Töredékes cseres-tölgyesek a Zákányi-dombokon (Asphodelo-Quercetum roboris Borhidi in Borhidi et Kevey 1996)

I present the results of a phytosociological analy-sis of 50 samples of oak-hornbeam forests on sand (Fraxino pannonicae-Carpinetum), which grow in the southwestern part of Hungary in Inner Somogy. The habitat of these forests is un-der slight influence of groundwater, which manifests itself in the species composition of these forests. The forests differ sharply from the oak-hornbeam forests (Helleboro dumetorum-Carpin-etum) growing on loess in the neighbouring Zselic. The species composition somewhat resembles that of hardwood gallery for-ests on sand (Knautio drymeiae-Ulmetum), beech woods on sand (Leucojo verno-Fagetum), and oak-hornbeam forests along the Dráva River (Veronico montanae-Carpinetum). The Fagetalia elements in its understorey (Actaea spicata, Astran-tia major, Dentaria enneaphyllos, Oxalis acetosella, etc.) are probably relics of the Beech I. phase (2500 and 800 B.C.) of the Holocene, when the climate was more humid and less ex-treme. It also hosts species typical of the Aremonio-Fagion alli-ance (pl. Carex strigosa, Cyclamen purpurascens, Doronicum orientale, Erythronium dens-canis, Knautia drymeia, Polysti-chum setiferum, Primula vulgaris, Ruscus aculeatus, Tamus communis, Tilia tomentosa), whereby it exhibits a moderate sub-Mediterranean character.

This paper summarizes the phytosociological characteristics of scree forests (Tilio tomentosae-Fraxinetum orni) found in the Villány Hills, SW Hungary.The studied stands grow within the belt of oakhornbeam forests on northerly slopes covered with stony soil.They are under relatively strong sub-Mediterraneam climatic influence as attested by the occurrence of several Aremonio-Fagion and Quercion farnetto species : Asperula taurina, Doronicum orientale, Helleborus odorus, Lathyrus venetus, Lonicera caprifolium, Lunaria annua, Polystichum setiferum, Primula vulgaris, Rosa arvensis, Ruscus aculeatus, Ruscus hypoglossum, Scutellaria altissima, Tamus communis and Tilia tomentosa.The distribution of character species proportions is similar to that in the scree forests in the Mecsek Hills, with the exception of Quercetea pubescentispetraeae s.l. as well as Fagetalia and Tilio-Acerenion species that play a more and a less significant role, respectively.Syntaxonomically, this community is best assigned to the "Polysticho setiferi-Acerenion pseudoplatani Borhidi & Kevey 1996" suballiance.

This paper presents the phytosociological characteristics of the oak-hornbeam forests on the Harkány plain based on an analysis of 25 phytosociological samples. These forests are only weakly influenced by groundwater, and thus exhibit features of dry oak forests. They sharply differ from the oak-hornbeam forests (Veronico montanae-Carpinetum) growing on young alluvial deposits in the neighboring Drava plain. In species composition, they most resemble the oak-hornbeam forests (Corydali cavae-Carpinetum) of the also neighboring Nagynyárád plain that is covered with loess. Thus, as an association, they are identified with the latter. Owing to the sporadic occurrence of Aremonio-Fagion elements (Lonicera caprifolium, Luzula forsteri, Primula vulgaris, Tamus communis, Tilia tomentosa), this association exhibits a moderate sub-Mediterranean character.

A polycarpic, aromatic, often purplish, softly hairy or nearly glabrous perennial herb. Flowering shoots 10–30 (–60) cm long, square in section and ascending or erect. Non-flowering stems also square in section, creeping and rooting at many, but not all, nodes. Leaf laminae 4–35 (–80) × 6–40 (–80) mm, reniform to ovate–cordate, obtuse or subacute and coarsely crenate. Petioles highly variable in length from 10 mm in grassland to over 200 mm in woodland with dense canopy cover and dense ground vegetation. Bracteoles 1–1.5 mm, shortly hispid or pubescent. Flowers zygomorphic and hypogynous, borne in few (2–5)-flowered secund axillary whorls, the bracts not differing from the foliage leaves. Calyx tubular or tubular-campanulate, 15-veined, not gibbous at base, and somewhat two-lipped. Upper lip of the corolla flat with three triangular acuminate teeth that are 0.2–0.3 times as long as the tube. Lower lip with two teeth. Corolla tube narrowly obconical, straight and hairy within at the base of lower lip. Corolla (6–) 15–22 (–25) mm, usually blue–violet with purple spots on the lower lip; rarely pink or white. Stamens four, two long and two short, borne on corolla tube and lying below upper lip; anther cells at right angles to each other, each opening by a separate slit. Ovary four-celled and deeply four-lobed, each cell with one ovule. Style gynobasic, its branches equal. Hermaphrodite and male-sterile forms of flowers occur, the latter usually with smaller corollas than hermaphrodite flowers, and much-reduced, pollen-less stamens that are often included in the corolla tube. Clones usually bear either only hermaphrodite or only male-sterile flowers, but in rare cases both types are found on the same individual (Price 1991). Each flower produces a maximum of four obovoid, slightly angled, smooth nutlets with a mean air-dry mass of 0.69 mg (n = 100). Each is slightly angled owing to pressure exerted by the adjacent developing nutlets before dispersal, and each bears a grey protuberance which may be an elaiosome. The dimensions of the seed are 1.9 × 1.1 mm. Glechoma serbica Halacsy & Wettst., which has been recorded in former Jugoslavia, is probably an ecological modification of G. hederacea (Fl. Eur. 3). The southern counterpart of G. hederacea in Europe is ssp. hirsuta (Waldst. & Kit.) F. Hermann, sometimes referred to as G. hirsuta (Elias 1979, 1983). This has denser and longer hairs and longer calyx teeth than G. hederacea, and the corolla is pale blue. It has been recorded in Albania, Austria, Bulgaria, the Czech Republic, Greece, Hungary, Italy, former Jugoslavia, Poland, Rumania, central and south-west Russia, Sardinia and Sicily (Fl. Eur. 3). Intermediates, which are presumably hybrids between G. hederacea and G. hirsuta, sometimes occur (Fl. Eur. 3). In eastern Asia a more or less distinct, short-pubescent race occurs that is called ssp. grandis (A. Gray) Hara [also var. grandis A. Gray and var. longituba (Nakai) Kuprian] (Hulten 1971). In North America the variety micrantha Moricand [or var. parviflora (Benth.) House] is distinguished (Hulten 1971).

The boreal forest in Canada comprises a wide variety of ecosystems, including stabilized (overgrown) sand dunes, often referred to as sand hills. Globally, sandy soils are known for supporting a high diversity of invertebrates, including ants, but little is known for boreal systems. We used pitfall trap sampling in sand hill, aspen parkland and peatland ecosystems to compare their ant diversity and test the prediction that areas with sandy soils have higher invertebrate diversity compared to more mesic/organic soils. Overall, sand hills had ~45% more ant species compared to other sampled ecosystems from Alberta. Similar to other studies, local canopy cover within sand hills was found to be inversely related to ant species richness and diversity. Although sand hills are rare across the region, they are high biodiversity areas for ants, with the sand hills of north-central Alberta having higher species richness of ants compared to other studied areas in Canada.

In the establishment of mixed plantations, it is necessary to examine previously the relations of the principal and the admixed species and the most significant pests. This paper presents the results of the study of the gypsy moth caterpillar preference and performance on sweet chestnut and four oak species. Preference index is the highest for Hungarian oak (0.83) and Turkey oak (0.77), for sessile oak it is significantly lower (0.33), and for common oak it is equal to 0. In combination with sweet chestnut, the gypsy moth second-instar caterpillars prefer Hungarian oak, i.e. Turkey oak leaves. In combination with sessile oak or common oak, the gypsy moth caterpillars prefer sweet chestnut leaves. The analyzed parameters which characterise the performance of the gypsy moth fourth-instar caterpillars are lower for all study oak species compared to sweet chestnut, except in the case of Turkey oak. Based on the study results and the adopted principle that the mixture should be composed of the most favourable species, which will serve as the 'trap plant' during the gypsy moth outbreak, it can be concluded that Turkey oak is more favourable for the mixture with sweet chestnut than the other analyzed oak species.

We developed an index of biotic integrity (IBI) for the Sand Hills ecoregion within the upper Coastal Plain of the southeastern United States. This ecoregion exhibits differences in species composition among river basins and possesses a relatively depauperate fish fauna that has been affected by faunal homogenization. We also investigated whether this IBI could be improved by adding benthic macroinvertebrate information. Data collected from 70 wadeable stream sites were used to calculate 45 fish assemblage metrics. Twelve metrics within the categories of species richness, species composition, habitat guild, trophic guild, tolerance level, alien/invasive species, and individual fish condition were retained after screening all metrics for sensitivity to disturbance, redundancy, and ecological content. Heterogeneity of species composition among basins led to a greater reliance on richness, indicator species, trophic guild, and habitat guild metrics rather than on more geographically variable species composition metrics. Characteristic headwater assemblages provided the basis for some metrics, and invader species metrics were included to address faunal homogenization. The Sand Hills IBI (SHIBI) was more accurate ecoregion‐wide than IBIs that were developed for portions of the Sand Hills, correctly classifying about 60% of the disturbed sites compared with less than 30% for the other IBIs. However, the SHIBI was not highly responsive to gradients in site quality, as indicated by an R2 of 0.30 between SHIBI scores and instream habitat quality scores. This R2 value was improved to 0.49 by supplementing the SHIBI with a benthic macroinvertebrate index (the Ephemeroptera, Plecoptera, and Trichoptera index). We conclude that ecoregion‐wide IBIs should (1) be based on ecoregion‐wide data that characterize responses to disturbance and natural habitat gradients, (2) maintain a substantial ecological basis by including several metric classes, and (3) include metrics that address faunal homogenization where disturbance has increased the dispersion of nonnative species and native generalist species. In addition, combining information from different assemblages can enhance IBI responsiveness to disturbance and improve performance.Received May 5, 2016; accepted September 19, 2016 Published online December 8, 2016

Does forest fragmentation affect the same way all growth-forms?

Wildfires are integral to many forest ecosystems, yet their ecological effects are often influenced by historical land use and management. In this study, we assess the short-term impacts of fire and management on Castanea sativa Mill. stands in the fayal-brezal zone of northern Tenerife (Canary Islands), where traditional agroforestry systems have been widely abandoned. We established 12 transects across four stands: managed-burned, managed-unburned, oldfield-burned, and oldfield-unburned. We analyzed forest structure, understory species richness and composition, and soil nutrient content one year after a large wildfire. Forest structure has primarily been determined by management history, with oldfield plots showing greater tree density, basal area, and basal sprouting. Fire has had a limited effect on tree mortality, affecting ~10% of individuals on average. Understory species richness was significantly higher in managed plots, particularly those affected by fire, suggesting a positive interaction between disturbance and management. Species composition differed significantly among treatments, with Indicator Species Analysis identifying distinct taxa associated with each condition. Fire in oldfield plots led to increased compositional similarity with managed stands, indicating fire’s potential homogenizing effect. Principal Component Analysis of soil nutrients did not reveal clear treatment-related patterns, which was probably due to microenvironmental variability and the short post-fire interval. Overall, our results highlight the dominant role of land-use legacy in structuring these forests, with fire acting as a secondary but influential driver, revealing significant changes in species composition as well as in species richness. These findings have direct relevance for conservation and restoration strategies as well as for maintenance in these stands of Castanea sativa. They should also encourage managers of these protected areas, where land abandonment and fire are increasingly shaping forest dynamics.

Diversity and fruiting pattern of macrofungi associated with chestnut (Castanea sativa) in the Trás-os-Montes region (Northeast Portugal)

Natural stand changes in the forest reserve of Liedekerke were analysed during the period 1986-1996, using a permanent grid of circular plots. The monitoring concentrated on natural changes in species composition, using stem number and basal area as indicators, and changes in spatial distribution and colonization capacities of trees and shrubs, with special interest in the competition between exotic and indigenous species. After only a decade of monitoring important natural changes in the woody layer were detected. The pioneer forest is gradually maturing through self-thinning processes and shifts in species composition. The overall stem number decreased with 33.6%, while the basal area increased with 20.9%. Birch (Betula pendula/ pubescens) and indigenous oak (Quercus robur/petraea) remained dominant. More tolerant exotic species, like red oak (Quercus rubra) and sweet chestnut (Castanea sativa), are slowly increasing their share in the species composition and expanding their range. Pioneer species on the other hand, like aspen (Populus tremula), willow (Salix capreaicinerealaurita), alder buckthorn (Frangula alnus) and common (Alnus glutinosa) and grey alder (A. incana), strongly declined. Black cherry (Prunus serotina) seems to be slowly invading the forest due to its massive natural regeneration. Strong competition may be expected especially from rowan ash (Sorbus aucuparia), which showed similar regeneration and colonization capacities. Elder (Sambucus nigra) dramatically extented its range, though its share remains marginal. Beech remained absent most probably due to the lack of mature trees in the vacinity of the forest. Finally this change detection allowed that general predictions could be made on the future natural development and composition of this forest reserve, which could serve forest management decisions.

Summary 1 Habitat fragmentation and the resulting decline in population size can affect biotic interactions and reproductive success of plant species. We investigated the impact of habitat type, population size, morph type and frequency, plant density, floral display and predation on different reproductive components in 16 populations of the distylous self-incompatible perennial herb, Primula vulgaris , a rare, declining species in Belgium. 2 Although habitat type accounted for significant variation in population size, we did not find any relation between habitat type and either reproductive and vegetative characteristics. Population size, however, strongly affected reproductive success, such that plants in small populations produced significantly fewer fruits per plant and seeds per fruit, and therefore fewer seeds per plant. 3 No significant difference was found between morph types for any reproductive characteristic, nor an interaction with population size. However, when morph frequency was strongly biased ( ≥ 1 : 3), the proportion of flowers setting fruit and the number of seeds per fruit were significantly lower in individuals of the common morph type. 4 Within populations, individual plants varied tremendously in size and floral display. Total number of fruits per plant significantly increased with floral display, but the highest fruit set per flower was found at intermediate flower number. 5 The proportion of fruit suffering pre-dispersal predation per plant significantly increased with floral display, but this did not offset the potential fitness gains of producing a large display. Furthermore, the absolute number of predated fruits per plant was significantly and positively affected by the interaction of the total number of fruits per plant and the density of the population.

Traditionally, community ecologists assumed that spe-cies differ in some aspects of their traits or responsesto the environment (i.e. their niches), which allow themto coexist in the same habitat (Hutchinson 1957, 1959).Recently, Hubbell (2001) and others (e.g. Bell 2001,2003) have suggested that this view is inadequate toexplain the diversity often observed in speciose systems.For example, hundreds to thousands of tree species livein tropical forests, which only have a handful of limitingresources such as water, light, and a variety of macro- andmicronutrients. Such high diversity, with so few resources,they argue, cannot be explained by niche theory.As an alternative to the traditional niche theory,Hubbell (2001) developed a neutral theory of commu-nity structure (see also Caswell 1976; Hubbell 1979;Hubbell & Foster 1986; Bell 2000, 2001, 2003; Chave L Chave 2004). In the neutral theory, pat-terns of species diversity, relative abundance, andcomposition are primarily a function of the size of themetacommunity, the dispersal rate of organisms withinthe metacommunity, and the rates of generation (spe-ciation) of new species (Bell 2001; Hubbell 2001; Chave2004). Because species are assumed to be identicalecologically, Hubbell termed his a ‘neutral theory’, bydirect analogy to neutral genes in population genetics.Hubbell further termed his theory ‘unified’ in that it issimultaneously able to predict diversity and relativeabundance of organisms in a locality, as well as bioge-ographic patterns of species composition.In this essay, I overview the key assumptions (inputs)required and the insights (outputs) that can be gainedfrom each framework. While a complete discussion ofall of the assumptions and predictions of these modelsis beyond the scope of this essay (but see Chase

Plant extracts are important natural resources that may have antimicrobial and antibiofilm effects against pathogens. This study was conducted to investigate the in vitro antimicrobial activities of methanol extracts of some medicinal plants (Achillea nobilis subspecies neilreichii (A. Kern.) Velen., Aetheorhiza bulbosa (L.) Cass, Allium paniculatum L, Asphodelus aestivus Brot., Ballota nigra L., Cistus laurifolius L., Cistus salviifolius L., Dioscorea communis (L.) Caddick and Wilkin, Galium verum L., Hypericum triquetrifolium Turra, Paliurus spina-christi Mill., Primula vulgaris Huds. subspecies rubra (Sm.) Arcang., Ranunculus arvensis L. and Teucrium polium L.) from Balıkesir province in Türkiye. Preliminary antimicrobial activity screening was conducted for all extracts. Antibiofilm activity studies were conducted on mature Candida albicans biofilms. Moreover, the cytotoxicities of A. paniculatum flower extract on A549 and Vero cell lines were determined using a colorimetric tetrazolium-based assay. A. paniculatum flower, P. vulgaris root, C. laurifolius, C. salviifolius, and A. nobilis displayed good activity [minimum inhibitory concentrations (MIC): 9.75, 156, 312, 312 and 312 μg/mL, respectively] against C. albicans American Type Culture Collection 10231. Biofilm studies were conducted on these plant extracts. The methanol extract of A. paniculatum flower decreased the number of C. albicans [colony-forming unit (CFU)/mL] in mature biofilm statistically at 32 x MIC and higher concentrations (p < 0.01). A. paniculatum flower extract had a cytotoxic effect (killing more than 50% of cells) at high concentrations, and its effect on Vero cells was similar to that on A549 cells. This study demonstrated the importance of the methanol extract of A. paniculatum flower as a natural alternative against C. albicans infections, including biofilms.

Human influence on the environment is so extensive that virtually all ecosystems on the planet are now affected by biological invasions. And, often, ecosystems are invaded by multiple co‐occurring non‐native species. Hence, it is important to understand the impacts these invasions are producing on biodiversity and ecosystem processes.Here, we present results of a 2‐year long field experiment where we tested the effects of co‐occurring invasive C4African grasses in a Cerrado area in central Brazil. We compared plant and arthropod communities, plant biomass, and soil nitrogen dynamics and soil chemical characteristics across five experimental treatments:Urochloa decumbensremoval;Melinis minutifloraremoval; bothU.decumbensandM.minutifloraremoval;U.decumbensandM.minutiflorainvaded plots; and uninvaded Cerrado. We hypothesized that selective removal of invasive grasses would have distinct effects on the native ecosystem structure and functioning. We expected that each invasive grass would produce a different type of impact on the native ecosystem and that their impacts would be synergistic when co‐occurring.Removal ofM.minutifloradoubled native plant diversity and biomass when compared to invaded plots, whereas removal ofU.decumbensdid not alter these parameters. Cerrado plots had four times more plant species than plots cleared of invasives. Removal of invasive grasses did not affect the species richness or community composition of soil epigeal fauna. Cerrado soils had lower fertility, organic matter content and pH than invaded soils. The effects were generally higher when both invasive grasses were removed, suggesting impacts were synergistic, butM.minutiflorahad greater effects on plants and soils thanU.decumbens. Both invasive species produced negative impacts, but a single species was the main driver. We also detected persistent effects of the invasive grass species on the ecosystem after 2 years of removal.We conclude that invasive species of the same functional group have similar types of effects in native ecosystems, but the magnitude of impact was largely dependent on invasive species biomass and cover. Where multiple invasive species are present, research and management of invaded ecosystems should tackle the interacting effects of co‐occurring invaders.