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Abstract The role of climate in shaping the postglacial history of Patagonia (41–55°S) east of the Andes is evident in new pollen and charcoal data from Mallín Fontanito (44.91oS, 71.57oW) and their comparison with other paleoenvironmental records in the region. Between 17,800–13,000 cal yr BP, evidence of heath-steppe vegetation with some Nothofagus and little fire activity at M. Fontanito suggest cold, dry conditions in early late-glacial time. From 13,000–7000 cal yr BP, increased Nothofagus pollen and charcoal levels imply expanding tree cover and more fires, consistent with warming. Between 7000 and 4000 cal yr BP, closed Nothofagus forest was established at M. Fontanito during a period of low fire activity and effectively wetter conditions than before. Fluctuations in pollen and charcoal levels after 4000 cal yr BP are consistent with increased submillennial climate variability. The environmental history at M. Fontanito is similar to other records from central Patagonia east of the Andes (44-50oS); however, differences in the timing of fires and human occupation suggest that pre-European burning was local in nature. At a regional scale, composited Nothofagus pollen abundance and charcoal data east of the Andes (41-55oS) reveal latitudinal differences in the timing of forest establishment and fire that relate to changes in the strength and position of the Southern Westerly Winds (SWW) through time. Notably, the SWW were south of their present position between 14,000 and 9000 cal yr BP, leading to dry conditions across the region. The present storm-track position was established after 7000 cal yr BP, when region-wide increases in precipitation occurred. Highlights • A new record of past vegetation and fire comes from central Patagonia, Argentina. • Climate controlled fire regionally, but human-set fires were locally important. • Multiple site comparison suggests shifts in the Southern Westerlies through time. • SWW were south of present position in the early Holocene, resulting in more fires. • SWW strengthened and moved to present position by 7 ka, resulting in less fire. [ABSTRACT FROM AUTHOR]

Extreme climatic events are among the drivers of recent declines in plant biomass and productivity observed across Arctic ecosystems, known as "Arctic browning." These events can cause landscape‐scale vegetation damage and so are likely to have major impacts on ecosystem CO2 balance. However, there is little understanding of the impacts on CO2 fluxes, especially across the growing season. Furthermore, while widespread shoot mortality is commonly observed with browning events, recent observations show that shoot stress responses are also common, and manifest as high levels of persistent anthocyanin pigmentation. Whether or how this response impacts ecosystem CO2 fluxes is not known. To address these research needs, a growing season assessment of browning impacts following frost drought and extreme winter warming (both extreme climatic events) on the key ecosystem CO2 fluxes Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP), ecosystem respiration (Reco) and soil respiration (Rsoil) was carried out in widespread sub‐Arctic dwarf shrub heathland, incorporating both mortality and stress responses. Browning (mortality and stress responses combined) caused considerable site‐level reductions in GPP and NEE (of up to 44%), with greatest impacts occurring at early and late season. Furthermore, impacts on CO2 fluxes associated with stress often equalled or exceeded those resulting from vegetation mortality. This demonstrates that extreme events can have major impacts on ecosystem CO2 balance, considerably reducing the carbon sink capacity of the ecosystem, even where vegetation is not killed. Structural Equation Modelling and additional measurements, including decomposition rates and leaf respiration, provided further insight into mechanisms underlying impacts of mortality and stress on CO2 fluxes. The scale of reductions in ecosystem CO2 uptake highlights the need for a process‐based understanding of Arctic browning in order to predict how vegetation and CO2 balance will respond to continuing climate change. Extreme climatic events are among the drivers of vegetation damage and decline observed across Arctic ecosystems in recent years; termed "Arctic browning." Although these events can cause landscape‐scale vegetation damage, their impacts on ecosystem CO2 balance are little understood. Here, it is demonstrated that these events can have major impacts on CO2 balance, considerably reducing the carbon sink capacity of the ecosystem across the growing season. These impacts can be similar when associated with shoot mortality, or with shoot stress responses. [ABSTRACT FROM AUTHOR]

Highlights • Land-use legacies in soil and vegetation persist after nearly 150 years after abandonment of agriculture. • Moderate increases in nutrient availability alter small-scale diversity and community assembly. • Typical heathland vegetation persists despite lack of management. • Plant–soil feedback is a likely mechanism underpinning different vegetation states. Abstract Land-use legacies are recognized determinants of vegetation dynamics and plant community assembly. The duration of these legacies and how they influence the structure of vegetation communities developing naturally in nutrient-poor ecosystems is not well understood. Here, we focus on the effects of increased nutrient availability from previous agricultural practices on multiple vegetation properties in a heathland where agriculture and domestic grazing ceased near 1870 and 1895, respectively. We compared diversity, compositional and functional properties of the vegetation responses to land-use legacies in the soil between areas with different agricultural histories (previously cultivated vs. uncultivated). Diversity measures were found to be higher in the previously cultivated soils. β-diversity was mainly driven by changes in species relative cover and increased with increasing nutrient availability in the cultivated area. Furthermore, functional traits related to nutrient acquisition (SLA and Leaf Nitrogen content) and the changes in vegetation composition were directly linked to soil properties only in the previously cultivated part of the heathland. Together these results revealed a shift to a deterministic control of the plant community, where increased nutrient availability leads to stronger associations between soil and vegetation properties. This suggests that as nutrients become available, niche differentiation and competitive interactions become the predominant underlying mechanisms structuring the community. Our study shows that land-use legacies of moderate intensity can alter the assembly mechanisms and diversity patterns in unmanaged vegetation that can be maintained after more than a century since cessation of agricultural practice. Identifying land-use legacies and understanding how they structure heathland communities can thus lead to management decisions adapted to the specific assembly mechanisms and result in a more effective management. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Restoration of nutrient-enriched heathlands and similar dry habitats via topsoil removal requires the re-assembly of above and belowground communities to attain fully functional ecosystems. Top-soil removal provides unique opportunities to study the assembly processes, but research has traditionally focused on succession of the aboveground part of the ecosystem. Oribatid mites are a dominant group of soil mesofauna in the belowground part of heathlands. They possess attributes for bioindication and have shown high sensitivity to environmental changes during succession. However, few studies have focused on changes in functional community profiles and the factors shaping them with time. We sampled heathlands of different restoration ages located in East Belgium, studied traits of oribatid mite communities of a chronosequence, and assessed the interaction between traits and abiotic variables using community weighted means (CWM) and an iterative co-correlation analysis between abiotic parameters, species trait attributes and species abundances (iterative RLQ analysis). Our study suggests that moisture preferences, concealability (i.e. defence mechanism against desiccation and predation), and body length were the dominant traits structuring the oribatid mite communities. We found that both dispersal and environmental filters shape the assembly of oribatid mite communities, but these drivers dominate different stages of succession. Moreover, trait assemblages deriving from three well-defined eco-morphological groups closely followed these constraints in time. Thus, the shifting dominance of specific groups provides valuable insight on the soil community functioning in a changing environment. [ABSTRACT FROM AUTHOR]

Applying mulch to severely burned soils is common practice in fire-prone areas such as the NW Spain. Mulch that provides >80% cover can reduce post-fire soil erosion by up to 90%; however, this level of cover can sometimes be difficult to achieve in remote areas due to the logistic constraints. Although application of mulch strips is a possible alternative approach, there is no information available about the effectiveness of this technique. Such information is critical in protected areas where mulch application can modify the recovery of natural vegetation by altering the soil moisture regime. In this study, the effects of the application of 20 m wide straw mulch strips on soil erosion, soil moisture and vegetation recovery were assessed during the first year after a high-severity fire that occurred in September 2020 in two European dry-heathland areas. During the first year after the fire, the mean sediment yields in the untreated plots were 18.5 Mg ha−1 and 33.8 Mg ha−1, respectively at the Lobios and Vilariño study sites. Although the straw mulch strips reduced soil erosion by >70% on average, erosion rates remained high at both sites. Soil moisture contents in mulch-treated areas were significantly higher than in untreated areas during spring and summer. Mulching affected vegetation recovery in different ways, i.e., it had neutral to positive effects, depending on the study site. No alteration in species composition was observed in either of the sites as a result of treatment application. In summary, the reduction in soil erosion after the application of straw mulch strips covering 67% of burned soil under the conditions of the present study under the conditions of the present study reduced a 70–75% of soil erosion after a high-severity wildfire. • Straw mulch strips significantly reduced (70–75%) post-fire soil erosion. • Mulch application increases soil moisture relatively to the control in spring-summer. • The effects of mulch on vegetation cover ranged from neutral to positive. • Mulching did not affect plant species richness. [ABSTRACT FROM AUTHOR]

Abstract A high-resolution pollen record in a peat sequence from the Altai Mountains of Xinjiang, China, allows reconstruction of the regional vegetation and climate changes that occurred during the Holocene. Pollen distributions from the sequence indicate that the vegetation community in the Altai Mountains region transitioned through five general phases: forest and desert steppe, wet steppe, desert steppe, steppe, and finally forest and desert steppe. These vegetative phases imply that the regional climate changed from a cold and dry early Holocene to a warmer and wetter early-mid Holocene and then to a cold and rather dry mid-Holocene that was followed by a cool and wet late Holocene and finally by warm and dry conditions for the last millennium. These regional changes in climate are roughly consistent with local changes previously reconstructed from organic geochemical paleoclimate proxies in the same peat sequence by Zhang et al. (2016), but with some minor but important differences that reflect local factors. Regional comparisons reveal that the Holocene climate changes in the Altai Mountains are generally consistent with those of most arid central Asian regions that are influenced mainly by westerlies. However, they are out-of-phase with the climate histories of regions controlled by the Asian monsoons, indicating that the Asian monsoons did not extend to the high-altitude mountain regions of arid central Asia during the Holocene. We postulate that the regional Holocene moisture variations have been mainly modulated by NAO variations that affected transport of water vapor from the North Atlantic Ocean by the westerlies. Moreover, local factors that include topography of the mountains and glacial meltwater events in the high-altitude regions also contributed to the climate changes in the Altai Mountains. In addition, air temperatures related to summer insolation of the Northern Hemisphere might have played an important role in modulating moisture in the region, but only after the local montane ice-sheets had disappeared by the mid-Holocene. Highlights • Pollen records from a peat sequence from Xinjiang Altai Mountains reveal Holocene vegetation changes. • Pollen-based reconstruction of Holocene climate changes in the Altai Mountains. • Comparisons of Holocene climate changes in Altai Mountains with arid central Asian and monsoonal Asian regions. • Explanations proposed for Holocene vegetation and climate changes in the Altai Mountains. [ABSTRACT FROM AUTHOR]

Background and Aims An understanding of mycorrhizal variation, orchid seed germination temperature and the effect of co-occurring plant species could be critical for optimizing conservation translocations of endangered plants with specialized mycorrhizal associations. Methods Focusing on the orchid Thelymitra epipactoides, we isolated mycorrhizal fungi from ten plants within each of three sites; Shallow Sands Woodland (SSW), Damp Heathland (DH) and Coastal Heathland Scrub (CHS). Twenty-seven fungal isolates were tested for symbiotic germination under three 24 h temperature cycles: 12 °C for 16 h–16 °C for 8 h, 16 °C for 16 h–24 °C for 8 h or 27 °C constant. Fungi were sequenced using the internal transcribed spacer (ITS), nuclear large subunit 1 (nLSU1), nLSU2 and mitochondrial large rRNA gene (mtLSU). Orchids were grown to maturity and co-planted with each of ten associated plant species in a glasshouse experiment with tuber width measured at 12 months after co-planting. Key Results Two Tulasnella fungal lineages were isolated and identified by phylogenetic analyses, operational taxonomic unit 1 (OTU1) and ' T. asymmetrica '. Fungal lineages were specific to sites and did not co-occur. OTU1 (from the SSW site) germinated seed predominantly at 12–16 °C (typical of autumn–winter temperature) whereas ' T. asymmetrica ' (from the DH and CHS sites) germinated seed across all three temperature ranges. There was no difference in the growth of adult orchids germinated with different OTUs. There was a significant reduction in tuber size of T. epipactoides when co-planted with six of the commonly co-occurring plant species. Conclusions We found that orchid fungal lineages and their germination temperature can change with habitat, and established that translocation sites can be optimized with knowledge of co-occurring plant interactions. For conservation translocations, particularly under a changing climate, we recommend that plants should be grown with mycorrhizal fungi tailored to the recipient site. [ABSTRACT FROM AUTHOR]

Different habitat types that support similar densities of a particular species may not be equally suitable for that species and this may impact on the ability of that species to grow, reproduce, and survive. Here we investigate the impact of habitat quality on the performance of the UK’s rarest snake which inhabits both lowland heath and adjacent areas of managed conifer plantation located on former lowland heath. Annually, over an 8 year period (2009–2016), we recaptured known individual smooth snakes ( Coronella austriaca ) in these two habitat types and compared their survivorship, using Program MARK, and growth rates, estimated ages, reproductive outputs, emigration/immigration, and body condition, using regression analysis and GLM. When compared with snakes from plantations those inhabiting open heathland had higher growth rates, were larger for any given age, had a higher body condition and females produced more embryos for a given body size. Smooth snake survivorship rates within the two habitats were similar. Whilst the body condition of snakes in heathland did not change during the study it declined in plantations and this decline was correlated with increasing plantation age and tree canopy cover. Our data show that although smooth snakes occur in both habitat types the overall quality of open heathland is superior to that of plantations, particularly in the long term. This study has potentially important implications for the conservation of smooth snakes and other reptile and vertebrate species inhabiting coniferous plantations, where management practices aimed at reducing ground vegetation cover, such as cattle grazing and the use of herbicides, are also used. The combination of increasing canopy cover and these additional ground vegetation control measures are likely to significantly reduce further the time period over which plantations can be utilised by these taxa. [ABSTRACT FROM AUTHOR]

The Dutch heathlands have been redefined in the last century. They have gone from being largely commons under a pastoral regime developed and performed by cooperating local residents of varying backgrounds, to becoming protected nature areas run by eco-managerial professionals. At the same time, farming is becoming an increasingly industrialised agribusiness under equally professionalised farm managers. This has resulted in the landscape being divided between a high-tech agriculture and high-science ecology that seeks thereby to balance and compensate for the anthropocentric loss of nature in core agricultural areas by promoting an ‘anti-anthropic’ rewilding on the margins. Now, however, there is a growing reaction to this polarisation leading to new forms of contemporary ‘commons’ as a cultural natural landscape exemplified here by the introduction of the ‘Heathland Farm’ as a basis for alternative forms of agro-environmental use. [ABSTRACT FROM AUTHOR]

Comprehending the decomposition process is crucial for our understanding of the mechanisms of carbon (C) sequestration in soils. The decomposition of plant biomass has been extensively studied. It revealed that extrinsic biomass properties that restrict its access to decomposers influence decomposition more than intrinsic ones that are only related to its chemical structure. Fungal biomass has been much less investigated, even though it contributes to a large extent to soil organic matter, and is characterized by specific biochemical properties. In this study, we investigated the extent to which decomposition of heathland fungal biomass was affected by its hydrophobicity (extrinsic property) and melanin content (intrinsic property). We hypothesized that, as for plant biomass, hydrophobicity would have a greater impact on decomposition than melanin content. Mineralization was determined as the mineralization of soil organic carbon (SOC) into CO2 by headspace GC/MS after inoculation by a heathland soil microbial community. Results show that decomposition was not affected by hydrophobicity, but was negatively correlated with melanin content. We argue that it may indicate that either melanin content is both an intrinsic and extrinsic property, or that some soil decomposers evolved the ability to use surfactants to access to hydrophobic biomass. In the latter case, biomass hydrophobicity should not be considered as a crucial extrinsic factor. We also explored the ecology of decomposition, melanin content, and hydrophobicity, among heathland soil fungal guilds. Ascomycete black yeasts had the highest melanin content, and hyaline Basidiomycete yeasts the lowest. Hydrophobicity was an all-or-nothing trait, with most isolates being hydrophobic. [ABSTRACT FROM AUTHOR]

Questions: What is the general pattern of species co-occurrence in managed heathlands? Is the pattern consistent among functional groups? Is it ruled by species competition, or by contrasting environments at a fine scale? Does grazing pressure and herbivore species condition species interactions? Location: Erica mackayana wet heaths, Galicia, NW Iberian Peninsula. Methods: A null model approach was used to compare species co-occurrence with generated random matrices from 54 10-m transects. The C-score was obtained from the multispecies presence/absence matrix for each transect of shrubs and graminoids recorded at 25-cm intervals. Differences in canopy height were recorded to assess the importance of the environment compared to inter-specific competition. Results were linked to different levels of grazing pressure and herbivore species. Results: Species segregation was the main pattern for all species, but mainly among graminoid species compared to shrubs. Graminoids showed an even proportion of segregated pairs explained by different canopy heights and competition. These differences were mainly species environmental requirements of canopy height. Levels of grazing pressure enhanced species segregation in graminoids but had no effect on shrubs or the total species set. Conclusions: Competition and canopy height affect the E. mackayana heathland composition, but differently for functional groups. A heterogeneous vegetation profile with shrub mats and open gaps created by light grazing promotes species coexistence within mats and competition in gaps. I suggest this is an optimum structure for the habitat to be targeted through management. [ABSTRACT FROM AUTHOR]

At the beginning of the eighteenth century, the heathlands of the Surrey, Berkshire and Hampshire borders covered at least 100,000 acres. They were generally condemned as inhospitable, barren and unproductive waste and were vilified by agricultural improvers at the end of the century. But already in the 1720s their gradual disappearance was foreshadowed by the turnpiking of roads across the heaths and the development of country estates for the nouveaux riches within easy reach of London. Over the ensuing 250 years the parliamentary enclosures of 1780-1830, the building of railways, the founding of land-hungry institutions, the annexation of great swathes for military use, and the inexorable progress of large-scale urbanization meant that by the Second World War only small areas of open heathland remained. Designation as 'green belt' after 1947 saved most of this residue, but, today, pressure for commercial, residential and transport development remains a significant and growing threat. [ABSTRACT FROM AUTHOR]

The importance of competition in low productive habitats is still debated. Studies which simultaneously evaluate preemption of resources and consequences for population dynamics are needed for a comprehensive view of competitive outcomes. We cultivated two emblematic species of European heathlands (Calluna vulgaris and Molinia caerulea) in a nursery for 2 years at two fertility levels, reproducing the productivity gradient found in phosphorus (P)-depleted heathlands in southwest France. The second year, we planted Ulex europaeus seedlings, a ubiquitous heathland species, under the cover of the two species to evaluate its ability to regenerate. Half of the seedlings were placed in tubes for exclusion of competitor roots. We measured the development of the competitors aboveground and belowground and their interception of resources (light, water, inorganic P). Ulex seedlings’ growth and survival were also measured. Our results on resources interception were consistent with species distribution in heathlands. Molinia, which dominates rich heathlands, was the strongest competitor for light and water in the rich soil. Calluna, which dominates poor heathlands, increased its root allocation in the poor soil, decreasing water and inorganic P availability. However, the impact of total competition and root competition on Ulex seedlings decreased in the poor soil. Other mechanisms, especially decrease of water stress under neighbouring plant cover, appeared to have more influence on the seedlings’ response. We found no formal contradiction between Tilman and Grime’s theories. Root competition has a primary role in acquisition of soil resources in poor habitats. However, the importance of competition decreases with decreasing fertility. [ABSTRACT FROM AUTHOR]

Abstract: Questions: How open was the landscape prior to agriculture? Did agriculture start earlier in the south than in the north? How did the vegetation change in different regions after the introduction of agriculture? Location: Coast of SW and W Norway. Methods: The REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) model is applied for pollen‐based vegetation reconstruction in 19 time windows over the last 9,000 years. Pollen data from 63 sites (lakes and bogs) are compiled and systematically used for data analysis so that the structure of vegetation change in space and time is captured. Results: Estimated cover of selected trees, shrubs, Calluna, graminids and herbs indicate a partly open outer coast throughout the Holocene. The highest tree cover is estimated for 8,200–6,200 cal. BP. Broad‐leaved trees (Fraxinus, Quercus, Tilia and Ulmus) spread from south to north and were present in the whole region at the end of the Mesolithic (5,950 cal. BP). Larger spatial variation in tree cover and a step‐wise reduction in deciduous trees after 5,700 cal. BP is concordant with increases in open‐land taxa indicating human activity. Vegetation changes caused by agriculture are indicated in the very south from ca. 5,950 cal. BP. Distinct human‐induced vegetation changes with spatial differentiation took place from 4,200 to 1,700 cal. BP, when most of the areas earlier covered by deciduous woodland had been transformed to cultivated fields, grasslands and heathlands. Increased Poaceae cover from 1,700 cal. BP probably reflects the expansion of mown meadows in addition to pastures. Conclusions: Capturing continuous changes of vegetation structure in space and time elucidates open areas along the western coast prior to the introduction of agriculture. Agriculture started earliest in the very south and spread rapidly along the whole coast prior to the Late Neolithic. Differences within the study area have existed in all time periods, reflecting different land‐use practices adapted to different natural conditions. [ABSTRACT FROM AUTHOR]

The influences of wildfire through population dynamics and life history for two species of small mammals in a south-east Queensland heathland on Bribie Island are presented. Trapping results provided information on breeding, immigration and movement of Melomys burtoni (Grassland melomys) and Rattus lutreolus (Swamp rat). We first investigated and optimized the design of trapping methodology for producing mark-recapture population estimates to compare two adjacent populations, one of which was subjected to an extensive wildfire during the two year study. We consider how well rodents survive wildfire and whether the immediate impacts of fire or altered habitat have the greatest impact on each species. We found the R. lutreolus population was far more influenced by the fire than the M. burtoni population both immediately after the fire and over 18 months of vegetation recovery. [ABSTRACT FROM AUTHOR]

Although plant-soil interactions are increasingly recognized as an important factor in ecosystem restoration, their effects on community assembly during de novo ecosystem establishment are largely unknown. In a heathland restoration trial after topsoil removal we introduced either only aboveground heathland species with fresh herbage or both above- and belowground heathland species with sods to facilitate community assembly. Sod inoculation increased resemblance of the microbial community to the reference system, with a higher fungal and lower bacterial proportion to the community structure. Also densities of bacteriophagous and phytophagous nematodes, Acari and Collembola increased after sod inoculation. The cover of heathland plant species increased by 49% after sod inoculation. The introduction of solely aboveground heathland species increased the cover of these species by only 13%, and did not affect soil community assembly. Additionally, the increase in cover of heathland species over time was inversely correlated to the cover of mesotrophic grassland species. Inverse correlations were also observed between changes in fungal and bacterial abundances. Simultaneous introduction of key species of both above- and below-ground communities had a critical effect on the establishment of both communities, providing a potential shortcut for successful restoration of target ecosystems on disturbed soils. [ABSTRACT FROM AUTHOR]

The threshold below which population declines impact the effectiveness of plant reproduction is essential for the identification of populations that can no longer spontaneously recover following habitat management or restoration, below the minimum viable population (MVP) size. We hypothesized that risk of reproductive limitation can be evaluated from combined analysis of pollen activity, ovule fertilization and germination in the context of population demographics and fragmentation. The marsh gentian (Gentiana pneumonanthe), a rare emblematic species of European heathland and fen, was investigated at the southern limit of its range in eighteen populations encompassing one to several hundred thousand individuals, spanning small fragments to extensive well-preserved areas. An index of habitat fragmentation was determined from GIS; field surveys determined the ratio of juvenile to reproductive age states; fluorescence microscopy of pistils determined, for each population, the proportion of flowers exhibiting active pollen tube growth. Analysis of seed lots determined the ovule fertilization rate and seed germination capacity. Some of the small populations occupying restricted habitat fragments showed high rates of pollination (100%) and ‘normal’ age state demographics. However, reproductive characters all exhibited exponential rise to maximum relationships with population size, indicating clear tipping points (for pollination, at a threshold of 7 reproductive adults, and for ovule fertilization rate and germination at 42 reproductive adults). Thus although small populations may set seed, exhibit a ‘normal’ age state structure, and may appear viable, reproductive effectiveness declines when population size falls below 42 generative individuals and < 7 is an indicator of strong limitation. Although many remnant populations of G. pneumonanthe are in the order of 50–150 individuals these should be not be considered as MVPs; they are on the brink of calamity. [ABSTRACT FROM AUTHOR]

It is well known that soils are influenced by the plant species that grow in them. Here we consider the effects of management-induced changes to plant communities and their soils during restoration within a 20-year manipulative experiment where the aim was to change a late-successional community dominated by the weed, Pteridium aquilinum , to an earlier-successional grass-heath one. The ecological restoration treatments altered the above- and below-ground components of the community substantially. Untreated plots maintained a dense Pteridium cover with little understory vegetation, cutting treatments produce significant reductions of Pteridium , whereas herbicide (asulam) produced significant immediate reductions in Pteridium but regressed towards the untreated plots within 10 years. Thereafter, all asulam-treated plots were re-treated in year 11, and then were spot-sprayed annually. Both cutting and asulam treatments reduced frond density to almost zero and resulted in a grass-heath vegetation. There was also a massive change in biomass distribution, untreated plots had a large above-ground biomass/necromass that was much reduced where Pteridium was controlled. Below-ground in treated plots, there was a replacement of the substantive Pteridium rhizome mass with a much greater root mass of other species. The combined effects of Pteridium -control and restoration treatment, reduced soil total C and N as and available P concentrations, but increased soil pH and available N. Soil biological activity was also affected with a reduction in soil N mineralization rate, but an increased soil-root respiration. Multivariate analysis showed a clear trend along a pH/organic matter gradient, with movement along it correlated to management intensity from the untreated plots with low pH/high organic matter and treated plots with to a higher pH/lower organic matter in the sequence asulam treatment, cut once per year to cut twice per year. The role that these changed soil conditions might have in restricting Pteridium recovery are discussed. [ABSTRACT FROM AUTHOR]

Background: Heathlands are relatively abundant in the landscape of the western Mediterranean region, especially in the Strait of Gibraltar region, where it is locally known as herriza. They are associated with a mild Mediterranean climate regime and with acid, nutrient-poor soils. They harbour a high plant diversity, often viewed as a consequence of the transition between European Atlantic heathland and Mediterranean sclerophyllous shrubland floras. Aims: To determine whether species-rich Mediterranean heathlands, including the herriza, constitute distinct heathland formations rather than transitional vegetation units between Atlantic heathlands and Mediterranean garrigue shrublands. Methods: We quantified species richness, endemism and analysed the β-diversity of the woody component of Mediterranean heathland communities throughout its geographic range, with special emphasis on the Strait of Gibraltar region. Results: Mediterranean heathlands, including the herriza, are not transitional communities between Atlantic heathlands and Mediterranean shrublands. Woody species richness and, particularly, endemic richness was the highest in the herriza. Conclusions: The high biodiversity values of the herriza are a likely consequence of the ecological singularity of the Strait of Gibraltar region and its known role as a glacial refugium. Despite its treeless feature, the herriza deserves special recognition and protection from both in its European and North African extension. [ABSTRACT FROM AUTHOR]

Accumulating evidence shows that landscape fragmentation drives the observed worldwide decline in populations of pollinators, particularly in species of Lepidoptera and Hymenoptera. However, Little is known about the effects of landscape fragmentation on hoverfly (Diptera, Syrphidae) communities. Hoverflies provide varied ecosystem services: larvae contribute to waste decomposition (saprophagous species) and pest control (aphidophagous species), and adults pollinate a wide range of flowers., To determine how the diversity and quantity of resources for larvae and adults affect hoverfly abundance and species richness at three spatial scales, we recorded insect visitors of five target plant species in Belgian heathlands, habitats that have decreased considerably due to human activities., Hoverflies represented the most abundant visitors on two plant species, and the second most abundant visitors (after bumblebees) on the other target plant species. A large proportion of hoverflies observed were aphidophagous species associated with coniferous and deciduous forests. Resources for the larvae and floral resources for the adults influenced interactions among hoverflies and plants, but acted at different scales: larval habitat availability (distance to larval habitat) was relevant at the landscape scale, whereas adult resource availability (floral density) was relevant at the plot scale., Hoverfly abundance and species richness decreased with distance to larval habitat but increased with floral density. Moreover, landscape structure and composition had different effects according to hoverfly ecological traits. Landscape composition influenced aphidophagous but not saprophagous hoverflies, in that their abundance and species richness decreased with distance to forests. Maintenance of the interactions between plants and their hoverfly visitors requires complementary resources at both landscape and local scales. [ABSTRACT FROM AUTHOR]

Allochthonous resource movement across ecosystem boundaries creates episodic linkages between ecosystems. The sensitivity of the community to external resources of varying duration can alter the baseline upon which future pulses of allochthony can act. We explored the terrestrial ecosystem response to pulsed inputs of lake-derived resources with a manipulative experiment in a subarctic heathland where we assessed plant community and nutrient availability responses to additions of midge carcasses (Diptera: Chironomidae). Insect carcasses were added as either a one-time pulse or a 4-yr press to simulate differing durations of allochthony, which is common in the area. We found that midge pulses significantly elevated soil inorganic [N] in the first year (7× over background levels) but were significantly diminished (1.5×) by the second year after the initial pulse. The press treatment continued to elevate total soil inorganic [N] to 13× over background levels by the fourth year of midge additions, but then declined to 3.6× background in year 5 when experimental midge additions had ceased. In contrast to the soil inorganic N response, plant biomass was similar in pulse-addition and control plots over the course of the experiment. However, by the second year of the study plant biomass in press-addition plots were significantly higher than controls (>50%), and continued to increase over the 4 yr of the press treatment. Midge addition stimulated dominance of graminoids and thatch litter in plots that had previously been primarily heathland vegetation, a response that persisted 4 yr post-midge addition. Our findings suggest that soil and plant community responses to persistent insect carcass deposition (e.g., press) into heathland vegetation has the potential to carry forward in a way that modifies the baseline ecosystem conditions upon which additional allochthony may act. [ABSTRACT FROM AUTHOR]

Chalk mining industry in Western Pomerania reflects a history of almost 300 years, and has left behind a typical post-mining landscape. Thus, more than 50 formerly exploited areas are known on the islands of Rügen and Wolin. Historical quarry sizes range from 0.1 to 42 hectares, the median is 1.3. Chalk quarries are recolonised by a wide range of species and develop attractive and species-rich communities. To the extent that recolonisation progresses, they act as refugia for rare or local species. Currently, a total of 543 vascular plant species are found in these chalk quarries. Species number ranges from 97 to 218 in thoroughly studied sites, with a median of 138. Of the total floristic inventory, 67% are indigenous species, 18% are archaeophytes and 12% neophytes. Quarries abandoned long ago and remotely situated are home to nearly 90% indigenophytes, whereas those quarries close to settlements or with easy access are tendentially characterised by numerous synanthropic plants. 100 species overall (= 18.4%) belong to Red List categories of Mecklenburg-Western Pomerania. In 22 quarries studied in more detail, Red List percentages show a spectrum from 3.7 to 23.5%, and higher values are found in sites with open habitats and considerable biotope diversity. Among vegetation types, the anthropo-zoogenic heathland and grassland harbours 40% Red List species and occupies the first place concerning nature conservation aspects. A noteworthy percentage of endangered plants is found in fresh-water and bog vegetation, as some quarries are in contact with the aquifer. Succession was and is the impetus for vegetation development. A transect exemplarily demonstrates the vegetation zonation within a chalk quarry and distinguishes headslope, backslope, and footslope and the quarry floor. The respective plant communities are classified into Cornus sanguinea bush stage, Picris hieracioides-Daucus carota community, and basiphilous mesoxerophytic grassland. [ABSTRACT FROM AUTHOR]

Scale-dependency of pattern and process is well-understood for many ecological communities; however, the influence of spatial scale (sampling grain) in detecting temporal change in communities is less well-understood. The temperate lowland heathlands of south-east Australia are one of the most fire-prone ecosystems on earth. Despite the extensive literature documenting the effect of time since fire on heathlands, we know little about how sampling grain influences trends in vegetation variables over time, and whether these trends are scale-dependent. Using 3500 ha of heathland in the Gippsland Lakes Coastal Park, south-east Australia, we investigated how above-ground species composition and diversity, and trends in these variables with increasing time since fire, were influenced by sampling grain (1 m2, 10 m2, 100 m2, 900 m2, 1 ha, 4 ha). Sampling grain influenced patterns detected in vegetation variables and in some instances, significantly affected their relationship with time since fire. Richness decreased with time since fire, with mean richness decreasing at three of the four grains, while total richness decreased at half of the sampled grains. Evenness ( J) decreased with increasing time since fire for all grains except 1 m2. The decline in diversity ( H) with time since fire appeared to be independent of scale, as all grains decreased significantly with increasing time since fire. Community heterogeneity demonstrated a weak response to time since fire across most grains. Changes in composition among young (0-6 years since fire), intermediate (9-19 years) and old (23-27 years) sites were dependent on sampling grain, with all grains exhibiting significant differences in composition, apart from the 1 m2 grain and the 100 m2 grain (presence/absence data). Overall, species composition, richness, evenness, diversity and community heterogeneity were dependent on the scale at which the vegetation was sampled. In addition, trends in many of these vegetation variables with increasing time since fire were scale-dependent. This work provides strong evidence that sampling at multiple grains contributes substantially to understanding pattern and process in heathlands. [ABSTRACT FROM AUTHOR]

The large increases in reactive nitrogen (N) deposition in developed countries since the Industrial Revolution have had a marked impact on ecosystem functioning, including declining species richness, shifts in species composition, and increased N leaching. A potential mitigation of these harmful effects is the action of N as a fertiliser, which, through increasing primary productivity (and subsequently, organic matter production), has the potential to increase ecosystem carbon (C) storage. Here we report the response of an upland heath to 10 years of experimental N addition. We find large increases in plant and soil C and N pools, with N-driven C sequestration rates in the range of 13–138 kg C kg − 1 . These rates are higher than those previously found in forest and lowland heath, mainly due to higher C sequestration in the litter layer. C sequestration is highest at lower N treatments (10, 20, and 40 kg N ha − 1 yr − 1 above ambient), with evidence of saturation at the highest N treatment, reflecting a physiologically aged Calluna vulgaris ( Calluna ) canopy. To maintain these rates of sequestration, the Calluna canopy should be managed to maximise it's time in the building phase. Scaling our results across UK heathlands, this equates to an additional 0.77 Mt CO2e per annum extra C sequestered into plant litter and the top 15 cm of heathland soil as a result of N deposition. The bulk of this is found in the litter and organic soil horizons that hold an average of 23% and 54% of soil C, respectively. This additional C represents around 0.44% of UK annual anthropogenic GHG emissions. When considered in the context of falling biodiversity and altered species composition in heathland, policy focus should remain on reducing N emissions. [ABSTRACT FROM AUTHOR]

Increased atmospheric deposition rates of nitrogen (N) and sulphur (S) are known to affect soil biogeochemistry and cause a decline in plant biodiversity of heathlands. Concomitant declines of heathland invertebrates are mainly attributed to changes in vegetation composition and altered habitat structure. While there may also be effects on animals through altered plant chemistry, these have received little attention up to now. Here, we remedy this by quantifying soil nutrient and acid buffering status, vegetation composition and structure, plant nutrient stoichiometry, and densities and species richness of Diptera and Carabidae in two large heathland systems. Soil acid buffering status appeared to be a key driver for plant P availability. Sod-cutting was found to further increase plant N:P ratios, suggesting increased P-limitation. Vegetation N:P ratio was negatively linked to invertebrate density and species richness, and was found to impact fauna more strongly than vegetation structure and plant species richness. The relationship between invertebrates and plant C:N ratio was weaker and less consistent, suggesting that for invertebrates, plant P is generally more limiting than N. Our results imply that the role of plant stoichiometry is underestimated in explaining declines of heathland invertebrates, and we here provide a novel mechanistic model including this pathway. Management should therefore not only focus on restoring habitat structural complexity, attention should be paid to restoring plant stoichiometry. This can be achieved through restoring biogeochemical soil conditions, especially by mitigating soil acidification, while measures solely focusing on removal of accumulated N by means of sod-cutting should be avoided. [ABSTRACT FROM AUTHOR]

Oligotrophic semi-natural systems are threatened by high levels of nitrogen deposition. To mitigate these effects, drastic techniques such as sod-cutting and topsoil removal are applied to reduce nitrogen loads in existing systems and expand their area on former agricultural fields. We assessed the effects of these techniques along with the influence of previous land-use, isolation and vegetation development on subsequent microbial community assembly in restored agricultural areas. Microbial community phenotypic structure was measured using PLFA-analysis, along with soil chemistry and vegetation development. Differences in soil nitrogen pools due to restoration techniques were the most differentiating factor for both microbial community assembly and vegetation development. Only after topsoil removal was resemblance of both below- and above-ground communities to well-developed heathlands increased within 10–15 years. After sod-cutting both microbial community and vegetation composition remained more similar to agricultural sites. The relative contribution of agricultural sites and heathlands in the direct vicinity had more pronounced effects on local microbial community composition than current land-use in all study sites including agricultural areas and heathlands. Vegetation development was apparently of minor importance for microbial community assembly, since characteristic belowground assembly preceded that of aboveground development in both restoration contexts. [ABSTRACT FROM AUTHOR]

Questions Natural regeneration is central to plant conservation strategies. Worldwide, many Juniperus species are threatened due to their failure to regenerate. We focus on Juniperus communis in areas of NW Europe where it is declining and ask: what advice is available to land managers on natural regeneration methods, and when applied, how effective has this been? Methods We synthesize knowledge on the efficacy of management interventions and conditions associated with J. communis regeneration. In field trials, we test interventions where knowledge is lacking. We assess regeneration of J. communis, creation of regeneration microsites and germination of sown seed in response to the interventions. Results Although J. communis occurs in different habitats, there is consistency in site conditions important for regeneration (unshaded/open, short ground vegetation, disturbed/bare ground, low herbivore pressure). In calcareous grasslands, areas with regeneration are stony/bare or vegetation is short or sparse; in upland acid grasslands and dry heathlands regeneration locations are disturbed areas sometimes with a moss cover. Several interventions (grazing, scarification, turf stripping) can create regeneration conditions. The synthesis identified cattle grazing and ground scarification for further testing on upland acid grasslands. In the resulting field trials, regeneration was rare and recorded on only one cattle-grazed site. An exposed moss layer characterized regeneration microsites but there was insufficient evidence that either intervention increased regeneration microsite frequency. Few sown seeds germinated. Conclusions Different interventions or intensities of these appear to be required depending on habitat type. Broadly, on calcareous grassland intense scarification or soil stripping is needed, while on dry heathlands light scarification is suitable. On upland acid grassland, cattle grazing and ground scarification do not reliably result in regeneration. Creation of favourable mossy regeneration microsites is unlikely following intervention, unless soil fertility is low. Land-use change, increased climate warming and pollution are pressures acting on J. communis and may cause habitat loss and altered site conditions (e.g. soil fertility), making it difficult to create regeneration microsites at all J. communis sites. Other constraints on regeneration may operate (e.g. seed predation and low seed viability) and managers should assess population and site potential before undertaking management. [ABSTRACT FROM AUTHOR]

Throughout the last decades, Calluna vulgaris (L.) Hull heathlands have declined across Europe and nowadays their conservation is particularly challenging at the southern edge of their distribution. In the Nature Reserve of Vauda (north-western Italy), six restoration treatments were applied (extensive annual goat browsing, one-off mowing, annual mowing, one-off fire without and with annual browsing, and annual fire) and their effects on plant diversity and the cover of C. vulgaris , its competitor grass Molinia arundinacea Schrank, woody, and alien species were monitored between 2005 and 2011. In the short-term, most of the treatments changed the vegetation community, reducing C. vulgaris cover according to a gradient of increasing biomass removal. In the mid-term, C. vulgaris , M. arundinacea , woody and alien species cover followed different trajectories according to the treatment and functional group. Annual fire shifted the vegetation towards a M. arundinacea -dominated community, while extensive annual browsing did not affect the heathland community and resulted in the lowest increase in M. arundinacea , which showed a remarkable fitness in these environments. Moreover, annual burning and mowing were effective in reducing woody species encroachment ( p < 0.05), and fire treatments triggered a peak in alien species cover (mainly Panicum acuminatum Swartz) in the short-term. Six years after treatment, species richness and Shannon index did not differ between treated and control sites ( p > 0.05). In conclusion, these results highlight the need and potential benefit of integrating multiple techniques to preserve C. vulgaris heathlands at their southern edge. [ABSTRACT FROM AUTHOR]

Understanding the response of soil respiration to climate variability is critical to formulate realistic predictions of future carbon (C) fluxes under different climate change scenarios. There is growing evidence that the influence of long-term climate variability in C fluxes from terrestrial ecosystems is modulated by adjustments in the aboveground-belowground links. Here, we studied the inter-annual variability in soil respiration from a wet shrubland going through successional change in North Wales (UK) during 13 years. We hypothesised that the decline in plant productivity observed over a decade would result in a decrease in the apparent sensitivity of soil respiration to soil temperature, and that rainfall variability would explain a significant fraction of the inter-annual variability in plant productivity, and consequently, in soil respiration, due to excess-water constraining nutrient availability for plants. As hypothesised, there were parallel decreases between plant productivity and annual and summer CO emissions over the 13-year period. Soil temperatures did not follow a similar trend, which resulted in a decline in the apparent sensitivity of soil respiration to soil temperature (apparent Q values decreased from 9.4 to 2.8). Contrary to our second hypothesis, summer maximum air temperature rather than rainfall was the climate variable with the greatest influence on aboveground biomass and annual cumulative respiration. Since summer air temperature and rainfall were positively associated, the greatest annual respiration values were recorded during years of high rainfall. The results suggest that adjustments in plant productivity might have a critical role in determining the long-term-sensitivity of soil respiration to changing climate conditions. [ABSTRACT FROM AUTHOR]

Wild and prescribed fires can cause severe deterioration in water quality, including increases in sediment, nutrients and dissolved organic carbon (DOC). Due to the unpredictability of wildfires, few studies have been able to employ before-after, control-intervention experimental designs, or to evaluate fire-induced water-quality changes in the context of long-term datasets. Here, we present data from a lake draining a moorland catchment in the United Kingdom, part of a 22-site, 25 year monitoring network, which experienced a major wildfire in 2011. The main water-quality response was a large, sustained increase in nitrate concentrations, sufficient to raise acidity and aluminium concentrations, effectively reversing over a decade of recovery from the effects of acid deposition. Concurrently, we observed a clear reduction in DOC concentrations, contrasting with prescribed fire studies from similar ecosystems (none based on before-after studies) that have suggested that burning causes DOC to increase. However, data from a downstream water supply reservoir do suggest a fire-induced change in DOC quality towards more soil-derived aromatic organic compounds, and lake sediment data suggest a large increase in particulate organic carbon. We conclude that the biogeochemical responses to wildfire in our moorland catchment were broadly similar to those observed in forest ecosystems elsewhere, but that historically high nitrogen deposition has made the ecosystem particularly susceptible to nitrate leaching and (re-)acidification. The observed reduction in DOC concentrations casts some doubt on the widely held view that prescribed burning in moorland systems has contributed to long-term DOC increases. [ABSTRACT FROM AUTHOR]

We conducted a phytosociological analysis of more than 250 relevés in the Julian Alps and compared them with similar communities elsewhere in the Alps and in the Dinaric Alps to describe the following new syntaxa of alpine swards and heathlands from the alliance Caricion firmae (class Elyno-Seslerietea): Saxifrago squarrosae-Caricetum mucronatae, Saussureo pygmaeae-Caricetum rupestris, Seslerio sphaerocephalae-Dryadetum octopetalae, Homogyno discoloris-Vaccinietum gaultherioidis, Saxifrago paniculatae-Caricetum fuliginosae and Homogyno discoloris-Loiseleurietum caricetosum firmae, the new association Achilleo clavennae-Elynetum myosuroidis from the alliance Oxytropido-Elynion and two new syntaxa from the alliance Loiseleurio-Vaccinion (class Loiseleurio-Vaccinietea): Homogyno alpinae-Vaccinietum gaultherioidis and Empetro-Vaccinietum gaultherioidis rhododendretosum hirsuti. Many species that are rare, of conservation concern or protected in Slovenia occur in the newly described communities. [ABSTRACT FROM AUTHOR]

The statistical modelling of joint species abundance is currently receiving increasing attention in the ecological literature because it complements earlier descriptive accounts of the effect of disturbance on community change with quantitative measures of spatial covariation among species at different spatial scales. Using a hierarchical Bayesian approach, we fitted both temporal and spatial plant cover data to a joint distribution model of plant abundance of the dominant plants in wet heathlands ( Erica tetralix, Calluna vulgaris and Molinia caerulea) undergoing nitrogen deposition over several decades. The spatial analysis was based on pin-point cover data from 114 Danish sites with a total of 1509 randomly placed plots along a nitrogen deposition gradient. The temporal analysis was based on pin-point cover data from 22 sites with a total of 986 observations from plots that had been resampled at least three times since 2007. The spatial variation was partially explained by nitrogen deposition, as the cover of Erica decreased significantly with nitrogen deposition, whereas the cover of both Calluna and Molinia increased (albeit non-significantly) with nitrogen deposition. There was a strong and significant positive spatial covariation between Erica and Calluna. Oppositely, there was a strong and significant negative spatial covariation between Calluna and Molinia. The spatial covariation between Erica and Molinia was not significantly different from zero. There were no significant changes in the cover of any of the three species since 2007. However, by including data from 2004, the previously reported result of a significant decreasing cover of Erica was confirmed, and the cover of Calluna increased significantly. We conclude that the statistical modelling of joint species abundance is a potentially powerful tool to understand the effect of the alteration of nitrogen dynamics on community composition. This is essential to design management practices aligned with the predicted effects of varying levels of nitrogen deposition on community structure. The study also demonstrated the insight gained on the community dynamics by the use of hierarchical Bayesian models. [ABSTRACT FROM AUTHOR]

Characterization of the impacts of climate change on terrestrial carbon (C) cycling is important due to possible feedback mechanisms to atmospheric CO concentrations. We investigated soil organic matter (SOM) dynamics in the A1 and A2 horizons (~0-5.1 and ~5.1-12.3 cm depth, respectively) of a shrubland grass ( Deschampsia flexuosa) after 8 years of exposure to: elevated CO (CO), summer drought (D), warming (T) and all combinations hereof, with TDCO simulating environmental conditions for Denmark in 2075. The mean C residence time was highest in the heavy fraction ( HF), followed by the occluded light fraction and the free light fraction ( fLF), and it increased with soil depth, suggesting that C was stabilized on minerals at depth. A2 horizon SOM was susceptible to climate change whereas A1 horizon SOM was largely unaffected. The A2 horizon fLF and HF organic C stocks decreased by 43 and 23% in response to warming, respectively. Organic nitrogen (N) stocks of the A2 horizon fLF and HF decreased by 50 and 17%, respectively. Drought decreased the A2 horizon fLF N stock by 38%. Elevated CO decreased the A2 horizon fLF C stock by 39% and the fLF N stock by 50%. Under TDCO, A2 horizon fLF C and N stocks decreased by 22 and 40%, respectively. Overall, our results indicate that shrubland SOM will be susceptible to increased turnover and associated net C and N losses in the future. [ABSTRACT FROM AUTHOR]

Can drivers of temporal vegetation changes and their interactions be modelled in dynamic ecosystems? Kepfer-Rojas et al., in this issue of Applied Vegetation Science, studied species richness and cover in an unmanaged heathland to address this topic. Complex interactions between drivers and their degree of spatial dependence condition the success of each functional group, in a scenario of permanent competition. [ABSTRACT FROM AUTHOR]

Bumblebees are the predominant wild pollinators for many plant species in temperate regions. A bumblebee colony requires pollen and nectar throughout its lifetime, but degraded and fragmented habitats may have gaps in the temporal and spatial continuity of floral resources., Heathlands are open biotopes that provide favourable habitat for bumblebees like Bombus jonellus, a declining species in Belgium. In heathlands, ericaceous species are the main plants that provide pollen and nectar for bumblebees. Although the nectar composition of ericaceous species has been previously studied, data on pollen composition remain scarce., We examined bumblebee diets (composition of their pollen loads) in Belgian heathlands over the course of a colony lifetime to assess the fidelity of bumblebees for ericaceous species. We compared nutritional values by investigating the chemical composition (amino acids, polypeptides and sterols) of the pollen of the ericaceous and dominant non-ericaceous species present in pollen loads. No relationship was detected between the abundance of a particular plant species in bumblebee loads and its pollen composition., The successive flowering periods and the nutritional quality of pollen of ericaceous species offer valuable resources for bumblebees. Ericaceous species represent a large part of bumblebee diets in heathlands, especially in early spring and late summer when the diversity of other flowering species was low., Bumblebee pollen loads also contained non-ericaceous flowering species that grow outside heathlands. Thus, land planning must incorporate conservation strategies for the different elements of the landscape matrix, including heathlands, peatlands, meadows and margins. [ABSTRACT FROM AUTHOR]