Modelling the stability of Cladonia-Scots pine forest (Cladonio-Pinetum Juraszek 1927) within Bory Tucholskie National Park using the repeated chronosequence method

Cladonio−Pinetum Juraszek 1927 forest is protected in Europe as the Natura 2000 habitat. Nowadays its naturalness is often considered to be doubtful. In spite of the many research, the knowledge about ecology and dynamics of this community is still insufficient. The aim of the research is to define the stability of the community within ‘Bory Tucholskie' National Park. The site is located in the area of the best developed patches of the habitat, in north−western Poland. Two datasets of relevés were used. The first comes from published data and includes 123 relevés made in year 2000. The other comes from own fieldworks performed in 2014. Due to the high homogeneity of geology and soils of the study site, repeated chronosequence method could be used to compare both datasets. The information about herb and moss layers of all relevés was compared using DCA method. The change in community was measured as a shift in the position within the main gradient of DCA over 14−year period. It was calculated for 122 pairs of relevés. Than the model of the speed of community change was computed for the main gradient. We used two methods of calculation of duration of the lichen−rich pine forests. The first was based on the calculated ranges of distinguished associations and the other used the model of cover of species connected to Cladonio−Pinetum forest. As the speed of community change in the gradient and the distance between distinguished communities were known, the time of community duration could be computed. According to obtained results, Cladonia−Scots pine forest (Cladonio−Pinetum) and lichen rich fresh pine forest (Leucobryo−Pinetum with Cladonia) of ‘Bory Tucholskie' National Park will last for 64−109 years. This result shows, that the considered Natura 2000 habitat is unstable. It is the possible development stage within managed forest stands and active conservation is necessary where its preservation is needed

Application of cluster analysis to distinguish the tendencies of vegetation changes on the example of the dynamics of communities affected by surface fire in the Peucedano-Pinetum community in the Kampinoski National Park

The programme of testing the progeny of permanent seed stands, parent trees, seed orchards and seedling seed orchards that has been run in Poland enables to determine the genetic value and silvicultural quality of the progeny of components of primary forest material. A better knowledge of population variability and adaptability to particular environmental conditions also allows for the updating and verification of principles regarding the use of the seed base in testing regions, as well as the determination of possibility for forest reproductive material to be transferred. The article presents the research on assessment of survival and growth among progeny from 26 permanent seed stands of silver fir that originates from Lublin, Radom and Łódź Regional Directorates of the State Forests, at four testing grounds located in the Kielce, Suchedniów, Tomaszów and Zwierzyniec forest districts. Each research plot was founded with 4 replicates, each with 3−year−old saplings. After 5 years of growth, mean rates of survival ranged from 70.4% at the Kielce site to 92.7% in Tomaszów. The lowest survival rate (30.5%) was noted for local origin (Starachowice), while the highest (93.8%) characterised the local standard from Zwierzyniec. Mean height varied from 54.1 cm in the case of the Suchedniów to 80.0 cm in the case of Tomaszów, albeit with the shortest firs originating from the Starachowice local standard and the tallest from the Tomaszów local standard. Analysis of variance components revealed that the environmental conditions (described by study area) played major role in shaping the variability. This effect was responsible for around 75% of the variance in height and 60% of that relating to survival. In contrast, origin (genetic factor) was most likely responsible for 7% of the noted variance in height or 4% of that relating to survival