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Six mire sites designated as mixed mires on the geological maps Örebro NV and NO have been surveyed. All of them were found to be entirely ombrotrophic bogs. The necessity of considering the composition of the vegetation in drawing the distinction between ombrotrophic and minerotrophic mire sites is pointed out. 

The author has re-mapped two areas on Skagershultamossen. The new maps have been compared with maps of the same areas from 1910, made by L. von Post. The vegetation changes are small. The open water surfaces have diminished in number and extent. The theory of cyclic succession on peat bogs finds no support from the maps. Plant communities have been delimited as to correspond to those on the old maps and defined through analysis of a number of sample plots

A review is presented on the literature about the distribution of savannas in humid climates in Africa and Asia and their vegetation dynamics. Sections are devoted to African lowland and montane savannas (the latter divided into southern, eastern, western and northern African), Madagascar, Indian subcontinent, SE Asia and New Guinea. It is concluded that the extension of savannas under humid climatic conditions and the relation to the distribution of forests is a function of cultivation, grazing by domestic and wild animals, present and previous climate, geomorphology and soil characteristics. Once established, savannas are often maintained by fires, both natural and man-made.

Montane savannas are generally brought about by man's clearing, cultivation and burning. Fire is a stochastic variable; it creates an ecotone sensu stricto (an environmentally stochastic stress zone) at the forest/savanna border. On the other hand, if geomorphology and soil are the determinants, the transition between forest and savanna would have the character of an ecocline (a gradient zone) with fundamentally different conditions.

In humid African lowland climates forests expand into savannas if the latter are not maintained by man. Whether forests also expand in less humid climates is disputed. In montane areas forest expansion may be delayed on degraded soils and when diaspores are lacking

Data from transects on the shores and drawdown area of a small reservoir in Tanzania with a strongly fluctuating water level were used to illuminate a spatial and shortterm temporalvariation in the vegetation of a borderzone. Vegetation data were related to the position of the sample plots in relation to a water level gauge and to time (seasonal changes and changes between two consecutive years).

Few perennial species survived the rainy season in the zone exposed to the fluctuating water level. Most plants were annuals that colonized yearly. The vegetation under the full supply level (=FSL) was sparse and related to Eriochloetum nubicae and Ecliption albae. An observed great variation between sites and years of this kind of vegetation seems to be due to the unstable character of the sites with frequent recolonization of bare land.

The need to distinguish formally between ecotones (in a strict sense) and ecoclines is stressed. The drawdown area has (a) a peak in β diversity just below FSL, (b) no β diversity in a zone below FSL that was not flooded the preceding rainy season and (c) a certain amount of β diversity further down.(a) and(b) are considered typical of an ecotone. (c) is interpreted as a 'shortterm ecocline' of colonizing annuals between two rainy seasons. The system belowFSL as a whole is an ecotone. The shore above FSL is an ecocline with high α and β diversity.

A downward movement of plant species during the dry season is demonstrated using canonical correspondence analysis. Thus, this ecotone is driven by the environment and no internal (autonomous) control is likely to occur

Flarks are reported to occur in mires in Qathlamba (the Drakensberg Range) of the Maloti, Lesotho at an altitude of 3200 m a.s.l. Flarks are not previously reported from Africa. Conditions for the formation and maintenance of flarks are discussed. It is argued that local waterlogging is a more likely explanation for the formation of flarks in Qathlamba than frost action.

The production of fine roots in originally root-free ingrowth cores was studied in an ombrotrophic mire ecosystem in central Sweden (14°42'N, 60°10'E). The estimated production values, which should be considered conservative , were 51 g^.m^-2 in hummocks and 86 g^.m^-2 in lawns (= upper hollow level). This represents 38% of the total measured production of vascular plants (increment in coarse roots not included) in hummocks and lawns, respectively. In the first year of study more than 50% of the fine root standing crop was found above 10 cm depth. In the second year, which was very dry, the roots penetated significantly deeper.

When surrounded by growing Sphagnum the rhizomes of Scirpus cespitosus grow vertically upwards in pace with the Sphagnum. It was found that there is a considerablevariation in rhizome growth between years and it is assumed that this variation is determined by variation in Sphagnum growth. The latter variation is assumed to be dependent on the weather. Simple and multiple regression analysis of rhizome growth on various weather variables gave the following results:(1) Moisture conditions are decisive for the growth. (2) The distribution in time of the moisture is more important than mean values from a certain period. (3) Although moisture in June and Augus tof the current year was important, the moisture conditions of August of the previous year explained ca 60% of the variation. (4) A combination of the two variables Birot's wetness index in August of the previous year and the same index in current June gave r² = 0.80.

Soligenous mires are common at high altitudes in the mountains of Lesotho, southern Africa. The flora and vegetation are distinctive and the mires form ecosystems not found elsewhere. Peat is formed mainly from the roots of vascular plants and is generally shallow. Bryophytes play a subordinate role in the vegetation. Flarks and thufur occur at the highest altitudes. The mires are heavily grazed and are rapidly being destroyed, particularly through gullying caused by intense grazing upslope from the sites. A project to export water to South Africa is now being put into effect. This will severely affect the mires through inundation of sites and increased pressure on remaining land. The new infrastructure in these areas also causes destruction. An appeal is made for international pressure to save the remaining mires in Lesotho.

Composition of hill slope vegetation was studied in a semi-arid part of upland Tanzania where all grazing had been banned for 12 yr. The hills had been severely overgrazed previously and suffered from heavy gully and sheet erosion. Eight vegetation types are described. Floristic gradients revealed by numerical ordination techniques were found to be related mainly to degree of erosion, soil type and succession. The more or less bare soil that prevailed after grazing had ceased is now covered by grassland, woodland and immature secondary forest. The grasslands are still characterized by early successional species and they will probably remain open grassland as long as frequent burning continues. Brachystegia woodlands may have developed during earlier periods when the field layer was sparse due to grazing. The grazing had reduced the frequency of fire which in turn promoted the establishment of Brachystegia spp. Secondary forests are believed to have developed mainly where fires were not frequent, particularly at higher altitudes.