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Povzetek: The spread of neophytes (non-native plant species) challenges the conservation status and ecological integrity of forests, especially in lowland areas. Long-term resurvey studies are needed to evaluate the temporal dynamics of neophytes in forests; however, such data are scarce. In 2023, we resampled a set of 45 permanent vegetation plots (established in 1992/93) in two forest vegetation types: oak–hornbeam forests dominated by Quercus robur and colline oak–beech forests dominated by Q. petraea. Over the last 30 years, oak forests have experienced extensive oak tree mortality, with the degree of habitat degradation being greater in Q. robur forests. In the early 1990s, only three neophytes with low abundance were recorded across all plots. In the 2023 resurvey, the total number of neophytes increased to 22 species (15 herbaceous and 7 woody species), comprising 6.9% of the total species pool in the understory layer. The increase in the plot-level number and cover of neophytes was significant in plots dominated by Q. robur but not in those with Q. petraea. The most frequent neophytes were Impatiens parviflora (present in 31% of plots), Solidago gigantea (27%), Erigeron annuus (16%) and Erechtites hieraciifolia (16%). The richness and cover of neophytes were significantly affected by the tree layer cover (negative correlation) and the degree of soil disturbance (positive correlation). All neophytes established in disturbed patches, whereas the occurrence of I. parviflora was exceptional as it was able to colonize less degraded, shaded understory environments. Habitat degradation (the mortality-induced loss of stand-forming oak trees resulting in extensive tree layer cover decrease) emerged as a key driver promoting neophyte proliferation, coupled with the impact of management-induced disturbances affecting overstory and soil conditions. The spread is expected to continue or even intensify in the future because novel light regimes and disturbances make forest habitats less resistant to neophyte proliferation.
Ključne besede: long-term vegetation change, invasive non-native plants, oak mortality, Quercus robur, Quercus petraea, canopy openness, Impatiens parviflora, Slovenia
Objavljeno v DiRROS: 19.04.2024; Ogledov: 1; Prenosov: 0
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Povzetek: In this paper, the influences of stacking methods and drying places of split oak firewood in winter conditions (Quercus cerris) have been experimentally and theoretically investigated, due to the great importance of use in heating with such wood. The research was conducted on a sample of 48 pieces of logs with bark made of freshly cut oak. The logs were obtained by mechanized technology with the help of grafting by a hydraulic splitter and a chainsaw. Each log was measured for a research length of 0.30 m, marked with numbers 1-24. On each log, the weight was measured on a scale of 5 kg with an accuracy of 0.5 grams. Drying of logs was performed in two places. The first drying place was in outdoor conditions, sheltered from the snow and ventilated. The second place was indoors, at approximately constant room temperature. The logs were stacked in a crossed way for better air circulation. They were dried between 15/12/2020 and 15/02/2021, a total of 62 days. The average initial weight of logs dried in the facility was 1130.3 g, in the dried state the average weight was 952.87 g, which represented 84.3% of the original weight. The average initial weight of logs dried in outdoor conditions was 1192.125 g, in the dried state 1076.37 g, which represented 90.29% of the original weight. The average initial water content in the logs dried in the facility was 37.9%, in the dried state it was 27.5%. For logs dried in outdoor conditions, the average initial amount of water was 36.6%, in the dried state the average amount of water was 31.2%.
Ključne besede: weight, drying methods, splitting firewood, oak, stacking methods
Objavljeno v DiRROS: 09.04.2024; Ogledov: 65; Prenosov: 26
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Povzetek: The ectomycorrhizal association of Tuber spp. in orchards is essential for truffle production. In this sense, this study aimed to evaluate the ectomycorrhizal association of Tuber aestivum Vittad. and Tuber brumale Vittad. in pecan after five years of cultivation in an orchard. The experiment was conducted in Santa Maria – Rio Grande do Sul, Brazil, in a pecan orchard planted with seedlings inoculated with these two species of truffles. The orchard was characterized in terms of soil physical and chemical properties and soil type. Initially non-inoculated plants, plants inoculated with Tuber aestivum (TA), and plants inoculated with Tuber brumale (TB) were evaluated for the percentage (%) of roots colonized by Tuber spp., other ectomycorrhizae, and non-mycorrhizal roots. A reduction in the colonization of both truffle species was observed five years after transplanting the seedlings to the orchard but they have the potential to maintain the ectomycorrhizal association with pecan seedlings.
Ključne besede: Carya illinoinensis, ectomycorrhiza, truffle, tuber
Objavljeno v DiRROS: 26.03.2024; Ogledov: 92; Prenosov: 55
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Povzetek: Larch (Larix decidua) showed good growth and adaptability to ecological conditions in Bosnia and Herzegovina. The research aims to determine the variability of the morphological traits of larch in the seed stand near Kakanj, the variability at the beginning of heartwood formation, and correlations among these properties.In the larch seed stand, established by seedlings 2+0 in 1979, an area of 0,45 hectares was set aside. The heights and breast height diameters of the trees were on that area were measured in 2002 and 2020, and the basal area and volume were calculated. In 2020, the trees were drilled at breast height with a Presler drill to measure the proportion of heartwood. Average values of all properties for 2002 and 2020 were calculated. The ten, five and one best trees were selected according to the properties of breast height diameter, height, basal area, volume, and the intensities of selection for these traits were calculated. The Pearson correlation coefficient among all investigated traits were calculated. The average breast height diameter of 41-year-old trees was 24,6 cm, average height 21,8 m, basal area 0.0499m2 and volume 0.3745 m3 (table 1), while in 2002. the average breast height diameter was 15,5 cm, height 18,2 m, basal area 0,020 m2, and volume 0,128 m3 (table 1). Between 2002 and 2020, there was an overtaking of trees in breast height diameter and height and thus the base and volume (table 2). The average larch tree starts heartwood formation at the age of 14 years (table 1). The earliest heart-wood formation occurs in the sixth year (tree 495) and the latest in the 32nd year (table 4). Pearson coefficient showed a high positive correlation between breast height diameter and height in 2002 (ta-ble 9), which means that trees with a good height increase also have a good thickness increase. As a result, the correlation between breast height diameter and basal area and breast height diameter and volume, height and basal area, height and volume, and basal area and volume are statistically signifi-cant. Pearson’s correlation coefficient for the year 2020 showed a negative correlation between the be-ginning of heartwood formation and all other traits (table 10), i.e., trees that formed heartwood earlier have higher values of growth traits.The results will be used in the selection processes of larch individuals with good height and thickness growth and early heartwood formation.
Ključne besede: European larch, morphological properties, core formation, selection
Objavljeno v DiRROS: 25.03.2024; Ogledov: 80; Prenosov: 42
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Povzetek: Bosnia and Herzegovina is located in Southeast Europe, and more than half its area of 51.129 km² belongs to forests and forest lands. 93% of the forests of Bosnia and Herzegovina are natural forests and have many plant species, many of which are endemic. There are eight oak species growing in Bosnia and Herzegovina. The most important ones are Quercus robur (despite being almost extinct due to overexploitation during the late XIX and early XX century), and Quercus petraea. Pedunculate oak in Bosnia and Herzegovina is found in mixed stands with common hornbeam and in pure stands under exceptional conditions, with a total area of about 30,000 ha. In this paper, the data of the studies carried out in the pedunculate oak forests of Bosnia and Herzegovina were compiled and a general evaluation was made. The results of phenological observation in pedunculate oak provenance test in Bosnia and Herzegovina through the years showed statistically significant differences among provenances in the beginning, end and duration of individual phenological phases. Researches on growth showed overtaking of provenances through the years, and best results in provenance Jelah for the most of investigated years. The research results on showed a significant positive correlation between the height and root collar diameter in provenance test and most of the investigated .The remaining pedunculate oak populations in Bosnia and Herzegovina have a good genetic structure and can be used as a seed stands for collecting seed material and producing seedlings for afforestation with this species
Ključne besede: Pedunculate oak, Bosnia and Herzegovina, afforestation
Objavljeno v DiRROS: 25.03.2024; Ogledov: 67; Prenosov: 48
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