The aim of this study was to obtain data for elaboration of methods that would be suitable for detection of assimilative apparatus damage, if the damage is still in its latent phase. The needles are covered with epicuticular waxes, which have a protective function, but are also damaged by air pollution first.

The damming of the Volta River has resulted in reduced flooding and an increase in mangrove cutting, accompanied by the virtual collapse of agriculture and fishing in the estuary. Another ecological consequence of the reduced level of flooding has been reduced dispersal of seedlings of the principal mangrove, Rhizophora racemosa. Therefore, after cutting of this species, recolonization is either by conspecifics growing at very high densities or by one of a number of weed species, particularly Typha domingensis, Acrostichum aureum, Paspalum vaginatum, Cyperus articulatus, Sesuvium portulacastrum and Philoxerus vermicularis. Environmental data collected in the vicinity of the mangroves and each of the weed species have enabled suggestions to be made as to whether R. racemosa or Avicennia africana would be the more suitable mangrove to replant. Recommendations have also been made to introduce the palm Nypa fruticans to the area, together with the development of nature-based tourism, both of which would provide alternative means of income generation, thereby reducing the need to cut remaining mangroves.

The objectives of this study were (I) to establish allometric relationships between the stem volume and biomass of the stem, branches, leaves and the leaf area, and crown dimensions of individual trees, (II) to determine the relative aboveground biomass distribution, (III) to determine the vertical gradient of the specific leaf area and (IV) to estimate the aboveground stand biomass and the leaf area. Diameter at 0.3m height above ground and height of each tree were measured as the basic biometrical characteristics. The coefficient of the shape of the trunk was found by Huber's method.

The studies of grass communities, which spread in deforested areas, also involved observations of soil thermal regimes. Three sites were chosen in order to determine differences in diurnal and seasonal variations of soil temperatures: (1) open site (barren) without plant cover, (2) site covered by a young, lower and thinner stand of Avenella flexuosa, and (3) old, dense stand of Calamagrostis villosa with a layer of plant litter on the soil surface. Soil temperatures were measured at the soil surface and in the soil depth of 5 and 10 cm. In summer months, the greatest differences in maximal temperatures recorded at the soil surface and at the 5, 10 cm depth between the bare site and the old stand of C. villosa represented 21.6, 15.9, 12.4 deg C, respectively. Soil temperatures measured in the bare plot in autumn months were lower than those in grass stands.

The soil water retention potentials and other hydrolimits of individual soil horizons of podzolized soil were determined in the stand of Picea abies (Mecuvka, the Beskids, Czech Republic) on godulic sandstone. Different hydropedologic characteristics for the individual soil horizons were found. Extreme values were detected for the albic E horizon, which importance for water and nutrient status of forest stand on podzolic soil is discussed.

The cloned saplings of Norway spruce (7 years old) were exposed to ambient UV-B irradiation or enhanced BV-B irradiation (+25 %) continuously over three growing seasons. Comprehensive analysis of CO2 assimilation and chlorophyll a fluorescence was performed at the end of the third growing season to evaluate the influence of enhanced UV-B irradiation. The analysis resulted in observations of decreased photosynthetic activity, mainly of RUBISCO activity, as a result of long-term influence of enhanced UV-B irradiation. Morever, the deep impact of enhanced UV-B irradiance on the level of electron transport and thus enhanced sensitivity to photo-inhibition was demonstrated.