Tree-Ring Chronology of Silver Fir and Its Dependence on Climate of the Kaszubskie Lakeland (Northern Poland)
The current paper presents investigation of the response of silver firs growing near Kartuzy in the Kaszubskie Lakeland (northern Poland) to climate conditions. Tree-ring width series covering the period of 1914-2006 were built and correlated with mean monthly temperature and precipitation. Dependence of the growth of analysed firs on winter, early spring and summer temperature was observed. Significant relation to moisture availability was detected only for January. Analysis of pointer years revealed similar driving forces that were obtained by correlation and response function investigation. Reaction of firs from the Kaszubskie Lakeland to the extreme climate conditions is analogous to the exhibited at other sites of this species localised outside distribution range. Investigated silver firs seem to have found favourable growth conditions in the studied area and further cultivation of that species in northern Poland may turn to be successful.
The paper presents selected properties of the organic soils developed in boreal mire spruce forests (Sphagno girensohnii-Piceetum) in the Romincka Forest (NE Poland). Additionally, the relationship between soil fertility and forest stand productivity was investigated. Data from 12 soil profiles, differing in terms of peatland ecological type (raised bog, transitional bog and fen) was used. The significance of the differences in soil properties among peatland types was assessed with the Kruskal-Wallis test. Soil fertility was described using soil trophic index (SIGo), whereas stand productivity according to site index (SI) value. The properties of the analysed soils varied significantly in terms of peatland type. Soils from fens were more fertile (SIGo 25–31), less acidic (pH > 5.7), with lower total potential acidity (36–40 cmol(+)·kg−1), higher base saturation (77–79%), Ca2+ content (116–136 cmol(+)·kg−1) and base exchange capacity (123–145 cmol(+)·kg−1) than soils from transition or raised bogs. No significant effect of soil fertility on the site index of stands growing on analysed soils was observed (r = 0.385, p = 0.216).
I present dendroclimatological analysis of coniferous tree species growing under the same environmental conditions in the WULS-SGGW Forest Experimental Station in Rogów (51°49' N, 19°53' E, ca. 190 m a.s.l). The study focuses on silver fir, European larch, Scots pine and Douglas fir. For each species, tree-ring width and annual sensitivity chronologies were developed for the period 1931-2010. Analysed species show considerable similarity of their radial increment course (GLK up to 67%, the t-value of 3,5-9,5). The relationship obtained for of the influence of climate conditions on radial growth of these species is typical of the relationships reported from other locations in lowland Poland. Late winter and early spring temperature, especially during February-March, is the main factor affecting tree-ring formation. The general relationship demonstrates that this seasonal thermal limitation operates at an inter-regional and interspecific level in determining the growth of coniferous tree species in Poland. Whereas, the dependence of these species on precipitation is much less significant.
As tree height is one of the important variables measured in forestry, much effort is made to provide its fast, easy and accurate determination. We analysed precision of two widely available smartphone applications (Smart Measure and Measure Height) during the field measurements of tree height. The data was collected in three Scots pine stands in central Poland. We found negative systematic error of both tested applications regardless the distance of the measurement (15 or 20 m). RMSE values of the height estimates varied from 1.01 to 2.46 m depending on the application used and the distance of the measurement. Value of the calculated absolute and relative errors significantly (p < 0.015) positively depended on the actual height of the measured trees and was more diverse for higher trees. Smartphone applications seem to be promising measurement tool for tree height determination, however as for the time being they require improvement before wider introduction into the forest practice.
This paper investigates the slenderness of black locust (Robinia pseudoacacia) trees in relation to the biosocial status of the trees, stand age class, crown parameters and habitat type. The research material was collected on 35 research plots in the Sława Śląska, Sulechów and Głogów forest districts in western Poland and comprises 1058 trees. For each tree, we measured height (h) as well as diameter at breast height (d) and determined its biosocial status (Kraft class), crown length (CL) and relative crown length (rCL). The age class and habitat type were assessed at the plot level. Because the obtained values for slenderness (s=h/d) diverged significantly from the normal distribution, we used Kruskal-Wallis and Mann-Whitney tests to investigate the influence of the above-mentioned parameters on the h/d ratio. Black locust slenderness ranged from 0.31 to 1.95 with an average of 0.91 (standard deviation 0.24). It furthermore differed significantly between Kraft classes (the higher the biosocial status, the lower the slenderness) and age classes (the older the trees, the lower their slenderness). We also found a significant effect of the habitat type (in oligotrophic sites trees formed more slender trunks than in mesotrophic sites) and crown parameters on the h/d ratio (decreasing with increasing crown length and relative crown length). The obtained results suggest that the slenderness of black locust does not differ substantially from native broadleaved trees in Poland.
Dead wood plays an important role for the biodiversity of forest ecosystems and influences their proper development. This study assessed the amount of coarse woody debris in municipal forests in Warsaw (central Poland). Based on the forest site type, dominant tree species and age class, we stratified all complexes of the Warsaw urban forests in order to allocate 55 sample plots. For these plots, we determined the volume of dead wood including standing dead trees, coarse woody debris and broken branches as well as uprooted trees. We calculated the amount of dead wood in the distinguished site-species-age layers and for individual complexes. The volume of dead matter in municipal forests in Warsaw amounted to 38,761 m3, i.e. 13.7 m3/ha. The obtained results correspond to the current regulations concerning the amount of dead organic matter to be left in forests. Only in the Las Bielański complex (northern Warsaw) volume of dead wood is comparable to the level observed in Polish national parks or nature reserves, which is still far lower than the values found for natural forests. In general, municipal forests in Warsaw stand out positively in terms of dead wood quantity and a high degree of variation in the forms and dimensions of dead wood.
Among the invasive tree species identified in Polish forests, black cherry (Prunus serotina Ehrh.) appears to pose the greatest threat. The objective of this study was i), to determine the abundance of this species in the forests managed by the State Forests National Forest Holding (PGLLP) and ii), to characterise the ecological conditions that it is found in. The source data was obtained from the State Forests Information System (SILP) database. In Polish forests, black cherry mostly occurs as an understory plant and is present in a total area of 99,185 hectares, which is 1.4% of the forest area under the management of the PGLLP. Although Prunus serotina can be found within a wide range of habitats, it most commonly occurs on sites that can be considered average in terms of fertility (mixed coniferous and mixed deciduous types) developed primarily on rusty soils (podzols).
The study investigates the influence of climate conditions on radial increment of oak, with special concern to the situations when analysed trees formed conspicuously wider or narrower tree-rings. The research material was collected in four locations in central Poland within natural range of pedunculate and sessile oaks. The elaborated residual chronologies were correlated with CRUTS 2.1 climate data. The analyses included thermal and pluvial conditions spanning from April of the year prior to ring formation to September of the current growth year. Special interest was paid to simple water ability index that combined both temperature and precipitation during the vegetation season. Additionally, pointer year analysis was carried out to determine situations when conspicuously smaller or larger increment was formed.
Investigated chronologies cover the period of 1927–1992 (Łochów), 1845–1992 (Płońsk), 1868–1992 (Pułtusk), and 1796–1992 (Sokołów). The analysed oaks from sites in central Poland exhibit growth patterns comparable with those known form previous studies concerning that species, where influence of precipitation (higher and positive) and temperature (negative) have been observed. Extreme growth reactions expressed by negative and positive pointer years turned to present high dependence of analysed oak’ growth on water availability during vegetation season.
The paper discusses periodic climate changes in Europe determined on the basis of dendrochronological data dating back one thousand years. In tree-ring width sequences of trees growing in Poland there are approximately 8-, 11-, 100- and 180- year periods. The tree-ring widths of oaks growing in Poland for the last centuries are characterised, without any significant amplitude, by 8- and 11-year periods (Tab. 1). In turn, chronologies of pine, spruce, larch, oak and fir growing in Europe are characterised by 100- and 180-year periods (Tab. 2). Cycles of dendrochronological variables approximate cycles of air temperature and North Atlantic Oscillation NAO as well as those of solar activity. The forecast of annual growth (ring width) for 2001-2100 was calculated by interference of the tree-ring width cycles determined by the sinusoidal regression method. Because of much longer empirical sequences of specific periods, the credibility of forecasts for tree-ring widths is greater than that for air temperature.