount on the abundance and frequency of insect visitors to the Lamiaceae species Salvia pratensis L., S. verticillata L., Thymus serpyllum L., Betonica officinalis L. syn. Stachys officinalis (L.) Trevis., and Origanum vulgare L. The species were grown in two different habitat types (dry grassland vs. railway embankment) in the Lublin Upland, Poland. We found significant inter-species, inter-habitat, and inter-year disparities in the pollen mass and total energy amount per unit area. Canonical correspondence analysis (CCA) revealed that the blossom cover, species richness, and diversity noted at the plant community level significantly influenced the distribution of insect visitors to Lamiaceae species. The pollen caloric value and pollen abundance (but not the protein content in the pollen) had a considerable impact on the abundance and frequency of honeybees, bumblebees, and solitary bees in Lamiaceae flowers. Butterflies, beetles and flies did not respond to these factors. The model including all variables explained 66.4% of the observed variance. The studied Lamiaceae species, due to abundant flowering and good pollen nutritional value should be considered in the protocols to improve food resources, especially for social bees; however, disparities in pollen quantity and energy amount should not be ignored.

Open access

Bożena Denisow, Sebastian Antoń and Małgorzata Wrzesień

Abstract

During the monitoring of populations of Anemone sylvestris L. (Ranunculaceae), a protected species in Poland, we found that the seed set is impaired. The flower is considered an adaptation that has coevolved to achieve effective pollination and successful fertilization. Therefore we have focused on the morphological and anatomical characteristics of the flowers of A. sylvestris L. as a prelude to the study of the species’ pollination biology and plant breeding system. The large size of the flower (50.6 ± 16.4 mm in dimensions) and its bowl shape fulfil both the biotic pollination syndrome and the aerodynamic requirements for pollen dispersal and capture. The opening and closing of the perianth provide a shelter for beetles. The odourless perianth, absence of nectar, scarcity of pollen (approximately 200 000 pollen grains per flower) and its traits - small size (axis P = 18.52 ± 1.0 μm; E = 16.59 ± 0.9 μm), lack of balsam on the exine surface, starch accumulation in more than 95% of pollen grains correspond to the specialization in anemophily. The stigma is papillous, the dense hairs are situated between single carpels indicating adaptation to capturing dry pollen and specialization in the wind pollination syndrome. The flower of A. sylvestris is an example for an intermediate form between entomophily and anemophily, i.e. a secondary and more advanced feature among Ranunculaceae.