Seasonal changeability of soil enzyme activity has not been entirely known. The aim of the paper was presenting the seasonal changeability in enzyme activity in fresh forest sites. From 10/06/2007 to 20/06/2008 samples were taken seven times at 6-weeks’ intervals from two sample plots representing sites Lśw, LMśw, BMśw and one for Bśw site. Activity of dehydrogenase, protease and urease have been marked in the soil samples. As a result of conducted research the minimum value for enzymatic activity was found in October 2007 and April 2008. Maximum values for the activity of studied enzymes were noted in January and June 2007 and 2008, while no statistically significant differences were found between enzymatic activity marked in June 2007 and June 2008.

The aim of the study was to discover habitat preferences of the forest dung beetle Anoplotrupes stercorosus (Scriba, 1791). Beetle specimens were collected using modified Barber traps in the Białowieża Forest, in 1999. In total, 14980 specimens of the forest dung beetle were collected. According to the obtained results, the optimal habitat types of the beetle in question included fresh broadleaved forest, fresh mixed broadleaved forest, fresh mixed coniferous forest, moist broadleaved forest and fresh coniferous forest. It was discovered that the beetle in question was more abundant in fresh forest habitats than in moist and boggy forest habitats or in alder swamp forests.

One of the methods limiting the damages done by Armillaria species is to decrease the number of dead wood stumps attacked by it, particularly it refers to deciduous tree stumps.The objective of the presented paper was an attempt to estimate the possibility to select some saprotrophic fungi species whose ability of decaying oak wood is higher and faster than that of Armillaria ostoyae (Romagn.) Herink and Armillaria gallica Marxm & Romagn, and which could be utilized in a biological protection method preventing Armillaria root-wood attack. All analyzed wood samples were colonized by tested mycelia. Among the fungi which could be utilized in a biological method of protection against root mould caused by Armillaria, the fungus Tramestes versicolor has shown to be the best suited for this purpose. Four different isolates were tested, which have confirmed their efficiency in decaying oak heartwood. Therefore, this fungus could be used for the elaboration of a biopreparation protecting effectively against Armillaria root rot.

The present research was conducted in managed stands of Scots pine (Pinus sylvestris L.) at different age in Poland. All the investigated stands were planted and thinned according to selection thinning. Analysis of spatial structure concerned trees of different categories (DBH classess) depending on the age of stand. Spatial distribution of trees was investigated using two commonly used methods: Clark-Evans R index and Ripley’s L(t) function. In stands of age 43 and 65 the effect of the initial spacing was observed and all living trees were distributed regularly at the smallest distances and at larger spatial scale they were spaced randomly. Random type of spatial structure of trees was observed when smaller and larger trees were taken into consideration, separately. In case of stands at the age 90 the effect of the initial planting on the spatial structure of trees was not observed even at the smallest distances independently of the category of trees taken into account. All living trees in these stands were distributed randomly. Only in two stands clumps of trees were observed and one concerned smaller trees and the other – larger trees. Size differentiation index was small for all stands. The lowest values was ascertained in the oldest stands.

In contrast to other natural objects situated within boundaries of the city of Poznań, the former ecological site “Bogdanka” distinguishes itself by its exceptional floristic values. The flora of this object comprises 527 taxons of vascular plants derived from 91 families and 295 genera, of which 180 can be found on rare and threatened species lists. In addition, 15 species under legal protection as well as 34 species from all country and regional lists of rare and endangered species occur here. The most valuable floristic elements include: Iris sibirica, Galium odoratum, Hierohloë odorata, Trollius europaeus or Dianthus superbus. Several trees with monumental or close to monumental circumferences as well as splendid trees can also be found in this site. The area should regain its protected status as soon as possible.