Reductions in tree-ring widths of silver fir (Abies alba Mill.) as an indicator of air pollution in southern Poland

The aim of the study was to investigate how the emission of pollutants to the atmosphere from the late 19th century until modern times has been recorded in rings of silver fir trees growing in southern Poland. Samples were collected from 24 firs growing in the Beskid Niski Mountains (Western Carpathians). Using a Pressler borer, a single core was collected from each tree. Within the samples, tree-ring widths were measured. On this basis, reductions of tree-ring widths were calculated and subsequently divided into three classes according to their severity. Study results indicate that growth reductions at the site studied were influenced by the pollution emitted from the now-defunct Central Industrial Region, which developed most rapidly from 1920 to 1940, and began to decline after World War II. These emissions were probably responsible for reductions in the trees sampled in the years 1928–1947. On the other hand, reductions of tree-ring widths dating from 1951 to 1989 were caused by the post-war development of heavy industry throughout Poland, and in particular in the Upper Silesian Industrial Region, which developed at its most rapid rate from 1960 to 1990. The results obtained demonstrate that reductions of tree-ring widths in the silver firs studied are related to industrial air pollution in the 20th century. As industrial production declined and environmentally friendly technologies were introduced in the early 1990s, air pollution levels decreased and an increase in tree-ring widths followed in the silver firs studied. Further reductions of tree-ring widths have been observed in recent years (since 2009), which may be caused by air pollution due to low-stack emissions from domestic boilers. The analysis conducted demonstrates that a reduction in tree-ring widths in silver fir is a sensitive bioindicator of air pollution

Can we distinguish between tree-ring eccentricity developed as a result of landsliding and prevailing winds? Consequences for dendrochronological dating

The aim of our study was to compare patterns of tree-ring eccentricity developed in Nor-way spruce trees as a result of landsliding with the one caused by the prevailing wind (in 2 study sites), and with the normal growth of trees (in 2 reference sites). We sampled 20 trees per study site and 10 per reference site. Two cores were taken from each tree (120 cores in total) from the upslope and downslope, windward and leeward sides of stems. Ring widths measured on opposite sides of stems were compared using the method of percent eccentricity index. Graphs of the index obtained for individual trees were analysed. Statistical indicators were calculated for a percent eccentricity in-dex. Disturbance events were dated and the response index was calculated. The results show that the patterns of eccentricity developed as a result of the prevailing winds and due to landsliding differ from one another and from the reference sites. The results suggest that the impact of the prevailing wind on tree growth is more severe than the impact of landsliding. The difference may result from the slow-moving character of the landslide under study. The results, however, indicate that wind impact should be taken into account in dendrogeomorphic research and that the impact of mass movements should be considered in dendroecological studies on wind

Relief evolution of landslide slopes in the Kamienne Mts (Central Sudetes, Poland) - analysis of a high-resolution DEM from airborne LiDAR

The aim of the study is to reconstruct the development of landslide relief in the Kamienne Mountains (Central Sudetes, SW Poland) based on a DEM from LiDAR data. Analyses of relief and geological maps in ArcGIS 10.5 and of slope cross-sections in Surfer 14 allowed to distinguish different types of landslide relief, developed in latites and trachybasalts lying above claystones and mudstones. The types vary from small, poorly visible landslides to vast landslides with complex relief. They were interpreted as consecutive stages of geomorphic evolution of hillslope-valley topography of the study area. Two main schemes have been established which explain the development of landslide slopes in the Kamienne Mts: (1) upslope, from the base of the slope towards the mountain ridge and (2) downslope, beginning on the top of the mountain ridge. The direction of landslide development depends on the thickness of volcanic rocks in relation to underlying sedimentary rocks. When the latter appear only in the lowest part of the slope, landslides develop upslope. If sedimentary rocks dominate on the slope and volcanic rocks form only its uppermost part, landslides develop downslope. The results show that landsliding leads to significant modifications of relief of the study area, including complete degradation of mountain ridges

Activity of slow-moving landslides recorded in eccentric tree rings of Norway spruce rrees (Picea Abies Karst.) - an example from the Kamienne MTS. (Sudetes MTS., Central Europe

We found ubiquitous evidence of ongoing slope instability by analysing the vari-ability of tree-ring eccentricity index in trees growing on three apparently relict landslide slopes in the Sudetes (Poland, Central Europe). Slow movement of these landslide bodies occurs in the present-day conditions and is recorded almost every year, although with vari-able intensity. Correlation of dendrochronological record with the rainfall record from a nearby station in Mieroszów for the 1977–2007 period is very poor for two deep-seated ro-tational slides at Mt Suchawa and Mt Turzyna but considerably better for a shallow flow-slide at Mt Garbatka. While this may reflect higher permeability of heavily jointed rocks involved in deep-seated sliding this could be linked with imperfections in the rainfall rec-ord. Dendrochronology proved capable of detecting minor displacements within landslides which otherwise show no geomorphic evidence of recent activity. Therefore, claims for the entirely relict nature of the landslides are not substantiated

Triggering factors and temporal variability of colluvium movements within a landslide slope – dendrochronological analysis at the example of Skalka landslide (Moravskoslezské Beskydy)

The aim of the study was to determine the temporal variability o landsliding and differences in the activity of individual part of a small land-slide. Dendrochronological methods have been applied: tree-ring eccentricity was analysed for 60 Norway spruce trees. The most dynamic landsliding occurred in: 1975, 1993, 1985, 1968–1969 and 1995. The number of wood-growth disturbances recording landsliding in particular years matches well with precipitation totals for summer half-years (e.g. landsliding and precipitation in: 1968, 1972, 1975, 1977, 1985, 2010) and to the smaller degree with totals for winter half-years (e.g. 1961). Results indicate uneven activity of particular landslide sections. The movement in particular parts of the landslide is triggered during various precipitation events or due to other factors (e.g. 1992–1993 earthquakes with epicentres in Beskid Sądecki Mts)

Indeks dekoncentryczności przyrostów rocznych drzew - narzędzie do identyfikacji współczesnych ruchów osuwiskowych

Stem shapes and tree-ring width were examined in spruces (Picea abies) growing on landslide-affected slopes in Moravskoslezské Beskydy (Western Carpathians, Czech Republic). In contrast to spruce trees growing on a stable slope, they are tilted upslope – in the upper parts of slopes, while in the near-channel zone they are bent downslope. It was found that on the underside of stems, influenced by gravity, wider tree rings are produced. The first years of tree-ring eccentricity were identified as the period of the initiation/reactivation of landsliding. In order to date them dendrochronologically, the eccentricity index of tree rings [%] and its yearly variation [%] were used. The proposed method of dendrogeomorphic analysis of landslides enables one to obtain the dynamic description of slopes and to study landslide activity, not only contemporary one, but also in the past. Depending on the stand age, it is possible to study the last tens to hundreds of years. Percent eccentricity index enables one to present and compare the intensity of mass movements between individual trees, study sites and landslide slopes – contrary to the reaction wood analyses – so far popular dendrogeomorphic method. Using eccentricity index and its yearly variation, it is possible to determine the presence of contemporary landsliding on slopes, to study its temporal and spatial variability and to outline the zone with domination of mass movements induced by fluvial erosion. The proposed method can be used in practice, in identification of contemporary active landslides, which can threaten existing or planned infrastructure and facilities

Niszczenie naturalnych odcinków koryt rzecznych na skutek niewłaściwej zabudowy – przykład dolin Czadeczki i Krężelki (Beskid Śląski)

Channels of Czadeczka and Krężelka rivers (Beskidzie Śląski Mts) are at present subjected to regulation because of which these rivers have lost their natural character, partially still preserved. The reasons for the river regulation have been analysed. Using archival maps, the buildings erection time has been analysed on valley floors, in the immediate vicinity of river channels for the period 1790–2012. Next, the distribution of existing buildings has been compared with hydraulic structures in the channels developed in order to regulate the Czadeczka and the Krężelka reaches, such as: concrete and stone embankments reinforcing the channel banks, check dams on channel bottoms. Results indicate a strong correlation between the number of buildings on valley floors in the 20th century and channel regulation. The mechanism of destroying rare, preserved natural river reaches is based on irrational permission allowing construction of buildings in areas threatened by floods and lateral erosion of rivers. Consequently, the inhabitants, in fear of floods and erosion of land or house foundations, seek river regulation that gives them a false sense of security. Natural river reaches are destroyed though efficient protection against floods and lateral erosion is still not provided and the range of possible losses increases even more due to continued building erection

Dendrochronological dating as the basis for developing a landslide hazard map – An example from the Western Carpathians, Poland

Most landslide hazard maps are developed on the basis of an area’s susceptibility to a land-slide occurrence, but dendrochronological techniques allows one to develop maps based on past land-slide activity. The aim of the study was to use dendrochronological techniques to develop a landslide hazard map for a large area, covering 3.75 km2. We collected cores from 131 trees growing on 46 sampling sites, measured tree-ring width, and dated growth eccentricity events (which occur when tree rings of different widths are formed on opposite sides of a trunk), recording the landslide events which had occurred over the previous several dozen years. Then, the number of landslide events per decade was calculated at every sampling site. We interpolated the values obtained, added layers with houses and roads, and developed a landslide hazard map. The map highlights areas which are poten-tially safe for existing buildings, roads and future development. The main advantage of a landslide hazard map developed on the basis of dendrochronological data is the possibility of acquiring long se-ries of data on landslide activity over large areas at a relatively low cost. The main disadvantage is that the results obtained relate to the measurement of anatomical changes and the macroscopic charac-teristics of the ring structure occurring in the wood of tilted trees, and these factors merely provide in-direct information about the time of the landslide event occurrence

Dendrochronology as a source of data for landslide activity maps - an example from Beskid Żywiecki Mountains (Western Carpathians, Poland)

We applied dendrochronological methods for dating landslide activity in the study area (3.75 km2), on the slopes of Sucha Mountain (1040 m a.s.l.), in the Beskid Żywiecki Mountains, in the Western Carpathians. 46 sampling sites were distributed throughout the study area. At each site we sampled 1-3 coniferous trees: Norway spruces (Picea abies Karst.) and/or silver firs (Abies alba Mill.). From each tree 2 cores were sampled: one from the upslope and the other from the downslope side of the stem. Based on tree-ring widths measured for opposite sides of stems we have calculated eccentricity index values and dated past landslide events. Mean frequency of landslides was obtained for each sampling site. Finally, the data was interpolated into a map of landslide activity. Inverse Distance Weighting (IDW) interpolation has been applied. For most of the study area we found medium (19 sites) and low (23 sites) levels of landslide activity. The highest level of activity was recorded for the largest landslide slope and for the one small landslide. The study conducted on Sucha Mountain has shown that dendrochronology can be an effective method for analysing landslide activity and may be useful in further studies, including those for landslide hazard and risk assessments

Zanieczyszczenie atmosfery przez zakłady przemysłowe położone w północnej części Wyżyny Śląskiej zapisane w przyrostach rocznych sosny zwyczajnej

Pines growing close to Tarnowskie Góry Chemical Plant and Miasteczko Śląskie Zinc Foundry produced reduced tree rings from 1950 to 1990 when compared with pines growing 60 km from the factories. Tree ring reductions occurred concurrently with the operation of the chemical plant and zinc foundry. Ring widths of the sampled pines are inversely proportional to the sulphur dioxide emissions from the Miasteczko Śląskie Zinc Foundry and the volume of production in the Tarnowskie Góry Chemical Plant. This demonstrates that the growth of trees was suppressed by emissions from the factories. Pines growing close to the zinc foundry started to produce reduced rings in 1965 and tree rings were very heavily suppressed in the 1970s. Reductions were noted from the time when the zinc foundry started to operate up until the present day. Reduced rings in 2000–2009 are produced by pines growing close to the zinc foundry and also those growing at a distance of 60 km from it. This indicates that ring reductions in 2000–2009 are not necessarily the effect of pollution emissions by the foundry. Tarnowskie Góry Chemical Plant emitted atmospheric pollution as early as 1925–1930 and as a result large tree ring reductions and many missing rings were identified in cores collected from pines growing close to the chemical plant. Tree ring reductions and missing rings occurred from 1955 to 1985 in pines growing close to the chemical plant. Pines have started to produce relatively wide rings since 1985 when the volume of production in the chemical plant rapidly decreased. This indicates that the plant reduced harmful emissions to the atmosphere from this date onwards