Knowledge of the quantity of twig dry mass (available fodder) of saplings is crucial for understanding tree recruitment under wild ungulate browsing pressure in forest ecosystems. Therefore, this ...study aimed to develop allometric equations for estimating twig dry mass using sapling structural data and to model the twig dry mass of saplings of various species in various size classes while quantitatively describing the variations among tree species. Sapling biomass samples were taken for six widely spread tree species in two national parks in Poland. After drying the biomass samples in the oven for 72 h at 65 °C, the data were analyzed, and models were generated using the ordinary least squares and generalized additive methods. The results confirmed our hypothesis that different tree species differ in their allometric properties. The twig dry masses of Acer pseudoplatanus and Carpinus betulus were best estimated by basal diameter, whereas those of Picea abies, Abies alba, and Fagus sylvatica were best estimated by sapling height. In contrast, the model quality for Fagus sylvatica and Sorbus aucuparia was enhanced by combining the sapling height with the mean largest crown length (MLCL). For all species, the twig dry mass distribution was linear along sapling height classes and exponentially increased with shoot diameter classes, with coniferous species exhibiting the highest correlation. On the other hand, the proportion of twig dry mass to total sapling dry mass followed the order S. aucuparia > A. alba > P. abies > F. sylvatica > C. betulus > A. pseudoplatanus. The developed allometric equations contribute significantly to the already available collection of published biomass equations. Moreover, they extremely useful in estimating the browsing potential of tree saplings falling within size ranges conducive to herbivore browsing.
The relative importance of environmental factors and species pool in natural regeneration processes is still intensively disputed. Is environmental filtering especially important for species with ...higher requirements for temperature and soil fertility? Is the seed source limitation especially pronounced among tree species with lower dispersal abilities? Trees, seedlings and saplings measurements were conducted in 600 plots of 0.05 ha distributed in a regular grid in the Tatra Mountains (elevation range 817–1797 m a.s.l.). Boosted regression trees were used to analyse the relationships between the numbers of young trees, factors acting as environmental filters and the potential seed source availability. The most important factor affecting the distribution of young trees of most species was elevation; bedrock type was the second most important factor for
Acer pseudoplatanus
, while potential solar radiation was important for
Sorbus aucuparia
. The relationship between the presence of mature trees and abundance of young ones was strong in
Fagus sylvatica
, moderately strong in
A. pseudoplatanus,
and weak in
Picea abies, Abies alba
and
S. aucuparia
. The role of environmental factors in shaping the abundance of young trees varies strongly among species, while the seed source availability is very important for large-seeded trees.
•The Gorce Mountains reserve’s larch population’s genetic uniqueness was proved.•No contamination by alien species of Japanese larch and Euro-Japanese larch was found.•The larches from the Gorce and ...Tatra Mountains have significant genetic differences.•The reserve is a potential source of forest reproductive material.
Conservation of valuable populations must be based on a thorough understanding of their genetic variation, especially for species negatively affected by human activities. We investigated the population of larch from the nature reserve in the Gorce Mountains, which was established to preserve a unique stand of Larix decidua subsp. polonica, a remnant of one of the largest native complexes of this species. The chloroplast marker ll-TaqI was used to investigate whether the gene pool of the analysed population was contaminated with the alien larch species. We used eleven nuclear DNA microsatellite markers (nSSRs) to examine this population’s genetic diversity and verify the hypothesis about historical use of the larch from the reserve as a source of reproductive material for the Tatra Mountains. The link between the reserve population and the European larch’s ancestral groups was also verified. No contamination of the studied pool of individuals by alien species was found. The study showed high genetic variability in larch from the Gorce Mountains (HE = 0.689, HO = 0.671). The differentiation between the Gorce and Tatra National Park populations was FST = 0.038 (p < 0.001). Trees from the reserve and the national park formed two distinct genetic groups. We rejected the hypothesis that the nature reserve was the source of the regeneration material used in the Tatra Mountains. The study proved the uniqueness of the reserve population, and confirmed the appropriateness of the protection measures taken.
•We compared stand structure in managed and unmanaged ravine forest.•Metrics related to dead trees showed only subtle differences.•Characteristics related to living trees performed much better in ...this comparison.•Spatial distribution of trees differed mainly at small distances (up to 5 m).
The aim of this study was to compare the forest stand structure in managed and unmanaged ravine forests. The study was conducted in the Carpathians and the Krakow-Częstochowa Upland (SE Poland). We used 24 plots, of which 13 were from managed forests and 11 from unmanaged areas. We used 12 metrics related to both living and dead trees. The density of large living trees, quadratic mean diameter and maximum diameter were higher in the unmanaged forests, while the total density of all living trees, percentage of dead trees and number of stumps were higher in the managed forests. In addition, we found only subtle differences related to dead trees. The point pattern analysis also showed differences in the spatial distribution of trees. In unmanaged forests, we found a tendency towards tree aggregation, which was significant in several plots at small distances (up to 5 m), thereby suggesting the common presence of trees with multiple stems. In managed forests, we did not find any significant deviations from random patterns.
Our findings show that forest management significantly influences the stand structure in ravine forests. Surprisingly, although metrics related to dead trees are considered as the best indicators of naturalness, we detected only subtle differences between managed and unmanaged forests. The characteristics related to living trees performed much better when distinguishing between managed and unmanaged stands. This is probably due to the specific habitat conditions in ravine forests characterized by steep slopes and highly dynamic dead biomass. In addition, a lack of tree clusters in managed forests is probably a result of selective cutting of trees with multiple stems. Finally, we conclude that the analysis of stand structure is more sensitive for the detection of management than a comparison of the plant species composition.
The primary objective of this study was to characterise the edaphic conditions of forest areas in the Pieniny National Park (PNP), and to describe the dependencies between properties of forest soils ...and types of forest plant communities. The “Soil Trophic Index” (SIGg) for mountainous areas was applied. The evaluation of the trophism for 74 forest monitoring employed the soil trophic index for mountainous areas SIGg or SIGgo. Plant communities in the forest monitoring areas were classified according to the Braun-Blanquet’s phytosociological method. Soils of PNP present in the forest monitoring areas were mostly classified as eutrophic brown soils (72.9%), rendzinas (10.8%), brown rendzinas (5.41%), and rubble initial soils (5.41%). Pararendzinas, dystrophic brown soils, and gley soils were less common (total below 5.5%). In the forest monitoring areas of PNP, eutrophic soils predominate over mesotrophic soils. High SIGg index of the soils is caused by high values of acidity and nitrogen content. The Carpathian beech forest
and thermophilic beech forest
associations are characterised by high naturalness and compatibility of theoretical habitats. The soils of the Carpathian fir forest
subcommunity is characterised by a higher share of silt and clay particles and lower acidity as compared to the Carpathian beech forest
subcommunity. The soils of the forest monitoring areas in PNP stand out in terms of their fertility against forest soils in other mountainous areas in Poland.
Scrobipalpa chrysanthemella (E. Hofmann, 1867) was recorded for the first time in Poland. In addition, new data on the occurrence of 13 Lepidoptera species in the Bieszczady National Park are ...presented. Elachista dimicatella Rebel, 1903 was reported for the first time from Poland outside the Tatra Mountains.
•Browsing by ungulate herbivores is concentrated upon deciduous tree short saplings.•The most preferred tree species are: rowan, sycamore maple and goat willow.•Browsing frequency is positively ...correlated with stand openness.•Browsing frequency is not related to environmental variables.•CWD accumulation affects the browsing frequency in a non-linear way.
We analyzed the effects of natural disturbances on relationships between forest regeneration and ungulate browsing. Specifically, we asked if natural disturbances affect preferences of ungulate herbivores towards tree species and size classes; and how local and landscape-scale environmental factors affect spatial patterns of ungulate browsing in disturbed forest ecosystems. Our research was conducted in the Tatra National Park, a mountain range affected by large-scale intense disturbances over the last few decades. We used field data collected in a network of regularly distributed 600 circular sample plots where young trees were recorded and examined for browsing signs. Using forage ratio, the Ivlev’s electivity index and chi square tests, we found that the preferences of wild ungulates were similar to those known from undisturbed forests. Our analyses showed preference for deciduous species, especially rowan, sycamore maple and goat willow. The most common species, Norway spruce was strongly avoided by browsing ungulates. Short saplings from 0.5 m to 1.3 m tall were the most browsed size class. Effects of environmental variables on browsing were analyzed with zero-inflated negative binomial models. The occurrence of browsing was positively related to the total number of young trees and mature tree mortality. This suggests the influence of disturbances on spatial patterns of browsing pressure. The browsing frequency (number of browsed individuals per plot) was affected by mature tree mortality and densities of young palatable trees, including silver fir, sycamore maple and rowan. Elevation, geology, soil type, and potential solar radiation did not show any significant influence on the browsing frequency. Browsing frequency was also positively related to the distance to roads and hiking trails, indicating the role of human pressure upon the behaviour of ungulate herbivores. In addition, we analyzed the effects of accumulation of coarse woody debris (CWD) on browsing frequency and found this relationship to be nonlinear. Analysis for all tree species revealed that at low levels of CWD, the browsing frequency increased with CWD accumulation as a consequence of forest regeneration. However, a large amount of CWD (>25 m3) resulted in a decrease in browsing frequency, and this relationship was species-specific.
We analysed the distribution of trees along the elevation gradient in two national parks located in the Western Carpathians (49°30′–49°37′ N; 19°28′–20°15′ E), dominated by natural forest stands to ...answer two questions: do immature trees occur at higher elevations compared to mature ones? Has the upper limit of the distribution of the seedlings increased during the period under study, and were the changes proportional to the increase in the mean annual temperature in that period? Data used in our study had been collected in permanent sample plots, distributed regularly over the entire forest area in two national parks. The measurements were taken twice, separated by at least 12 years. We analysed the upper distribution range of the most abundant tree species following tree ontogenic stages for two measurement times. The analysed tree species showed contrasting patterns of the distributions of saplings related to the distributions of mature individuals. In one of the national parks, two species (Silver fir and European beech) showed a significant upward expansion. As three measurements were taken in this park, we found that the expansion has increased over time. In the second national park, located only 45 km to the west from the first one, we found no upward expansion in the distribution of both European beech and Silver fir, while Sycamore maple showed a slight downward trend. We conclude that the dynamics of the tree distributions along the elevation gradient in the mountain areas do not follow a uniform path; the indirect effects of changes in environmental conditions may produce different patterns, reflecting the complex nature of the interactions shaping the distributions of the trees.
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•Young trees showed contrasting patterns of dispersal related to the mature ones.•Dynamics of tree distributions in the mountains does not follow a uniform path.•Expansion commonly attributed to climate changes but can be strongly modified by other factors.•Tree population dynamics is a key issue for forest management practices.
The yew gall midge Taxomyia taxi has been found for the first time in the Polish Carpathians. The site lies in the "Yews in Mogilno" ("Cisy w Mogilnie") nature reserve in the western part of the ...Beskid Niski (Low Beskid) Mountains. The species occurs over an area of ca. 37 ha, mostly in the northern, lowest-lying parts of the reserve. 19.4% of the inspected specimens of the European yew were found to exhibit signs of feeding by gall midges. Most of the infested yews (86.7%) were barren, 8.2% were females and 5.1% males. The yew gall midges displayed no clear preferences in relation to the health status of the host plants, although yews with a healthier photosynthetic apparatus were selected more often.
The dynamics of a seedling bank was studied in four plots located in the Krynica Experimental Forest, southern Poland. Each sample plot was divided into eight sectors, in which germinants and ...seedlings were mapped, measured, and labelled; their survival was checked twice a year between 1989 and 1996. Maps of relative light intensities on the forest floor in sample plots were produced on the basis of measurements conducted in June and August 1991. During the entire period of study, European beech (
Fagus sylvatica L.) made up over 96% of germinants and seedlings. Numbers of beech germinants varied strongly (from 0 to 1178) among plots and years. Each year of abundant germination was followed by one or two years of scarce germination, and there was an increasing trend in the number of germinants in three plots between 1989 and 1996. Seedling emergence was almost independent of relative light intensity and first-season survival was positively, but weakly correlated with it. Long-term survival of seedlings was low and strongly related to relative illumination. Results of analyses of spatial patterns in seedlings suggested that some microsites were more conducive than others to germination and early survival of seedlings. Survival among taller germinants was greater than among shorter ones. A true seedling bank was observed only in two plots, where relative light intensities were 9 and 15% of full sunlight. In a plot with relative light intensity of 4%, the seedling bank was unstable and in the least illuminated plot (<3% of full sunlight) no seedling bank was formed. Results indicate that, even in a strongly shade-tolerant species like beech, formation of a seedling bank requires the occurrence of canopy openings in the close proximity.
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