Abstract Gradient, which is largely considered to be related to water level in mires, is referred to as a microtopographic mud bottom to carpet to lawn to hummock level gradient or the hummock level to intermediate level (lawn) to flark level gradient. The relationship of this vegetation gradient to various physical water level characteristics was studied. The general classification used in the present summary paper divides the aro vegetation of the inland of Northern Ostrobothnia into two main groups: (a) treeless fen aro vegetation (Juncus supinus, Carex lasiocarpa, Rhynchospora fusca, Molinia caerulea) and (b) heath aro vegetation (Polytrichum commune). The first group (a) was divided into fen aro wetlands with an approximately10 cm peaty layer at most and into aro fens with a peat layer thicker than 10 cm. The treatment of the water level gradient was divided into three main groups. (1) The mean water level correlated with mire surface levels (microtopographic gradient) within mires with slight water level fluctuations and partly within mires with considerable water level fluctuations. (2) Three habitat groups could be distinguished on the basis of the range of water level fluctuation i.e. mires with slight water level fluctuations, mires with considerable water level fluctuations and the aro vegetation with extreme water level fluctuations. (3) The timing of water level fluctuations indicated that there are different types of patterns within aro wetlands, the seasonal pattern being mainly a response to yearly snow melt and the several-year-fluctuation pattern being related to the regional groundwater table fluctuation in mineral soils (heath forests). A link was suggested between the stability of the water regime and peat production in local aapa mire – aro wetland environments. From the point of view of peatland plants the direction of variation from a stable to an unstable water regime in aapa mire – aro wetland environments represents a transition towards more and more harsh ecological conditions, partly forming a gradient through natural disturbance. A qualitative functional model was provided for the mire – aro wetland systems of Northern Ostrobothnia. The model supposes differences in the characteristics of peat between two functional complexes within a mire system. Finally, the model for local mire – aro wetland systems was converted to a general from: diplotelmic (acrotelm) mires were divided into two subtypes (diplotelmic water stabilization mires, diplotelmic water fluctuation mires) and the relationship of those subtypes to percolation mires and seasonal wetlands was considered.

Moore in Südafrika sind wichtige, aber bedrohte Ökosysteme. Etwa 20.200 ha, zwei Drittel der südafrikanischen Moore, befinden sich auf der Maputaland Coastal Plain. Eukalyptusplantagen und gängige Anbaumethoden, die Dränung beinhalten, bedrohen die Existenz der Moore. Ein besseres Verständnis von Prozessen und Eigenschaften der Moore Maputalands ist dringend erforderlich, um effektive Schutzstrategien zu entwickeln. Diese Dissertation untersucht die Moorbildung in Maputaland aus einer bodenkundlichen Perspektive, um Voraussetzungen für effektive Schutzmaßnahmen und Renaturierungsmaßnahmen abzuleiten sowie Ratschläge für nachhaltigere Anbaumethoden auszuarbeiten. Per Großrestanalyse wurden Moor- und Torfbildungsprozesse untersucht. Auf Grundlage von 141 in Feldarbeit untersuchten Bodenprofilen wurden 15 unterschiedliche Moorsubstrate beschrieben und in genetische Substratgruppen sowie botanische Torftypen kategorisiert. Für diese Substrate wurden die folgenden physikalischen und chemischen Bodeneigenschaften bestimmt: Kohlenstoffgehalt, C/N Verhältnis, elektrische Leitfähigkeit, pH-Wert, Trockenrohdichte, Porenverteilung, gesättigte und ungesättigte hydraulische Leitfähigkeit sowie maximaler kapillarer Aufstieg. Zudem wurden die Auswirkungen von Degradierung auf die physischen und chemischen Eigenschaften der Moore untersucht. Hierfür wurden die eben benannten Kenngrößen für Substrate in verschiedenen Degradierungsstufen gemessen. Auf Grundlage der Veränderungen der Bodeneigenschaften werden die Verluste von Ökosystemfunktionen durch Degradierung diskutiert. Anhand der Häufigkeit der Substrattypen in den unterschiedlichen hydrogeomorphologischen Moortypen werden angepasste Empfehlungen für Schutz, Renaturierung und nachhaltigere landwirtschaftliche Nutzung der Moore erarbeitet, basierend auf den ermittelten Substrateigenschaften. Darüber hinaus werden auf Grundlage aktueller Klimaprognosen zukünftige Stresssituationen für die Moore durch den Klimawandel analysiert. / Peatlands in South Africa are important and threatened ecosystems. They are of great socio-ecological significance, as sources of freshwater, fertile land, material for construction, medicinal plants, habitat for specialised plants and animals, and as an attraction for ecotourists. Some 20.200 ha, about two thirds of South Africa’s peatlands, are located at the Maputaland Coastal Plain. Eucalyptus plantations and common cultivation practices which include drainage are threatening the existence of the peatlands. This dissertation investigates peatland formation in Maputaland from a soil-related point of view, in order to identify the requirements for effective conservation and restoration measures, as well as more sustainable cultivation practices. Insights into peat formation processes were obtained through a macrofossil analysis. Based on the field examination of 141 soil profiles, 15 different peatland substrates were described and categorised into genetic substrate groups, and botanical peat types. Mean values for the following physical and chemical properties were determined for each substrate: Carbon content, C/N ratio, electrical conductivity, pH-value, bulk density, pore size distribution, saturated hydraulic conductivity, unsaturated hydraulic conductivity and maximum capillary rise. Moreover, the effect of degradation on the physical and chemical properties of South African peatlands was explored. Therefore, the aforementioned properties were measured for substrates at different degrees of degradation. Based on the changes in the soil properties thus established, the loss of ecosystem functions through degradation is discussed. By considering the frequency of occurrence of the substrate types in different hydrogeomorphic peatland types, adapted implications for conservation, restoration and cultivation are derived. In addition, based on the actual projections of climate change, estimations about future stress on the peatlands were derived.