Andrzej Nienartowicz

Biomass of Scots pine-silver birch tree stand 25 years after afforestation of former agricultural land

: In 2O15, the structure of a forest stand growing on former agricultural land in subunit 277n of the Przymuszewo Forest Division (Regional Directorate of State Forests RDSF in Torun) was described. The study area was afforested in 199O - mostly with Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth) and several seedlings of the European beech – after many years of agricultural cultivation of grain and potato crops. Characteristics of the forest stand comprised the following parameters: species composition and species diversity, density of individual components, the average tree diameter at breast height (DBH), and the height and aboveground biomass of trees divided into individual species. The species structure, dendrometric characteristics and spatial dis- tribution of trees studied in 2015 were compared with the situation assessed in 2000. Based on DBH and height values, as well as the use of dendrometric tables and basic wood density for tree species, the above- ground biomass and total biomass of trees with a minimum diameter of 7 cm were calculated. The aboveground and total biomass for trees with DBH less than 7 cm was calculated on the basis of density and weight of trees according to the classification into species and height classes. The aboveground and total biomass of the whole tree stand, including spontaneous non-native and invasive Padus serotina Ehrh., was compared with the standing biomass of agricultural areas in the Tuchola Forest region as well as with other Scots pine-silver birch plantations on former agricultural lands described in ecological literature. The paper presents also the differences in assessments of aboveground pine biomass at the study site obtained when using conver- sion factors established during direct measurements carried out in forests of the Przymuszewo Forest Division and conversion factors applied during inventories conducted in Poland according to the IPCC recommendations for international reporting submitted to the United Nations Economic Commission for Europe, FAO and UNFCCC

New localities and habitat preferences of common milkweed Asclepias syriaca L. in Toruń (Central Poland)

The paper presents the location and general description of habitats and plant communities with common milkweed occurring within the city limits of Torun. The data set comprised new localities of this species as well as those where Asclepias syriaca has been observed for several years but the sites have not been described in the ecological literature. Releves made at these sites were compared with those described by Puchalka et al. (2013) from three sites of Asclepias syriaca in Torun. A larger set of new sites included in the analysis allows for a more accurate description of the impact exerted by some ecological factors, e.g. afforestation, on the growth of the studied species. As evidenced by the new sites of Asclepias syriaca found recently in Torun and the surrounding area, it is necessary to monitor the dynamics of the population and to undertake the research on the impact of common milkweed on plant communities.

Changes in the plant cover of the dune hill in Folusz near Szubin (NW Poland) between 1959 and 2012: the problem of preservation of xerothermic grasslands in the agricultural landscape

The dune hill in Folusz is one of the most interesting sites with xerothermic vegetation in the Polish lowland. It is different from other sites by the fact that xerothermic vegetation covers a single dune located amidst large areas of Molinia meadows rather than slopes of river valleys. Vegetation occurring on the hill represents a cold Stipa steppe with rare species of floodplain meadows and has long aroused the interest of botanists. In the 19th century and in the early 20th century, observations in this area were carried out by German botanists (L. Kuhling, F. Spribille, H. Miller, W. Bock). In the 1930s, the investigation was continued by botanists from the University in Poznan. After World War II, it was one of the main research sites for botanists and ecologists from the University in Torun, and recently also from the universities in Bydgoszcz. Floristic lists were compiled by all the aforementioned researchers, which describe the state of flora in the subsequent periods, and when collated in tables, they help to determine the directions of changes occurring in the area over a hundred years. Not all the materials obtained in the past were published. A lot of interesting data were preserved in the Torun centre in the form of actual vegetation maps and releves. This paper presents the comparison of vegetation from 1959, plotted on the unpublished vegetation map by J. Wilkon-Michalska, with the vegetation in 2013. Changes in the land cover were also analysed through a series of aerial photographs from 1961, 1975, 1986 and 2005. The GIS and GPS technology was used in the spatial analysis. Furthermore, the analysis of flora changes was performed, including the comparison of data presented in ecological literature with unpublished data collected by J. Wilkon-Michalska in 1956-1964. In addition, numerical analysis of releves from both these periods and from 2012 was performed. The objective of all the analyses was to determine how the changes were affected by spontaneous development of oak trees on the dune and destructive human activity related to exploitation of the sand, afforestation of the dune with pine, birch and oak, and planting of common lilac. An effort was also made to assess the importance of including the Folusz dune hill within the Natura 2000 site − PLH040027 „Molinia meadows in Folusz” − for preventing further degradation of xerothermic vegetation.

Afforestation of heathlands and its influence on the land cover, accumulation of plant biomass and energy flow in the landscape: An example from Zaborski Landscape Park

In the mid-19th century, the sheep industry played a considerable part in sheep breeding in Pomerania. Livestock grazing took place on extensive heathlands developed as a result of land deforestation performed in the 17th and 18th century, as well as during and after the Napoleonic wars. The sheep industry and the related textile craft developed until the 1890s when the Prussian government began the restoration of forests after the period of their excessive exploitation. The Prussian government policy contributed to the afforestation and the growing forest range through purchasing of landed estates, in particular the Polish ones, and creating forest divisions, followed by reconstruction of forests. This paper presents the history of the Widno estate belonging to Mr. Konstanty Przytarski. The estate was located in the northern part of the present-day Zaborski Landscape Park, near the town of Brusy and Chojnice. In 1894, the estate was sold to the Prussian forest administration. The paper presents changes in the land use and the forest above-ground biomass. Furthermore, changes in the structure of the energy flow network through the natural and production-cultural subsystems are presented. The network structure was analysed according to the methodology presented by H.T. Odum. Data contained in the sales contract of the Widno estate were used in the analysis, together with a forest inventory book of the Prussian Forest Inspectorate Zwangshoff and inventory books of the Polish Inspectorate Przymuszewo. The study highlighted the increasing role of sheep breeding on small family farms established by employees of the forest division on the leased lands. This form of activity refers to the economic traditions in the region of Zabory.

Influence of land cover and structure of tree stands on pollen deposition in Zaborski Landscape Park

The paper presents a comparison of modern pollen deposition in Tauber traps after one-year exposure at two research sites – Laska and Widno, located in the northern part of the Zaborski Landscape Park in the Pomerania Province (Northern Poland). The studied sites were circular in shape with a radius of 2 km and an area of 1256 ha each. They were characterised by similar contribution of forest and non-forest areas, as well as similar species composition and area covered by tree species. Both sites differed, however, in the location of traps in relation to forest areas and distribution of deciduous trees amid pine monocultures. At the former site, a Tauber trap was placed in the open field, i.e. in xerothermic meadow, in the western part of the Laska village. At the latter site, a trap was placed on the borderline between meadows of the Widno village and the surrounding forests. At the site of Laska, scattered deciduous trees occurred mostly in the form of small clusters amid extensive pine monocultures surrounding the village. Whereas at the site of Widno, deciduous tree species covered larger areas in the form of more fertile oak-hornbeam forests, beech forests and birch woods amid pine forests. The size of area covered by tree species and the amount of pollen deposition by these trees were positively correlated at both sites. In addition, the average annual pollen deposition was calculated for each site for seven most abundant tree species during the period of 1999–2010. By comparing the arithmetic means, it was found that the pollen deposition at the site of Widno is higher for most of the studied arboreal species compared with the site of Laska, but these differences are statistically significant only in the case of birch and hornbeam. Surface pollen samples from the sites of Laska and Widno were compared in terms of pollen deposition with 4 other sites from the Zaborski Landscape Park and with the site located in the Las Piwnicki nature reserve in the Toruń Basin.