High Mountain Habitats Research Articles

Witness of the Little Ice Age—One of the Oldest Spruces in Poland (Śnieżnik Massif, Sudetes, SW Poland)

During an interdisciplinary study of the mire “Torfowisko pod Małym Śnieżnikiem”, a very old specimen of the Norway spruce (Picea abies L.) was encountered. The aim of the present work was to perform a detailed examination of this tree, to compare it to other spruce trees on the mire, and to provide support for establishing protection for this tree stand. Tree ring cores were sampled at 1.3 m above ground using a Pressler borer, in two field campaigns: June and July 2023, the latter campaign aiming to find the oldest trees. A total of 46 trees were sampled, yielding 84 measured radii. Tree ring widths were measured down to 0.01 mm under a stereomicroscope. The oldest sampled tree yielded a total of 370 tree rings in the two radii, representing the period 1653–2022. The average tree ring width for this oldest tree equals 0.33 mm/year, and shows low values (on average 0.19 mm/year) for the period 1742–1943, i.e., during the Little Ice Age cooling. Changes in the tree ring width coincide with periods of cooling and warming in the nearby Tatra Mountains. The oldest tree does not stand out from other trees from the population with respect to height or trunk diameter. A comparison of the age of this tree to the oldest spruce trees in Poland indicates that it is one of the longest living specimens of this species. Considering the natural character of the stand, the remaining flora, and the peat-forming processes taking place within the mire “Pod Małym Śnieżnikiem”, we argue that the mire should become protected by the law as soon as possible in order to preserve this valuable high mountain habitat.

Thermal tolerance does not explain the altitudinal segregation of lowland and alpine aquatic insects

Elevation gradients provide powerful study systems for examining the influence of environmental filters in shaping species assemblages. High-mountain habitats host specific high-elevation assemblages, often comprising specialist species adapted to endure pronounced abiotic stress, while such harsh conditions prevent lowland species from colonizing or establishing. While thermal tolerance may drive the altitudinal segregation of ectotherms, its role in structuring aquatic insect communities remains poorly explored. This study investigates the role of thermal physiology in shaping the current distribution of high-mountain diving beetles from the Sierra Nevada Iberian mountain range and closely related lowland species. Cold tolerance of five species from each altitudinal zone was measured estimating the supercooling point (SCP), lower lethal temperature (LLT) and tolerance to ice enclosure, while heat tolerance was assessed from the heat coma temperature (HCT). Alpine species exhibited wider fundamental thermal niches than lowland species, likely associated with the broader range of climatic conditions in high-mountain areas. Cold tolerance did not seem to prevent lowland species from colonizing higher elevations, as most studied species were moderately freeze-tolerant. Therefore, fundamental thermal niches seem not to fully explain species segregation along elevation gradients, suggesting that other thermal tolerance traits, environmental factors, and biotic interactions may also play important roles.

Cuticular Hydrocarbon Profiles of Himalayan Bumble Bees (Hymenoptera: Bombus Latreille) are Species-Specific and Show Elevational Variation.

Bumble bees are important pollinators in natural environments and agricultural farmlands, and they are in particular adapted to harsh environments like high mountain habitats. In these environments, animals are exposed to low temperature and face the risk of desiccation. The Eastern Himalayas are one of the recognized biodiversity hotspots worldwide. The area covers subtropical rainforest with warm temperature and high precipitation as well as high mountain ranges with peaks reaching up to 7,000m, shaping a diverse floral and faunal community at the different elevational zones. To identify possible adaptation strategies, we investigated the cuticular hydrocarbon profiles of four bumble bee species occurring at different elevational ranges in Arunachal Pradesh, the northeastern most state in India. At 17 locations along an elevational gradient, we collected workers of two species from lower elevations (B. albopleuralis and B. breviceps; ~ 100m - 3,000m asl) and two species from higher elevations (B. prshewalskyi and B. mirus; ~ 2,800m - 4,500m asl). The CHC profiles of all four species showed a significant degree of variation in the composition of hydrocarbons, indicating species specificity. We also found clear correlation with elevation. The weighted mean chain length of the hydrocarbons significantly differed between the low and high elevation species, and the proportion of saturated hydrocarbons in CHC profiles significantly increased with the elevational range of the bumble bee species. Our results indicate that bumble bees living at high elevations reduce the risk of water loss by adapting their CHC composition on their cuticle, a phenomenon that has also been found in other insects like ants and fruit flies.

Response of Origanum dictamnus L. (Cretan dittany) to Five Species of Root-Knot Nematodes (Meloidogyne spp.).

Cretan dittany (Origanum dictamnus L.) is an aromatic and medicinal plant, local endemic of the island of Crete, Greece, occurring naturally to high rocky mountain habitats. Due to its commercial interest, cultivation of this plant has been recently expanded. Since natural infestations by Meloidogyne spp. in field cultivated plants have not been found, its response to infection by M. javanica, M. incognita, M. arenaria, M. hapla and M. luci was investigated in pot experiments. In all experiments, roots of dittany plants exhibited neither galls nor egg masses in contrast to the roots of tomato plants used as controls. Therefore, Cretan dittany appears to be resistant to the five Meloidogyne species tested.

A new subspecies of Apamea ingloria (A. Bang-Haas, 1912) from northern Tien Shan Mountains (Lepidoptera: Noctuidae: Noctuinae: Xylenini: Apameina)

A new subspecies of Apamea ingloria (A. Bang-Haas, 1912), Apamea ingloria postnikovi ssp. n. is described from the high mountain habitats of the Ketmen Ridge in the Northern Tien Shan Massif. The diagnostic comparison is made with the nominate subspecies and A. kaszabi Varga, 1982. Adults, male genitalia and basal abdominal sternites are illustrated.

Two new species of subtribe Monoctonina Mackauer from Europe (Hymenoptera, Braconidae, Aphidiinae).

Falciconus hispanicus sp. n. and Monoctonus montenegrinus sp. n. are described as new members of the subtribe Monoctonina from Spain and from high mountain habitats of Montenegro, respectively. The main diagnostic characters of the newly described species and their host plant-host aphid associations are discussed.

GABB: A global dataset of alpine breeding birds and their ecological traits

Alpine ecosystems represent varied climates and vegetation structures globally, with the potential to support rich and functionally diverse avian communities. High mountain habitats and species are under significant threat from climate change and other anthropogenic factors. Yet, no global database of alpine birds exists, with most mountain systems lacking basic information on species breeding in alpine habitats, their status and trends, or potential cryptic diversity (i.e., sub-species distributions). To address these critical knowledge gaps, we combined published literature, regional monitoring schemes, and expert knowledge from often inaccessible, data-deficient mountain ranges to develop a global list of alpine breeding bird species with their associated distributions and select ecological traits. This dataset compiles alpine breeding records for 1,310 birds, representing 12.0% of extant species and covering all major mountain regions across each continent, excluding Antarctica. The Global Alpine Breeding Bird dataset (GABB) is an essential resource for research on the ecological and evolutionary factors shaping alpine communities, as well as documenting the value of these high elevation, climate-sensitive habitats for conserving biodiversity.

Genotoxic effects of transboundary pollutants in Pinus mugo in the high mountain habitats

This study evaluated the environmental genotoxic load of mountain and alpine habitats of Slovak mountains caused by the total mixture of air pollutants at 69 sites using the phytoindicator Pinus mugo. The level of overall genotoxicity was determined by pollen grain abortion assay. This shows that the test is sensitive enough to detect contamination from more distant sources, including long-range transboundary pollutants. It extends the applicability of this test to mountain environments. Soil and plant samples (pollen, one-two year old needles) were collected during a three-year growing period (2011–2013). The study identified source regions of pollutants by assessments at different altitudes and slope exposures. The highest genotoxicity was found in the Little Fatra Mts. on Suchy Mt., with pollen abortivity 3.52 % which represented a 23.5 times higher genotoxic load than at the control site. Samples from mountain peaks showed a higher genotoxicity in 2012 than in 2011 on most mountains. A gradual increase of pollen abortivity and needle Pb content (one year old) with increasing altitude was found in the vertical transect in Belian Tatras. The influence of subsoil type was analysed; higher genotoxicity and Pb content in soil and needles were found on limestone subsoil (Sivy vrch Mt.) and higher values of needle Cd were on granite (Brestova Mt.). The highest Pb and Cd concentrations in needles were measured in the Great Fatra Mts. on Krizna Mt. situated between highly-industrialized areas. The other mountain ranges with the high loading by Pb, Cd were Chocske vrchy Mts. and Low Tatra Mts. The lead content increased with needle age, but the correlation between soil Pb and needle Pb was not confirmed. The positive correlation between soil Pb and abortivity was found only at mountain peaks. The results showed a significant impact of both local industrial and transboundary sources of pollutants. Based on the results, the studied Slovak mountains were not strongly burdened by Pb, Cd and an overall mixture of air pollutants. This methodological approach may contribute to the assessment of urban exposome by comparing the external exposure in urban environment of big cities with background - mountain areas, where the only possible source is long-range transport.

Overall phylogenetic relationships of Scutellaria (Lamiaceae) shed light on the origin of the predominantly Caucasian and Irano-Turanian S. orientalis group

Scutellaria is one of the largest genera in the Lamiaceae with an estimated 400–500 species with a nearly worldwide distribution. Most species occur in the N hemisphere, with the Caucasus and the wider Irano-Turanian region housing a large number of taxa, many of them considered endemic. We present an overall phylogeny of the monophyletic genus Scutellaria based on rapidly evolving plastid regions (matK-trnK, rpl16, trnL-F). Three well-supported clades are evident, which render the currently accepted S. subg. Scutellaria paraphyletic to S. subg. Apeltanthus, which appears nested in “clade A”, in which the African S. schweinfurthii is sister to all remaining taxa, followed by other lineages of S. subg. Scutellaria. Ancestral states of 12 morphological characters frequently used as diagnostic from subgenus to species level were reconstructed with BayesTraits. The S. orientalis group appears as a major radiation in the Caucasus area and the Irano-Turanian region that may comprise up to a quarter of the species in the genus. This radiation corresponds to a monophyletically defined S. sect. Lupulinaria, characterized by decussate inflorescences and specialized (e.g. cucullate) bracts. Our phylogenetic data present significant resolution at the species level within the S. orientalis group, indicating complex geographically centred patterns of speciation in adaptation to steppe and high mountain habitats, including multiple evolution of pinnate and tomentose leaves. The detailed infrageneric classification of Juzepczuk (1951, 1954) mostly does not reflect natural groups. Citation: Salimov R. A., Parolly G. & Borsch T. 2021: Overall phylogenetic relationships of Scutellaria (Lamiaceae) shed light on the origin of the predominantly Caucasian and Irano-Turanian S. orientalis group. – Willdenowia 51: 395–427. Version of record first published online on 23 December 2021 ahead of inclusion in December 2021 issue.

Exploring Plant Functional Diversity and Redundancy of Mediterranean High-Mountain Habitats in the Apennines

We analyzed plant functional diversity (FD) and redundancy (FR) in Mediterranean high-mountain communities to explore plant functional patterns and assembly rules. We focused on three above-ground plant traits: plant height (H), a good surrogate of competition for light strategies, and specific leaf area (SLA) and leaf dry matter content (LDMC), useful indicators of resource exploitation functional schemes. We used the georeferenced vegetation plots and field-measured plant functional traits of four widely spread vegetation types growing on screes, steep slopes, snowbeds and ridges, respectively. We calculated Rao’s FD and FR followed by analysis of standardized effect size, and compared FD and FR community values using ANOVA and the Tukey post hoc test. Assemblage rules varied across plant communities and traits. The High FRH registered on snowbeds and ridges is probably linked to climatic filtering processes, while the high FDH and low FDSLA and FDLDMC on steep slopes could be related with underlying competition mechanisms. The absence of FD patterns in scree vegetation pinpoint random assembly processes which are typical of highly unstable or disturbed ecosystems. Improved knowledge about the deterministic/stochastic processes shaping species coexistence on high mountain ecosystems should help researchers to understand and predict vegetation vulnerability to environmental changes.

Avian ecology and community structure across elevation gradients: The importance of high latitude temperate mountain habitats for conserving biodiversity in the Americas

Mountains are excellent systems for studying biodiversity as they promote rapid species turnover across relatively short elevational distances. Most research on biogeographic patterns in mountains has focused on tropical regions; far less is known about diversity across elevational gradients and their relative contribution to conservation in temperate mountains, particularly at high latitudes. To better understand the composition, ecology, and evolutionary history of high-latitude temperate mountain bird communities, we evaluated species richness, functional redundancy, and phylogenetic diversity across three elevation-specific habitats (upper montane, subalpine, alpine) in north temperate (9 mountains in British Columbia, Canada; 54°N) and south temperate (10 mountains in Chile; 39°S) regions representing distinct biogeographic origins. North temperate mountains had greater absolute species richness (77 versus 63 species), while south temperate mountains supported a greater proportion of the regional species pool (63% versus 44%). North temperate species richness increased with elevation to an ecotonal peak at treeline and then declined (subalpine = 58, alpine = 30 species), while the highest richness in south temperate mountains occurred at and above treeline (41 species). Similar species turnover patterns were observed in both systems with alpine habitats supporting the most distinct avifauna. Functional traits varied between regions with proportionally more migrants in the north, compared to more habitat specialists and cavity nesters in the south, particularly in the alpine. North temperate bird communities exhibited lower functional redundancy and higher total phylogenetic diversity, indicating a community susceptible to losing ecosystem functions and evolutionary potential. Southern communities contained greater functional redundancy and more evolutionarily isolated species, consistent with convergent evolution in challenging, high elevation habitats. Overall, in north temperate mountains, greater species richness and phylogenetic diversity, coupled with lower functional redundancy, particularly below treeline, highlights the importance of montane forests for biodiversity. In south temperate mountains, a distinct, speciose community at and above treeline, in combination with supporting a large proportion of the regional species pool, indicates a unique system with disproportionate conservation value. One-third of birds detected in north temperate mountains are considered of national or international conservation concern, compared to 9.5% of southern mountain birds. However, only 18% of the 63 species observed in the south temperate Andes (and only 5% of alpine species) have had a conservation status assessment. With increasing climate change and habitat loss pressures across elevations, temperate mountains in the Americas have significant conservation value and appear particularly important for maintaining regional biodiversity.

Diagnostic Species Diversity Pattern Can Provide Key Information on Vegetation Change: An Insight into High Mountain Habitats in Central Apennines

High mountain ecosystems are hotspots of biodiversity that are highly vulnerable to climate warming and land use change. In Europe, high mountain habitats are included in the EC Directive 92/43/EEC (Habitats Directive) and the identification of practices facilitating effective monitoring is crucial for meeting HD goals. We analyzed the temporal changes in species composition and diversity on high mountain EU habitats and explored if the subgroup of diagnostic species was able to summarize the comprehensive information on plant community variations. We performed a re-visitation study, using a set of 30 georeferenced historical plots newly collected after 20 years on two EU habitats (Galium magellense community growing on screes (8120 EU) and Trifolium thalii community of snowbeds (6170 EU)) in the Maiella National Park (MNP), which is one of the most threatened Mediterranean mountains in Europe. The presence of several endangered species and the availability of a botanical garden, a seed bank, and a nursery, make the MNP an excellent training ground to explore in situ and ex situ conservation strategies. We compared overall and diagnostic species richness patterns over time by rarefaction curves and described the singular aspects of species diversity (e.g., richness, Shannon index, Simpson index, and Berger–Parker index), by Rènyi’s diversity profiles. Diversity values consistently varied over time and across EU habitat types, with increasing values on scree communities and decreasing values on snowbeds. These changes could be associated with both land use change, through the increase of grazing pressure of Apennine chamois (Rupicapra pyrenaica ornata), which determined a rise of nitrophilous species in the scree community, and an increase of grasses at the expense of forbs in snowbeds, and to climate change, which promoted a general expansion of thermophilous species. Despite the two opposite, ongoing processes on the two plant communities studied, our results evidenced that diagnostic species and overall species followed the same trend of variation, demonstrating the potential of diagnostics for EU habitat monitoring. Our observations suggested that the re-visitation of historical plots and the implementation of frequent monitoring campaigns on diagnostic species can provide important data on species abundance and distribution patterns in these vulnerable ecosystems, supporting optimized in situ and ex situ conservation actions.

Changes in pools of organic matter and major elements in the soil following prescribed pastoral burning in the central Pyrenees

High-mountain soils are rich in partially decomposed organic matter, which is highly sensitive to mineralization and fire. Prescribed burning is performed in the Pyrenees to keep subalpine grasslands open for grazing. The compositions of the ash, litter and duff layers, and the particulate organic matter (POM) of the topsoil in the 0–1, 1–2, 2–3, and 3–5 cm depths were analyzed in relation to the nutrient availability after the prescribed burning of a stand encroached by erizón (Echinospartum horridum). The concentrations of C, N, P, and S and organic components (nonstructural, hemicellulose, cellulose, and lignin-type) were determined before the prescribed burn and 0, 6, 12, 18, and 24 months after the prescribed burn. The fire consumed the aboveground biomass, the litter and part of the duff layer, and the most thermostable (i.e., lignin-type) components and the least volatile elements (P, S) were selectively preserved in the resulting ash. Prescribed burning caused significant losses of organic-C and N only in the 0–1 cm depth (–72% and –68%, respectively). The organic-C loss was mostly (82%) from the POM, whereas the N loss was from more similar proportions of the POM (57%) and the nonparticulate organic matter (NPOM) (43%). However, few changes were observed in the composition of the organic matter, which pointed to a largely uneven combustion that resulted in a substantial part of the organic matter remaining largely untouched by the fire. After 6 months, the duff layer was depleted in hemicellulose by 32% compared to immediately after the burn, and fragmentation of the POM into the NPOM was observed. During the second spring, N- and P-rich charred POM were incorporated into the top 1 cm, while C-rich charcoal particles underwent fragmentation and vertical transport into the deeper soil. The preburn ecosytem was limited by P, and likely also by S. The plant available N showed transient increases of 1.5–2.1 times the immediate postburn levels for nitrate-N at 12 months after burning, and of up to 10–20 times for ammonium-N at 18 months. In contrast, the concentrations of plant-available P and S gradually declined to 1.8–3.3 and 1.8–4.0 times, respectively, lower at 24 months after the burn. Results indicated that fire-induced increases in the nutrient availability can be short-lived in high-mountain habitats, but steadier and likely more persistent nutrient inputs can derive from the gradual breakdown of charred organic matter.

Ecophysiology of a lacertid community in the high Moroccan mountains suggests conservation guidelines.

Lizard species may differ in their ecophysiology due to adaptation, plasticity and/or phylogeny. In restrictive environments, ecophysiological differences of species living in sympatry are expected to reveal long-term evolutionary responses to the abiotic environment while competitive interactions should be limited. These influences can be disentangled by combining field monitoring with experimental tests. Here, three lacertid lizard species, Atlantolacerta andreanskyi, Scelarcis perspicillata and Podarcis vaucheri sharing high mountain habitats in Oukaimeden (High Atlas, Morocco), were studied. In the field, spatiotemporal variation of the thermal and hydric environment used by the lizards was monitored using data-loggers. In the lab, thermal and hydric ecophysiology was estimated through assessments of preferred temperatures (Tp) and water loss (WL) rates. Species differed in microhabitat use and, hence, in their exposure to variations in temperature and humidity. However, they only differed in their WL (A. andreanskyi>S. perspicillata>P. vaucheri) while their Tp were similar. Such partial differences of species in in the fundamental niche, likely derived from their long-term independent phylogenetic trajectories, can be used to predict their responses to climate and habitat shifts in this and other parts of their respective ranges. Results also confirm previous suggestions that, together with thermal physiology, hydric physiology plays a prominent role in the organisation of lizard communities in the temperate region.

Annual and perennial high-Andes species have a contrasting freezing-resistance mechanism to cope with summer frosts

In high-mountain habitats, summer frosts have negative consequences for plant fitness, therefore high-mountain plants have developed mechanisms of avoidance and tolerance to cope with freezing temperatures. Various hypotheses have been proposed to explain the prevalence of one freezing-resistance mechanism over another, focusing on thermal conditions without a consensus. We hypothesize that the prevalence of a freezing-resistance mechanism depends on the life-history strategy of the species, and is probably the consequence of a trade-off between growth/reproduction and the cost of the mechanism. Specifically, short-lived annual species should be freezing avoidant, whereas perennial long-lived species should be freezing tolerant. We used thermal analysis to determine the mechanism of freezing resistance of leaves and flowers for 10 annual and 14 perennial herb species from an alpine ecosystem in the Central Chilean Andes. We found that 70% of the annual species, their flowers and leaves were freezing avoidant, indicating that avoidance was their predominant freezing-resistance mechanism. In the case of perennial species, both mechanisms were almost equally represented in flowers and leaves. Overall, our results showed that a species freezing-resistance mechanism depends on its life-history strategy, and that leaves and flowers of single species exhibit the same freezing resistance mechanism, suggesting a common whole plant strategy. Further, freezing resistance strategies were not found to be mutually exclusive. In some cases, a specific combination of phenological, structural, and functional strategies may determine how freezing resistant vegetative and reproductive organs are to freezing during the growing season.

High tourism activity alters the spatial distribution of Hazel Grouse (Tetrastes bonasia) and predation on artificial nests in a high-mountain habitat

Human presence can significantly reduce habitat availability for wildlife. We investigated the impact of the distance from hiking trails and number of tourists on the number of sites occupied by Hazel Grouse (Tetrastes bonasia) and on the predation rate of artificial nests in two forest types (spruce and beech) in the Tatra Mountains (Poland). The study was carried out in the Tatra National Park from 2009 to 2014. Presence of Hazel Grouse males was detected in spring by playing territorial calls of this species from an electronic device. A total of 79 sites occupied by Hazel Grouse were found, and 174 artificial ground nests were monitored. Data on the number of tourists gathered at entry points and at trail crossings in the Tatra National Park were used to estimate levels of tourism activity. Sites occupied by Hazel Grouse were mostly located farther from hiking trails and in places with low tourist numbers. Artificial nests were mainly predated by mammals (85%) in both spruce and beech forests.

Does the life-history strategy determine the freezing resistance of flowers and leaves of alpine herbaceous species?

In high-mountain habitats, summer frost events can have negative consequences for plant fitness. Despite this, most studies have evaluated the consequences of frosts for vegetative structures of perennial plants, and neither for leaves nor for flowers of annual plants. We hypothesize that the degree of freezing resistance of flowers and leaves of a species depends on its life-history strategy (LHS), and is probably the consequence of a trade-off between growth/reproduction and the cost of the freezing resistance. Specifically, flowers and leaves of short-lived annual species should be less freezing resistant than those of perennial plant species. We compared the freezing resistance of flowers and leaves of 10 annual and 12 perennial plant species from the Andes of central Chile using the electrolyte leakage method. Temperature damage for 50% tissue (LT50) of annual species was − 9.6 °C in flowers and − 11.9 °C in leaves. In perennial species, LT50 was similar in flowers (− 12.3 °C) and leaves (− 12.5 °C). Despite that, these differences were not significant (except the flowers of annual species), we found remarkable differences between LHS when freezing resistance was analyzed species by species. Like this, 58% and 83% of perennial species resist temperatures ≤ − 10 °C in their flowers and leaves, respectively, compared with only 30% and 40% of annual species. Additionally, in most of the species, the freezing resistance of leaves was greater than that of flowers, with this proportion being greater in annual (58%) than in perennial species (43%). Thus, we concluded that the degree of freezing resistance depends on the LHS, such that annual species, which are less freezing resistant than perennial species, have an infrequent occurrence and a distribution restricted to low elevation in high-mountain habitats.

Circannual variation in habitat use of the White‐winged Snowfinch Montifringilla nivalis nivalis

High mountain areas are subject to strong seasonal fluctuations, and species inhabiting these particular environments show a high degree of habitat specialization to cope with extreme abiotic conditions. Estimates of habitat use are influenced by the spatial and seasonal scales at which they are evaluated, so studies at multiple scales are important in order to explore adaptive responses to seasonal environments. In the present study, we assessed habitat use of the White‐winged Snowfinch Montifringilla nivalis subsp. nivalis (henceforth Snowfinch) during breeding and non‐breeding seasons at three different spatial scales (diameters of 100, 250 and 500 m). Although Snowfinches clearly used high‐elevation habitats in both seasons, there was evidence that they are less specific during the non‐breeding period: the variance explained by habitat and topographical factors was lower in winter than in the breeding season. Moreover, our results suggest that the use of habitat is scale‐dependent. This pattern was especially relevant in the breeding season, perhaps because habitat use might be more related to nest‐site selection and specific foraging sites to provide food for nestlings. Snowfinches use high mountain habitats throughout the year, probably as a consequence of physiological and morphological specializations typical of high‐elevation species, but in winter they show a certain flexibility in habitat use. Snowfinches might thus adopt a flexible specialist strategy. This could represent a trade‐off to overcome possible effects on survival, condition and fitness, which can be particularly strong in harsh, unpredictable environments.

Viola guaxarensis (Violaceae): a new Viola from Tenerife, Canary Islands, Spain

Viola guaxarensis M. Marrero, Docoito Diaz & Martin Esquivel, sp. nov., belonging to V. sect. Melanium Ging. (Violaceae), is described and illustrated. It is a small chamaephyte currently known in only two localities within the high-mountain zone of Tenerife, Canary Islands. Data on aspects of its morphology, ecology, rarity and conservation status are provided, as well as the differences between this new taxon and the other two species from the Canary Island high-mountain habitats, V. cheiranthifolia Humb. & Bonpl. and V. palmensis Webb & Berthel., which are presumed to be the closest relatives.

<i>Aphidius geranii</i> sp. n. (Hymenoptera: Braconidae) from Southeast Europe – a new member of the <i>Aphidius urticae</i> s. str. group

Aphidius geranii Tomanovic and Kavallieratos, sp. n., is described as an additional member of the Aphidius urticae s. str. group from high-mountain habitats of Southeast Europe. The new species was reared from Amphorophora sp./Geranium coeruleatum associations. Parasitoid guilds associated with G. coeruleatum are discussed. Key for identification Aphidius spp. on Geranium plants in Europe is given.