Current issue: 56(4)
Under compilation: 57(1)
The effect of nitrogen fertilizers on the photosynthetic capacity of conifers is assessed on the basis of literature. The review emphasizes the role of changes of needle mass as a factor affecting the result of nutrient application. In particular, the increase in needle mass results in a considerable increase in photosynthetic capacity. The effect of fertilization on the photosynthetic rate seems to be of minor importance. The effect on the photosynthetic rate is, however, poorly documented as is the case for the effect of fertilization on the respiration rate. There is evidence that proper application of nitrogen fertilizers may double the photosynthetic capacity of conifers, mainly as a result of increase in needle mass.
The PDF includes a summary in English.
The dependence of elastic and tensile properties of coniferous trees on the share of summer wood can be presented as linear functions, if the soft wood is considered as a statically indefinite structure. By eliminating the share of summer wood by a certain function presented in the article, the elastic and tensile properties are the linear functions of density.
The functions are proved right by conducting strength tests on pine. Practical implications of the derived functions in rating the quality of wood are also presented.
The PDF contains a summary in Finnish.
The study area is state owned forest of Vesijako in southern middle Finland that has earlier been intensively managed with slash-and-burn agriculture. Reforestation of broad-leaved forests into coniferous forest with controlled burning has been studied on 76 sample plots.
The article describes the practice of leasing forest stands to leaseholders who executed the controlled burning and forest regeneration and management according a leasing contract. The results of the reforestation with coniferous trees shows that sowed pine (Pinus silvestris) stands give good results but spruce (Picea abies) must be planted as a seedling. For the state this method of forest improvement is cost effective and should be used more widely.