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The Mirambel woodland on the margins of the Millevaches plateau (Massif Central) is one of the few ancient broad-leaved woodlands in France. Historical sources show that it has occupied the same surface area for the past 250 years, despite being in a region that underwent considerable anthropogenic changes during this period. We explored the Mirambel's Holocene history and ancientness by means of soil charcoal analysis, chosen because of its high accuracy on a local scale. We excavated five pedoanthracological pits in the woodland and its open marginal spaces. The 29 radiocarbon dates ranged from the Atlantic (8700–5500 cal yr. BP) – Subboreal transition to the Subboreal (5500–2800 cal yr. BP) and Subatlantic (2800–0 cal yr. BP, i.e. AD 1950) periods, revealing the existence of fire events corresponding to six contemporaneous cultural periods: Neolithic (ca. 3877–2991 cal yr BC), Neolithic-Chalcolithic transition (ca. 2528–2525 cal yr BC), Protohistory (ca. 147 cal yr BC), Roman period (ca. 326–579 cal AD), Middle Ages (ca. 732–1187 cal AD), and contemporary times (ca. 1781 cal AD to present day). Three Tilia charcoal fragments dating from ca. 3717–2919 cal yr BC indicated the presence of a diversified Mid-Holocene deciduous woodland featuring Tilia and Acer nowadays-absent taxa in this area. Deciduous Quercus and Fagus sylvatica dominated most of the soil profiles, as they do nowadays in the woodlands. Other taxa (Salix, Corylus avellana, Betula) were identified, as well as in the current vegetation. The occurrence of Cytisus-type (Fabaceae) and Calluna vulgaris suggested that there were forest clearing phases at all the points sampled. Widely varying levels of abundances may reflect differences in the duration of these open phases.

Heather, Calluna vulgaris, is a key species of European dry heath and central determinant of its conservation status. The established Calluna life cycle concept describes four phases—pioneer, building, mature, and degeneration—distinguishable by growth and vitality characteristics of undisturbed plants grown from seeds. However, little is known about the life cycle and ageing of plants subjected to severe disturbance, although measures to this effect (burning, mowing) are common in heathland management. We studied the vitality of over 400 heather plants by examining multiple morphological (plant height, long shoot and inflorescence lengths, flowering activity), anatomical (growth rings) and environmental (management, nitrogen deposition, climate) attributes. We found Calluna vitality to be mainly determined by the aboveground stem age, and that severe disturbances promote vigorous vegetative regeneration. Ageing-related shifts in the habit and vitality of plants resprouting from stem-base buds is similar to that of seed-based plants, but the former revealed higher vitality when young, at the cost of a shorter life span. In contrast, plants originating from decumbent stems resemble building-stage plants but apparently lack the capacity to re-enter a cycle including stages other than degeneration-type. As a consequence, we supplemented the established heather life cycle concept with a post-disturbance regeneration cycle of plants derived from resprouting. We conclude that management of dry lowland heathlands should include rotational small-scale severe disturbance to support both seed germination and seedling establishment as well as vegetative regeneration chiefly of young heather plants capable of resprouting from buds near rootstock.

Calluna vulgaris (Ericaceae) is the most widespread and prevalent woody species of the European dry heathland, from the African side of the Strait of Gibraltar to northern Europe. However, previous biogeographic analyses of this species have ignored the western Mediterranean region, despite its preponderant role as a major glacial refugium for European biota. Here, we explore the existence of further Pleistocene glacial refugia for C. vulgaris in the Iberian Peninsula and the Strait of Gibraltar area and provide new insights into the post-glacial colonization of Europe by this emblematic heathland species. We carried out phylogeographical analyses of C. vulgaris samples from 44 locations using four plastid markers (matK, trnH-psbA, trnL-F and rpl16). We built palaeodistribution models using MAXENT to identify possible refugia for C. vulgaris during the mid-Pliocene, Last Interglacial (LIG), Last Glacial Maximum (LGM) and mid-Holocene. Our results identified a genetic lineage exclusive to the Strait of Gibraltar area s.l. (south-western Iberian Peninsula and north-western tip of Africa) as the most probable close to the clade of origin of the species. This lineage also had more private haplotypes than more recent, Eurosiberian clades. The obtained data highlighted two main refugia for C. vulgaris during the LGM, one around the Strait of Gibraltar and another in the north-western Iberian Peninsula. The Strait of Gibraltar area is a major centre of origin or glacial refugium for the heather C. vulgaris. However, the north-western Iberian Peninsula seems to have acted as a secondary glacial refugium for the more recent, Eurosiberian lineage of this species. This study stresses the importance of the Strait of Gibraltar area in the biogeographic history and conservation of the heather and, by extension, the European heathland habitat.

Since the 1950s there has been a question about the introduction of gradual felling and the formation of future stands from the existing young growth in Scots pine (Pinus sylvestris L.) stands in Ukraines Polissya. We should note that this type of felling has not been practically applied so far. The research was performed at the trial plot, which was established in 2006 in the 84-year-old pine forest of the Teterivsky Forestry State Enterprise. After the first stage of evenly- gradual felling, the completeness of the stand was 0.3-0.4. According to the accounting conducted, the number of seedlings was 192,000 pcs per ha-1 of which Scots pine was 90%. In 2011, this area was divided into 4 sections (equal in area) and 2 methods of even-gradual felling were carried out: for section N 1, 100% of trees were cut down; in the section N2, 50% of trees were cut down (completeness - 0.2-0.3); on the section N3, 75% of trees were cut down (completeness – 0.1); on section N 4, all trees remained (completeness – 0.3-04). The study of the process of natural regeneration and the state of living above-ground cover is carried out according to D. V. Vorobyovs method. Young plantations were found to consist of Scots pine (57-76%), silver birch (Betula pendula Roth) (7-10%), English oak (Quercus robur L.) (10-16%), and European aspen (Populus tremula L.) (3-32%). Furthermore, we have found that the largest share of viable young growth is observed in the sections without preservation and with preservation of 25% of trees (71-72%). The value of the projective cover of the grass-shrub layer in the sections of the experiment ranges from 60 to 90%, and the species composition is defined to be quite close one. The most common are revealed to be as follows: heather (Calluna vulgaris (L.) Hull) 7-31% (most in the section without preserving the mother canopy), wood small-reed (Calamagrostis epigejos (L.) Roth) 7-78% (most in the section with 25 % of preservation), and lily of the valley (Convallaria majalis L.) 5-45% (most in the section with 100% of preservation). The success of natural regeneration of Scots pine in the sections of the experiment is defined to be quite satisfactory one, and the number of young growth of this species is 3307-5640 pcs per ha-1. It is evenly distributed over the area (incidence ranges from 75 to 100%) and is 12 years old. To conclude, conducting two-stage evenly-gradual felling in the pine forests of fresh mixed coniferous forests allows forming even-aged stands of natural origin.

The response of soil microbial communities to a changing climate will impact global biogeochemical cycles, potentially leading to positive and negative feedbacks. However, our understanding of how soil microbial communities respond to climate change and the implications of these changes for future soil function is limited. Here, we assess the response of soil bacterial and fungal communities to long-term experimental climate change in a heathland organo-mineral soil. We analysed microbial communities using Illumina sequencing of the 16S rRNA gene and ITS2 region at two depths, from plots undergoing 4 and 18 years of in situ summer drought or warming. We also assessed the colonisation of Calluna vulgaris roots by ericoid and dark septate endophytic (DSE) fungi using microscopy after 16 years of climate treatment. We found significant changes in both the bacterial and fungal communities in response to drought and warming, likely mediated by changes in soil pH and electrical conductivity. Changes in the microbial communities were more pronounced after a longer period of climate manipulation. Additionally, the subsoil communities of the long-term warmed plots became similar to the topsoil. Ericoid mycorrhizal colonisation decreased with depth while DSEs increased; however, these trends with depth were removed by warming. We largely ascribe the observed changes in microbial communities to shifts in plant cover and subsequent feedback on soil physicochemical properties, especially pH. Our results demonstrate the importance of considering changes in soil microbial responses to climate change across different soil depths and after extended periods of time.

This investigation was conducted to identify the content of metals inCalluna vulgaris(familyEricaceae),Empetrum nigrum(familyEricaceae),Festuca vivipara(familyPoaceae) andThymus praecoxsubsp.arcticus(familyLamiaceae), as well as in the soils where they were growing in eight geothermal heathlands in Iceland. Investigation into the vegetation of geothermal areas is crucial and may contribute to their proper protection in the future and bring more understanding under what conditions the plants respond to an ecologically more extreme situation. Plants from geothermally active sites were enriched with metals as compared to the same species from non-geothermal control sites (at an average from about 150 m from geothermal activity). The enriched metals consisted of Cd, Co, Cu, Fe and Ni inC. vulgaris; Cd, Mn and Ti inE. nigrum; Hg and Pb inF. vivipara; and Cd, Fe and Hg inT. praecox. Notably,C. vulgaris,E. nigrum,F. viviparaandT. praecoxhad remarkably high concentrations of Ti at levels typical of toxicity thresholds. Cd and Pb (except forC. vulgarisandF. vivipara) were not accumulated in the shoots of geothermal plants.C. vulgarisfrom geothermal and control sites was characterised by the highest bioaccumulation factor (BF) of Ti and Mn;E. nigrumandF. viviparaby the highest BF of Ti and Cr; andT. praecoxby the highest BF of Ti and Zn compared to the other elements. In comparison with the other examined species,F. viviparafrom geothermal sites had the highest concentration of Ti in above-ground parts at any concentration of plant-available Ti in soil.

The maintenance of protected lichen species and their biodiversity in general depends on good management practices based on their distribution and habitat preferences. To date, 10 of the 17 protected lichen species of Hungary have been recorded in the Bakony Mts including the Balaton Uplands region. Habitat preferences of three protected Cladonia species (C. arbuscula, C. mitis and C. rangiferina) growing on underlying rocks of red sandstone, basalt, Pannonian sandstone and gravel were investigated by detailed sampling. We recorded aspect, underlying rock type, soil depth, pH and CaCO3 content, habitat type (as defined by the General National Habitat Classification System Á-NÉR), all species of lichen, bryophyte and vascular plants as well as percentage cover of exposed rock, total bryophytes, lichens, vascular plants and canopy, degree of disturbance and animal impacts. Sporadic populations of these species mostly exist at the top of hills and mountains in open acidofrequent oak forests, but they may occur in other habitats, such as closed acidofrequent oak forests, slope steppes on stony soils, siliceous open rocky grasslands, open sand steppes, wet and mesic pioneer scrub and dry Calluna heaths. Cladonia rangiferina was found to grow beneath higher canopy cover than either C. arbuscula or C. mitis in the Balaton Uplands. Furthermore, there were significant differences in canopy cover between occupied and unoccupied quadrats in the case of all three species. Cladonia rangiferina is a good indicator species of natural habitats in Hungary due to its restricted distribution and low ecological tolerance. These results may lead to the adoption of effective conservation methods (e.g. game exclusion, artificial dispersal) in the future.

The increasing dominance of purple moor-grass Molinia caerulea in heathland ecosystems in the UK is of growing concern due to its detrimental impact on plant and animal diversity on sites of nature conservation interest. The use of free-ranging ponies to reduce Molinia dominance was investigated from 2017 to 2019 within a 425 ha site on Dartmoor, UK. Salt blocks were used to attract the ponies to a Molinia-dominated area of heath within the site, away from their previously-preferred grazing areas. The impact of pony grazing was assessed by measurements of vegetation structure and plant species composition. The increased presence of ponies in the vicinity of the salt blocks increased the percentage occurrence of bare ground, reduced sward surface height, reduced percentage occurrence of Molina and increased the germination of heather Calluna vulgaris seedlings. The conclusions of this research are that salt blocks can be used to attract ponies to graze targeted areas of Molinia-dominated heathland. Through their grazing and trampling, ponies can reduce the dominance of Molinia, leading to an increase in the germination and establishment of heather seedlings.

The paper is concerned with 137Cs distribution peculiarities in the forest bio-geocenosis components of the Ukrainian Polissia fresh groves. Investigations were carried out on experimental areas laid in Naro-dyshy Forestry. Before measuring 137Cs specific activity, all samples were dried to air-dry state and homog-enized. The density of soil radioactive contamination was 267±9.6 kBq/m2. 137Cs specific activity in the bio-geocenosis components differed by several orders of magnitude, with the minimum in deep horizontal soil layers (28–30 cm layer – 40 Bq/kg) and the maximum in the above-ground phyto-mass of some plant species (Dryopteris carthusiana (Vill.) – 85,937 Bq/kg). In addition, significant fluctuations in radionuclides specific activity between separate components of forest bio-geocenosis have been identified. Thus, the components of pine stands can be arranged in a line by reducing 137Cs specific activity: shoots > internal bark > needles > outer bark > thin branches > thick branches > tree, while grass-shrub cover is characterized by the follow-ing line: Dryopteris carthusiana (Vill.) > Vaccinium myrtillus L. > Calluna vulgaris (L.) Hull >Vaccinium vitis-idaea L. > Lycopodium clavatum L. > Orthilia secunda (L.) >Luzula pilosa (L.) Willd. Moss cover is characterized by higher values of specific radionuclide activity as compared with lichen cover, where the epiphytic lichen species have lower 137Cs content than epigeic ones. Soil cover retains the major share of the total radionuclide activity in pine bio-geocenosis and amounts to 76.66 %, while forest litter retains 14.24% and soil mineral layers – 62.42 %. Other components amount to 23.34 %, where pine stands and moss cover account for 12.02 % and 11.04 % respectively, and undergrowth, lichen and grass-shrub cover account only for 0.28 %. The main phytocenosis phytomass falls upon tree stands and accounts for 85.10 %, and moss cover – 14.48 %, while the role of other vegetation layers in this ecotope was insignificant and amounted to 0.42 %. 137Cs total activity distribution by components differs significantly from the distribution of phytomass per area unit. Thus, the maximum share of gross 137Cs total activity is retained by the tree stands (51.49 %) and moss cover (47.32 %). The fraction of the remaining layers is insignificant – 1.19 %, and is presented in the following order by the reduction of radionuclides retention capacity: grass-shrub cover > lichen cover > undergrowth. In pine bio-geocenosis, the key components in the capacity to retain and intensity of radionu-clides biogeochemical circulation are forest soil, tree stands and moss cover.

In this article, we examined the indicative value of a relationship between two non-pollen palynomorphs (NPPs), fungal HdV-10, related to the presence of Calluna vulgaris, and HdV-31A, which is testate amoeba – Archerella flavum. Both are frequently present on slides designated for pollen analysis, prepared from Sphagnum peat. We analysed three profiles from three extensive ombrotrophic peatlands in northern Poland, in which the content of testate amoebae (TA) was examined and TA-inferred depth to the water table (DWT) was reconstructed. The new analysis of palynological samples regarding NPPs revealed that strong increases in HdV-10 content were mostly simultaneous to HdV-31A declines. However, the relations between both types were not statistically significant. The rapid increases in HdV-10, despite the fact that this type of conidiospores is related to drier habitats on peatlands, were tentatively interpreted as an indicator of rapid rises in the water table level which, in consequence, might have stimulated the production of these spores by fungi. In addition, a negative correlation between HdV-31A and Arcella discoides and positive one, but weaker, in case of HdV-10 (attributed by some authors to species Trichocladium opacum (Corda) S Hughes) and A. discoides show a link between mutual fluctuations of both NPPs and hydrological instabilities on peatland. The Bagno Kusowo bog, the westernmost peatland subjected to the study, displayed an intriguing agreement between the presence of peat sections with strong increases in HdV-10 and cold climate events affecting Europe. Our study reveals that counting even a limited number of NPP types during the standard pollen analysis of Sphagnum peat may support the interpretation of results, especially, in cases when the investigation lacks testate amoeba analysis. When the reconstruction of TA-inferred DWT is provided, it may introduce additional information about the patterns of hydrological dynamics.

The present paper gives new records of the following taxa in SE Europe and adjacent regions, together with significant data pertaining to them: the pathogenic fungus Arthrocladiella mougeotii; the liverwort Riccia frostii; the mosses Campylopus fragilis, C. introflexus and Tomentypnum nitens; the fern Allosorus persicus; the monocots Allium atropurpureum and Sisyrinchium montanum; and the dicots Calluna vulgaris and Santolina chamaecyparissus.

Prunus serotina is one of the worst invasive alien plants throughout Europe, able to rapidly replace autochthonous vegetation and form monospecific stands both in open lands and forested areas. Invasion by shrubs and trees due to abandonment of traditional management practices, is one of the major threats to the conservation of “European dry heaths”, a priority habitat included in the Council Directive 92/43/EEC. The aim of this study was to assess the effects of P. serotina invasion on heathland vegetation in terms of species composition and cover, with special regards to the dominant Calluna vulgaris and Molinia arundinacea, in an area of North-Western Italy subjected to massive invasion by this alien species. We collected data on the plant cover along an invasion gradient in 10 linear transects running from P. serotina invaded stands towards non invaded ones. P. serotina differently affected the heathland vegetation. In particular, the cover of C. vulgaris and other typical heathland species such as Cytisus scoparius sharply decreased at P. serotina cover increasing. On the contrary, positive or no effect of P. serotina cover was found on M. arundinacea. Our results showed that shaded conditions created by the alien tree disfavored light demanding C. vulgaris and C. scoparius, enabling fast grower M. arundinacea to outcompete and replace them. This study emphasizes the urgency to develop management strategies to effectively control P. serotina spread in the area and to restore typical heathland species.

The study central goal was to analyze secondary succession in a degraded peatland: (1) Sphagnum distribution trends and (2) successional patterns. Main study sites were adjacent abandoned pastures, where grazing was carried out in former peatland and where degradation had occurred, hereafter referred as degraded peatland. (1) Degraded peatland was mapped in 2006 (while it was still a pasture, grazed for over 30 years), and throughout the study period in 2013 (2 years post-abandonment) and 2015 (4 years post-abandonment). The baseline assessment of 2006 revealed that Sphagnum spp. were present in 7% of the area, which pointed at the resilience of the peat ecosystem. After the grazing ceased, Sphagnum cover increased to 17% and 39%, in the next 2 and 4 years respectively post animal removal. (2) To gain a general comprehension of flora and vegetation changes along the regenerative sucession, 48 permanent plots were established in the degraded peatland. In two other study sites, a further twenty plots were established, ten plots in a semi-natural peatland area where grazing ceased 30 years ago and ten others in a natural peatland. These were monitored between July 2012 and July 2015 (triannual). After 4 years, the formerly degraded peatland showed considerable recovery with a growth of Sphagnum spp. cover as well as other species like Calluna vulgaris, tending to become more similar to semi-natural and natural peatlands. Grazing cessation induced the regenerative succession that could lead to self-recovery, which, in optimal conditions, could be an alternative to active restoration in Azores.

Soil carbon (C) pools and plant community composition are regulated by nitrogen (N) and phosphorus (P) availability. Atmospheric N deposition impacts ecosystem C storage, but the direction of response varies between systems. Phosphorus limitation may constrain C storage response to N, hence P application to increase plant productivity and thus C sequestration has been suggested.We revisited a 23‐yr‐old field experiment where N and P had been applied to upland heath, a widespread habitat supporting large soil C stocks. At 10 yr after the last nutrient application we quantified long‐term changes in vegetation composition and in soil and vegetation C and P stocks.Nitrogen addition, particularly when combined with P, strongly influenced vegetation composition, favouring grasses over Calluna vulgaris, and led to a reduction in vegetation C stocks. However, soil C stocks did not respond to nutrient treatments. We found 40% of the added P had accumulated in the soil.This study showed persistent effects of N and N + P on vegetation composition, whereas effects of P alone were small and showed recovery. We found no indication that P application could mitigate the effects of N on vegetation or increase C sequestration in this system.

Phytoremediation of mine soils contaminated by potentially toxic elements (PTEs) requires the use of tolerant plants given the specific conditions of toxicity in the altered soil ecosystems. In this sense, a survey was conducted in an ancient Hg-mining area named “El Terronal” (Asturias, Spain) which is severely affected by PTE contamination (As, Hg, Pb) to obtain an inventory of the spontaneous natural vegetation. A detailed habitat classification was performed and a specific index of coverage was applied after a one-year quadrat study in various sampling stations, seven species were finally selected (Agrostis tenuis, Betula celtiberica, Calluna vulgaris, Dactylis glomerata, Plantago lanceolata, Salix atrocinerea and Trifolium repens). A total of 21 samples (3 per plant) of the soil–plant system were collected and analyzed for the available and total concentrations of contaminants in soil and plants (roots and aerial parts). Most of the studied plant species were classified as non-accumulating plants, with particular exceptions as Calluna vulgaris for Pb and Dactylis glomerata for As. Overall, the results revealed interest for phytoremediation treatments, especially phytostabilization, as most of the plants studied were classified as excluder metallophytes.

As the dominant vegetation species of most British moorlands, Calluna vulgarisis the focus of much scientific interest. While multiple approaches for quantifying the life cycle of the species have ...

The modern radioactive contamination of the representatives of the grass-bush tier of pine plantations in the conditions of subors forests of Ukrainian Polissia is investigated. The density of radioactive soil contamination within the sample plots varied from 148 to 440 kBq/m2. Significant fluctuations of the specific activity values of 137Cs for all research species were found — from 6166 Bq/kg to 171862 Bq/kg. The maximum values of 137Cs were found in terrestrial phytomass of Pteridium aquilinum (L.) Kuhn, and minimal — in Vaccinium uliginosum L. Intensity indices of 137Cs in terrestrial phytomass of grass-bush tier for all research species varied in wide ranges: the coefficient of accumulation from 0.8 to 58.6, the transition factor — from 17 to 574 m2·kg–1·10–3. According to the results of one-factor dispersion analysis, the representatives of the grass-bush cover on the ability to accumulate 137Cs were classified in 6 groups. By the accumulation intensity of 137Cs in subors forests, the plants can be placed in the following order: Pteridium aquilinum (L.) Kuhn > Melampyrum pretense L. > Calluna vulgaris (L.) Hull > Vaccinium myrtillus L. > Molinia caerulea (L.) Moench > Vaccinium vitis-idaea L. > Ledum palustre L. > Vaccinium uliginosum L. The concentration of 137Cs in the species of grass-bush cover has a close linear relationship with the magnitude of the density of soil radioactive contamination.

The aim of our studywas to research the connection between the flower structure and the duration of flowering of Calluna vulgaris(L.)Hull and its cultivars. Our tasks were to investigate the flower structure of bud bloomers and double-flowered Calluna vulgaris(L.)Hull cultivars, to compare it with the structure of C. vulgaris flower; to analyze the data of phenological observations of C. vulgarisand its 10 cultivars flowering phase during 2015–2018. The methodswere phenological observations and microscopic examinations. Results.Common features for C. vulgaris and cultivars concerning to their flowering are racemose inflorescences, an arrangement of flowers, acropetal succession. The flower structure of ‘Dirry’, ‘Mullion’, ‘Golden Carpet’, ‘Winter Red’ is similar to that of C. Vulgaris. Among this group, ‘Winter Red’ finishes blooming the first and ‘Dirry’ is the last due to its compound inflorescence. An increased number of petals, full sterility and long flowering period characterize flowers of double-flowered cultivars. Bud bloomers ‘Alicia’, ‘Bonita’ belong to f.diplocalyx Jansen. They are characterized by different flowering periods. ‘Alicia’ blooms the longest (85±7 days) among investigated C. vulgaris cultivars and ‘Bonita’ blooms about 53 days. Conclusions.C. vulgaris cultivars that have the same flower structure as species begin to bloom, as well as common heather, in the third decade of July. The duration of C. vulgaris cultivars flowering period depends also on the peculiarities of the inflorescence structure. Therefore, in order to predict the duration of cultivars flowering, it is necessary to study the features of their inflorescences structure. Double-flowered cultivars are worth to be used more often in gardening due to their high decorativeness and long flowering period. The issue of preserving the color of bud bloomers flowers needs further research. When using the cultivars of C.vulgaris with different types of flowers and duration of flowering, we can create landscapes of high and long decorative features

Shoots of Calluna vulgaris, Erica carnea, Juniperus communis subsp. nana, Picea abies, and Pinus mugo subsp. mugo covered with felty, melanized epiphytic mycelia typical for brown felt blight caused by Herpotrichia pinetorum were collected at several locations in the Swiss Alps. Most cultures prepared from the mycelia on J. communis subsp. nana and P. abies were H. pinetorum, whereas the majority of cultures from P. mugo subsp. mugo and C. vulgaris were identified by internal transcribed spacer ITS1-5.8S-ITS2 sequencing and morphology as Allantophomopsis cytisporea. The fungus tolerates low temperatures, has an optimum between 16°C and 24°C, and ceases to grow at 28°C. 35°C is lethal. A. cytisporea is known as the causal agent of cranberry black rot on Vaccinium macrocarpon but has never been described as a snow mold. A. cytisporea is an endophyte in C. vulgaris but seems able to kill leaflets and whole shoots during winter. The epiphytic mycelium can expand from C. vulgaris to neighboring shoots of P. mugo subsp. mugo and J. communis subsp. nana below the snow where it forms epiphytic mycelial mats reminiscent of H. pinetorum. H. pinetorum has a strong antibiotic effect against A. cytisporea at 4°C and 20°C, whereas A. cytisporea grows faster at these temperatures. The effects of climate change on the interaction between the two snow mold fungi and their consequences on regeneration of woody plants at timberline are discussed.

Blanket peatlands are globally rare, and many have been severely eroded. Natural recovery and revegetation (‘self-restoration’) of bare peat surfaces are often observed but are poorly understood, thus hampering the ability to reliably predict how these ecosystems may respond to climatic change. We hypothesised that morphometric/topographic-related microclimatic variables may be key controls on successional pathways and vegetation patterning in self-restoring blanket peatlands. We predicted the occurrence probability of four common peatland plant species (Calluna vulgaris, Eriophorum vaginatum, Eriophorum angustifolium, and Sphagnum spp.) using a digital surface model (DSM) generated from drone imagery at a pixel size of 20 cm, a suite of variables derived from the DSM, and an ensemble learning method (random forests). All four species models provided accurate fine-scale predictions of habitat suitability (accuracy > 90%, area under curve (AUC) > 0.9, recall and precision > 0.8). Mean elevation (within a 1 m radius) was often the most influential variable. Topographic position, wind exposure, and the heterogeneity or ruggedness of the surrounding surface were also important for all models, whilst light-related variables and a wetness index were important in the Sphagnum model. Our approach can be used to improve prediction of future responses and sensitivities of peatland recovery to climatic changes and as a tool to identify areas of blanket peatlands that may self-restore successfully without management intervention.

The distribution of Calluna minor in Nizhny Novgorod oblast is described on the basis of published sources, herbaria, and original data. This species prefers water bodies with well-warmed shallow areas and high mineralization. This species should be included in the regional Red Data Book due to its location at the edge of its distribution. It is advisable to increase the rarity level of this species in the region. Recommendations on its conservation are proposed.

summary Thorne Waste, S. Yorkshire, is a large raised bog, subject to extensive commercial peat extraction, which retains some re-flooded, revegetated peat cuttings. The composition of the vegetation of some of these cuttings (96 sampled quadrats, each of 25 m2) has been related to a number of environmental variables. Revegetation sequences in the abandoned cuttings (all less than 60 years old and with less than 20 cm peat infill) were established by stratigraphical analyses. In some cuttings a basal layer of ericaceous peat apparently marks temporarily drier conditions preceding deeper inundation. Some former mire species (e.g. Sphagnum imbricatum have not survived the peat-cutting period even on uncut surfaces (baulks) but these have been much drained and burnt. The revegetated cuttings contained species typical of poor-ten (e.g. Carex curta) as well as of ombrotrophic mires (e.g. Andromeda polifolia); chemical analyses indicated weakly minerotrophic peat water. This may favour such species as Sphagnum recurvum. There was no indication of chemical enrichment from inflow from surrounding farmland, from underlying mineral ground or from the clay-lined canals excavated across the bog. Release of cations following drainage and re-flooding may provide some explanation. Only soluble reactive phosphorus (SRP) concentration in peat water samples showed consistent and significant seasonal variation, with the lowest values in summer. There were also only a few consistent differences in water chemistry amongst most of the vegetation units identified by TWINSPAN. Nodum 4 (Eriophorum–Sphagnum) stands (richest in ombrotrophic species) occupied the least minerotrophic conditions. One culling, dominated by Juncus, effuses, had no ombrotrophic species (nodum 6). Water concentrations of Ca2+, Na+, K+ NH4+, SO42 and SRP were significantly larger here than in other cuttings and peat fertility (estimated phytometrically) and K, N and P concentrations in peat extracts were significantly greater than in a Sphagnum-dominated cutting. The J. effuses samples had strong negative loadings on axis 2 of a Principal Components Analysis (PCA) of the Adriatic data; concentrations of NH4+, Na+ and SO42 in the water showed significant negative correlation with axis 2 ordination scores. Seasonal fluctuation of water level was similar in most cuttings (the J. effuses cutting was exceptional) but variation in depth relative to the peat surface (caused by excavation to different depths) was related to floristic variation. PCA axis 1 may reflect a water-table gradient with TWINSPAN noda 2 (Calluna Sphagnum recurvum) and particularly 1 (Pteridium Campylopus) occupying drier conditions than the others. The wetter cuttings (except the J. effusus site) supported most ombrotrophic and poor-fen species. They were not readily segregated into discrete vegetation types and the two TWINSPAN classes (noda 3 and 4) that accommodated them showed much overlap on the PCA ordination. Nodum 4 samples tended to have higher loadings on PCA axis 2 and to be more species-rich than nodum 3 samples. Species-richness was strongly positively correlated with PCA axis 2. This may reflect, in part, stand maturity, vegetation with most species having been disturbed least recently.

summary Frost hardiness in Calluna vulgaris (L.) Hull, which had received ammonium nitrate applications in the field for 30 months, was assessed using scores of visible injury and measurements of the rate of total electrolyte leakage from excised shoots following controlled freezing treatments in the laboratory. There was good overall correlation between the two methods (Spearman correlation coefficient 0.77), but leakage measurements were more sensitive than injury scores to the effects of nitrogen. Visible injury was not significantly altered by nitrogen supply (Kruskal-Wallis non-parametric test). Ion leakage was analyzed in different ways, using either calculations of the first-order rate coefficients or expressions of relative conductivity. These analyses produced similar results with respect to the effect of frost and nitrogen. Shoots of nitrogen-fertilized (40, 80 and 120 kg ha−1 yr−1) C. vulgaris sampled in October 1991 showed significantly (P < 0.05) less leakage after overnight frosts of −15 and −20 °C than did the water-treated controls. In October the temperature which killed 50% of the shoots (LT50), derived from the leakage data, was raised by at least 4 °C by the highest nitrogen treatments compared with the control plants. Frost treatments to pot-grown C. vulgaris in November produced similar visible injury to attached and excised shoots from the same plants, both being significantly less damaged by a −18 °C frost after a 7-month exposure to an NaNO3 mist solution (1.0 mM, pH 4.5) than were water-misted controls. Ammonium-mist treatments also marginally reduced frost injury, but the effects were not statistically significant. These results demonstrate that frost hardiness of C. vulgaris in the field can be assessed rapidly and accurately in the laboratory by analysis of electrolyte leakage from excised shoots.

• Ericoid mycorrhizas are believed to improve N nutrition of many ericaceous plant species that typically occur in habitats with impoverished nutrient status, by releasing amino acids from organic N forms. Despite the ubiquity of mycorrhizal formation the mechanisms and regulation of nutrient transport in mycorrhizal associations are poorly understood. • We used an electrophysiological approach to study how amino acid transport characteristics of Calluna vulgaris were affected by colonization with the ericoid mycorrhiza fungus Hymenoscyphus ericae . • Both the V max and K m parameters of amino acid uptake were affected by fungal colonization in a manner consistent with an increased availability of amino acid to the plant. • The ecophysiological significance of altered amino acid transport in colonized root cells of C. vulgaris is discussed.

A total of 107 putative ericoid mycorrhizal endophytes were isolated from hair roots of Calluna vulgaris from two abandoned arsenic/copper mine sites and a natural heathland site in southwest England. The endophytes were initially grouped as 14 RFLP types, based on the results of ITS-RFLP analysis using the restriction endonucleases Hinf I, Rsa I and Hae III. ITS sequences were obtained for representative isolates from each RFLP type and compared phylogenetically with sequences for known ericoid mycorrhizal endophytes and selected ascomycetes. The majority of endophyte isolates (62-92%) from each site were identified as Hymenoscyphus ericae, but a number of other less common mycorrhizal RFLP types were also identified, all of which appear to have strong affinities with the order Leotiales. None of the less common RFLP types was isolated from C. vulgaris at more than one field site. Neighbour-joining analysis indicated similarities between the endophytes from C. vulgaris and mycorrhizal endophytes isolated from other Ericaceae and Epacridaceae hosts in North America and Australia.

Clear—cuttings cause significant changes in boreal forest ecosystems and have long-term effects on populations of understory plants. The aim of our studies was to determine the impact of clear-cuttings on understory mosses and vascular plants populations after clear-cuttings. The species diversity of particular populations in mature stands before cuttings and after one year was determined. Results of investigations corroborated changes in coverage, frequency, and prominence value of predominant Ericaceae plants. We determined the different response of Vaccinium vitis-idaea L., V. myrtillus L. and Calluna vulgaris (L.) Hull. Plant species that are particularly sensitive to clear—cuttings have been identified also. Assessing the viability of moss populations in mature forest stands and deforested areas showed that moss species are most sensitive to environmental changes after clear—cuttings. These investigations could justify the conservation of sensitive forest plant populations and non-wood forest resources.

The coastal heathlands of North-west Europe are valuable cultural landscapes, created and maintained over millennia by a land-use regime involving burning and grazing. These heathlands are now critically threatened throughout their range by land-use change and, increasingly, climatic changes. The climatic change impacts are complex, as the coastal heathland regions are experiencing increased temperature and precipitation, but also increased frequency and severity of extreme events, such as drought. Previous studies reveal that established heathland vegetation, including Calluna, are vulnerable to drought, but also that these vulnerabilities vary throughout the range, and with successional stage after fire. Recruitment from seed is an important regeneration strategy for Calluna heathland vegetation after burning, and our study is the first to assess how the seed germination and early seedling growth of Calluna respond to drought. We will do this in a lab germination experiment, where we will expose Calluna seeds to five different drought treatments, from -0.25 MPa to -1.7 MPa, and measure germination, and record germination percentage, germination rates, and seedling growth, below-ground allocation, and functional traits (Specific Leaf Area, Specific Root Length). To allow assessment of variation in drought responses due to geographic origin, successional stage, and the maternal plants’ drought exposure, we will conduct this experiment on seeds from 540 Calluna plants sampled from across three drought treatments (control, 50%, and 90% coverage), in three successional stages after fire (pioneer, building, mature), in two regions (60N, 65N), using a factorial design.

The potential of vegetation recovery through resprouting of plant tissue from buds after the removal of aboveground biomass is a key resilience strategy for populations under abrupt environmental change. Resprouting leads to fast regeneration, particularly after the implementation of mechanical mowing as part of active management for promoting open habitats. We investigated whether recovery dynamics of resprouting and the threat of habitat conversion can be predicted by optical and structural stand traits derived from drone imagery in a protected heathland area. We conducted multivariate regression for variable selection and random forest regression for predictive modeling using 50 spectral predictors, textural features and height parameters to quantify Calluna resprouting and grass invasion in before-mowing images that were related to vegetation recovery in after-mowing imagery. The study reveals that Calluna resprouting can be explained by significant optical predictors of mainly green reflectance in parental individuals. In contrast, grass encroachment is identified by structural canopy properties that indicate before-mowing grass interpenetration as starting points for after-mowing dispersal. We prove the concept of trait propagation through time providing significant derivates for a low-cost drone system. It can be utilized to build drone-based decision support systems for evaluating consequences and requirements of habitat management practice.

This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: diatom alga Stauroneis neofossilis, parasitic fungus Anthracoidea arenariae, horsetail Equisetum hyemale, liverwort Harpanthus flotovianus, mosses Fissidens exilis and Rhizomnium punctatum, monocots Epipactis helleborine subsp. orbicularis, Himantoglossum calcaratum subsp. rumelicum and Schoenus nigricans and dicots Calluna vulgaris, Mahonia aquifolium and Willemetia stipitata subsp. albanica.

The coastal heathland of Western Europe, dominated by Calluna vulgaris L., was previously maintained by prescribed-burning and grazing to the extent that the Calluna became anthropogenically adapted to regular burning cycles. This 5000&ndash, 6000-year-old land management practice was essential for local biodiversity and created a vegetation free from major wildland fires. In Norway, recent neglect has, however, caused accumulation of live and dead biomass. Invasion of juniper and Sitka spruce has resulted in limited biodiversity and increasing wildland fire fuels. At the Kringsj&aring, cabin and sheep farm, Haugesund, an area of previous fire safe heathland has been restored through fire-agriculture. Kringsj&aring, is located close to several important Viking Age sites and the Steinsfjellet viewpoint, a popular local tourist destination. The motivation for the present study is to analyse this facility and investigate possibilities for synergies between landscape management and tourism as a route to sustainable transitions. The present study compares restored heathland vegetation with unmanaged heathland at Kringsj&aring, The potential for activities is also analysed based on the proximity to the tourist attractions in the region. The Kringsj&aring, area demonstrates different vegetation conditions depending on level of afforestation, Calluna heath maintenance, and gracing. Within a few minutes&rsquo, walk, dense Sitka spruce communities with desert-like forest floor may be compared to native forest floors, Calluna dominated heathland, and grazing fields. It turns out that Kringsj&aring, may become a showcase for resuming prescribed burning and grazing for fire-safe rich landscapes, while offering cultural and historical experiences for all age groups. Moreover, tourism may become a source of income required for supporting ongoing restoration initiatives. To start working on a common vision, preferably aligned with existing "Homeland of the Viking Kings" tourism approach, should be one of the first steps along this path.

Research highlights: Moisture diffusion coefficients for stems and branches of degenerated Calluna vulgaris L. have been obtained and a mathematical model for the drying process has been developed and validated as an input to future fire danger modeling. Background and objectives: In Norway, several recent wildland&ndash, urban interface (WUI) fires have been attributed to climate changes and accumulation of elevated live and dead biomass in degenerated Calluna stands due to changes in agricultural activities, i.e., in particular abandonment of prescribed burning for sheep grazing. Prescribed burning is now being reintroduced in these currently fire prone landscapes. While available wildfire danger rating models fail to predict the rapidly changing fire hazard in such heathlands, there is an increasing need for an adapted fire danger model. The present study aims at determining water diffusion coefficients and develops a numerical model for the drying process, paving the road for future fire danger forecasts and prediction of safe and efficient conditions for prescribed burning. Materials and methods: Test specimens (3&ndash, 6 mm diameter) of dead Calluna stems and branches were rain wetted 48 hours and subsequently placed in a climate chamber at 20 &deg, C and 50% relative humidity for mass loss recordings during natural convection drying. Based on the diameter and recorded mass versus time, diffusion coefficients were obtained. A numerical model was developed and verified against recoded mass loss. Results: Diffusion coefficients were obtained in the range 1.66&ndash, 10.4 &times, 10&minus, 11 m2/s. This is quite low and may be explained by the very hard Calluna &ldquo, wood&rdquo, The large span may be explained by different growth conditions, insect attacks and a varying number of years of exposure to the elements after dying. The mathematical model described the drying process well for the specimens with known diffusion coefficient. Conclusions: The established range of diffusion coefficients and the developed model may likely be extended for forecasting moisture content of degenerated Calluna as a proxy for fire danger and/or conditions for efficient and safe prescribed burning. This may help mitigate the emerging fire risk associated with degenerated Calluna stands in a changing climate.

The New Zealand tea tree Leptospermun scoparium (mānuka) is widely known for the antimicrobial properties of its honey. Mānuka is native to New Zealand, growing in a range of environments, including the Central Volcanic Plateau of the North Island, where it is currently threatened by the spread of exotic invasive weeds such as heather (Calluna vulgaris) and Scotch broom (Cytisus scoparius). Here, we characterise for the first time the aboveground volatile organic compounds (VOCs) produced by mānuka in this area, during summer and winter seasons, in weed-invaded and non-invaded stands. We measured plant volatiles at four sites, each with a distinct combination of woody species: (1) conspecific stands of mānuka; (2) mānuka and another native species (Dracophyllum subulatum); and mānuka with one of two European invasive plants, (3) heather or (4) Scotch broom. We also quantified herbivore damage on target mānuka plants and analysed microclimatic variables (soil nutrients, air temperature and soil water content) to investigate their impact on volatile emissions. Our results reveal a strong seasonal effect on volatile emissions, but also significant differences between sites associated with biotic and abiotic changes partly driven by invasive plants. Overall, volatile emission rates from mānuka were typically lower at sites where invaders were present. We point to several factors that could contribute to the observed emission patterns and areas of interest for future research to provide a comprehensive understanding of VOC emissions in nature. Given the vital role of volatile compounds in plant communication, we also recommend future studies to be performed in multiple seasons, with larger sample sizes and more study sites to expand on these findings and explore the ecological impacts of changes in VOC emissions during plant invasion.

Biomass and chemical composition in six dominant field and bottom layer species have been recorded for 5 years after a wildfire in a coastal pine forest in Sveio, West Norway, in June 1992. As a follow-up of this study, the percentage coverage of field and bottom layer species and the regeneration of main tree species (Pinus sylvestris, Betula pubescens, and Salix spp.) were recorded in 1997, 2001, and 2008. Preliminary results indicate that the three dominant field layer species, Calluna vulgaris, Molinia caerulea, and Pteridium aquilinum, had expanded at the expense of other species, in particular Vaccinium myrtillus, V. vitis-idaea, Deschampsia flexuosa, and pioneer moss species, for example, Polytrichum spp. Seedlings of pine and saplings of birch and other deciduous species had established in the burned areas, and the succession of these species was followed and compared with nearby control plots. The strong growth of Calluna vulgaris after the fire indicates that periodic controlled burning may be an alternative management method of balancing carbon uptake rates in coastal areas of western Norway.

Vegetation at ecotone transitions between open and forested areas is often heavily affected by two key processes: climate change and management of large herbivore densities. These both drive woody plant state shifts, determining the location and the nature of the limit between open and tree or shrub‐dominated landscapes. In order to adapt management to prevailing and future climate, we need to understand how browsing and climatic factors together affect the growth of plants at biome borders. To disentangle herbivory and climate effects, we combined long‐term tree growth monitoring and dendroecology to investigate woody plant growth under different temperatures and red deer (Cervus elaphus) herbivory pressures at forest–moorland ecotones in the Scottish highlands. Reforestation and deer densities are core and conflicting management concerns in the area, and there is an urgent need for additional knowledge. We found that deer herbivory and climate had significant and interactive effects on tree growth: in the presence of red deer, pine (Pinus sylvestris) growth responded more strongly to annual temperature than in the absence of deer, possibly reflecting differing plant–plant competition and facilitation conditions. As expected, pine growth was negatively related to deer density and positively to temperature. However, at the tree population level, warming decreased growth when more than 60% of shoots were browsed. Heather (Calluna vulgaris) growth was negatively related to temperature and the direction of the response to deer switched from negative to positive when mean annual temperatures fell below 6.0°C. In addition, our models allow estimates to be made of how woody plant growth responds under specific combinations of temperature and herbivory, and show how deer management can be adapted to predicted climatic changes in order to more effectively achieve reforestation goals. Our results support the hypothesis that temperature and herbivory have interactive effects on woody plant growth, and thus accounting for just one of these two factors is insufficient for understanding plant growth mechanics at biome transitions. Furthermore, we show that climate‐driven woody plant growth increases can be negated by herbivory. © 2020 The Authors. Ecological Applications published by Wiley Periodicals LLC on behalf of Ecological Society of America This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Background and Aims Plant secondary metabolites play critical roles in plant stress tolerance and adaptation, and are known to be influenced by the environment and climate changes, yet the impacts and interactions of multiple climate change components are poorly understood, particularly under natural conditions. Methods Accumulation of phenolics and emissions of volatile organic compounds (VOCs) were assessed on heather, Calluna vulgaris, an abundant evergreen dwarf shrub in European heathlands, after 6 years of exposure to elevated CO2, summer drought and nighttime warming. Key Results Drought alone had the strongest effects on phenolic concentrations and compositions, with moderate effects of elevated CO2 and temperature. Elevated CO2 exerted the greatest impact on VOC emissions, mainly by increasing monoterpene emissions. The response magnitudes varied among plant tissue types and chemical constituents, and across time. With respect to interactive effects of the studied climate change components, the interaction between drought and elevated CO2 was most apparent. Drought mainly reduced phenolic accumulation and VOC emissions, while elevated CO2 mitigated such effects. Conclusions In natural ecosystems, co-occurring climate factors can exert complex impacts on plant secondary metabolite profiles, which may in turn alter ecosystem processes.

Tree planting is increasingly being proposed as a strategy to combat climate change through carbon (C) sequestration in tree biomass. However, total ecosystem C storage that includes soil organic C (SOC) must be considered to determine whether planting trees for climate change mitigation results in increased C storage. We show that planting two native tree species (Betula pubescens and Pinus sylvestris), of widespread Eurasian distribution, onto heather (Calluna vulgaris) moorland with podzolic and peaty podzolic soils in Scotland, did not lead to an increase in net ecosystem C stock 12 or 39 years after planting. Plots with trees had greater soil respiration and lower SOC in organic soil horizons than heather control plots. The decline in SOC cancelled out the increment in C stocks in tree biomass on decadal timescales. At all four experimental sites sampled, there was no net gain in ecosystem C stocks 12-39 years after afforestation-indeed we found a net ecosystem C loss in one of four sites with deciduous B. pubescens stands; no net gain in ecosystem C at three sites planted with B. pubescens; and no net gain at additional stands of P. sylvestris. We hypothesize that altered mycorrhizal communities and autotrophic C inputs have led to positive 'priming' of soil organic matter, resulting in SOC loss, constraining the benefits of tree planting for ecosystem C sequestration. The results are of direct relevance to current policies, which promote tree planting on the assumption that this will increase net ecosystem C storage and contribute to climate change mitigation. Ecosystem-level biogeochemistry and C fluxes must be better quantified and understood before we can be assured that large-scale tree planting in regions with considerable pre-existing SOC stocks will have the intended policy and climate change mitigation outcomes.

Ornamental heather (Calluna vulgaris) production is characterized by high risks such as occurrence of fungal diseases and plant losses. Given the general absence of formal research on this economically important production system, farmers depend on their own approaches to assess plant vitality. We provide a reproducible, affordable and transparent workflow for assessing ornamental plant vitality with spectroscopy data. We use hyperspectral imaging as a non-invasive alternative for monitoring plant performance by combining the long-term experience of experts with hyperspectral images taken with a portable hyperspectral camera. We tested a custom-made setup deployed in a horticultural production facility and screened thousands of heather plants over a period of 14 weeks during their development from cuttings to young plants under production conditions. The vitality of shoots and roots was classified by experts for comparison with spectral signatures of shoot tips of healthy and stressed plants. To identify wavelengths that allow distinguishing between healthy and stressed heather plants, we evaluated the datasets using Partial Least Squares regression. Reflectance in the green (519–575 nm) and red-edge (712–718 nm) region of the spectrum was identified as most important for classifying plants as healthy or stressed. We transferred the trained Partial Least Squares regression model to independent test data obtained on a different date, correctly classifying 98.1% of the heather plants. The setup we describe here is adjustable and can be used to measure different plant species. We identify challenges in data evaluation, point out promising evaluation approaches, and make our dataset available to facilitate further studies on plant vitality in horticultural production systems.

Winter temperatures are projected to increase in Central Europe. Subsequently, snow cover will decrease, leading to increased soil temperature variability, with potentially different consequences for soil frost depending on e.g. altitude. Here, we experimentally evaluated the effects of increased winter soil temperature variability on the root associated mycobiome of two plant species (Calluna vulgaris and Holcus lanatus) at two sites in Germany; a colder and wetter upland site with high snow accumulation and a warmer and drier lowland site, with low snow accumulation. Mesocosm monocultures were set-up in spring 2010 at both sites (with soil and plants originating from the lowland site). In the following winter, an experimental warming pulse treatment was initiated by overhead infrared heaters and warming wires at the soil surface for half of the mesocosms at both sites. At the lowland site, the warming treatment resulted in a reduced number of days with soil frost as well as increased the average daily temperature amplitude. Contrary, the treatment caused no changes in these parameters at the upland site, which was in general a much more frost affected site. Soil and plant roots were sampled before and after the following growing season (spring and autumn 2011). High-throughput sequencing was used for profiling of the root-associated fungal (ITS marker) community (mycobiome). Site was found to have a profound effect on the composition of the mycobiome, which at the upland site was dominated by fast growing saprotrophs (Mortierellomycota), and at the lowland site by plant species-specific symbionts (e.g. Rhizoscyphus ericae and Microdochium bolleyi for C. vulgaris and H. lanatus respectively). The transplantation to the colder upland site and the temperature treatment at the warmer lowland site had comparable consequences for the mycobiome, implying that winter climate change resulting in higher temperature variability has large consequences for mycobiome structures regardless of absolute temperature of a given site.

216 p. Efectos de las deposiciones atmosféricas de nitrógeno en el funcionamiento de los brezales de Calluna vulgaris (L.) Hull de la cordillera cantábrica.= Calluna-vulgaris-heathlands located at the southern-most distribution area (Cantabrian Mountains, NW Spain) are currently threatened by global change drivers such as atmospheric nitrogen (N) depositions that affect their functioning, structure and plant species composition. The main aim of the present Doctoral Thesis was to evaluate the effects of different atmospheric N loads in Cantabrian Mountains heathlands at two different life-cycle stages (young- and mature-phase). Field measured bulk inorganic N deposition rates in the Cantabrian Mountains ranged between 2.8 kg N ha-1 yr-1 and 4.6 kg N ha-1 yr-1, with higher N deposition rates during the wet period. The prevailing N chemical form in atmospheric depositions is from oxidized compounds (NOY). The distribution and fate of these airborne N inputs in the Calluna-heathland were traced with 15N isotope. These heathlands were able to retain ∼72% of total N inputs in the short-term (< 1 year). The soil organic horizon immobilized ∼47% of the N inputs. During the second year, ∼95% of N inputs was likely lost by denitrification fluxes during the winter-spring period. Leaching losses were negligible over two years, suggesting that these heathlands were not N saturated. Furthermore, we aimed to evaluate the effects of different levels of experimentally simulated N deposition on the functioning, structure and composition of Cantabrian Calluna-heathlands. The increase in atmospheric N loads resulted in a subsequent increase in soil ammonium (NH4+) with long-term N inputs (10 years); although soil nitrate (NO3-), total N, organic carbon (C), and available phosphorus (P) pools remained unchanged. Besides, Calluna shoot N and P contents and litter N content also increased, which was accordingly reflected in higher N:P ratios. The greatest P demand by Calluna biomass from P-poor soils was supplied by the increase in acid phosphatase enzymatic activity to mineralize organic P, and by the extent of Calluna roots colonized by mycorrhizal fungi to support the higher P uptake. There were no changes in soil microbial biomass C and N contents in response to higher N availability, as well as in urease (N cycle) and β-glucosidase (C cycle) enzymatic activities associated to microbial nutrient demand. The lack of response of several soil properties and microbial nutrient contents could be due to extreme climatic conditions and short period of physiological activity in these montane areas, indicating that montane heathlands are highly resistant to increased N loads. Furthermore, plant community composition and plant species richness remained unchanged in response to enhanced N inputs, likely due to the resistant and resilient mechanisms of heathland dominant vegetation. However, at life-form level, percentage of cover of N-tolerant graminoids and forbs species increased with higher N availability, while the cover of bryophytes and lichens declined. There was a stimulation of Calluna vulgaris vital rates (shoot growth and flowering) in response to short-term N inputs, but the first symptoms of N saturation were observed under long-term N inputs (10 years) through a declined trend in these vital rates. The heathland life-cycle stage conditioned the response to enhanced N loads through stronger N-related effects in young stands compared to mature ones. In Cantabrian heathlands, the N critical load was set in the range of 10-20 kg N ha-1 yr-1 for both young and mature stands, based mainly on changes in Calluna flowering and shoot N content at 14.6 kg N ha-1 yr-1.

Global change drivers can interact in synergistic ways, yet the interactive effect of global change drivers, such as climatic warming and species invasions, on plant pollination are poorly represented in experimental studies. We paired manipulative experiments to probe two mechanistic pathways through which plant invasion and warming may alter phenology and reproduction of native plant species. In the first, we tested how experimental warming (+1.7°C) modulated flowering phenology and how this affected flowering overlap between a native plant (Dracophyllum subulatum) and an invasive plant (Calluna vulgaris L.). In the second experiment, we explored how variation in the ratio of native to invasive flowers, and the overall quantity of resources in a floral patch, affected the reproduction of the native species. We hypothesized that the flowering overlap of native and invasive plants would be altered by warming, given that invading plants typically exhibit greater phenological plasticity than native plants. Further, we hypothesized that pollination of native plant flowers would decrease in floral patches dominated by invasive plant flowers, but that this effect would depend on total floral density in the patch. As predicted, the invasive plant had a stronger phenological response to experimental warming than the native plant, resulting in increased flowering overlap between the native the invasive plants. There was a four-fold increase in the number of native flowers co-flowering with high densities of invasive flowers suggesting native plant competition for pollinators with invasive plants under a warmed climate. In the second experiment, we found depressed seed masses of the native species in high density floral patches that were dominated by invasive flowers relative to high density floral patches dominated by native flowers. At low floral densities, seed mass of native plants was unaffected by invasion. Together, these results demonstrate that by increasing their phenological overlap, warming may enhance the magnitude of existing competition for pollination exerted by an invasive plant on a native plant, particularly in plant patches with high floral density. Our results illustrate a novel pathway through which global change drivers can operate synergistically to alter an important ecosystem service: pollination.

The distribution of nine chloroplast DNA haplotypes in four insular North-Atlantic and four European coastal Atlantic populations of Calluna vulgaris in the glacial zone of the range has been analyzed in comparison with that in six marginal southern populations in the nonglacial zone of the Atlantic and Mediterranean regions. As a result, two hypothetical Pleistocene refugia (HPRs) for this C. vulgaris population group have been revealed, one in the Cevennes mountain range and the other in the Southern Alps (Trento). Judging from the 1–FST value, it has been found that the group of populations in the glacial Atlantic zone and adjacent European coastal Atlantic region is genetically similar to the HPR in the Cevennes at a highly significant level (p ≥ 0.999) and less similar to the HPR in Trento; however, it differs significantly from other Mediterranean and Atlantic populations. It has been concluded that the most probable hypothetical Pleistocene refugium for the recent C. vulgaris populations of the northeastern Atlantic and European coastal Atlantic regions was in the west of the Mediterranean, in the Cevennes, while the additional refugium was in the Southern Alps. Possible directions of the postglacial dispersal and recolonization of habitats by C. vulgaris populations from the western Mediterranean to the northeast of the Atlantic and to Scandinavia have been revealed.

The present study evaluated the anti-gout potential of an ethanolic extract fromCalluna vulgarisL. Hull (ECV). A preliminary phytochemical analysis of ECV was performed by spectrophotometric and HPLC-PDA-MS methods. Hypouricemic effect of ECV was testedin vivousing the oxonate-induced hyperuricemia model in rats, systolic blood pressure being also monitored in hyperuricemic animals. The anti-inflammatory and analgesic effects of ECV were investigated by the carrageenan-induced paw oedema and Randall-Selitto test in rats. The results of the phytochemical analysis of the extract obtained fromC. vulgarisshowed the main chemical constituents were flavonoids and chlorogenic acid. ECV showed significant and dose-dependent hypouricemic effects in oxonate-treated rats, increasing the urinary excretion of uric acid. The tested extract produced statistically significant anti-inflammatory and analgesic effects at the dose of 500 mg/kg. This study offers a new perspective regarding the anti-gout potential ofC. vulgaris.

The effect of prescribed burning for conservation management of plant communities is controversial for moorlands growing on peat. These ecosystems provide many services that may be damaged by fire, hence it is important to fully assess its impact on all aspects of ecosystem structure and function experimentally over relatively long time‐scales. This paper describes change in community composition, major plant species, and plant functional types on moorland on peat in upland Britain over 60 years subject to 3 burning treatments after an initial burn in 1954/1955: no further burn and burning at 10‐ and 20‐year intervals (all ± sheep grazing). Data were analysed using multivariate and univariate methods. Vegetation composition and individual species abundance reflected the degree of disturbance. The least disturbed was dominated by Calluna vulgaris and pleurocarpous mosses, whereas the most disturbed treatment (burned every 10 years) had greater Eriophorum vaginatum , Sphagnum spp., acrocarpous mosses, liverworts, and lichens. The 20‐year treatment was intermediate in response disturbance. Repeated burning increased species abundance‐weighted Ellenberg values for moisture, reaction, light through time, and fertility; the exception was the 10‐year rotation for fertility. These confirm that prescribed burning is not deleterious to peat‐forming species (Eriophorum spp. and Sphagnum spp.), indeed these species were found in greater abundance in frequently burned treatments. It also confirms that a no‐burn policy will lead to increasing dominance of C. vulgaris , a flammable, fire‐adapted shrub, which increases summer wildfire risk. These results inform conservation management policy for moorland vegetation growing on peat; for this site, a 20‐year prescribed burning rotation is recommended.

In this study, we used a comprehensive tree-ring network from Estonia and investigated Scots pine (Pinus sylvestris L.) radial growth responses to changing climate conditions, considering differences in site conditions and local climates. To assess whether climate influences Scots pine radial growth consistently across the country, we developed thirteen tree-ring width chronologies for pine populations growing in four forest site types – Cladonia, Calluna, Myrtillus, and Rhodococcum – in four sub-regions of Estonia and compared these to climate data. A correlation analysis between ring-width indexes and monthly resolved temperature and precipitation applied over the period of 1955–2006 revealed significant positive correlations with winter/early spring temperatures and the total precipitation of late summer in the year prior to growth. High mean temperatures in August of the year prior to growth were negatively related to pine growth, particularly on islands and in the Northeast of Estonia. Scots pine growth on mesic and medium fertile Myrtillus and Rhodococcum sites in the Southeast exhibited greater sensitivity to mean February−April temperatures, while high temperatures and low precipitation at the end of the summer of the previous growing season limited radial growth of pine on the islands and in the North-eastern sub-region. A principal component analysis conducted on mean index chronologies and a hierarchical cluster analysis performed on bootstrapped correlation coefficients showed that local climate is the main driver of common growth, followed by ecological site conditions. A moving correlation analysis, performed over the period of 1955–2006, using 30-year windows shifted by one year showed that climate-growth relationships are not stable in changing climatic conditions. Associations between Scots pine tree-ring width and winter temperatures are getting weaker.

Root-colonizing fungi can form mycorrhizal or endophytic associations with plant roots, the type of association depending on the host. We investigated the differences and similarities of the fungal communities of three boreal ericoid plants and one coniferous tree, and identified the community structure of fungi utilizing photosynthates from the plants studied. The fungal communities of roots and soils of Vaccinium myrtillus, Vaccinium vitis-idaea, Calluna vulgaris and Pinus sylvestris were studied in an 18-month-long experiment where the plants were grown individually in natural substrate. Photosynthates utilizing fungi were detected with DNA stable-isotope probing using 13 CO2 (13 C-DNA-SIP). The results indicated that the plants studied provide different ecological niches preferred by different fungal species. Those fungi which dominated the community in washed roots had also the highest 13 C-uptake. In addition, a common root endophyte without confirmed mycorrhizal status also obtained 13 C from all the plants, indicating close plant-association of this fungal species. We detect several fungal species inhabiting the roots of both ericoid mycorrhizal and ectomycorrhizal plants. Our results highlight that the ecological role of co-occurrence of fungi with different life styles (e.g. mycorrhizal or endophytic) in plant root systems should be further investigated.

AIMS: To apply the Landscape Reconstruction Algorithm (LRA) to pollen count data from multiple sites to estimate local vegetation abundance and compare with charcoal‐derived records of burning. LOCATION: Exmoor, southwest England, UK. METHODS: Pollen count data from 16 sites were transformed to estimates of distance‐weighted vegetation abundance using the LRA (REVEALS and LOVE models), correcting for bias in pollen production and dispersal. Charcoal concentration data from six sites were normalized using Box‐Cox transformation to produce z‐scores. Moving‐window correlation was undertaken to compare pollen percentage values for key taxa (Calluna, Poaceae) and localized burning. Estimates of distance‐vegetation abundance (LRA output) and time‐averaged charcoal z‐scores were compared to assess the role of burning as a driver for upland vegetation cover. RESULTS: Comparison of pollen percentage and normalized charcoal z‐scores show little correlation between vegetation cover and burning. Estimates of distance‐weighted vegetation abundance and normalized charcoal data show relationships between vegetation change and burning at four of the six sites. The relationships are site‐specific: three sites suggest burning promoted grass‐dominated vegetation, at one site burning promoted heather‐dominated vegetation, and in two sites there is no apparent relationship. CONCLUSIONS: The patterning of vegetation within uplands is a crucial part of ecosystem service delivery, and contemporary and future management benefits from understanding of ‘long‐term’ development, i.e. patterns over millennia. The correction of biases within pollen production and dispersal to produce local vegetation estimates has demonstrated spatial heterogeneity in vegetation cover on Exmoor that is not otherwise evident in the pollen percentage data (which retain a strong influence of the regional vegetation cover). The relationship between LRA‐derived vegetation cover and burning is not apparent in comparisons between pollen percentage data and charcoal records. This implies that studies that use pollen proportional data alone can misrepresent the relationship between vegetation cover and fire. This study demonstrates that fire has been an important part of the development of this cultural landscape.

В итоге сравнительного анализа распространения 9 гаплотипов хлоропластной ДНК в четырех островных северо-атлантических и четырех европейских приатлантических популяциях Calluna vulgaris ледниковой зоны ареала, с одной стороны, а также в шести маргинальных южных популяциях внеледниковой зоны Атлантики и Средиземноморья, с другой, выявлены два гипотетичных плейстоценовых рефугиума (ГПР) этого вида. По параметру 1-FST установлено, что изучавшаяся группа популяций ледниковой зоны Атлантики и смежной европейской Приатлантики на высоко достоверном уровне (р 0.999) генетически сходна с ГПР в Севеннах, в меньшей мере с ГПР в Тренто, но резко отличается от других тестированных популяций Средиземноморья и Атлантики. Сделан вывод о том, что наиболее вероятный гипотетический плейстоценовый рефугиум для современных популяций C. vulgaris северо-восточной Атлантики и Приатлантики располагался на западе Средиземноморья, в горном массиве Севенны, а аддитивный - в Южных Альпах (Тренто). Выявлены вероятные направления пост- гляциальной реколонизация популяций C. vulgaris из западного Средиземноморья на северо-запад Атлантики и в Скандинавию.

The exact cause of population dieback in nature is often challenging to identify retrospectively. Plant research in northern regions has in recent decades been largely focussed on the opposite trend, namely increasing populations and higher productivity. However, a recent unexpected decline in remotely-sensed estimates of terrestrial Arctic primary productivity suggests that warmer northern lands do not necessarily result in higher productivity. As large-scale plant dieback may become more frequent at high northern latitudes with increasing frequency of extreme events, understanding the drivers of plant dieback is especially urgent. Here, we report on recent extensive damage to dominant, short, perennial heath and tundra plant populations in boreal and Arctic Norway, and assess the potential drivers of this damage. In the High-Arctic archipelago of Svalbard, we recorded that 8-50% of Cassiope tetragona and Dryas octopetala shoots were dead, and that the ratios of dead shoots increased from 2014 to 2015. In boreal Norway, 38-63% of Calluna vulgaris shoots were dead, while Vaccinium myrtillus had damage to 91% of shoots in forested sites, but was healthy in non-forested sites. Analyses of numerous sources of environmental information clearly point towards a winter climate-related reason for damage to three of these four species. In Svalbard, the winters of 2011/12 and 2014/15 were documented to be unusually severe, i.e. insulation from ambient temperature fluctuation by snow was largely absent, and ground-ice enforced additional stress. In boreal Norway, the 2013/14 winter had a long period with very little snow combined with extremely low precipitation rates, something which resulted in frost drought of uncovered Calluna plants. However, extensive outbreaks of a leaf-defoliating geometrid moth were identified as the driver of Vaccinium mortality. These results suggest that weather and biotic extreme events potentially have strong impacts on the vegetation state of northern lands.