Iskanje po repozitoriju

A+ | A- | | SLO | ENG

Ključne besede: hiperspektralna kamera, nevronska mreža, klasifikacija, slovenske lesne vrste
Objavljeno v DiRROS: 05.06.2025; Ogledov: 415; Prenosov: 153
Celotno besedilo (45,03 KB)

Objavljeno v DiRROS: 05.06.2025; Ogledov: 470; Prenosov: 224
Celotno besedilo (71,18 KB)

Povzetek: Understanding competition between trees is essential for sustainable forest management as interactions between trees in uneven-aged mixed forests play a key role in growth dynamics. This study investigated nine competition indices (CIs) for their suitability to model the effects of neighboring trees on silver fir (Abies alba) growth in Dinaric silver fir-European beech (Fagus sylvatica) forests. Although numerous competition indices have been developed, there is still limited consensus on their applicability in different forest types, especially in mature, structurally complex forest stands. The indices were evaluated using the adjusted coefficient of determination in a linear model wherein the volume growth of the last five years for 60 dominant silver fir trees was modeled as a function of tree volume and competition index. The results demonstrated that distance-dependent indices (e.g., the Hegyi height-distance competition and Rouvinen-Kuuluvainen diameter-distance competition indices), which consider the distance to competitors and their size, perform better than distance-independent indices. Using the optimization procedure in calculating the competition indices, only neighboring trees at a distance of up to 26-fold the diameter at breast height (DBH) of the selected tree (optimal search radius) and with a DBH of at least 20% of that of the target tree (optimal DBH) were considered competitors. Therefore, competition significantly influences the growth of dominant silver firs even in older age classes. The model based solely on tree volume explained 32.5% of the variability in volume growth, while the model that accounted for competition explained 64%. Optimizing the optimal search radius had a greater impact on model performance than optimizing the DBH threshold. This emphasizes the importance of balancing stand density and competition in silvicultural practice.
Ključne besede: sustainable forest management, Dinaric silver fir-European beech forests, Competition indices, CIs, optimal search distance, optimal diameter at breast height, DBH
Objavljeno v DiRROS: 05.06.2025; Ogledov: 488; Prenosov: 294
Celotno besedilo (8,69 MB)
Gradivo ima več datotek! Več...

Povzetek: Understanding public attitudes toward wildlife is crucial for the success of conservation efforts, particularly for species that might elicit mixed perceptions. For the first time in Slovenia, we conducted a study on attitudes and knowledge about the Eurasian lynx among primary, lower and upper secondary school pupils. Participants between the ages of 9 and 19 took part in the survey (N = 1312). The aim of the study was to determine the general acceptance and knowledge of the lynx and identify the key factors that influence the formation of attitudes and knowledge. The survey results show a good acceptance of the species among the younger generation and a high level of support for its conservation. A higher amount of knowledge was positively associated with less fear of the species, more interest in learning and higher support for conservation. Living in a region with a permanent lynx presence was associated with less fear and more interest in learning about the species. No differences in acceptance and support for lynx conservation were detected between regions with or without the permanent presence of the species. Year of education was positively associated with the amount of knowledge about lynx, while gender was partially associated with the amount of fear but mainly with support for conservation. Against this background, we provide guidance for planning future communication and education activities for the long-term conservation of the species.
Ključne besede: eurasian lynx, pupils, attitudes, knowledge, education, conservation
Objavljeno v DiRROS: 04.06.2025; Ogledov: 759; Prenosov: 269
Celotno besedilo (2,00 MB)
Gradivo ima več datotek! Več...

Povzetek: Growth dynamics of cold subarctic and subalpine forests are primarily sensitive to temperature, but growth responses may vary across regions or shift over tree ontogeny. Systematic assessments of spatial, interspecific, and demographic variation in temperature and moisture limitation of tree growth at cold distribution margins are essential for enhancing our understanding of how these ecosystems will evolve under climate regimes. To address this gap, we built a network of 22 tree-ring width chronologies from cold forests covering two regions (Fennoscandia, European Alps), three species (Pinus sylvestris, Pinus cembra, Larix decidua), and two age cohorts (45–100 and >150 years). We combined daily climate-growth correlations with the process-based Vaganov-Shashkin growth model to identify differences in critical growth factors between species and age cohorts. In addition, we assessed the coincidence of unusually wide and narrow tree rings with years of specific climatic anomalies. Although growing season temperature was the dominant growth-limiting factor, seasonal effects of water balance on tree growth were considerably large and varied systematically between regions, species, and particularly age cohorts. The growth of young P. sylvestris in Fennoscandia responded negatively to water balance and narrow rings coincided with wet years. In contrast, the growth of young P. cembra in the Alps was drought-limited. Old trees of all species and both age cohorts of L. decidua in the Alps showed limited sensitivity to water balance. The patterns of climate-growth responses in cohort chronologies based on tree age at the year of coring were similar to ontogenetic shifts of climate-growth responses if chronologies were based on the cambial age of individual rings. Our results stress the need to account for interspecific and demographic differences in sensitivity to climate in large-scale studies of cold forest ecosystems.
Ključne besede: boreal forest, Larix, subalpine forest, pinus, tree ring, Vaganov-Shashkin model
Objavljeno v DiRROS: 04.06.2025; Ogledov: 540; Prenosov: 257
Celotno besedilo (10,22 MB)
Gradivo ima več datotek! Več...