The purpose of the study was an assessment of LiDAR point clouds for automating the mapping of land use and land cover changes, mainly land abandonment and the process of secondary forest succession. Detailed information about land cover was determined based on airborne laser scanning data. The presented study focuses on the analysis of the spatial range and structure of vegetation. The study area was located in Milicz district in the voivodeship of Lower Silesia – the central west part of Poland. The areas of interest were parcels where agricultural land had been abandoned and forest succession processes had progressed. Analysis of the spatial range of the secondary forest succession was carried out using a reclassified nDSM. Reclassification of the nDSM was done using > 1 m, > 2 m and > 3 m for the pixel values, representing the height of vegetation above the ground. Parameters such as height of vegetation, standard deviation of height and cover density were calculated, to show the process of the increase in forest succession on abandoned agricultural land. The results confirmed a discrepancy between the cadastral data and the actual use of the plots. In the study area, more than three times as much forested and wooded area was detected than had been recorded in official databases. Analyses based on airborne laser scanning point clouds indicated significant diversity in the vertical and horizontal structure of vegetation. The results demonstrated gradual succession of greenery in the research area.
We talk to the pioneering climate-change researcher Prof. Hans Joachim Schellnhuber about the role of decency in fighting climate change, and why excellent climate science requires freedom and trust.
Prof. Paweł Rowiński, Vice-President of the Polish Academy of Sciences, talks about how climate change will affect Poland and what signs of it should we look for in our rivers.
Arctic glaciers respond quickly to climatic conditions, which is why they play a special role as climate warming indicators. Studying them in the long term is the key to understanding future global environmental changes.
The development of linear infrastructure increases the degree of fragmentation of natural areas and has a negative impact on biodiversity and the range of available ecosystem services. The basic competing land use model is expanded to include infrastructure development. The extended model leads to the conclusion that due to the dual impact of the infrastructure (lowering the value of ecosystem services and increasing the private rents to developed land), the size of the natural area in the long-term equilibrium will be lower compared to the basic model. The preservation of nature ceases to be profitable enough. Infrastructure also reduces the marginal costs of conversion and thus increasing the volume of natural land being converted at avery moment along the transition path. If the decisions on optimal management of natural areas and infrastructure development are undertaken together, the result is a lower density of the infrastructure network and a larger ecosystem area in the steady state.
Land cover change (LCC) is important to assess the land use/land cover changes with respect to the development activities like irrigation. The region selected for the study is Vaal Harts Irrigation Scheme (VHS) occupying an area of approximately 36, 325 hectares of irrigated land. The study was carried out using Land sat data of 1991, 2001, 2005 covering the area to assess the changes in land use/land cover for which supervised classification technique has been applied. The Normalized Difference Vegetation Index (NDVI) index was also done to assess vegetative change conditions during the period of investigation. By using the remote sensing images and with the support of GIS the spatial pattern of land use change of Vaal Harts Irrigation Scheme for 15 years was extracted and interpreted for the changes of scheme. Results showed that the spatial difference of land use change was obvious. The analysis reveals that 37.86% of additional land area has been brought under fallow land and thus less irrigation area (18.21%). There is an urgent need for management program to control the loss of irrigation land and therefore reclaim the damaged land in order to make the scheme more viable.
In the present paper we show results of our research on the contents of selected heavy metals in the surface and subsurface water layers of the estuarine lake Gardno. Obtained results show that there are substantial differences between concentrations of lead, copper and zinc in surface microlayer and subsurface waters. We observed that the surface microlayer is capable of accumulating much higher amounts of these metals than the subsurface waters. Analysis of seasonal changes in heavy metal concentrations in surface microlayers and subsurface waters shows some periodicity of these changes.
In the recent years earlier appearance of late blight on potato crops and the increase of infection pressure of Phytophthora infestans has been observed due to the changes in its population. The occurrence of P. infestans on potato plants at early plant growth stages points to the possibility of existence of other infection sources such as infected seed tubers or volunteer plants and their increasing role in the disease epidemiology. These changes have led to late blight epidemics developing earlier and more severely than previously and changes in the occurrence and development of first symptoms of P. infestans infection on potato plants. In the years 1997–2006, field studies were conducted at the Plant Breeding and Acclimatization Institute of Bonin with the emphasis on comparison of time of the occurrence and incidence level of late blight of potato. The criteria for pathogen infection pressure assessment were assumed to be the percentage of haulm destruction at the end of growing season and area under the disease progress curve (AUDPC), the late blight development rate defining the increase of destruction of above ground plant parts in unit time and also tuber yield and its healthiness. The observations carried out at Bonin revealed that both time of occurrence and severity of late blight differed and were dependent upon meteorological conditions and upon the year. Late blight occurred the earliest at Bonin in 2001 (42 days after planting). The time of occurrence of late blight depends upon rainfall in May and June. A very high infection rate of the pathogen was observed, particularly in 2006 (0.517) and in 2004 (0.400) despite late time of late blight appearance in the season. In these years AUDPC on the unprotected cultivar was 0.071 and 0.508, respectively. The 10 years of observations conducted at Bonin revealed that the yield and occurrence of tuber late blight depended mostly upon meteorological conditions in particular years.
Prof. Mirosław Kofta, a psychologist from the University of Warsaw’s Faculty of Psychology and Institute for Social Studies, discusses political change in Poland, authoritarian personality, and civil society.