Phytosociological analysis of noble hardwood forests (Ostryo-Tilienion platyphylli) in the Karst and its neighbouring regions (SW Slovenia)

In SW Slovenia, at Gora under Železna Vrata and Petnik gorge near Branik – both on the northern edge of the Karst, in the collapse doline Orleška Draga at Sežana and under Brkinski Rob at the contact of the Karst and Brkini Hills, we conducted a phytosociological analysis of the stands whose tree layer is dominated by Tilia platyphyllos, T. cordata, Acer pseudoplatanus, Ulmus glabra, in places also Carpinus betulus and Ostrya carpinifolia, and classified them into three associations, Corydalido ochroleucae-Aceretum pseudoplatani, Paeonio officinalis-Tilietum platyphylli and Fraxino orni-Aceretum pseudoplatani. The latter was described as a new. Also new is a secondary large-leaved lime association Lamio orvalae-Tilietum platyphylli on the sites of montane beech forests (Lamio orvalae-Fagetum) in the Čepovan valley, at the contact of the Dinaric and sub-Mediterranean phytogeographical regions of Slovenia.

Diversity of Ostrya carpinifolia Forests in Ravine Habitats of Serbia (S-E Europe)

We investigated vegetation in ravine habitats of Serbia, in order to classify hop hornbeam (Ostrya carpinifolia Scop.) forests in syntaxonomic terms, assess the effects of environmental factors on their floristic differentiation, and detect the biodiversity components of the analyzed communities. Both K-means clustering and Bayesian classification revealed five ecologically interpretable groups of forests that belong to the alliances Ostryo carpinifoliae-Fagion sylvaticae, Ostryo carpinifoliae-Tilion platyphylli, Fraxino orni-Ostryion carpinifoliae, Pseudofumario albae-Ostryion carpinifoliae, and Achilleo ageratifoliae-Ostryion carpinifoliae. Canonical correspondence analysis indicated that these alliances are clearly differentiated along a combined light–moisture gradient (from shade and mesic to sunny and xeric variants). The alpha diversity increases from xeric to mesic alliances. A lower alpha diversity in xeric forests may be explained by the stress conditions that prevent mesic species from colonizing the saxatile habitats. Extremely high—almost the greatest possible—values of both the species turnover and beta diversity were detected in all variants of the analyzed forests. Such high diversity may be the result of the strong environmental gradients in ravine habitats. The investigated forests represent an important pool of rare, paleo-endemic species that survived Quaternary glaciations in ravine refugia.

Can we use dendrogeomorphology for the spatial and temporal analysis of less intensive mass movement processes?: A case study of three debris flows in NW and W Slovenia

Debris flows can transport large amounts of material and therefore present a significant threat to infrastructure and human life. In this research, we used tree-ring width analyses to quantify the response of trees to three debris flow events in NW Slovenia (Javoršček, Srpenica) and W Slovenia (Nikova) for which we know the time of origin. We attempted to date these and similar tree responses in the past and compared the patterns between different tree species. Altogether, we sampled 147 trees across a range of tree species (Fagus sylvatica, Pinus sylvestris, Fraxinus excelsior, Fraxinus ornus, Acer pseudoplatanus, Picea abies, Juglans regia, Acer campestre, Tilia cordata and Ostrya carpinifolia), including reference trees that were outside the debris flow fan. For 91 trees, we constructed tree-ring chronologies and used pointer-year analysis to identify years that had abnormal growth. For the remaining trees (mostly Ostrya carpinifolia, Tilia cordata and Acer pseudoplatanus), we either could not accurately distinguish tree rings or two samples from a single tree showed significantly different growth patterns. The growth patterns of Fagus sylvatica and Picea abies following debris flow events showed a weak response at the Javoršček site and no clear responses at the other two sites. Tree species responded similarly at the same locations. Due to the lack of a clear response pattern, we were not able to reconstruct past debris flows.

Phytosociological overview of the Fagus and Corylus forests in Albania

Aim: The aim of this study is to analyze the mesophilous forests of Albania including Fagus sylvatica and submontane Corylus avellana forests. Mesophilous Albanian forests are poorly known and were not included in the recent syntaxonomic revisions at the European scale. Study area: Albania. Methods: We used a dataset of 284 published and unpublished relevés. They were classified using the Ward’s minimum variance. NMDS ordination was conducted, with over-laying of climatic and geological variables, to analyze the ecological gradients along which these forests develop and segregate. Random Forest was used to define the potential distribution of the identified forest groups in Albania. Results: The study identified seven groups of forests in Albania: Corylus avellana forests, Ostrya carpinifolia-Fagus sylvatica forests, lower montane mesophytic Fagus sylvatica forests, middle montane mesophytic Fagus sylvatica forests, middle montane basiphytic Fagus sylvatica forests, upper montane basiphytic Fagus sylvatica forests, upper montane acidophytic Fagus sylvatica forests. These can be grouped into four main types: Corylus avellana and Ostrya carpinifolia-Fagus sylvatica forests, thermo-basiphytic Fagus sylvatica forest, meso-basiphytic Fagus sylvatica forest and acidophytic Fagus sylvatica forests. This scheme corresponds to the ecological classification recently proposed in a European revision for Fagus sylvatica forests Conclusion: Our study supports an ecological classification of mesophilous forests of Albania at the level of suballiance. Analysis is still preliminary at the level of association, but it shows a high diversity of forest types. Taxonomic reference: Euro+Med PlantBase (http://ww2.bgbm.org/EuroPlusMed/) [accessed 25 Novemeber 2019]. Syntaxonomic references: Mucina et al. (2016) for alliances, orders and classes; Willner et al. (2017) for suballiances.

Sites and communities with Ruscus aculeatus in the southwestern Julian Alps (western Slovenia) / Rastišča in združbe z vrsto Ruscus aculeatus v jugozahodnih Julijskih Alpah (zahodna Slovenija)

We examined the localities and sites of the Mediterranean thermophyte Ruscus aculeatus in the southwestern part of the Julian Alps and confirmed its relatively frequent occurrence in the hilly and submontane belts up to 980 m a.s.l. It occurs predominantly on sunny aspects, gentle to very steep slopes and very stony (rocky) sites, in very different soil types and plant communities of deciduous forests, mainly with predominating tree species of Fraxinus excelsior, Carpinus betulus, Fagus sylvatica and Ostrya carpinifolia. Its northernmost sites known in Slovenia are in pioneer forests on abandoned agricultural areas in Breginjski Kot between Borjana and Sedlo, and on rockslide under the Polovnik ridge (Morizna), and are presumably younger in origin. Given the climate change (warming) in the last decades it is expected to spread further into the mountains (including the Bovec region). Key words: phytosociology, phytogeography, Ruscus aculeatus, Julian Alps, SloveniaSITES OF LOMELOSIA GRAMINIFOLIA (SCABIOSA GRAMINIFOLIA) ON THE NORTHEASTERNMOST KNOWN LOCALITY IN THE ALPS Izvleček Raziskali smo nahajališča in rastišča toploljubne mediteranske vrste Ruscus aculeatus (bodeča lobodika) v jugozahodnem delu Julijskih Alp in ugotovili njeno razmeroma pogosto uspevanje v gričevnem in podgorskem pasu, vse do nadmorske višine 980 m. Raste večinoma na prisojnih legah, na položnih do zelo strmih in zelo kamnitih (skalnatih) rastiščih, v zelo različnih talnih tipih in rastlinskih združbah listnatih gozdov, predvsem s prevladujočimi drevesnimi vrstami Fraxinus excelsior, Carpinus betulus, Fagus sylvatica in Ostrya carpinifolia. Njena do zdaj najbolj severozahodna nahajališča v Sloveniji, v pionirskih gozdovih na opuščenih kmetijskih površinah v Breginjskem kotu med Borjano in Sedlom in na podornem gradivu pod grebenom Polovnika (Morizna), so domnevno mlajšega izvora. Ob podnebnih spremembah (otoplitvi) zadnjih desetletij lahko pričakujemo njeno širjenje še bolj proti goram (tudi na Bovško). Ključne besede: fitocenologija, fitogeografija, Ruscus aculeatus, Julijske Alpe, Slovenija

Altitude and Vegetation Affect Soil Organic Carbon, Basal Respiration and Microbial Biomass in Apennine Forest Soils

Both altitude and vegetation are known to affect the amount and quality of soil organic matter (SOM) and the size and activity of soil microbial biomass. However, when altitude and vegetation changes are combined, it is still unclear which one has a greater effect on soil chemical and biochemical properties. With the aim of clarifying this, we tested the effect of altitude (and hence temperature) and vegetation (broadleaf vs pine forests) on soil organic carbon (SOC) and soil microbial biomass and its activity. Soil sampling was carried out in two adjacent toposequences ranging from 500 to 1000 m a.s.l. on a calcareous massif in central Italy: one covered only by Pinus nigra J.F. Arnold forests, while the other covered by Quercus pubescens Willd., Ostrya carpinifolia Scop. and Fagus sylvatica L. forests, at 500, 700 and 1000 m a.s.l., respectively. The content of SOC and water-extractable organic carbon (WEOC) increased with altitude for the pine forests, while for the broadleaf forests no trend along the slope occurred, and the highest SOC and WEOC contents were observed in the soil at 700 m under the Ostrya carpinifolia forest. With regard to the soil microbial community, although the size of the soil microbial biomass (Cmic) generally followed the SOC contents along the slope, both broadleaf and pine forest soils showed similar diminishing trends with altitude of soil respiration (ΣCO2-C), and ΣCO2-C:WEOC and ΣCO2-C:Cmic ratios. The results pointed out that, although under the pine forests’ altitude was effective in affecting WEOC and SOC contents, in the soils along the broadleaf forest toposequence this effect was absent, indicating a greater impact of vegetation than temperature on SOC amount and pool distribution. Conversely, the similar trend with altitude of the microbial activity indexes would indicate temperature to be crucial for the activity of the soil microbial community.

A Leaf Selfie: Using a Smartphone to Quantify Leaf Vulnerability to Hydraulic Dysfunction

Accurate predictions of species distribution under current and future climate conditions require modeling efforts based on clear mechanistic relationships between climate variables and plant physiological functions. Vulnerability of leaves to xylem embolism is a key mechanistic trait that might be included in these modeling efforts. Here, we propose a simple set-up to measure leaf vulnerability to embolism on the basis of the optical method using a smartphone, a light source, and a notebook. Our data show that this proposed set-up can adequately quantify the vulnerability to xylem embolism of leaf major veins in Populus nigra and Ostrya carpinifolia, producing values consistent with those obtained in temperate tree species with other methods, allowing virtually any laboratory to quantify species-specific drought tolerance on the basis of a sound mechanistic trait.

Conversion of Pinus nigra Plantations with Natural Regeneration in the Slovenian Karst: The Importance of Intermediate, Gradually Formed Canopy Gaps

Since the mid-19th century, Pinus nigra plantations have played a key role in the restoration of degraded European landscapes. Nowadays, these plantations are aging and prone to natural disturbances, insect infestations, and diseases. For their successful gradual conversion, knowledge of optimal gap spatiotemporal dynamics is crucial. We studied herb and natural regeneration patterns along with site factors on 477 subplots within 44 plots distributed over four stand types: closed stand (14% diffuse light), open stand (21%), gap edge (23%), and gap (57%). Despite the abundant Quercus petraea, Q. cerris, and Q. pubescens mast year, no one-year seedlings were recorded, which is likely due to the summer drought. Short seedlings (h < 20 cm) of Quercus sp., Fraxinus ornus and Ostrya carpinifolia were more successful within closed stands. Short Quercus seedlings were positively associated with soil depth and negatively associated with soil nutrients, distance to seed trees, and Sesleria autumnalis coverage. Taller Quercus seedlings required more light than both of its strongest competitors and were positively related to humid soils and less rocky sites. Ungulate overbrowsing significantly impeded natural regeneration. The results indicate a satisfactory Quercus density for conversion and the importance of advanced regeneration, which should be gradually, but persistently, released by progressively widening gaps.

Ramondo-Ostryetum carpinifoliae – a new association from the hop-hornbeam forests of the Sharri Mountains, Kosovo

In Europe, the genus Ramonda is represented with three species: Ramonda nathaliae, Ramonda serbica and Ramonda myconi. The first two are endemic Balkan species that are distributed also in Kosovo. These species grow in limestone as well as serpentine substrates, forming chasmophytic vegetation. The species Ramonda nathaliae is found in Macedonia, Greece, Serbia and in two localities in Kosovo, in the Sharri Mountains (Luboten and Gotovushë). R. nathaliae forms the following plant associations in the serpentines of Macedonia: Asplenio­Ramondetum nathaliae and Scorzonero-Ramondetum nathaliae, and the Achilleo­Ramondetum nathaliae in limestone substrates. Ostrya carpinifolia is charateristic species in Querco pubescentis-Ostryetum carpinifoliae, Ostryo-Fagetum, Querco-Ostryetum carpinifoliae and Corylo colurnae-Ostryetum carpinifoliae. This paper presents plant communities of Ramonda nathaliae and Ostrya carpinifolia in a limestone habitat, where the proposed new plant association named Ramondo­Ostryetum carpinifoliae ass. nova. is described. This plant community belongs to the class Quercetea pubescentis, order Quercetalia pubescenti­petraeae and alliance Fraxino orni­Ostryion. It was found and described on the limestone substrate on Mt. Luboteni (at 960–982 m a.s.l.).