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1:. Introduction: Water-soil-vegetation relationships in the natural Biebrza wetlands1.1 Wetlands in the hydrological systemsTomasz Okruszko Wetlands may be able to play different roles in the landscape depending on the source of water; hydrological feeding of wetlands may be rain fed (ombrogenic), groundwater fed (topogenic and soligenic) or river fed (fluviogenic). Ombrogenic - Wetlands with a difficult outflow and where there is a low level of evapo-transpiration tend to be rainfed or ombrogenic. The catchment tends to be very small and in extreme conditions, such as dome peatlands there is no catchment and the only water source is rainfall. These wetlands are typically found in mountains or close to the sea. Soligenic - Wetlands with a of soligenic type of delivery tend to occur near the edge of larger valleys on local groundwater outcrop or small localised peatlands on the slopes of moraine hills. The most common areas occupied by soligenic wetlands are the upper parts of the river basin when they occupy a cross-section of the valley and the river that drains them. Topogenic - Wetlands with topogenic type of delivery occur watershed areas or on the bottom of wide basins. A characteristic feature of such wetlands is strong hydration with little mobility in the ground water, which in Summer cannot always make up for the water evaporation. Fluviogenic - River fed wetlands could be compared to retention reservoirs where there is typically a flood reserve. Such wetlands occur where water reserves are created by a suitably big catchment area. Rainfall or thaw freshets that occur in river basin run to the bottom of the valley causing heavy irrigation or flooding in the area for limited period. Regular occurrence and long duration of the inundation are basic factors of fluviogenic delivery. Being aware of the hydrological type of delivery forms the first step for understanding the chemical and biological functional requirements of wetlands ecosystems. Lecture aims on introduction of the wetlands function in the catchment depending on their hydrological type. 1.2 Water-related physical attributes of organic soils of natural wetlands Jan Szatyłowicz • the organic soil solid phase characterisation (botanical composition, degree of decomposition and ash content), • basic physical properties (particle and bulk density, porosity), • soil water characteristic of peat soils (factor influencing on the characteristic), • saturated and unsaturated hydraulic conductivity of organic soil, • water storage in peat soil profiles and soil volume changes, • peat accumulation, • organic soil classification. 1.3 Wetland vegetation - background concepts (influence of habitat and management, natural vs. seminatural wetlands, zonation, structure of phytosociological and ecological classifications) Wiktor Kotowski We will introduce principles of vegetation science and review major concepts related to wetland vegetation classification and background of observed vegetation patterns. The relation between vegetation typologies and wetland types will be addressed, with special reference to riparian habitats. We will also explain methodological approach to vegetation studies, analysing examples of descriptive surveys, analyses of vegetation-habitat relationships and experimental studies on community mechanisms. 1.4 Characterisation of major vegetation types in undrained wetland habitats (examples from the Biebrza Valley), understanding natural zonation Wiktor Kotowski Major vegetation types typical for undrained wetland will be described, including: tall helophytes, tall sedge communities, sedge-moss fens, bogs, alder forests, bog forests. Focusing on natural riverine wetlands, we will discuss concepts explaining vegetation zonation patterns in terms of abiotic conditions and biotic interspecific interactions. 2:. Hydrology and soil properties of organic wetlands: Biebrza as an example of relationships in wetlands - transition from natural to transformed2.1 Hydrology of the Biebrza Upper BasinOkke Batelaan • An identification of the key hydrological processes occurring in the Biebrza Upper Basin; The processes are described as a result of the geographical, hydrogeological and meteorological conditions of the catchment. The more anthropogenic influences of the hydrology are treated in later lectures. • A description will be given of the current state of the hydrological knowledge of the hydrology of the Upper Basin by way of a short overview of analyses of hydrological data. This description includes an analysis of the hydrometeorology, surface water and groundwater system. • A presentation of the results of groundwater modelling and distributed catchment runoff modeling in dependence of topography, soil, land-use and meteorology. • A presentation of local groundwater-surface water interaction measurements and modelling at a headwater section of the Upper Biebrza River. • A zooming in to some transects along which detailed time series of groundwater levels have been observed and are complemented by vegetation and nutrient cycling mapping. 2.2 Flooding and Inundation in the Lower Biebrza Basin Jarosław Chormański • Importance of flooding in wetlands • Surface water hydrology of the Biebrza Lower Basin • Flood and inundation: different water types • Floods observation: water level dynamics • Flood and Inundation mapping in wetland area (measurements, Remote Sensing, GIS-based hydraulic modeling) • Relation between flood extent, inundation and vegetation zones in Lower Biebrza Basin. 2.3 Water-related physical attributes of organic soils of transformed wetlands Jan Szatyłowicz • characteristic of moorsh formation process, • influence of moorshing process on water storage and water transmission in soil, • peat shrinkage and hydrofobicity, • soil subsidence, • capillary rise in soils. 2.4 Water quality aspects in the hydrology of wetlands Marek Gielczewski / Ignacy Kardel • A presentation of patterns and changes in groundwater quality in dependence to different soil (peat and mursh) types dominating in the Biebrza valley • An analysis of the seasonal and annual trends in groundwater quality in the Biebrza valley • A presentation of patterns and changes in surface water quality in dependence to different soil (peat and mursh) types dominating in the Biebrza valley • An analysis of the seasonal and annual trends in surface water quality in the Biebrza river 3:. Management and restoration of wetlands differing in the degree of human disturbancePart 13.1 Characterisation of major vegetation types in drained wetland habitats (examples from the Biebrza Valley), changes in vegetation patterns after drainage, role of management in suboptimal hydrological conditions Wiktor Kotowski Typical vegetation types of moderately drained wetlands are various types of wet meadows - eutrophic hay meadows, mesotrophic litter meadow, tall herb communities. In more intensively drained sites, biodiversity declines and species-poor grassland communities establish. Drainage can also enhance succession process. On this background we will discuss the ecological role of vegetation management in riparian landscapes. 3.2 Spontaneous secondary succession in drained and not managed wetlands - information from spatial analyses, rate of changes in time and management solutions Hubert Piorkowski Most of open wetlands in temperate zone used to exist in semi-natural conditions under mowing or grazing management. Cessation of this landuse is followed by fast successional changes of vegetation. The rate of changes in time and their spatial extent in the Biebrza Valley will be demonstrated by means of remote sensing and spatial analyses. Management solutions and usefulness of management support systems will be discussed. 3.3 The impact of land use changes and management on the trophic status and biodiversity of wetlands Martin Wassen Land use is one of the factors most directly influencing biodiversity (ecosystems, species and genotypes of plants, animals and micro-organisms). Large part of the Earth surface is under production. The intensity of current production methods and the impacts on the physical-chemical conditions of the soil (water and nutrient status) are important driving forces of the decrease of biodiversity. Furthermore, land use also affects the remaining nature areas, through environmental impacts such as desiccation, acidification, eutrophication and fragmentation. Knowledge of key-processes vital for ecosystem functioning is therefore required in order to be able to improve ecosystem quality as a condition to biodiversity conservation. Ratification of the Convention of Biodiversity by many countries implies that loss of biodiversity should be prevented and counteracted. Important means are the protection of nature areas, e.g. through survival strategies for forest and other types of nature, and the restoration of lost nature, e.g. by taking agricultural land out of production, reversing eutrophication processes and rewetting wetlands. For understanding eutrophication, i.e. the process of nutrient enrichment of ecosystems we primarily need to know which nutrient(s) is limiting primary productivity. Next, quantification of pools and fluxes of limiting nutrients is required. The effect of potential increases of nutrient availabilities can then be predicted by analyzing the various nutrient fluxes operating in these ecosystems. In wetlands these fluxes include atmospheric deposition, nutrient supply by flooding and groundwater flow, nutrient leaching to groundwater and for nitrogen fixation and denitrification. Also grazing or harvesting natural products in the form of hay production should bee considered. Increased availabilities may also result from changes in soil nutrient turnover rates due to altered ecosystem properties such as changes in hydrological dynamics and acidification. Management often strives for decreasing productivity and preventing ecosystem succession towards higher productive ecosystems. We quantified (annual) nutrient flows along productivity gradients in floodplains, fens and meadows. We also identified key processes for ecosystem functioning and related them to landscape features on one hand and vegetation structure, plant species composition and plant diversity on the other hand. Results will be discussed in relation to the type of nutrient limitation, plant diversity - productivity patterns and management. 3.4 Ecohydrological investigations of Flemish river valleys. Basis for development of ecosystem visionsOkke Batelaan / Patrick Meire In the last 10 years many ecohydrological studies have been performed in Flemish river valleys. Several of them were executed in the framework of developing an ecosystem vision for mostly valuable floodplain areas. Ecosystem visions have been defined in these studies as: A tool for nature policy with as purpose the optimalisation of the quality and structure of ecosystems in a certain area. By designing an ecosystem vision the administrations hope to gain an insight into the potentials of valley areas. With potential is meant the possibilities for nature development and restoration, while taking into account irreversible abiotic conditions, management and land organization. Ecosystem visions result therefore in the spatial mapping of potentials, up to parcel level, and give orientation to the determining factors and processes, thereby identifying resulting bottlenecks. In this lecture the methodology of the ecosystem visions is described, including the ecohydrological field and desktop studies, such as vegetation mappings, hydrological system modeling, eco-hydrological system analyses and scenario testing. Examples of ecohydrological investigations in different valleys are given, which indicate that vegetation types in specific areas are determined by a complex set of biotic and abiotic conditions. It is shown that the ecohydrological relationships are process scale and spatially dependent. Part 2 3.5 Water management, nature conservation and restoration attempts in Dutch lowland polder areas Martin Wassen In the Netherlands reclamation of wetlands has a long history. The famous Dutch struggle against the water by building dams and pumping out water has turned many lakes and marshes and even parts of the sea into land. Nowadays, the struggle against water has turned into a struggle for water in areas where agriculture, drinking water companies and wetland nature reserves compete for fresh and unpolluted water. This lecture gives an overview of Dutch water management practices and addresses current issues in water management for nature conservation in relation to other water users. Examples of restoration attempts will be given aiming at reducing the unwanted effects of drainage, acidification and eutrophication and re-establishment of plant species. 3.6 Water management and nature restoration in the Schelde estuary: an example of conservation in multi stakeholder settings Patrick Meire • a short introduction on the wetlands in the Schelde basin with special emphasis on the Schelde estuary • a description of the major factors leading to the deterioration of the wetlands, especially the tidal marshes and how this has lead to major problems concerning water quality, water quantity and biodiversity • a short description of the present management plans dealing with safety, shipping, water quality and nature • presentation of a new integrated approach for the management of the estuary and the basin with emphasis on the role of wetlands in this. 3.7 Wetlands as water users in Integrated River Basin Management Plans Tomasz Okruszko Integrated River Basin Management (IRBM) should focus not only on water supply for the different type of water users, such as agriculture, industry or household, but also on maintaining water dependent ecosystems. To do this, some fundamental issues need to be determined such as whether the wetlands are a) the water user; b) part of water resources or; c) the structure for modifying water quantity and quality in the catchment. In most cases where there are competing water users, the water distribution decisions are based on a comparison of how significant the losses will be for each water user if his water needs are not met. As a general rule the water boards or other water management bodies try to balance surface and ground water resources with the water needs of the particular water users. Surface water balance models or regional groundwater models are generally used for establishing catchment scale water management plans and determining water policies. Water management plans are identified by comparison of model results in terms of decision criteria for particular alternative of water management (often called a scenario). Each alternative contains a combination of the system parameters, such as the volume of the projected reservoirs; decision rule parameters, area of irrigation schemes and a hierarchy of the water users. Typically basins that are used for human purposes undergo considerable intensification, particularly of biogenic substances as the sustainability of the wetland ecosystems is not factored into the water management plans. In order to perform necessary calculations, where wetland ecosystem function is also considered, the water demand of different type of wet habitats also has to be included in the decision process. Hydrological characteristics of particular ecosystems could be employed for this purpose. Their type of hydrological feeding describes, in general, the sources of water, the yearly water hydrograph describes the water needs and specific hydrological parameters (flooding frequency, maximum depth of groundwater, average waterlogging period) might be used as decision criteria. An additional approach may be to model the response of the particular wetland ecosystem to water deficit in terms of productivity and/or vegetation composition. These approaches will not solve all the problems of which water user is more important and how to set a hierarchy of water users in the river basin. However it is a complex issues with ecological, sociological and economical considerations and the proposed approach at least creates an understandable method for communicating with decision makers about wetlands, how much water is needed and the moment when water deficit in wetlands occurs IRBM plans should recognise the presence of wetlands in the catchment. On one hand there are important functions, which wetlands can perform as a service provider, for example as a sink of biogens or for water retention. On the other hand wetlands are water users just like all other dependants on water from the river basin. | ||||||||||||
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