Biscutella laevigata L. is known as a Tl hyperaccumulator. In Poland Biscutella laevigata occurs in the Tatra Mts (Western Carpathians) and on the calamine waste heap in Bolesław near Olkusz (Silesian Upland). The purpose of this work was to evaluate whether plants of both populations were able to accumulate an elevated amount of thallium in their tissues. The plants were cultivated in calamine soil in a glasshouse for a season and studied at different ages -from 2-week-old seedlings to 10-month-old adults. Additionally, the plants were grown for ten weeks in calamine soil with EDTA to enhance Tl bioavailability. The total content of Tl in plant tissues after digestion was determined by ICP-MS, whereas its distribution in leaves was studied by LA-ICP-MS. Of the total content of Tl in the soil in the range of (15. . The translocation factor was 6.1 in the soil and 2.2 in the soil with EDTA; the bioconcentration factor amounted to 10.9 and 5.8, respectively. The plants from both populations did not contain a Tl amount clearly indicating hyperaccumulation (100-500 mg•kg -1 d.m.), however, high (>1) translocation and bioconcentration factors suggest such an ability. It is a characteristic species-wide trait; B. laevigata L. is a facultative Tl hyperaccumulator. The largest Tl amount was located at the leaf base, the smallest at its top. Thallium also occurred in trichomes, which was presented for the first time; in this way plants detoxify Tl in the above-ground parts. Leaves were much more hairy in the Bolesław plants. This is an adaptation for growth in the extreme conditions of the zinc-lead waste heap with elevated Tl quantity.

Atriplex tatarica is an invasive annual plant from Central Asia. It is an early successional species of disturbed habitats, tolerant of a high content of NaCl. It grows also by the roadsides, on lawns by the streets and other places in cities sprayed with salt during snowfalls. The paper presents results of the analysis of abundance and patterns of occurrence of this invasive subhalophytic plant by the roadsides in the Warsaw city. We found that frequency and distribution of Atriplex tatarica increased significantly over the last few decades. The species grows chiefly along main streets which are de-iced. It forms monodominant patches of different length at the zone closest to the street verge. The NaCl concentration there is significantly higher than in the zones more distant from the street verge, although this parameter is very variable. The cover of other species increases with an increasing distance from the roadside verge

The research was conducted on four patches of thermophilous oak wood in Białowieża Primeval Forest: Awith a woodstand: oak + approx. 30-year-old hornbeam + hornbeam brushwood; B -with a hornbeam stand formed by natural seed fall after logging (ca. 1920) oaks; C -after logging oaks and replanted (ca. 1965) with pine and oak; D -with a natural low-density oak stand. Species composition and seed bank density were estimated using the seedling emergence method. Seedling emergence was observed over two vegetation seasons. Research demonstrated that: 1) the species abundance of the seed banks depends on canopy cover (A, B approx. 50 species; C, D approx. 70 species); 2) the floristical similarity (Sørensen's index) of the seed bank and ground vegetation is higher in the undisturbed patch D (0.50) than in disturbed patches (0.30-0.35); 3) species diversity in plots A, B, C, D (H'=12.5; 13.4; 15.5; 16.9) and seed bank density per m 2 (432.5; 958.0; 1486.5; 2268.0) are negatively correlated with the degree of patch shading; 4) the average weight of diaspores in the seed banks of shady plots is lower (A, B approx. 0.003 g) than that of sunny plots (C, D approx. 0.08 g); 5) the share of long-lived diaspores increases in patches after logging.

Seedling emergence from soil seed bank was studied during 3 growing seasons 1997-1999 in: 1) 60 plots in 3 parts of the Potentillo albae-Quercetum patch: A - with Carpinus betulus (hornbeam) present only in the herb layer (canopy cover ca. 50-60%), B - after tree felling, at present with hornbeam dominating the shrub layer (cover > 90%), C - invaded by hornbeam 30-40 years ago (cover ca. 90%), and in 2) 60 soil samples from objects A, B, C kept in an unheated glasshouse. The results suggest that the seed bank realised in natural conditions is poorer in species with high light requirements (the Ellenberg indicator values for light (L ≥ 6) and their seedlings in comparison with the potential seed bank estimated in glasshouse conditions (field: A- 24; B - 17; C- 7, glasshouse : 44; 38; 32 species / 2 m², field: 321; 108; 14, glasshouse: 785; 1205; 177 seedlings / m², respectively). Contrarily, more species and seedlings with moderate light demand (L = 3-5) appeared in the field plots (field: A- 26; B- 25, glasshouse: 20; 14 species / 2 m², field: 1014; 310, glasshouse: 328; 71 seedlings / m²). The shading by hornbeam negatively influences the size of the seed bank (field: A - 1743; B - 1226; C - 680, glasshouse: 1547; 3274; 459 seedlings / m²) and its species richness (field: A- 55; B - 48; C - 19, glasshouse: 76; 59; 56 taxa / 2 m²). Nomenclature: syntaxa - Matuszkiewicz (1981), taxa - Mirek et al. (1995)

Tolerance to heavy metals in plants is a model process used to study adaptations to extremely unfavorable environments. One species capable of colonizing areas with high contents of heavy metals is Armeria maritima (Mill.) Wild. A. maritima plants growing in metalliferous areas differ in their morphological features and tolerance levels to heavy metals compared to individuals of the same species growing in non-metalliferous areas. The A. maritima adaptations to heavy metals occur at the organismal, tissue, and cellular levels (e.g., the retention of metals in roots, enrichment of the oldest leaves with metals, accumulation of metals in trichomes, and excretion of metals by salt glands of leaf epidermis). This species also undergoes physiological and biochemical adaptations (e.g., the accumulation of metals in vacuoles of the root’s tannic cells and secretion of such compounds as glutathione, organic acids, or HSP17). This work reviews the current knowledge on A. maritima adaptations to heavy metals occurring in zinc–lead waste heaps and the species’ genetic variation from exposure to such habitats. A. maritima is an excellent example of microevolution processes in plants inhabiting anthropogenically changed areas.