This contribution presents LAI data of 17 Norway spruce stands of different age (from 15 to 102 years) and health status (defoliation ranging from 0 to 40 %) located in the Těšínské Beskydy Mts. (NE of the Czech Republic). Defoliation degree was estimated by ocular observation and LAI was estimated indirectly on the base of gap fraction method using LAI-2000 PCA (Li-Cor, USA). It was found that LAI decreased with stand age (approximately from 12.6 to 8.5) whereas defoliation increased. Therefore, strong relationship between defoliation and LAI as well as gap fractions was found. LAI appears valuable parameter for health status of stand evaluation due to linear relationship (r² = 0.87) between LAI and defoliation. As LAI can be estimated more objectively by a canopy analyzer then the degree of canopy defoliation by ocular observation, there is a perspective for a wide use LAI in forest practice. The LAI values can be used for the evaluation of health status of Norway spruce stands.

In a quest to improve the diversity and conservation of native tree species in tropical African forests, gap regeneration remains all-important nature-promoting silviculture practice and ecosystem-based strategy for attaining these ecological goals. Nine gaps of varying sizes (286–2005 m²) were randomly selected: three each from undisturbed, slightly disturbed and disturbed areas within Bia Tano Forest Reserve of Ghana. Within individual gaps, four transects (North–South–East–West directions) followed by 10 subsampling regions of 1 m² at 2 m apart were established along each transect. Data showed 63 tree species from 21 families in the study. Although, all estimated diversity indices showed significant biodiversity improvements in all gaps at p < 0.05 level. Yet, there were no significant variations amongst gaps. Additionally, tree species differed between gaps at the undisturbed and the two disturbance-graded areas while no differences were presented between disturbance-graded areas. Balanced conservation between Green Star and Reddish Star species and imbalanced conservation between Least Concern, Near Threatened and Vulnerable species in the International Union for Conservation of Nature (IUCN) Red List were found, showing the reserve’s long-term prospects for economic and ecological benefits of forest management. Thus, there is a need for higher priority for intensive management to regulate various anthropogenic disturbances so as to protect the biological legacies of the reserve.

This study presents results from continuous measurements of stem CO₂ efflux carried out for seven experimental seasons (from May to October) in a young Norway spruce forest. The objectives of the study were to determine variability in the response of stem CO₂ efflux to stem temperature over the season and to observe differences in the calculated relationship between stem temperature and CO₂ efflux based on full growing season data or on data divided into periods according to stem growth rate. Temperature sensitivity of stem CO₂ efflux (Q₁₀) calculated for the established periods ranged between 1.61 and 3.46 and varied over the season, with the lowest values occurring in July and August. Q₁₀ calculated using data from the full growing seasons ranged between 2.30 and 2.94 and was often significantly higher than Q₁₀ calculated for the individual periods. Temperature-normalized stem CO₂ efflux (R₁₀) determined using Q₁₀ from growing season data was overestimated when the temperature was below 10 °C and underestimated when the temperature was above 10 °C, compared with R₁₀ calculated using Q₁₀ established for the individual periods. The differences in daily mean R₁₀ calculated by these two approaches ranged between −0.9 and 0.2 μmol CO₂ m⁻² s⁻¹. The results of this study confirm that long periods for determining the temperature dependence of stem CO₂ efflux encompass different statuses of the wood (especially in relation to stem growth). This may cause bias in models using this relationship for estimating stem CO₂ efflux as a function of temperature.

Stem respiration is an important component of an ecosystem’s carbon budget. Beside environmental factors, it depends highly on tree energy demands for stem growth. Determination of the relationship between stem growth and stem respiration would help to reveal the response of stem respiration to changing climate, which is expected to substantially affect tree growth. Common measurement of stem radial increment does not record all aspects of stem growth processes, especially those connected with cell wall thickening; therefore, the relationship between stem respiration and stem radial increment may vary depending on the wood cell growth differentiation phase. This study presents results from measurements of stem respiration and increment carried out for seven growing seasons in a young Norway spruce forest. Moreover, rates of carbon allocation to stems were modeled for these years. Stem respiration was divided into maintenance (R_m) and growth respiration (R_g) based upon the mature tissue method. There was a close relationship between R_g and daily stem radial increment (dSRI), and this relationship differed before and after dSRI seasonal maximum, which was around 19 June. Before this date, R_g increased exponentially with dSRI, while after this date logarithmically. This is a result of later maxima of R_g and its slower decrease when compared with dSRI, which is connected with energy demands for cell wall thickening. R_g reached a maxima at the end of June or in July. The maximum of carbon allocation to stem peaked in late summer, when R_g mostly tended to decrease. The overall contribution of R_g to stem CO₂ efflux amounted to 46.9% for the growing period from May to September and 38.2% for the year as a whole. This study shows that further deeper analysis of in situ stem growth and stem respiration dynamics is greatly needed, especially with a focus on wood formation on a cell level.