In this paper, the results of the research are presented on the content and transformation of nitrogen compounds in the Wel River (the largest tributary of the Drwęca River). The catchment area of the studied river is predominantly agriculturally developed. Along the river course, 6 sample collection sites were selected, situated in places with different land development of the drainage basin. The average concentration of total nitrogen in the water of the Wel River amounted to 1.807 mg/dm3, mineral nitrogen - 0.557 mg/dm3 and organic nitrogen - 1.250 mg/dm3. The organic form of nitrogen dominated at all sites (the average content for the whole river amounted to 69%). Nitrate nitrogen dominated in the pool of mineral nitrogen. The lowest concentrations of nitrates were being recorded at lakeland sites, whereas the highest - at two terminal sites situated within the lower reaches of the river, where the drainage basin has a typically agricultural character.

The aim of the study was to assess suitability of colour aerial photographs for mapping of soil cover transformed due to effect of anthropogenic denudation. The investigation was carried out in south-western part of the Brodnica Landscape Park, within the boundaries of rolling and hilly moraine plateau, used for agricultural purposes. The soil cover of that area is exposed to intensive influence of slope processes triggered by human agricultural activity. The anthropogenic denudation leads to truncation of soil profiles of top convex sections of slopes and hills’ summits. Soil material moved down the slopes is accumulated in the form of diluvium in hollows and lower sections of slopes. Two study sites were selected – Sumówko and Zbiczno. Within the boundaries of both study sites, detailed soil mapping took place consisting in preparation of irregular boreholes projection. Next, four sites were selected for soil pits, representing broad spectrum of transformations related to anthropogenic denudation. Based on obtained results and colour diversity of surface horizons, the spatial range of individual soil types was specified. It also enabled determination of anthropogenic denudation impact on formation of the soil cover. Totally eroded soils, classified as pelosols, located on hills’ summits, are characterized by very bright colours of surface horizons, resulting from content of calcium carbonate in glacial tills. The range of soil lessivés, prevailing within the slopes boundaries, where the erosion resulted in exposure of argic horizons rich in iron compounds and clay fraction, coincided with occurrence of brown colours. Bright grey surface horizons are characteristic of deluvial soils. This colour arises from sandy texture of deluvial material (low content of iron) in combination with humus nature. The soils located in relatively vast field depressions were covered with small thickness of diluvium, which was reflected in dark grey colours of surface horizons. These horizons are relatively rich in soil humus. Significant amounts of humus are related with mix of deluvial material with material formed in humus horizons, originally occurring on surfaces of soils rich in organic matter – black earths and organic soils.

We can expect significant changes in the plant cover structure and crop structure due to the climate change, and the response of plants with different photosynthetic pathways to global change may be crucial for agriculture. The paper analyzes the impact of habitat factors connected with the climate change: temperature and concentration of CO2 in the atmosphere on the change of C 3 and C 4 plants primary production (NPP). The Ehleringer model describing the balance between C 3 and C 4 plants indicates that a shift in the balance in favor of C 4 plants and the increase in CO2 levels, which has continued since the mid-nineteenth up to the present day, would require a temperature increase by 5-10°C. Nonetheless, this increase is much lower, while the review of previous studies and some phenomena observed in the Poland area: high level of NPP in maize crops and the increased in contribution of C 4 species in the flora indicate the shift in the balance in favor of C 4 plants. This fact can be explained by a factor not included to the Ehleringer model: the availability of water and nitrogen.

Representatives of the Fallopia genus: Fallopia japonica, Fallopia sachalinensis and Fallopia × bohemica are known as successful invaders, wide spread throughout Europe and North America. This paper focuses on the invasive Fallopia complex and presents some features (a wide ecological amplitude, high competition abilities, sexual reproduction by hybridization) responsible for the fact that all species of the Fallopia genus are aggressive and noxious invaders.

The use of a new notation together with the territory mapping method is proposed for imprecisely located singing males, owing to which a position of a bird can be noted more precisely in field surveys

Representatives of the Fallopia genus: Fallopia japonica, Fallopia sachalinensis and Fallopia × bohemica are known as successful invaders, wide spread throughout Europe and North America. This paper focuses on the invasive Fallopia complex and presents some features (a wide ecological amplitude, high competition abilities, sexual reproduction by hybridization) responsible for the fact that all species of the Fallopia genus are aggressive and noxious invaders.

Flavonoids extracted from Carpobrotus rossii possess cardioprotective activity and as such there is interest in maximising the per plant yield of these compounds. This field study was undertaken to determine the environmental variables driving flavonoid production. Results suggest that production of tannin and flavonoid metabolites is not controlled by a single variable alone, but through an interplay of variables linked to oxidative stress in the plant.

[EN] In the present study, we have investigated spatial and temporal changes in Pro levels in several monocotyledonous and
\ndicotyledonous halophytes growing in a littoral salt marsh located near the city of Alicante (SE Spain).

Roads are known for being corridors for not only migration of small animals, but also expansive, invasive and halophytic plants. At least sixteen wildly growing halophytes and many other salt-tolerant species were found along various types of roads in the Czech Republic. The most halophytes belonged to the families of Poaceae (23%) and Asteraceae (20%). Since many plants growing along roads are weeds, there is a real danger that these plants will invade nearby agricultural crops. Thus biological degradation of agricultural areas can be started.

In recent years biological invasions have become a serious ecological and socio-economic problem for many countries. Invasions are promoted by anthropogenic activity which is broadly understood as well as the instability of ecosystems. It carries a number of threats, often difficult to predict. The effects of invasion are long-term and occur on many levels of life. They can very often contribute to the extinction of native species, thus reducing biodiversity. According to the concept of sustainable development, the protection of biodiversity, and thus the prevention of biological invasions, is a necessary condition both to maintain the variety of nature, and to further the economic development of each country.