Red deer (Cervus elaphus) bark stripping on spruce with regard to spatial distribution of supplemental feeding placesKlemen Jerina
, Mihec Dajčman
, Miha Adamič
Povzetek: Forest damages caused by red deer and some other large herbivore species occasionally feeding on tree bark, are a grave ecological and economic problem in many parts of the world. Winter supplemental feeding is commonly used to mitigate the problem, but its effects are poorly known. This study, carried out at Pohorje (Slovenia) and including over 2,300 trees, used binary logistic regression to analyse the effects of supplemental feeding and many other factors on the probability of bark stripping on spruce. The probability of bark stripping depends on distance from the forest edge, density, age and tree species diversity of stands, slope and aspect of terrain, and red deer density; contrary to expectations, it is not related to distance from feeding places. As much as 35% of spruce trees were damaged. The damage was the highest in younger, denser pure spruce stands, whose favourable protective and microclimatic conditions (thinner snow cover, higher effective temperatures) make them a preferred winter habitat for red deer. They contain,however, little other food but bark. To prevent / diminish bark stripping we propose a stronger thinning of such stands. Supplemental feeding may reduce damage only in exceptional cases, when animals are lured and concentrated in less sensitive areas, but in general we advise against the use of this measure due to its other negative effects.
Ključne besede: red deer, Cervus elaphus, bark stripping, Norway spruce, Picea abies, forest damages, supplemental feeding, Slovenia, environmental factors
DiRROS - Objavljeno: 12.07.2017; Ogledov: 1366; Prenosov: 320
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Phytosociological description of mesophilous colline-submontane Fagus sylvatica and Carpinus betulus forests in Slovenian IstriaZvone Sadar
, Igor Dakskobler
Povzetek: A phytosociological analysis of 46 relevés of mesophilous colline and submontane Fagus sylvatica as well as (or) Carpinus betulus forests was conducted in Slovenian Istria. It was established that they are frequently syndynamically interrelated: in places, common hornbeam stands are merely a degradation stage on beech sites, and can be classified into the subassociation Ornithogalo pyrenaici-Fagetum fraxinetosum orni (its locus classicus is in the Goriška Brda Hills) and into the new subassociation Ornithogalo pyrenaici-Carpinetum betuli seslerietosum autumnalis. Compared with similar submontane stands from other parts of the western and southwestern Slovenia they are slightly poorer in species, with fewer diagnostic species of alliances Erythronio-Carpinion, Aremonio-Fagion and Tilio-Acerion, order Fagetalia sylvaticae and class Vaccinio-Piceetea, and with more diagnostic species of the order Quercetalia pubescenti-petraeae. Geographically, they are characterised by the taxon Helleborus odorus subsp. istriacus. Although they cover small areas these forests generate high yields and are therefore important both economically and as biotopes of protected species.
Ključne besede: phytosociology, synsystematics, beech sites, Ornithogalo-Carpinetum, Ornithogalo-Fagetum, Istria, Slovenia
DiRROS - Objavljeno: 15.06.2018; Ogledov: 1518; Prenosov: 841
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Patterns of understory community assembly and plant trait-environment relationships in temperate SE European forestsLado Kutnar
, Janez Kermavnar
Povzetek: We analyzed variation in the functional composition and diversity of understory plant communities across different forest vegetation types in Slovenia. The study area comprises 10 representative forest sites covering broad gradients of environmental conditions (altitude, geology, light availability, soil type and reaction, nutrient availability, soil moisture), stand structural features and community attributes. The mean and variation of the trait values were quantified by community-weighted means and functional dispersion for four key plant functional traits: plant height, seed mass, specific leaf area and leaf dry matter content. At each study site, forest vegetation was surveyed at two different spatial scales (4 and 100 m2 ) in order to infer scale-dependent assembly rules. Patterns of community assembly were tested with a null model approach. We found that both trait means and diversity values responded to conspicuous gradients in environmental conditions and species composition across the studied forests. Our results mainly support the idea of abiotic filtering: more stressful environmental conditions (e.g., high altitude, low soil pH and low nutrient content) were occupied by communities of low functional diversity (trait convergence), which suggests a selective effect for species with traits adapted to such harsh conditions. However, trait convergence was also detected in some more resource-rich forest sites (e.g., low altitude, high soil productivity), most likely due to the presence of competitive understory species with high abundance domination. This could, at least to some extent, indicate the filtering effect of competitive interactions. Overall, we observed weak and inconsistent patterns regarding the impact of spatial scale, suggesting that similar assembly mechanisms are operating at both investigated spatial scales. Our findings contribute to the baseline understanding of the role of both abiotic and biotic constraints in forest community assembly, as evidenced by the non-random patterns in the functional structure of distinct temperate forest understories.
Ključne besede: functional composition, functional diversity, ecological gradients, abiotic filtering, trait convergence, trait divergence, spatial scale, forest ground-layer vegetation, Slovenia
DiRROS - Objavljeno: 26.05.2020; Ogledov: 226; Prenosov: 172
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