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Erica comprises ~860 species of evergreen shrubs and trees ranged from Europe to southern Africa and Madagascar. Wood structure of the around 20 European species is well studied, but despite its relevance to adaptation across the wider geographic range, it has not yet been explored across the much greater diversity, particularly of southern African lineages. In this study, we examine wood structure of 28 Erica species from southern Africa. In the African Erica clade, loss of scalariform perforation plates could be driven by increased aridity and seasonality in the mid-Miocene, and its re-gain can represent an adaptation to freezing in the high elevation species E. nubigena. As vessels in Erica are mostly solitary, imperforate tracheary elements probably form a subsidiary conduit network instead of vessel groups. Increase of ray frequency in habitats with a prominent dry and hot season probably facilitates refilling of vessels after embolism caused by water stress. Wider rays are ancestral for the lineage comprising African Erica and the Mediterranean E. australis. The negative correlation between ray width and expression of summer drought is consistent with Ojeda's model explaining the diversification of seeders and resprouters among southern African Erica. [ABSTRACT FROM AUTHOR]

Questions: During the winter of 2014, an intense drought combined with sub‐zero temperatures resulted in a massive Calluna dieback in Norwegian heathlands. We studied the initial vegetation recovery under two management approaches: natural recovery and prescribed burning. We hypothesized that natural recovery will be slower in more drought‐affected sites, whereas burning will facilitate post‐fire recovery in all sites by effectively removing dead and damaged heath. Both natural recovery and post‐fire succession will be slower in the north. Location: Calluna heath in seven sites spanning an approx. 600‐km latitudinal gradient along the coast of Norway (60.22–65.69° N). Methods: After a natural drought, 10 permanent plots per site were either burnt or left for natural recovery. Vegetation data were recorded annually in 2016 (pre‐fire) and 2017–2019 (post‐fire) reflecting a factorial repeated‐measures design (n = 280). The data were analyzed using mixed‐effects models. Results: Two years after the drought, we observed high but variable Calluna damage and mortality. Over the four years of study, damaged Calluna recovered, whereas dead Calluna showed little recovery. Both the extent of the damage and mortality, as well as the rate of natural recovery, are only weakly related to site climate or environmental factors. Fire efficiently removed dead and damaged Calluna and facilitated post‐fire successional dynamics and recovery in a majority of sites. Conclusions: Extreme winter drought resulted in substantial and often persistent damage and dieback on Calluna along the latitudinal gradient. In sites with high mortality, prescribed burning removed the dead biomass and, in some cases, facilitated vegetation recovery. Traditional heathland management, which uses burning to facilitate all‐year grazing by Old Norse sheep in Atlantic coastal heathlands, can be an efficient tool to mitigate dieback events and more generally to increase resistance to and resilience after extreme drought events in the future. [ABSTRACT FROM AUTHOR]

IntroductionBiological life, atmospheric circulation and the Earth’s climate may be influenced by UV-B radiation. In plants, Ultraviolet Absorbing Compounds (UACs) are an indicator of UV-B exposure, and the abundance of UACs in pollen and spores of embryophytes is measurable using Fourier Transform Infrared (FTIR) micro-Spectroscopy. However, understanding the influence of common chemical pre-treatments on sub-fossil pollen and spores with a view to UV-B reconstruction still requires investigation.MethodsHere, peat samples collected from a Late Holocene raised bog were treated with different chemicals (HCl, KOH, and acetolysis) for varying treatment times (up to 210 min). Pollen or spores of three common taxa (Alnus, Calluna and Sphagnum) were isolated and FTIR spectra obtained on individual grains. The spectra were compared to modern pollen and spore samples collected nearby.ResultsSpectra of modern and sub-fossil samples show several visible differences related to lipid and protoplast contents. The results of chemical treatments on sub-fossil pollen and spores reveal that HCl produced limited changes, while KOH and acetolysis altered several peaks, including the UAC-related aromatic peak at 1516 cm−1. We observe that all treatments modify the FTIR spectra to some degree, from weakest (HCl) to strongest (acetolysis). With respect to reduction of UAC peak area and treatment time, we observe in some cases a significant log-decay relationship, notably for KOH treatment on Calluna pollen and acetolysis on Sphagnum spores. Compared to untreated control samples, UAC peak area in Alnus, Calluna and Sphagnum reduced by 68%, 69% and 60% respectively, after only 3 min of acetolysis treatment. After 60 minutes of acetolysis treatment UAC peaks were reduced by 77%, 84% and 88%.DiscussionDue to the potential for taxon-specific effects and significant reductions in UAC peak area even within short treatment times, our recommendation for future applications in palaeoecological studies on palynomorph chemistry is to avoid chemical digestions in the pollen extraction process in favour of separation methods including micro-sieving and density separation.

Heathers have been cultivated for several centuries, both the hardy heaths (Calluna, Daboecia and Erica) from the northern hemisphere and the more frost-tender species of Erica from southern Africa known as Cape heaths. In the late 19th century, a number of heather gardens were created, especially in Britain, and the popularity of heathers as long-lasting garden plants reached its zenith in western Europe and temperate North America in the late 20th century. At about the same time, deliberate breeding and selecting of Calluna vulgaris (ling) for flowers that lack normal sexual parts and remain bud-like led to a revolution in heather production with tens of millions of these bud-bloomer Calluna propagated each year for an ephemeral trade dominated by throwaway plants. Concomitantly, the diversity of hardy heathers offered by the trade has declined sharply with a small number of artificially raised clones, protected by plant breeders’ rights, now dominating the market. In contrast, the discovery of living lineages of a few Erica species that are extinct in the wild in South Africa has led to successful reintroduction programmes, particularly of Erica verticillata. The Erica Conservation Consortium, inaugurated in 2020, aims to coordinate and prioritise ex situ conservation of endangered Cape heaths.

The increasing frequency and severity of UK wildfires, attributed in part to the effects of climate change, highlights the critical role of fuel moisture content (FMC) of live and dead vegetation in shaping wildfire behaviour. However, current models used to assess wildfire danger do not perform well in shrub-type fuels such as Calluna vulgaris, requiring in part an improved understanding of fuel moisture dynamics on diurnal and seasonal scales. To this end, 554 samples of upper live Calluna canopy, live Calluna stems, upper dead Calluna canopy, dead Calluna stems, moss, litter and organic layer (top 5 cm of organic material above mineral soil) were sampled hourly between 10:00 and 18:00 on seven days from March-August. Using a novel statistical method for investigating diurnal patterns, we found distinctive diurnal and seasonal trends in FMC for all fuel layers. Notably, significant diurnal patterns were evident in dead Calluna across nearly all sampled months, while diurnal trends in live Calluna canopy were pronounced in March, June, and August, coinciding with the peak occurrence of UK wildfires. In addition, the moisture content of moss and litter was found to fluctuate above and below their relative ignition thresholds throughout the day on some sampling days. These findings underscore the impact of diurnal FMC variations on wildfire danger during early spring and late summer in Calluna dominated peatlands and the need to consider such fluctuations in management and fire suppression strategies., (© 2024. The Author(s).)

Gastrointestinal nematode (GIN) infections impact small ruminant health, welfare, and production across farming systems. Rising anthelmintic resistance and regulation of synthetic drug use in organic farming is driving research and development of sustainable alternatives for GIN control. One alternative is the feeding of plants that contain secondary metabolites (PSMs) e.g., proanthocyanidins (PA, syn. condensed tannins) that have shown anthelmintic potential. However, PSMs can potentially impair performance, arising from reduced palatability and thus intake, digestibility or even toxicity effects. In this study, we tested the trade-off between the antiparasitic and anti-nutritional effects of heather consumption by lambs. The impact of additional feeding of a nematophagous fungus (Duddingtonia flagrans) on larval development was also explored. Lambs infected with Teladorsagia circumcincta or uninfected controls, were offered ad libitum heather, or a control chopped hay for 22 days during the infection patent period. Eight days into the patent period, parasitised lambs were supplemented (or remained unsupplemented) with D. flagrans for a 5-day period. Performance and infection metrics were recorded, and polyphenol levels in the heather and control hay were measured to investigate their association with activity. The lambs consumed heather at approximately 20% of their dry matter intake, which was sufficient to exhibit significant anthelmintic effects via a reduction in total egg output (P = 0.007), compared to hay-fed lambs; the magnitude of the reduction over time in heather fed lambs was almost 10-fold compared to control lambs. Negative effects on production were shown, as heather-fed lambs weighed 6% less than hay-fed lambs (P < 0.001), even though dry matter intake (DMI) of heather increased over time. D. flagrans supplementation lowered larval recovery in the faeces of infected lambs by 31.8% (P = 0.003), although no interactions between feeding heather and D. flagrans were observed (P = 0.337). There was no significant correlation between PA, or other polyphenol subgroups in the diet and egg output, which suggests that any association between heather feeding and anthelmintic effect is not simply and directly attributable to the measured polyphenols. The level of heather intake in this study showed no antagonistic effects on D. flagrans, demonstrating the methods can be used in combination, but provide no additive effect on overall anthelmintic efficacies. In conclusion, heather feeding can assist to reduce egg outputs in infected sheep, but at 20% of DMI negative effects on lamb performance can be expected which may outweigh any antiparasitic benefits., Competing Interests: Conflict of interest statement None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Abstract: 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. [ABSTRACT FROM AUTHOR]

Ecosystems adapted to low nitrogen (N) conditions such as Calluna -heathlands are especially sensitive to enhanced atmospheric N deposition that affects many aspects of ecosystem functioning like nutrient cycling, soil properties and plant-microbial-enzyme relationships. We investigated the effects of five levels of experimentally-simulated N deposition rates (i.e., N fertilization treatments: 0, 10, 20 and 50 kg N ha − 1 yr − 1 for 3 years, and 56 kg N ha − 1 yr − 1 for 10 years) on: plant, litter, microbial biomass and soil nutrient contents, soil extracellular enzymatic activities, and plant root ericoid mycorrhizal colonization. The study was conducted in marginal montane Calluna -heathlands at different developmental stages resulting from management (young/building-phase and mature-phase). Our findings revealed that many soil properties did not show a statistically significant response to the experimental addition of N, including: total N, organic carbon (C), C:N ratio, extractable N-NO 3 − , available phosphorus (P), urease and β-glucosidase enzyme activities, and microbial biomass C and N. Our results also evidenced a considerable positive impact of chronic (10-year) high-N loading on soil extractable N-NH 4 + , acid phosphatase enzyme activity, Calluna root mycorrhizal colonization by ericoid fungi, Calluna shoot N and P contents, and litter N content and N:P ratio. The age of heathland vegetation influenced the effects of N addition on ericoid mycorrhizal colonization, resulting in higher colonized roots in young heathlands at the control, low and medium N-input rates; and in mature ones at the high and chronically high N rates. Also, young heathlands exhibited greater soil extractable N-NO 3 − , available P, microbial biomass N, Calluna shoot N and P contents, and litter N content, compared to mature ones. Our results highlighted that accounting for the N-input load and duration, as well as the developmental stage of the vegetation, is important for assessing the effects of added N, particularly at the heathlands' southern distribution limit. [ABSTRACT FROM AUTHOR]

Managed boreal pine forests are subject to regular clear cuts causing significant disturbances to these ecosystems. It is believed that, to some extent, they resemble natural cycles of forest growth, decline, and regeneration and can benefit, e.g., mutualistic relations among plants and pollinators. To study the impact of forest management (clear cuts) on pollinator visitation, we focused on three ericaceous plant species, Vaccinium myrtillus, V. vitis-idaea, and Calluna vulgaris, common elements of pine forest understory. Our observations, conducted in Lithuania, showed that there are no differences among control mature stands and clear cut areas in terms of visitation frequency for all three studied species. However, at least for C. vulgaris, a shift toward fly visits was observed in the clear cut site, showing that open areas are preferred habitats for these insects. Ants constituted an important share of visitors to flowers of V. myrtillus and C. vulgaris, suggesting their important role in reproduction of these plant species.

Although the effects of host plant quality on the performance of polyphagous herbivores are largely uniform across insect taxa, there are various exceptions to this rule. In particular, there are scattered reports of cases in which the relative quality of different hosts differs among larval instars of a single insect species. Such cases are explained either in terms of differences in the susceptibility of different aged larvae to plant defences or, alternatively, age-specific nutritional demands. Here we report the results of experiments that show that young larvae of the polyphagous common heath moth Ematurga atomaria (Lepidoptera: Geometridae) consistently attain higher weights on common heather Calluna vulgaris than bilberry Vaccinium myrtillus, whereas the rank order of these host plants is reversed in the final larval instar. Phytochemical analyses showed that differences in nutrient content of these plants are not likely to explain the observed pattern. Instead, the results are more consistent with the idea that the greater chemical defence of bilberry has a relatively stronger influence on young than old larvae.

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]

Premise of the research. Maiella miocaenica gen. et sp. nov. is described based on middle Miocene carbonaceous, three-dimensionally preserved remains. Morphological features of these remains reveal strong taxonomic affinities with the extant members of the tribe Ericeae, mainly with the monotypic genus Calluna. Methodology. Well-preserved fossil remains of flowers, fruits, and seeds collected at Lubstów and Tomisławice brown coal open-pit mines in Poland were studied using stereomicroscopy and scanning electron microscopy and compared to extant taxa of the tribe Ericeae. Pivotal results. The study documents the oldest-known Ericeae remains in the fossil record. Maiella has strong affinities to extant Calluna such as the thin and expanded calyx, similar to the corolla, a septifragal capsule, and many-bracted flowers. However, the morphology and microsculpture of the seeds are remarkably different in Maiella when compared to Calluna. Conclusions. Based on these morphological comparisons, we conclude that the studied remains pertain to a different genus and species related to Calluna and Erica. The presence of Maiella in the middle Miocene of Central Europe is in accordance with the previously published hypothesis of a European origin of the Ericeae and provides insights into the environmental conditions of the area during that period. [ABSTRACT FROM AUTHOR]

Managed boreal pine forests are subject to regular clear cuts causing significant disturbances to these ecosystems. It is believed that, to some extent, they resemble natural cycles of forest growth, decline, and regeneration and can benefit, e.g., mutualistic relations among plants and pollinators. To study the impact of forest management (clear cuts) on pollinator visitation, we focused on three ericaceous plant species, Vaccinium myrtillus, V. vitis-idaea, and Calluna vulgaris, common elements of pine forest understory. Our observations, conducted in Lithuania, showed that there are no differences among control mature stands and clear cut areas in terms of visitation frequency for all three studied species. However, at least for C. vulgaris, a shift toward fly visits was observed in the clear cut site, showing that open areas are preferred habitats for these insects. Ants constituted an important share of visitors to flowers of V. myrtillus and C. vulgaris, suggesting their important role in reproduction of these plant species. [ABSTRACT FROM AUTHOR]

Anthropogenic disturbance often drives habitat loss, ecological fragmentation and a decrease in biodiversity. This is especially problematic in islands, which are bounded and isolated systems. In the Azores, human settlement led to a significant contraction of the archipelago's original native forested areas, which nowadays occupy only small patches and are additionally threatened by the spread of invasive species. Focusing on Terceira Island, this study aimed to assess the composition of vascular plant communities, and the abundance and distribution patterns of vascular plant species in permanent 100 m² plots set up in the best preserved vegetation patches along an elevational gradient (from 40 to 1000 m a.s.l.). Sampling yielded a total of 50 species, of which 41 are indigenous and nine are exotic. The richest and best preserved communities were found between 600 m and 1000 m, corresponding to Juniperus- Ilex montane forest and Calluna-Juniperus altimontane scrubland formations. Nonetheless, exotic species were prevalent between 200 m and 400 m, with Pittosporum undulatum clearly dominating the canopy. These results support the high ecological and conservation value of the vegetation formations found in the island's upper half, while calling attention to the biological invasions and homogenization processes occurring at its lower half. Long-term monitoring in these plots will further reveal direction and rates of change in community composition, allowing for more informed management and conservation strategies in the island. [ABSTRACT FROM AUTHOR]

A species' habitat niche width informs its position on the generalist-specialist continuum, which is central to life-history theory and crucial to conservation planning. However, assessments of niche width are often based on local-scale studies or qualitative descriptions rather than broad, quantitative assessments conducted in heterogeneous landscapes. Here, we show how broad-scale, hierarchical occupancy models can clarify a species' niche width and degree of habitat specialism by evaluating the woodland-specialist classification of the European pine marten Martes martes. We deployed 526 camera-trap stations at 27 sites throughout a vast extent (~50 000 km2) in Scotland and modeled pine marten occupancy as a function of habitat characteristics using a hierarchical Bayesian analysis. Our model was flexible to trap happiness due to baiting at camera traps and accounted for spatial autocorrelation among and imperfect detection at camera-trap stations. We detected a positive association between pine marten occupancy probability and wooded habitats. However, pine marten occupancy probability was also high in numerous non-wooded habitats, including agricultural land, heather and heather grassland, semi-natural grassland and areas near anthropogenic structures. Our study is the first to record high pine marten occupancy in open habitats at broad spatial scales and thereby corroborates recent smaller scale indications that pine martens are more of a habitat generalist than previously thought. Our results guide ongoing conservation efforts by identifying that pine martens are not strict woodland specialists, but rather inhabit a mosaic of habitat types in the landscape. More broadly, our case study exemplifies how coupling hierarchical occupancy models with large-scale experimental designs can clarify a species' niche width and associated position on the generalist-specialist continuum. [ABSTRACT FROM AUTHOR]