Ilex Aquifolium Research Articles

Hydro-mechanical reinforcement of contrasting woody species: a full-scale investigation of a field slope

Soil bioengineering using vegetation is an environmentally friendly technique for slope stabilisation. Plants stabilise slopes by way of mechanical reinforcement (through root anchorage) and hydrological reinforcement (through transpiration-induced matric suction). However, little is known about the effects of a plant's functional group on slope hydrology and stabilisation. This makes it difficult for engineers to select appropriate species for soil bioengineering. In this study, full-scale field monitoring of a 20 m long vegetated embankment was conducted, with the aim to quantify and compare the hydro-mechanical reinforcement provided by three contrasting woody species (deciduous Corylus avellana, evergreen Ilex aquifolium and evergreen Ulex europaeus) native to a European temperate climate. The rainfall interception, matric suction and in situ soil strength were measured over two growing seasons. Evergreen species differed greatly in their water uptake, and sometimes exceeded the deciduous species. The evergreen U. europaeus induced the greatest suction (> 70 kPa) and soil shear strength (e.g. up to 136 kPa) because of its better developed above-ground shoot architecture for rainfall interception (up to 50% of incoming rainfall) and greater root length density for water uptake. This suggests that careful choice of species could greatly enhance slope stabilisation by increasing the soil shear strength.

Selective Shrub Management to Preserve Mediterranean Forests and Reduce the Risk of Fire: The Case of Mainland Portugal

The recurrent rural fires that occur annually in Portugal have reached great proportions due to a lack of effective landscape management. Attempts to solve this problem led to the legal imposition to cut back the vegetation in the fuel management areas, which has had a negative effect on biodiversity. National legislation protects three native plant species (Quercus suber, Q. rotundifolia and Ilex aquifolium). European legislation, through the Habitats Directive, also identifies some plant species that require strict protection, although it leaves out several endemic and rare plants. In this work we aim to differentiate the types of shrub plant material and their pyrophilic behavior, since the physical and chemical characteristics of vegetation can enhance or inhibit the progression of fire. Thus, based on phytosociological science, specifically at the class level, the dynamics of potential climatophilous vegetation in Portugal are presented and the classes that should be prioritized for control are identified. Based on ecology, it was possible to identify morphological patterns of vegetation. In short, the genera targeted for control under the National Forest Fire Protection Plan belong to the furthest states from the mature potential of a forest, generally consisting of heliophile shrubs and typically growing in degraded soils. The shrub species to be valued belong to dynamic states closer to the mature potential, consisting mainly of broad-leaved shrubs and those growing in better-preserved soils.

Tree recruitment in a drought- and herbivory-stressed oak-beech forest: Implications for future species coexistence

Mixed oak-beech forests are particularly valuable from an ecological and socioeconomic perspective but are increasingly exposed to anthropogenic impacts. We wonder whether anthropogenic change drivers, such as increased drought and ungulate populations affect optimal regeneration niches, species coexistence, and mixed-species forest dynamics. We compared understorey composition, structure and distribution with the overstorey counterpart in an oak-beech forest located at its southernmost European distribution (Central Spain) with increasing drought and ungulate herbivory for the last decades.Results showed that Ilex aquifolium and Prunus avium had greater representation in the recruitment layer as compared to the understorey layer whereas, for the dominant Quercus spp. and Fagus sylvatica, there was a tendency suggesting an expansion of Fagus at the expense of Quercus. Density of tree recruits showed strong differences across microsites. The greatest density was found under tree and under shrub cover whereas the lowest was found under woody debris. By species, Quercus regenerated better in open and shrub microsites whereas Fagus and Ilex regeneration was higher under tree cover. Large patches of shrub cover favoured Prunus avium recruitment, particularly against ungulate herbivory as it was the most heavily browsed species, followed by Quercus, Ilex and Fagus in a descending order. Herbivory occurrence and intensity on tree recruits strongly varied with the microsite, with greater herbivory levels in open microsites. Woody debris on the ground only protected tree recruits from browsing when they were located under tree cover.Overall, fenced areas with no ungulates showed greater tree species coexistence (28% increase in species richness) and recruitment abundance (81% increase) after 7 years of exclusion. We also found a large increase in tree recruit growth and height:diameter ratio (h:d) for all studied species when fenced. Fagus and Prunus avium showed the greatest growth and h:d increase, much greater than those of Quercus and Ilex. The h:d was identified as a reliable indicator of ungulate herbivory and reference values (under null levels of ungulate herbivory) were provided for each species.We conclude that there is an imperative need for adaptive management strategies that address the joint effects of climate change (e.g. increased drought) and ungulate herbivory in mixed oak-beech forests. The provision of different microsites, including patches of shrub cover in open microsites and woody debris under dense tree cover, will facilitate the availability of suitable regeneration niches for most species and will therefore promote future species coexistence.

Epiphyllous bryophytes in Arboretum Mlyňany (Slovakia)

Epiphyllous bryophytes in Arboretum Mlyňany (Slovakia)

Very high-resolution true color leaf-off imagery for mapping Taxus baccata L. and Ilex aquifolium L. understory population

According to the “Habitat” Directive 92/43/EEC, the conservation status of natural habitats depends on the occurrence of populations of their typical species. For some forest habitats, typical species do not occur as canopy dominant trees but are found in the understory. This is the case with the priority habitat ’‘Apennine beech forests with Taxus and Ilex’’ 9210*. Taxus baccata L. and Ilex aquifolium L. are evergreen tree species and occur as isolated trees or groups in the understory of beech dominated forests. Accordingly, the knowledge of the spatial pattern of populations of typical species is fundamental for habitat monitoring goals. In this perspective, this study aims to evaluate the potential of very high-resolution, true color, leaf-off imagery (pixel size = 0.11 m), supplied by Google Earth, for mapping these populations. Understory layer detection has been accomplished through an object-oriented approach, based on multiresolution segmentation. The classification was developed with thresholds based on spectral and geometric properties, as well as on textural and contextual information. The main critical issues are represented by site conditions, where shadowing can prevent crown detection. The thematic accuracy of the target species map resulted in a Producer Accuracy of 0.77 and a User Accuracy of 0.80. The proposed procedure offers a good methodological foundation with which to map the actual spatial extent of forest broadleaved deciduous habitat types, characterized by low abundance and patchily distributed populations of yew and holly.

Passive recovery of an urban forest in the Pacific Northwest after removal of invasive plants

Urban natural areas are often heavily invaded by non-native plants. To restore the biodiversity and ecosystem function of these areas, land managers commonly remove invasive species. Partnering with Portland Parks and Recreation, I studied a management-scale removal of Hedera spp., Clematis vitalba, Ilex aquifolium and Prunus laurocerasus from a 59 ha forested natural area in Portland, OR. Over four years, I compared the community composition of this area with contiguous control areas where invasive species remained intact. Hedera, the most abundant invader, was dramatically reduced in removal areas, along with Clematis and Ilex. Both the abundance and the diversity of native herbs and woody seedlings were substantially higher in removal areas, with Claytonia sibirica, Galium spp., Hydrophyllum tenuipes, Trillium ovatum, and Acer macrophyllum seedlings all showing significant increases. By 2015, the minimum native species richness for removal areas was 37, as determined by the Chao 2 estimator, versus 10 native species for control areas. In contrast, native shrubs and ferns showed no increase in response to invasive removal; in fact, control plots typically contained significantly higher stem densities of native shrubs and ferns than removal plots did. Few non-native species recolonized removal areas, except for seedlings of Clematis. Collectively, these results indicate that passive recovery of the herbaceous layer is possible at large scales following invasive species removal, but that active replanting of woody species may be needed. Partnerships between land managers and academic researchers are key to documenting the effects of management-scale removals.

Wood use in early medieval weapon production

In this paper, the analyses of wood remains from weapons that were found in early medieval graves in Belgium are presented. In addition, a large number of wood identifications from other early medieval weaponry from northwestern Europe (Germany, France, Switzerland, and England) was collected, resulting in a dataset of more than 800 items. The analysis of this dataset shows that the selection of wood taxa for specific weapons was largely similar all over northwestern Europe during this period and this selection can be explained by the physical and technical properties of each of these wood species. For instance, common ash (Fraxinus excelsior) being the preferred wood for arrow and spear shafts and alder (Alnus sp.) for scabbards. However, some regional differences emerged from this extensive dataset, e.g., the use of holly (Ilex aquifolium) for the production of axe handles being restricted to northern Belgium and poplar/willow (Populus sp./Salix sp.) being the preferred wood for shields in the UK, while these were mostly made from alder (Alnus sp.) in continental Europe. The results demonstrate the added value of wood anatomical analysis of mineralized wood particles preserved in the corrosion layer of metal objects, and weapons in particular, from archeological contexts. Clearly, taxonomic identifications have the potential to shed more light on material culture, technological craftsmanship, and the burial ritual in early medieval societies.

Identification and Quantitation of Ursolic and Oleanolic Acids in Ilex aquifolium L. Leaf Extracts Using 13C and 1H-NMR Spectroscopy.

Leaves of Ilex aquifolium L. have been used for their therapeutic properties. In previous studies, components contained in the leaves were first isolated by various chromatographic techniques. Then, quantitation of oleanolic and ursolic acids, which are responsible for the biological and therapeutic activities of the plant, was performed by HPLC, HPTLC, and somewhat by GC-MS. Our objective was to develop a simple method that allows the identification of compounds contained in the leaves of Corsican I. aquifolium and to quantify ursolic and oleanolic acids. Leaves were successively extracted with hexane and dichloromethane. The extracts were chromatographed on silica gel and the fractions of column chromatography submitted to 13C-NMR analysis, following a computerized method developed in the laboratory. 13C-NMR allowed the identification of various triterpenes including ursolic acid and oleanolic acid. Quantitation of both acids was achieved, for the first time, by 1H-NMR after validation of the method (accuracy, precision, linearity, limit of detection and limit of quantitation). Ursolic and oleanolic acids accounted for 55.3% and 20.8% of the dichloromethane extract, respectively. This represents 1.3% and 0.5% of the mass of dried leaves. 1H-NMR spectroscopy appeared as a powerful tool for a rapid quantitation of biologically active compounds from I. aquifolium.

The Toledo Mountains: A Resilient Landscape and a Landscape for Resilience? Hazards and Strategies in a Mid-Elevation Mountain Region in Central Spain

The Toledo Mountains are a mid-elevation mountain range that separates the Tagus and Guadiana basins in the central area of the Iberian Peninsula. The location of these mountains allows the development of typical Mediterranean vegetation with some Atlantic influence. Consequently, typical broadleaved evergreen Mediterranean vegetation currently dominates the regional landscape, with the remarkable presence of more mesophilous species in sheltered and more humid microsites such as gorges (e.g., Prunus lusitanica, Taxus baccata, Ilex aquifolium) and mires/bogs (e.g., Betula pendula susbp. fontqueri, Erica tetralix, Myrica gale). Palaeoecological studies in these mountains are essential to understand the long-term ecology and original distribution of these valuable communities and are key to assess their resilience. Understanding the hazards and opportunities faced in the past by the plant communities of the Toledo Mountains is necessary to enhance the management and protection of those species currently threatened. This study focuses on El Perro mire, a peatland on the southern Toledo Mountains (central Spain) where climatic variability has played a major role in landscape dynamics at multi-decadal to millennial timescales. Climatic events such as the 4.2 ka cal. Before Present (BP) or the Little Ice Age triggered relevant landscape changes such as the spread and latter decline of birch and hazel forests. Human communities also seemed to be affected by these events, as their resilience was apparently jeopardized by the new climatic conditions and they were forced to find new strategies to cope with the new scenarios.

Potential of thermal imaging in soil bioengineering to assess plant ability for soil water removal and air cooling

Soil bioengineering uses living vegetation to improve the ecological value and engineering performance of infrastructure slopes. Vegetation can stabilise slopes and provide co-benefits such as air cooling for potential mitigation of the urban heat island effect. This study represents the first attempt to apply the thermal imaging technique to simultaneously evaluate the abilities of plants to induce suction via transpiration (hydrological reinforcement) and cooling in the context of soil bioengineering. A pilot glasshouse experiment was performed to evaluate the use of thermal imaging to determine plant transpiration of Corylus avellana and Ilex aquifolium. Field thermal imaging was also carried out on a 20 m-long vegetated embankment where soil matric suction was measured. In addition to C. avellana and I. aquifolium, Ulex europaeus was also selected for testing in the field. U. europaeus had the greatest cooling effect, largest value of the index of stomatal conductance and the largest induced soil suction. Thermal imaging can be a useful preliminary tool to evaluate the cooling and water removal effects induced by different plant species. Whilst thermal imaging has a great potential to remotely estimate the transpiration of multiple individual plants at one time, plant surface temperature was subject to variabilities of environmental factors and above-ground plant properties that require further investigation before the technique can be widely applied.

Macrofungi of Mata da Margaraça (Portugal), a relic from the Tertiary Age.

Mata Nacional da Margaraça represents a rare example where the Atlantic climate influences the perpetuity of a small enclave of a previously widespread laurel forest. The higher relative humidity values (> 80%), which are almost constant all year long and the mild temperatures, rarely exceeding 30°C, even in the dry season (June to September), create an insular-like effect. The biological communities of Margaraça exhibit a transitory character. The forest is dominated by Quercus robur and Castanea sativa, yet Quercus suber, although less frequent, can also be found. The laurel species, such as Viburnum tinus, Ilex aquifolium, Laurus nobilis and the Portuguese endemic Prunus lusitanica ssp. lusitanica, relics from the ancient Portuguese Tertiary, comprise the understorey. The present work represents, to the best of our knowledge, the first regional macrofungal species list of the Mata da Margaraça published to date. The recent fires that occurred in the area have provided the opportunity to study the post-fire communities. The surveys were carried out in 2004 and later in 2018-2019. A total of 271 species were registered as belonging to Basidiomycota (≈ 80%) and Ascomycota (≈ 20%). The most represented Basidiomycota families were Russulaceae, Mycenaceae and Agaricaceae and the most represented Ascomycota families were Pyronemataceae and Pezizaceae. The new records to Portugal add up to a total of 88 species and another 116 species are new records to the province of Beira Litoral. Post-fire fungi account for 17 of the total of 271 species registered in these studies and most of these species are new to Portugal.

Wintertime photosynthesis and spring recovery of Ilex aquifolium L.

Abstract: Former studies using the chlorophyll fluorescence technique on evergreen Ilex aquifolium L. showed that its photosynthetic potential for electron transport in winter recovers quickly when exposed to more favorable conditions. Since little is known, however, about its photosynthetic carbon gain in winter, we investigated its leaf gas exchange over an entire winter and spring period. Measurements were made rotationally in the field and in the laboratory to also investigate if I. aquifolium profits from warmer phases during winter in terms of net carbon gain. From the end of autumn until the end of spring, three different climate-driven phases of photosynthetic responses could be distinguished: first, an acclimation phase which lasted until February and was characterized by a gradually decreasing light-saturated gross photosynthesis (Amax(gross)), decreasing apparent quantum yield of CO2-assimilation (ΦΦi) and a decreasing ability of these parameters to recover overnight inside the laboratory. At the same time, maximal quantum yield of PSII (Fv/Fm) could fully regenerate. In this phase, single warmer days had a positive effect on carbon assimilation. Second, a phase of relatively constant but low photosynthesis which was virtually unaffected by temperature, lasting for almost two months occurred. Here, Amax(gross) and Φi had lost their ability to recover from winter conditions in the field, while Fv/Fm was much less affected. I. aquifolium was still able to conduct positive light-saturated net photosynthesis at a leaf temperature of -0.5 °C, but during this time it could not profit from milder temperatures in terms of carbon gain. Third, a phase of increasing photosynthesis (spring recovery) occurred, starting in March when the 5-day average temperature was above 5 °C and radiation in the field increased, and where all parameters slowly recovered from winter depressions. Our findings show that I. aquifolium is photosynthetically active over the whole winter, even at temperatures around 0 °C. In terms of carbon gain, however, I. aquifolium does not profit from warmer phases during winter, despite the fast recovery seen in chlorophyll fluorescence measurements.

<p class="Body"><strong>Supplementary description of five species from the genus <em>Cecidophyopsis</em> (Eriophyoidea: Eriophyidae: Cecidophyinae)</strong></p>

Supplementary morphological descriptions of five Cecidophyopsis species collected in Europe (Serbia, Austria, Italy and Montenegro) are given: Cecidophyopsis vermiformis from Corylus avellana L. (Betulaceae), C. hendersoni from Yucca gigantea Lem. (Asparagaceae), C. verilicis from Ilex aquifolium L. (Aquifoliaceae), C. psilaspis from Taxus baccata L. (Taxaceae) and C. malpighianus from Laurus nobilis L. (Lauraceae). Males of C. vermiformis, C. verilicis, C. hendersoni and C. malpighianus, and immatures of C. hendersoni and C. verilicis, are described for the first time. C. verilicis is recorded for the first time in the fauna of Serbia and the European region. Female cuticle-lined internal genitalia of five Cecidophyopsis species are studied under confocal laser scanning microscopy. A several steps of oviposition in cecidophyines is proposed based on CLSM observations on their internal genitalia. Sequences of the barcoding region of the mitochondrial cytochrome oxidase subunit I (mtCOI) gene are given for the following species: C. hendersoni, C. verilicis, C. psilaspis and C. malpighianus.

East Asian origins of European holly oaks (Quercus section Ilex Loudon) via the Tibet‐Himalaya

AbstractAimMany subtropical organisms exhibit an East Asian‐Tethyan disjunction, a distribution split between East Asia and the Mediterranean. The underlying mechanisms and timing have remained unclear to date. The evolutionary history of Quercus section Ilex Loudon, a representative East Asian‐Tethyan disjunct lineage with a rich and widespread fossil record, was investigated to understand the key drivers of this disjunction.LocationEurasia.MethodsThe phylogeny of Quercus section Ilex was reconstructed using RAD‐seq. Divergence times were estimated based on three fossil calibrations. Ancestral range and niche were reconstructed on the calibrated tree to infer the timing of transitions in geographic distributions and niche. Convergence in ecological space was estimated by fitting alternative multiple‐regime Ornstein‐Uhlenbeck models. Leaf shape affinities among extant and fossil taxa of section Ilex were assessed using geometric morphometric approaches.ResultsSix clades were well resolved in section Ilex. Ancestral range reconstruction and divergence time dating suggest a wide distribution along the East Tethys seaway, with initial divergence at the mid‐Eocene, and all six clades originating before the Miocene. The section dispersed from East Asia to the Mediterranean at the Eocene‐Oligocene boundary. A shift toward higher elevations was detected in the Himalayan clade during the middle or late Miocene. European fossil lineages during the early Miocene differ in leaf morphology from later lineages, which we infer to be a consequence of adaptive differentiation or species turnover.Main conclusionsQuercus section Ilex was widespread along the East Tethys seaway from the middle Eocene onward. The European holly oaks originated from an East Asian ancestral lineage that dispersed to Europe via the Tibet‐Himalaya corridor in the Oligocene. Lowlands along the margins of the Himalayas and through an Oligocene Tibetan valley served as the dispersal route(s) for these species. Changing climates drove Miocene extinction and local adaptation of European lineages.

Vegetation changes in the Hasbruch forest nature reserve (NW Germany) depend on management and habitat type

AimsWe carried out vegetation studies in the ancient Hasbruch forest, which provided the unique conditions of unmanaged (UM) and managed (M) stands in two vegetation types Stellario-Carpinetum loniceretosum (POOR) and stachyetosum (RICH) stands in one closed forest allowing us to study (1) the changes in species composition and richness over 20 years considering the entire forest as well as (2) group-specific changes. LocationHasbruch forest in the lowlands of Lower Saxony, Germany. MethodsIn 2016 we resurveyed the vascular plant species composition of 79 semi-permanent plots analysed in 1996. General and group-specific trends as well as drivers of changes were analysed using DCA, PCA, LM, t-test, U test, ANOVA. ResultsTree and shrub layer coverage increased significantly in the entire forest. Herb layer species richness decreased significantly only in group RICH_UM. While the pH-value increased significantly in group POOR, it decreased significantly in group B. EIV F increased significantly in group POOR_M and decreased significantly in group RICH_UM. EIV L increased significantly in both of the managed groups, while it decreased significantly in group RICH_UM. An increase was found for EIV N in group POOR_M, whereas a decrease was found in group RICH_M. Strongly increasing species were Ilex aquifolium, Rubus fruticosus agg. and Hedera helix; strongly decreasing species Geum urbanum and Primula elatior. The change in species richness was positively affected by ΔpH and negatively affected by ΔT1cov in the entire forest. ConclusionsThe main drivers for changes in species richness and composition in the Hasbruch forest were light and water availability. The effects of the drivers strongly depended on the vegetation type. Changes in species composition were more pronounced in nutrient-rich forests than on nutrient-poor sites. In nutrient-rich forests, decreased groundwater influence led to decreased soil pH which especially affected typical woodland plants in a negative way. Management positively affected light-demanding species as well as some N-demanding species. Thus, unmanaged, nutrient-rich stands displayed the highest losses in species diversity. In the nutrient-poor stands, changes in species composition were not significantly related to changes in soil and management. However, increasing pH as well as increased Ellenberg L, F, and N values suggest a tendency towards eutrophication. This is possibly a consequence of N deposition and recovery from soil acidification.

Root Biomechanical Traits in a Montane Mediterranean Forest Watershed: Variations with Species Diversity and Soil Depth

Plant roots play a key role in stabilizing slopes, particularly in the Mediterranean region, characterized by rough and unstable terrain. However, forest species differ in their stabilizing capacities. The purpose of this study is to fill the gap of knowledge on root biomechanical properties of relevant Mediterranean trees and shrubs in relation to slope stability. Root specimens of typical montane Mediterranean tree and shrub species were sampled in Southern Italy. Root characteristics, such as tensile strength (Tr) and root area ratio (RAR), were assessed from live roots sampled in trenches, while root cohesion was calculated. Power law functions yielded the best fit for the relationship of Tr versus root diameter; however, no significant relationship was found between root strength and root moisture content. RAR varied amongst different tree and shrub species. Roots of Quercus cerris L. were the most resistant to breaking under tension, while roots of Ilex aquifolium L. had the highest tensile strength among all shrub species. Results provide quantitative information on the role of root systems of montane Mediterranean forest species in stabilizing soils and will improve modeling of landslide susceptibility to the prevention and mitigation of natural hazards in mountain environments.

Дендросозофіти ботанічного саду Чернівецького національного університету імені Юрія Федьковича

Встановлено, що у ботанічному саду Чернівецького національного університету в умовах відкритого ґрунту зростає 211 видів дендросозофітів із 87 родів, 37 родин, 2 відділів. Серед них із відділу Pinophyta провідними за кількістю видів є роди Pinus L., Abies Mill., Picea Dietr., Juniperus L., а із Magnoliophyta – Rhododendron L., Magnolia L., Acer L., Quercus L., Malus Mill. У Червоному списку МСОП досліджувані види віднесено до 6 категорій раритетності; з них переважає група таксонів з низьким рівнем ризику зникнення (82,9 % видів). До групи під загрозою зникнення (категорії CR, EN, VU) входить 20 видів. До Європейського Червоного списку внесено 9 із досліджуваних видів. 7 видів внесено до Червоної книги України (2009), а Syringa josіkaea – також до Додатку І Бернської конвенції. Показано, що в умовах ботанічного саду Чернівецького національного університету 174 із досліджуваних дендросозофітів формують життєздатне насіння, а у 42 із них відзначено самосів. Виявлено, що 192 види повністю пристосувалися до умов культивування і мають найвищий ступінь акліматизації (І). Виділено види, які в Чернівецькій області стали інвазійними (Robinia pseudoacacia L., Acer negundo L., Quercus rubra L.), а також типові для Буковини види; всі вони мають категорію LC у Червоному списку МСОП. Успішна акліматизація та здатність до насіннєвого розмноження більшості видів свідчать про те, що колекційні фонди ботанічного саду Чернівецького національного університету є потенціалом для ефективного збереження дендросозофітів ex-situ.

Hydrologic reinforcement induced by contrasting woody species during summer and winter

Vegetation can improve slope stability by transpiration-induced suction (hydrologic reinforcement). However, hydrologic reinforcement varies with seasons, especially under temperate climates. This study aims to quantify and compare the hydrologic reinforcement provided by contrasting species during winter and summer. One deciduous (Corylus avellana) and two evergreens (Ilex aquifolium and Ulex europaeus) were planted in 1-m soil columns. Soil columns were irrigated, left for evapotranspiration and then subjected to extreme wetting events during both summer and winter. Soil water content, matric suction and strength were measured down the soil profile. Plant water status and growth (above- and below-ground) were also recorded. The tested species showed differing abilities to remove water, induce suction and hence influence soil strength. During summer, only Ulex europaeus provided a soil strength gain (up to six-fold the value at saturation) along the entire depth-profile inducing high suction (e.g. 70 kPa), largely maintained after wetting events in deeper soil (0.7 m). During winter, the evergreen species could remove water but at slower rates compared to summer. Evergreens could slowly induce suction and hence potentially stabilise slopes during winter. However, there were large differences between the two evergreens because of different growth rate and resource use.

The role of secondary trees in Mediterranean mature forests for the conservation of the forest-dwelling bat Myotis alcathoe . Are current logging guidelines appropriate?

Forest cover in Europe has substantially increased in recent decades, resulting in extensive secondary forest cover (ca. 10-20 years) that is too young for many specialist forest-dwelling species. In the Mediterranean region, forests have historically been logged with detrimental effects on local biodiversity. Only a few small forest patches remain untouched. Specialist forest-dwelling species are often less studied than other species due to their lower population densities and the inherent difficulties involved in sampling. In fact, some forests species have only recently been discovered or described such as the Myotis alcathoe (Alcathoe bat) and so there is a remarkable dearth of information regarding their natural history, habitat requirements and conservation status. A total of 18 M. alcathoe bats were captured and radio-tracked in a 100-year-old Mediterranean forest which led us to locate and describe 18 different tree roosts. The structural traits of each roost and the surrounding habitat were studied to unravel the factors involved in roost selection. Alcathoe bats were found roosting in a wide variety of sites (holes, cracks and under bark) and tree species. Around 70% of the roosts were found in dead or decrepit trees. However, except for roost height, no special traits were selected. Due to the maturity of some common holly Ilex aquifolium , this typically secondary bush species was often used as a breeding roost. Our results provide new insights into how old and small secondary tree species play an essential role in the conservation of certain forest species. Considering that in 20 years of bat surveys in the region, breeding colonies of this forest species have only been found in this forest characterized by its remarkable maturity (50-100 dead trees/ha), we suggest that current forest management guidelines (recommending densities of 5-10 dead trees/ha), might not be enough to ensure the presence of breeding colonies of these tree-dwelling bats.

ŠUMSKA VEGETACIJA TREŠNJIKA KOD BANJE LUKE

Rad obrađuje šumsku vegetaciju potencijalnog Natura 2000 područja „Trešnjik” na Starčevici kodBanje Luke. Iako područje leži nadomak glavnog grada Republike Srpske, šumska vegetacija do sadanije bila istraživana. Istraživanje je ukazalo na veliki diverzitet šumskih staništa na relativno malomprostoru. Utvrđeno je ukupno sedam stanišnih tipova, klasifikovanih u dvije ekološki i florističkijasno definisane grupe: (i) Grupa stanišnih tipova bukovih šuma: (1) stanišni tip Athyrium filix-femina-Fagus sylvatica (čiste šume bukve); (2) stanišni tip Fagus sylvatica-Tilia tomentosa (šume bukvei srebrnolisne lipe); (3) stanišni tip Quercus petraea-Tilia tomentosa (degradacija prethodnog tipa,sa dominacijom lipe); (ii) Grupa stanišnih tipova kitnjakovih šuma: (4) stanišni tip Carpinus betulus-Quercus petraea (klimatogena šuma kitnjaka i graba); (5) stanišni tip Vaccinium myrtillus-Quercuspetraea (acidofilna kitnjakova šuma); (6) stanišni tip Carpinus orientalis-Quercus petraea (termofilnekitnjakove šume); (7) stanišni tip Fraxinus ornus-Carpinus orientalis (šikare bjelograbića i crnogjasena).