Fire has considerable impact on vegetation and organic soils properties. As we observed that the differences between vegetation of burnt and unburnt areas on the rich fen are visible 11 years after the fire, we assumed that the post-fire changes are long lasting, yet limited exclusively to the burnt areas. In order to check this hypothesis we studied spatial differentiation of physical and chemical properties of soils, and productivity capacities of burnt and unburnt areas in the fen in Biebrza National Park. We took soil samples from the neighboring burnt and unburnt areas, from the depth of 0–30 cm and 30–50 cm. We analyzed 21 parameters of the soils including: pH, ash content, moisture, bulk density, exchangeable K, Na, Ca, available P, N-NH4+, N-NO3−, total N, C, K, Na, Ca, Mg, Fe, P; and calculated C:N, C:P ratios. Surface layer of the burnt soils differed significantly from the unburnt soils in respect of 17 out of 21 parameters. The most pronounced difference was observed for available phosphorous (on average 6 times higher for the burnt soils). The differences in the deeper layer were mostly insignificant. The burnt areas were also characterized by twofold higher plant productivity than recorded for the unburnt areas. The influence of fire on peaty soils was long lasting but mostly limited to the surface layer of the soils. In the case of particular soil features, the post-fire differences were modified by advanced muck formation (moorshing) processes in the unburnt areas. Since the fire led to long lasting increase of fertility, the recovery of fen vegetation is unlikely.
Prof. Tomasz Okruszko explains what role wetlands play in the environment and how they are affected by human activity.
Wetlands play a significant role in agricultural landscape. They are the areas of exception-ally great natural values able to regulate water cycling in river catchments. In many cases they are the basic food source for bred animals.
Large areas of wetlands (c. 4 million ha) have been drained for agricultural purposes in Poland. Nevertheless, there are still numerous natural (or close to natural) wetlands, part of which is protected in nature reserves or national parks.
Having in mind the transformation of agriculture and the need of protecting water resources and natural environment, it is necessary to regulate the principles of utilisation and management of re-claimed wetlands. Water management should be adjusted to the type of an area and to environmental requirements. Regardless of the type and intensity of agricultural use of wetlands one has to aim at limiting rapid outflow of spring thaw and rainfall waters which means the reconstruction and increas-ing of natural retention capacity of the river catchment. It is necessary to provide an appropriate num-ber of water lifting facilities and their proper exploitation in land reclamation objects.
It is as well necessary to create appropriate organizational, legal and financial conditions stimu-lating actions to improve water balance and wetland protection.
The Włodawka River catchment of an area of 725 km2 covers the central and eastern part of the Łęczna-Włodawa Lake District. Evaluation of the role of hydrogenic areas in runoff creation was based on materials of the Department of Hydrography and the Institute of Meteorology and Water Management data. The analysis was conducted for selected catchments in which additional hydrometric measurements and water quality tests were done. Such parameters as: the share of hydrogenic surfaces in total catchment area, types of wetlands, their hypsometric location and position with reference to drainage streams were taken into consideration for evaluation. The degree of anthropogenic transformation of the marshland was expressed in terms of density and depth of the drainage ditches that dissect it. It was found that the drained gyttja of Krowie Bagno plays a considerable role in increasing the minimum discharge. Wetlands in the Włodawka River catchment influence the conditions of the runoff and water quality, which is noticeable, primarily, in the concentration of organic carbon, and of nitrogen and phosphorus compounds.
The Water Framework Directive (WFD), whose basic aim was to create a legal back-ground for water bodies’ protection, undoubtedly affects all economic sectors. Being a specific and distinctly different water user, agriculture will have the greatest share in the implementation of WFD out of all sectors of national economy. This results from its special character (60% of the country area used by agriculture), large volume of water consumed by evapotranspiration, diffuse pollution etc. Implementation of WFD will call for undertaking of many activities to restrict an unfavourable im-pact of agriculture on water resources and water related ecosystems. It is assumed that agriculture should also protect water resources. Accomplishment of this task imposes significant changes in the land use of river basins. Water management can be an essential factor deciding about the sustainable development of rural areas and biological diversity of agricultural landscape. Actions undertaken so far to implement the WFD are mainly limited to the protection of water quality from agricultural pol-lution. It is also necessary to undertake implementation of other aims of WFD. This refers especially to the provision of good hydromorphological status of water bodies, protection of water related eco-systems and effective water use.
In order to reconstruct environmental changes in the Borzechowo mire, a sediment core was subjected to macrofossil and stratigraphic analyses. The mire is located in the eastern part of the Pomeranian Lakeland (Tuchola Forest, northern Poland). It is a limnogenic mire, formed as a result of terrestrialisation of a water body. The time of basal peat accumulation was estimated by radiocarbon dating as 9860±130 14C BP (Gd-12393) and by palynological analysis as Preboreal. The analysis of macrofossils shows that in that period, considerable hydrological changes took place in the study area. These hydrological changes were caused by melting of dead ice blocks that was common place in the Late Glacial and the Early Holocene.
Anaerobic digestion (AD) is an adequate alternative to treat wastewater generated from fruit and vegetable processing (FVWW); likewise, in recent years, artificial wetlands (AWs) have been applied as a post-treatment process for anaerobi-cally pre-treated wastewater. The objective of this work was to design a sustainable treatment system for FVWW composed of upflow anaerobic reactors (UASB) with phase separation and an AW system that receive the anaerobically pretreated effluent. Using the design methodologies for the UASB reactors and artificial wetlands with sub-surface flow (AW-SSF), the parameters of the combined AD-AW system that treat a wastewater flow of 300 m3∙d–1 were calculated. The UASB acidogenic system was adjusted to a hydraulic retention time (HRT) of 10 h and organic loading rate (OLR) of 13.84 kg COD m–3∙d–1; meanwhile, the methanogenic and cascade UASB reactors with OLRs of 10.0 and 3.0 kg COD m3∙d–1, and HRTs of 11 and 10 h, respectively, achieve a high COD removal efficiency (above 94%), and an overall biogas production rate of 1.53 m3 of biogas per m3 of reactor capacity per day. According to the results obtained with the theoretical design, anaerobic-wetland combined system achieves an overall efficiency greater than 98%. The wastewater treated by the pro-posed system will allow the reuse of 30% of the water used in the washing of fruits and vegetables.