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Global warming significantly affects the frequency and intensity of wildfires in many fire-prone areas of the world and fire disturbance regimes are changing rapidly. Alongside this, controlled burning is often considered or implemented as an alternative method for nature protection. Here, we studied the post-fire secondary succession in dry heath habitat located in military training grounds to recognise the impact of fire on the effectiveness and rate of ecosystem recovery. We focus particularly on identifying indicator species for a given successional phase of Central European dry heath habitats and assessing their value for dating the last fire disturbance. The research involved 60 vegetation patches (plots of 25 m2), which were assigned to four post-fire age classes, namely: 1–5 years (Class A), 6–10 years (Class B), 11–15 years (Class C), and >15 years (Class D). In each study plot, species diversity and coverage of lichens, bryophytes and vascular plants were examined in addition to the physicochemical properties of the soil substrate. Cryptogams and vascular plants clearly differ in terms of the secondary succession pattern; specific sets of cryptogams correspond well to particular post-fire classes and are therefore good determinants of the post-fire succession stage. Spontaneous succession of plant vegetation eventually leads to complete recovery of the heath in a relatively short time. Nevertheless, great vegetation dynamics in the first years after a fire disturbance may result in seemingly different directions of succession. Post-fire classes did not differ noticeably in terms of soil properties, it follows that the effects of fire on soil conditions are negligible; though, a significant upward trend was observed for exchangeable form of K throughout the succession process. Our results indicate that sporadic fires reduce the undesirable overgrowth of heathlands or psamophilous grasslands and generally have a little negative side-effect on the ecosystem. The revealed succession patterns and defined sets of species characteristic for subsequent post-fire age classes are applicable to dating fire disturbances, regardless of whether the fire was planned or spontaneous. [Display omitted] • Structure of heath vegetation and period since fire disturbance are interrelated. • Post-fire succession of cryptogams and vascular plants follows a different pattern. • Contribution of specific sets of cryptogams determines post-fire succession stage. • Exchangeable K content shows upward trend in subsequent post-fire succession stages. • Extensively used military training areas outlines heath response on fire disturbance. [ABSTRACT FROM AUTHOR]

Eutrophication through atmospheric nutrient deposition is threatening the biodiversity of semi-natural habitats characterized by low nutrient availability. Accordingly, local management measures aiming at open habitat conservation need to maintain habitat-specific nutrient conditions despite atmospheric inputs. Grazing by wild herbivores, such as red deer (Cervus elaphus), has been proposed as an alternative to mechanical or livestock-based measures for preserving open habitats. The role of red deer for nutrient dynamics in protected open habitat types, however, is yet unclear. Therefore, we collected data on vegetation productivity, forage removal, quantity of red deer dung and nutrient concentrations in vegetation and dung from permanent plots in heathlands and grasslands (eight plots à 225 m2 per habitat type) on a military training area inhabited by a large population of free-ranging red deer over one year. The annual nutrient export of nitrogen (N) and phosphorus (P) by red deer grazing was higher than the nutrient import through red deer excreta, resulting in an average net nutrient removal of 14 and 30 kg N ha−1 a−1 and 1.1 and 3.3 kg P ha−1 a−1 in heathlands and grasslands, respectively. Even when considering approximate local atmospheric deposition values, net nutrient depletion due to red deer grazing seemed very likely, notably in grasslands. Demonstrating that grazing by wild red deer can mitigate the effects of atmospheric nutrient deposition in semi-natural open habitats similarly to extensive livestock grazing, our results support the idea that red deer are suitable grazing animals for open habitat conservation. [ABSTRACT FROM AUTHOR]

Background and aims: Heathlands are a broad vegetation type characterized by the dominance of evergreen shrub species that thrive on nutrient-poor soils, thus sensitive to small changes in soil conditions. Here we aimed to identify soil gradients related to climate, management and main species in wet heathlands. Methods: Soil nutrient levels, organic matter and acidity were studied at two soil depths on ninety plots from 18 sites in Erica mackayana wet heaths of NW Iberian Peninsula, in relation to presence and cover of structural plant species (shrubs and graminoids) at two scales: plot and site (landscape) scale. Results: We identified one main soil gradient explained by soil organic matter (SOM), the effective cation exchange complex (eCEC), available phosphorus (P), and Aluminium-Calcium ratio (Al:Ca). Cattle density had a positive correlation with the main gradient in the surface layer, all other climate and management factors were unrelated to soil conditions. Molinia caerulea had a positive relation with SOM, eCEC, basic cations and low Al:Ca ratio. Erica cinerea showed the opposite reaction at both scales. Ulex gallii showed a negative correlation with C:N ratio at the plot scale and deeper layer. Conclusion: SOM accumulation, low nutrient levels and Al toxicity explain the uniqueness of E. mackayana heathland vegetation and soils. Main indicator species react to soil conditions at plot and landscape scales. Cattle density correlated positively with soil nutrient levels, but density of wild ponies is unrelated to soil conditions. Large herbivores, especially ponies, are needed for conservation management of these heathlands. [ABSTRACT FROM AUTHOR]

Conservation priorities and decisions can be informed by understanding diversity patterns and the evolutionary history of ecosystems, and phylogenetic metrics can contribute to this. This project used a range of diversity metrics in concert to examine diversity patterns in the Sunshine Coast heathlands, an ecosystem under intense pressure. The species richness and composition of 80 heathland sites over nine regional ecosystems of heathland on the Sunshine Coast were enhanced with phylogenetic metrics, determined by barcoding 366 heath species of the region. The resulting data were added to an existing phylogeny of regional rainforest species. The diversity metrics for sites and regional ecosystems were compared using univariate and multivariate statistics. The phylogeny from this study, and the low phylogenetic diversity of the heathlands, is consistent with the theory that heath species evolved on the fringes on a wider Australian rainforest flora. Distinctive heathland communities were highlighted, and the existence of geographically scattered, but compositionally similar, phylogenetically even sites points to a possible "refugial environment", characterised by moisture and instability. This suggests contrasting conservation implications: the protection of distinctive communities but also the management of the dynamic processes in other wet and alluvial "refugial environments". The potential for more focused conservation priorities is enhanced. [ABSTRACT FROM AUTHOR]

The challenges facing I Banksia i species conservation in the south-eastern state of Victoria were the focus of an online workshop in May 2020. Banksias are iconic Australian plants, with a Gondwanan origin. [Extracted from the article]

Montane heathlands are among the most threatened semi‐natural ecosystems across Central Europe. Nevertheless, empirical studies on the effects of rejuvenation and restoration of montane heathlands have been scarce thus far.The aim of our study was to analyse the long‐term effects of heathland rejuvenation and restoration on carabid beetle assemblages. Our study took place in the Rothaar Mountains, one of the most important strongholds of montane heathlands in Central Europe. We considered four different successional stages: (i) early‐successional heathlands as a result of rejuvenation measures (EARLY), (ii) restored heathlands (RESTORED), (iii) late‐successional heathlands (LATE) and (iv) windthrows (WIND).Our study revealed that the composition of carabid beetle assemblages differed across the gradient. From the earlier to the later stages, beetle biomass, richness of macropterous, threatened and heathland species decreased, whereas moisture and shading indicator values increased. The number of indicator species peaked in EARLY and RESTORED. Solely brachypterous species had the highest species richness in the later seral stages.Overall, rejuvenation and restoration measures fostered specialised and threatened carabid beetle species of montane heathlands. In contrast, carabid beetle assemblages of the two later and dense successional stages consisted mainly of non‐threatened habitat generalists. Vegetation structure and the interrelated microclimate are assumed to be the key drivers of assemblage composition.For the long‐term conservation of montane heathlands and their specialised carabid beetle assemblages, we recommend rejuvenation by sod cutting and choppering in a mosaic‐like manner and at intervals that clearly exceed more than two decades. [ABSTRACT FROM AUTHOR]

Land-use, climate, and policy changes have impacted the fire regimes of many landscapes across northern Europe. Heathlands in oceanic climates are globally important ecosystems that have experienced an increase in the prevalence of destructive wildfire. Many of these landscapes are also managed using traditional prescribed burning that enhances their structural diversity and agricultural productivity. The changing role of wild and managed fire highlights a necessity to better understand the performance of fire behaviour prediction models for these ecosystems to support sustainable fire risk management. Our research evaluates the outputs of several empirical and quasi-empirical prediction models, as well as their varying software implementations, against observations of fire behaviour. The Rothermel model and its implementations predict rates of spread with similar accuracy to baseline empirical models and provide tolerable estimates of observed fire rate of spread. The generic shrubland empirical model developed by Anderson et al. consistently overpredicts observed rates of spread for prescribed burns in target fuel structures, but its predictions otherwise have a strong correlation with observed spread rate. A range of empirical models and software tools thus appear appropriate to assist managers who wish to evaluate potential fire behaviour and assess risk in heathland landscapes. [ABSTRACT FROM AUTHOR]

Bushfires are an intrinsic part of the New South Wales' (NSW) environment in Australia, especially in the Blue Mountains region (11400km2), that is dominated by fire prone vegetation that includes heathland. Many of the Australian native plants in this region are fire-prone and combustible, and many species even require fire to regenerate. The classification of the lateral and vertical distribution of living vegetation is necessary to manage the complexity of bushfires. Currently, interpretation of aerial and satellite images is the prevalent method for the classification of vegetation in NSW. The result does not represent important vegetation structural attributes, such as vegetation height, subcanopy height, and destiny. This paper presents an automated method for the three-dimensional modelling of heathland and important heathland parameters, such as heath shrub height and continuity, and sparse tree and mallee height and density in support of bushfire behaviour modelling. For this study airborne lidar point clouds with a density of 120 points per square meter are used. For the processing and modelling the study is divided into a point cloud processing phase and a voxel-based modelling phase. The point cloud processing phase consists of the normalisation of the height and extraction of the above ground vegetation, while the voxel phase consists of seeded region growing for segmentation, and K-means clustering for the classification of the vegetation into three different canopy layers: a) heath shrubs, b) sparse trees and mallee, c) tall trees. [ABSTRACT FROM AUTHOR]

ABSTRACT Nonmycorrhizal root-colonizing fungi are key determinants of plant growth, driving processes ranging from pathogenesis to stress alleviation. Evidence suggests that they might also facilitate host access to soil nutrients in a mycorrhiza-like manner, but the extent of their direct contribution to plant nutrition is unknown. To study how widespread such capacity is across root-colonizing fungi, we surveyed soils in nutrient-limiting habitats using plant baits to look for fungal community changes in response to nutrient conditions. We established a fungal culture collection and used Arabidopsis thaliana inoculation bioassays to assess the ability of fungi to facilitate host’s growth in the presence of organic nutrients unavailable to plants. Plant baits captured a representation of fungal communities extant in natural habitats and showed that nutrient limitation has little influence on community assembly. Arabidopsis thaliana inoculated with 31 phylogenetically diverse fungi exhibited a consistent fungus-driven growth promotion when supplied with organic nutrients compared to untreated plants. However, direct phosphorus measurement and RNA-seq data did not support enhanced nutrient uptake but rather that growth effects may result from changes in the plant’s immune response to colonization. The widespread and consistent host responses to fungal colonization suggest that distinct, locally adapted nonmycorrhizal fungi affect plant performance across habitats. IMPORTANCE Recent studies have shown that root-associated fungi that do not engage in classical mycorrhizal associations can facilitate the hosts’ access to nutrients in a mycorrhiza-like manner. However, the generality of this capacity remains to be tested. Root-associated fungi are frequently deemed major determinants of plant diversity and performance, but in the vast majority of cases their ecological roles in nature remain unknown. Assessing how these plant symbionts affect plant productivity, diversity, and fitness is important to understanding how plant communities function. Recent years have seen important advances in the understanding of the main drivers of the diversity and structure of plant microbiomes, but a major challenge is still linking community properties with function. This study contributes to the understanding of the cryptic function of root-associated fungi by testing their ability to participate in a specific process: nutrient acquisition by plants.

Global warming causes the replacement of lichens by shrubs in alpine and Arctic ecosystems. Since shrubs have lower albedo than lichens, this shrub encroachment can lead to a positive climatic feedback, resulting in higher temperatures in the surroundings. Therefore, gaining knowledge on the surface albedo of shrubs and lichens is important. Environmental factors also influence the surface albedo, but have often been neglected, potentially leading to biased results. In an experimental setup, we analyzed albedos of the lichen species Cladonia stellaris, Flavocetraria nivalis and Cetraria islandica, and how albedo changes with a stepwise replacement by the dwarf shrub Empetrum nigrum. Albedo was measured with radiometers in a paired set up. By setting certain environmental variables and species composition (monocultures) to be constant, we quantified the impact of environmental factors such as cloud cover, aspect and zenith angle on the surface albedo of two lichen species. Surface albedo (mean values ± SD) differed between C. islandica (0.155 ± 0.015), C. stellaris (0.364 ± 0.019), F. nivalis (0.350 ± 0.022) and E. nigrum (0.154 ± 0.016), and an increase in shrub cover at the expense of lichen cover led to a corresponding decrease in albedo. A 0.6 reduction in clearness index (more clouds) produced a 0.054 albedo decline. On the north‐facing aspect, albedo was 0.023 lower than on the south‐facing aspect. Albedo increased by 0.032 with an increase in zenith angle of 15°. Albedo variations caused by these studied environmental factors significantly affect the radiation budget of alpine and Arctic vegetation. We therefore stress the importance of considering environmental factors when surface albedos are estimated. Likewise, our species‐specific measurements can be a basis for further studies of the impact of climate change on alpine and Arctic vegetation and species‐related feedback mechanisms. [ABSTRACT FROM AUTHOR]

Root‐colonizing fungi form species‐rich assemblages with key functions in principal ecosystem processes, making them prospectively important players in conservation and applied ecology. Harnessing the processes and services they drive requires a better understanding of their patterns of diversity and community structure, and how these link to function. Here, we search for possible adaptations to contrasting environmental and host conditions, indicative of participation in habitat‐specific processes. We surveyed heathland and grassland habitats across a latitudinal gradient in Western Europe, using a spatially explicit design to assess community variation at scales from centimeters, to thousands of kilometers. Root‐associated fungi assemble into strongly site‐specific communities irrespective of habitat type, shaped by environmental factors and spatial distance operating at different scales, but also by a high level of endemism, likely to be determined by local stochastic processes such as drift and dispersal limitation at short distances. Despite the high site specificity in communities, they are dominated everywhere by a core set of lineages with little preferences toward habitat conditions or host phylogeny. Our results suggest a convergent evolution across phylogenetically distant lineages toward the root‐colonizing habit, and a functional redundancy in strategies for habitat colonization and host interaction. Further efforts are needed to integrate functional trait composition in future community ecology studies of root‐colonizing fungi. [ABSTRACT FROM AUTHOR]

The Habitats Directive is the cornerstone of EU nature conservation law charged with both the conservation and restoration of a wide degree of heathlands. However, heathlands in western-Europe are on a steady decline with grim prospects for the future, which can be contributed to the combined effect of nitrogen deposition and climate change. In turn, this article researches the capacity of the Habitats Directive to regulate aforementioned threats. It finds that the Directive is not sufficient with regard to the reintroduction of keystone species, connectivity restoration, climate change adaptation and/or mitigation measures - due to a lack of specific restoration norms. This article also assesses whether a Restoration Directive can serve as a supplementary means of achieving restoration in European heathlands. From an academic perspective, this article contributes to the debate on the functioning of the Habitats Directive and EU environmental law. From a societal perspective, there is a significant concern regarding excessive nitrogen deposition in combination with climate change in various EU countries. Whilst this problem should be studied from a multitude of disciplines, effective legal norms geared towards restoration play a distinctive role in solving this complex puzzle. [ABSTRACT FROM AUTHOR]

Anthropogenic airborne pollution has lowered soil pH for decades, while partial chemical recovery has been documented in recent years in northwest Europe; however, it remains uncertain how naturally acidic ecosystems, such as dry heaths, have responded. Here, we attempt to elucidate scale changes over decades in surface soil pH in dry heath ecosystems by encompassing 1336 historic measurements from 120 sites covering a time span from 1920 to 2015, an unmatched timespan. The data set had soil pH (1:1 soil–water) ranging from 3.06 to 6.38 with a mean of 3.86 ± 0.01. When analyzing the data in a change point model, initially a minor non-significant drop in pH (0.99) was seen before the change point followed by a weak non-significant positive trend. This may indicate that either there was a drop from the 1920s to 1942, after which soil pH probably increased, or that there has been no change in the entire period. We propose that the change is related to either (1) that the sulphur deposition peaked in the early 1980s and, as result, sulphur deposition decreased, which caused a small recovery of soil pH, or (2) that anthropogenic acidification did not significantly change soil pH in this naturally very acidic ecosystem. [ABSTRACT FROM AUTHOR]

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In the last decade, several major dwarf‐shrub dieback events have occurred in northern European coastal heathlands. These dieback events occur after extended periods with sub‐zero temperatures under snow‐free conditions and clear skies, suggesting that coastal heathlands have low resistance to winter drought. As climate projections forecast increased drought frequency, intensity, and duration, coastal heathlands are likely to experience more such diebacks in the future. There are, however, few empirical studies of drought impacts and responses on plant communities in humid oceanic ecosystems. We established a drought experiment with two distinct levels of intensified drought to identify responses and thresholds of drought resistance in coastal heathland vegetation. We repeated the experiment in two regions, separated by five degrees latitude, to represent different bioclimatic conditions within the coastal heathlands' wide latitudinal range in Europe. As coastal heathlands are semi‐natural habitats managed by prescribed fire, and we repeated the experiment across three post‐fire successional phases within each region. Plant community structure, annual primary production, and primary and secondary growth of the dominant dwarf‐shrub Calluna vulgaris varied between climate regions. To our surprise, these wide‐ranging vegetation‐ and plant‐level response variables were largely unaffected by the drought treatments. Consequently, our results suggest that northern, coastal heathland vegetation is relatively resistant to substantial intensification in drought. This experiment represents the world's wettest (2200 mm year−1) and northernmost (65°8'N) drought experiment to date, thus filling important knowledge gaps on ecological drought responses in high‐precipitation and high‐latitude ecosystems across multiple phases of plant community succession. [ABSTRACT FROM AUTHOR]

Summary: Though it is well established that species composition affects ecosystem function, the way in which species combine to control overall ecosystem functioning is still debated.In experimental mesocosms, we planted three functionally distinct dry‐heath species in varying proportions and measured multiple ecosystem properties related to nutrient cycling and carbon storage (hereafter functions). Overall ecosystem functioning was described as the main axes of variation in ecosystem functioning (functional space) and the proportion of ecosystem functions at high levels; for example, fast carbon and nutrient cycling (cluster‐based multifunctionality).The first functional space axis, related to nitrogen availability, was driven by plant species abundance, particularly that of legumes, which strongly affected many individual functions. The second, related to total plant biomass and woodiness, was mostly driven by the abundance of dwarf shrubs. Similarly, cluster‐based multifunctionality was related to the initial abundance of all species, but particularly the legume. Interactions between species also affected ecosystem multifunctionality, but these effects were smaller in magnitude.These results indicate that species interactions could play a secondary role to species abundance and identity in driving the overall ecosystem functioning of heathlands, but also that axes of variation in functional space are clearly linked to plant functional composition. [ABSTRACT FROM AUTHOR]

Post‐mining restoration of heathland habitats has met with mixed success. Failures are often ascribed to the complexity of replicating soil conditions: a scarcity of organic matter and microbial symbionts in stored overburden used for restoration is frequently implicated. Nonetheless, systematic investigation of the role of both interventions is lacking. Using a greenhouse trial and a large‐scale field experiment within a commercial kaolinite mine site, we explored how the addition of ericoid mycorrhizal fungi (ErMF) and organic matter influenced the establishment of dwarf ericoid species that characterize NW European Atlantic lowland heaths. Neither intervention had any positive effect on ericoid establishment in field or greenhouse conditions. In the greenhouse experiment, organic matter (from commercial refuse) increased heather (Calluna vulgaris) cuttings mortality, although surviving plants showed enhanced shoot growth when ErMF were added. All field plots were dominated by combinations of grasses, gorse (Ulex europaeus), and bare ground. Establishment of ericaceous plants was remarkably low (<4%) after 3 years and Erica tetralix and C. vulgaris abundance in organic matter (which increased pH) or ErMF treatments was reduced compared to untreated control. Although our experiments suggest that research on soil manipulation treatments is required to elucidate the conditions necessary for heathland establishment, corroboration of our greenhouse trial results in field conditions highlights the value of the former in informing the latter. We identify low pH, high lignin (e.g. pine) litter as one potentially worthwhile soil amelioration treatment and suggest how the use of naturally colonized/preinoculated "nursemaid" plants could facilitate heathland restoration. [ABSTRACT FROM AUTHOR]

The alpine vegetation of Europe and the Caucasus has experienced substantial changes due to climate warming and reduced grazing. Exposed ridge communities, such as alpine heaths, are presumed to be less vulnerable to such processes. Herein, we analyze long-term dynamics (over 37 years) of an alpine lichen heath in the Teberda State Biosphere Reserve, Karachaevo-Cherkessian Republic, Russia. We counted the shoots of all vascular plants present on permanent plots. Autocorrelated linear regressions, a non-metric multidimensional scaling ordination, and a fourth-corner analysis were applied to characterize the relationships between shoot numbers, climate variables (temperatures and precipitation), functional traits, and species strategies. Nine species, including dominant Festuca ovina L. and Antennaria dioica (L.) Gaertn., increased their abundances, whereas Carex spp. were observed to decrease. The overall dynamics were mainly driven by increasing mean temperatures during the growing season (July and August). None of the changes observed in the selected traits were correlated with increasing or decreasing numbers of species; however, some traits (plant height, specific root length, specific leaf area, and leaf carbon content) were potentially associated with climate variables. The observed dynamics suggested an overall increase in the abundance of herbaceous plants. Generally, our results support "greening" effects in tundra and alpine biomes. [ABSTRACT FROM AUTHOR]

We report new records of the very rare and endangered European Amazon ant, Polyergus rufescens (Latreille, 1798) in the Province of Limburg, Belgium in the summer of 2020. During a large-scale invertebrate survey in large heathland patches in Zonhoven and Houthalen workers and queens were collected with pitfall traps and observed at the site. The importance of this finding and suggestions on heathland management in favour of this species as well as its survival in the north of Belgium are discussed. [ABSTRACT FROM AUTHOR]

Questions: In some fire-prone ecosystems, bryophytes play a crucial role by providing the surface fuel that controls the fire return interval. Afroalpine heathlands are such an ecosystem, yet almost nothing is known about the bryophytes in this system. We do not know the level of species richness, or if there is a successive accumulation of species over time, or if some species are adapted to specific phases along the successional gradient, for example early-successional species sensitive to competition. Location: Afroalpine heathlands in Ethiopia. Methods: We made an inventory of all bryophytes in 48 plots of 5 m × 5 m, distributed along a chronosequence from 1 to 25 years post fire. The heathlands are located between 3500 m and 3800 m a.s.l. and are managed by traditional pasture burning with fire intervals of 8–20 years. Results: We found in total 111 taxa of bryophytes. Post-fire mortality was almost 100%. The youngest plots had only a few cosmopolitan species often found after fire. Initially, species richness increased monotonically while starting to level off around 15 years after fire, when many plots had around 30 species and a high cover of Breutelia diffracta, which is a key ground-living species, important as surface fuel. Most species were found with sporophytes, a pattern even stronger for the most frequent species. Conclusions: Interestingly, bryophyte diversity is already remarkably high by only 15 years after total eradication. The relatively slow accumulation of species in the first years after fire suggests that dispersal in space, and not time, is the major mechanism by which sites regain their diversity (i.e. spore banks play a smaller role than colonization of wind-borne spores). This indicates that the high species richness is built up through colonization from surrounding heathlands, and perhaps also from higher-altitude alpine grasslands and lower-altitude forests, and that the bryophyte diversity in this system is maintained by the traditional fire and grazing management. [ABSTRACT FROM AUTHOR]

Competition exerted by native plant communities is an important component of biotic resistance against the spread and impact of non-indigenous plant species in novel habitats. However, how the role of biotic resistance varies along environmental gradients to delay invasions is less clear. We conducted two field experiments to determine how competition from native communities affects colonization of a recognized invader of grasslands, Hieracium pilosella L., in the Fuegian steppe along different environmental gradients at regional and landscape scale. We assessed the role of competition on invader survival and growth along a climate gradient at regional scale (4.7–6.6 °C and 270–450 mm year−1), and across four major plant communities (i.e. meadows, grasslands, scrublands, and heathlands) along a topographic catena. At regional scale, the climate gradient showed a 33% reduction in H. pilosella survival at the coldest and wettest extreme, while reduced its biomass in 41% at the warmest and driest site, in the opposite extreme of the gradient. Competition caused a 34% decrease of the invader biomass, similarly along the climate gradient. At landscape scale, the topographic gradient had a stronger effect on invader survival reaching a 67% reduction in lowland meadows due to flooding events, while competition reduced in 29–39% the invader biomass only in grasslands or scrublands with negligible effects on low-resource heathlands. These results suggest that biotic resistance plays a significant and similar role along the climate gradient to delay invasion at regional scale, but at landscape scale is only determinant for rich-resource communities in absence of abiotic stresses. [ABSTRACT FROM AUTHOR]

Habitat degradation and fragmentation are recognized as major causes of biodiversity loss, and effective management to conserve habitats is highly dependent on our ability to assess their conservation status. In this study we introduce a new index (VCS, for vegetation conservation status) to assess the conservation status of plant communities, which reflect the identity of habitat types. The VCS index is based on the same probabilistic approach than the classical Simpson’s diversity index, but uses the concept of species pools to integrate the influence of ‘typical’ and ‘non-typical’ species on habitat conservation status. In addition to the effect of species identity, this index also allows the detection of change in conservation status because of variation in species-abundance distribution. As an example we applied the VCS index to two heathland habitats in French Brittany and we compared the values provided by the index to qualitative assessments by heathland experts. We also compared the performance of the VCS index against three other indices: species richness, species diversity and a more recent index of ‘favourable conservation status’. Among the four indices tested, the VCS index was the most effective in assessing the vegetation conservation status when compared against qualitative assessment by heathland experts. Moreover the VCS index, coupled with variance partitioning methods, allowed to quantify the contribution of expected causes of habitat degradation. This study demonstrates that the use of habitat-specific species pools to distinguish between typical and non-typical species, as well as the consideration of species abundances, are critical for an accurate assessment of the vegetation conservation status. The VCS index should therefore be a valuable tool for both managers and researchers involved in habitat conservation.

Conservation priorities and decisions can be informed by understanding diversity patterns and the evolutionary history of ecosystems, and phylogenetic metrics can contribute to this. This project used a range of diversity metrics in concert to examine diversity patterns in the Sunshine Coast heathlands, an ecosystem under intense pressure. The species richness and composition of 80 heathland sites over nine regional ecosystems of heathland on the Sunshine Coast were enhanced with phylogenetic metrics, determined by barcoding 366 heath species of the region. The resulting data were added to an existing phylogeny of regional rainforest species. The diversity metrics for sites and regional ecosystems were compared using univariate and multivariate statistics. The phylogeny from this study, and the low phylogenetic diversity of the heathlands, is consistent with the theory that heath species evolved on the fringes on a wider Australian rainforest flora. Distinctive heathland communities were highlighted, and the existence of geographically scattered, but compositionally similar, phylogenetically even sites points to a possible “refugial environment”, characterised by moisture and instability. This suggests contrasting conservation implications: the protection of distinctive communities but also the management of the dynamic processes in other wet and alluvial “refugial environments”. The potential for more focused conservation priorities is enhanced.

Questions: In fire-prone ecosystems, fire can enhance the flowering and fruiting of many species, a strategy assumed to be well represented in savanna. Despite this, there are surprisingly few studies assessing how prevalent fire-stimulated flowering is. Thus, we asked: (a) are there differences in the reproductive phenology of Cerrado plants between recently burned and unburned areas; (b) how does fire affect the speed of flowering and how does this differ between growth forms; and (c) what are the post-fire flowering (PFF) strategies of Cerrado species and is there evidence for high proportions of obligate PFF? Location: Open savannas (campo sujo in the Cerrado) in Central Brazil (Reserva Natural Serra do Tombador — RNST, 13°35–13°38' S and 47°45'–47°51' W). Methods: We established six plots, three recently and frequently burned (FB) and three excluded from fire for six years (E). In all treatments, the number of species flowering and fruiting was counted every 15 days for three months, and then at six, nine and 12 months after fire. We also counted the number of reproductive and vegetative shoots in 10 subplots (1 m × 1 m) per plot. Results: Approximately 66% of species studied were fire-stimulated, with half of these only flowering after fire (obligate PFF). Fire-enhanced flowering was rapid, with the clearest differences between burned and unburned plots seen in the first 30 days, and up to three months after fire, where there were up to two times more species flowering in the FB than E areas. Conclusions: The extremely high proportion of PFF species, at least five times that reported for heathlands and other shrub communities, highlights the role that shortinterval fire regimes have in savanna ecosystems, selecting for resprouting life forms and PFF dominance, particularly in herbaceous species. Rapid post-fire reproduction may be a strategy to disperse large quantities of seed into an environment with a small recruitment window. [ABSTRACT FROM AUTHOR]

Lichen heaths are declining in abundance in alpine and Arctic areas partly due to an increasing competition with shrubs. This shift in vegetation types might have important consequences for the microclimate and climate on a larger scale. The aim of our study is to measure the difference in microclimatic conditions between lichen heaths and shrub vegetation during the growing season. With a paired plot design, we measured the net radiation, soil heat flux, soil temperature and soil moisture on an alpine mountain area in southern Norway during the summer of 2018 and 2019. We determined that the daily net radiation of lichens was on average 3.15 MJ (26 %) lower than for shrubs during the growing season. This was mainly due to a higher albedo of the lichen heaths but also due to a larger longwave radiation loss. Subsequently, we estimate that a shift from a lichen heath to shrub vegetation leads to an average increase in atmospheric heating of 3.35 MJ d -1 during the growing season. Surprisingly, the soil heat flux and soil temperature were higher below lichens than below shrubs during days with high air temperatures. This implies that the relatively high albedo of lichens does not lead to a cooler soil compared to shrubs during the growing season. We predict that the thicker litter layer, the presence of soil shading and a higher evapotranspiration rate at shrub vegetation are far more important factors in explaining the variation in soil temperature between lichens and shrubs. Our study shows that a shift from lichen heaths to shrub vegetation in alpine and Arctic areas will lead to atmospheric heating, but it has a cooling effect on the subsurface during the growing season, especially when air temperatures are relatively high. [ABSTRACT FROM AUTHOR]

Heather is a slow-growing evergreen shrub, commonly found in moorlands and heaths of high nature conservation value. Heather-dominated areas are used as livestock pasture, and the flowers of heather are harvested also for the natural product industry. Classical studies have focused on the recovery of shoot biomass of heather, while the recovery of flowering after grazing or harvesting has received less attention. In this study, we examined the recovery of heather flowering in one harvesting experiment and two observational areas in northern Finland. The flowers of heather were collected manually by clipping the flowering shoots or stripping the flowers from the shoots or by machine harvesting. We counted the number of short shoots (SS), nonflowering long shoots (NFLS), and flowering long shoots (FLS) after harvesting. We also measured the length of FLS and counted the flowers they produced. Heathers started to recover by producing new short shoots, while the recovery of flowering was slow, and only in one out of the three areas, flowering recovered totally during our study. Our results suggest that the recovery was dependent on the age of heather or individual site characteristics rather than on the harvesting method. Because flowering is one of the most important stages of successful reproduction, which affects the long-term existence of heather-dominated ecosystems, the results of our study can contribute to new guidelines for management practices in heathlands. However, longer-term experiments on the rate of flowering recovery are needed especially if rotational cutting is favored as a management practice in heathlands in the future. [ABSTRACT FROM AUTHOR]

Climate change is expected to increase the frequency and intensity of extreme events in northern ecosystems. The outcome of these events across the landscape, might be mediated by species effects, such as niche construction, with likely consequences on vegetation resilience. To test this hypothesis, we simulated an extreme event by removing aboveground vegetation in tundra heathlands dominated by the allelopathic dwarf shrub Empetrum nigrum, a strong niche constructor. We tested the hypothesis under different climate regimes along a 200-km long gradient from oceanic to continental climate in Northern Norway. We studied the vegetation recovery process over ten years along the climatic gradient. The recovery of E. nigrum and subordinate species was low and flattened out after five years at all locations along the climatic gradient, causing low vegetation cover at the end of the study in extreme event plots. Natural seed recruitment was low at all sites, however, the addition of seeds from faster growing species did not promote vegetation recovery. A soil bioassay from 8 years after the vegetation was removed, suggested the allelopathic effect of E. nigrum was still present in the soil environment. Our results provide evidence of how a common niche constructor species can dramatically affect ecosystem recovery along a climatic gradient after extreme events in habitats where it is dominant. By its extremely slow regrowth and it preventing establishment of faster growing species, this study increases our knowledge on the possible outcomes when extreme events harm niche constructors in the tundra. [ABSTRACT FROM AUTHOR]

To understand impacts of post-disturbance assembly mechanisms on the functional diversity (FD) of plant communities, it is necessary to determine how the environment drives their functional trait composition. In the boreal forest, post-fire abiotic filters may control community assembly by selecting plants with specific traits. Ericaceous heaths are characterized by low FD and are thought to be subject to such filters. We hypothesized that soil parameters select for a specific suite of traits and act as a secondary abiotic filter in post-fire ericaceous heath and contribute to the observed reduction of FD. We measured six soil parameters, five functional traits, and plant species abundances in eight post-fire heath and four regenerating forest sites in Eastern Canada. We conducted a combined analysis of RLQ (R-table Linked to Q-table) and fourth-corner methods to examine the links between plant traits and plot-level soil parameters, mediated by species abundances. Only below ground traits were significantly linked to soil variables. Specific root length and ericoid mycorrhizal associations were negatively linked to total soil nitrogen, available ammonium, and pH. Post-fire heath soils favour a specific suite of species traits. Only a portion of the regional species pool possesses the above-mentioned traits, and when they are favoured by habitat conditions, they assemble into a community with low FD. The novelty of our study is here we show how the relationship between traits and soil chemistry can act as a secondary filter and exert community-level trait changes responsible for the low functional diversity observed in heaths. [ABSTRACT FROM AUTHOR]

In South Australia, Swamps of the Fleurieu Peninsula are critically endangered due to past vegetation clearance and changes in hydrology, but still contain a high diversity of threatened plant species. This vegetation community provides habitat for 82 threatened ground‐stratum plant species, including the nationally critically endangered subshrub Hibbertia tenuis which is endemic to these swamps. With infrequent burning, native ferns and taller shrubs outcompete these species. We conducted glasshouse trials to determine the potential of fire to regenerate threatened and other swamp plant species. Soil samples from eight swamps were used in germination trials with half of each sample treated with heat plus smoke, and half left untreated. Samples were spread onto trays (n = 188), and seedling emergence was recorded for twelve months. Emergence was dominated by native species (2649 seedlings m−2) compared to exotics (675 seedlings m−2). In total, 48 native and 25 introduced species germinated, with 21% of germinated native species absent from the above‐ground vegetation. The dominant native fern Gleichenia microphylla did not emerge from any soil samples, indicating that recovery likely lags behind that of ground‐strata species, giving them time to establish and set seed before being outcompeted. Thirty‐four rare or threatened species germinated, including five species absent from above‐ground vegetation. Of all native species that emerged, only five were confined to heat plus smoke treatments, suggesting most species will regenerate without fire if overstorey competition is reduced. However, seedling emergence of native shrubs/subshrubs more than doubled with the fire treatment. Of particular importance, H. tenuis showed an 18‐fold increase in germination when treated with heat plus smoke. This study supports the utility of ecological burns as a management tool to regenerate threatened plant species in long‐undisturbed peaty heathlands on permanent swamps. [ABSTRACT FROM AUTHOR]

The paper presents a comprehensive numerical analysis of vegetation within the class Loiseleurio-Vaccinietea Eggler ex Schubert 1960 in Southeastern Carpathians (Romanian Carpathians), specifically the cryophilous dwarf-shrub heathlands on windswept slopes and edges and acidophilous mesophilous dwarf-shrub communities in subalpine and alpine belts. Based on a large dataset of phytosociological relevés stored in the Romanian Grasslands Database (EU-RO-008), this contribution was focused on the variability of dwarf-shrub communities, their environmental preferences, and the main ecological factors shaping their floristic composition. All relevés were analyzed using hierarchical agglomerative clustering methods to identify the main vegetation groups. Direct and indirect ordination methods were used to identify the main gradients affecting the floristic composition of individual vegetation types. The numerical analysis revealed six well-defined communities, largely corresponding to associations described in syntaxonomical literature, according to their diagnostic species: Cetrario-Loiseleurietum procumbentis Br.-Bl. et al. 1939, Cetrario nivalis-Vaccinietum gaultherioidis (Hadač 1956) Hadač ex Šibík et al. 2007, Rhododendro myrtifolii-Vaccinietum Coldea et al. 1981, Campanulo abietinae-Juniperetum nanae Simon 1966, Campanulo abietinae-Vaccinietum myrtilli (Buia et al. 1962) Boşcaiu 1971, and Bruckenthalio-Juniperetum nanae (Horvat 1938) Coldea in Coldea et al. 2015. New syntaxa were identified at lower hierarchical levels (sub-associations) and new typifications were made. The floristic composition of target species-poor communities was mainly modelled by altitudinal range (temperature) and bedrock type. In Detrended Correspondence Analysis, the plant communities were arranged based on a gradient of altitude, from those occurring in the harshest environmental conditions, at highest elevations, with a floristic composition rich in heliophile species (alliance Loiseleurio-Vaccinion Br.-Bl. in Br.-Bl. et Jenny 1926) to communities distributed at lower elevations, on sites with higher mean annual temperatures and with a floristic composition rich in shade tolerating species (alliance Juniperion nanae Br.-Bl. in Br.-Bl. et al. 1939). Relevés of alliance Rhododendrion myrtifolii de Foucault ex Theurillat et Mucina in Mucina et al. 2016 were located in an intermediate position within studied communities. [ABSTRACT FROM AUTHOR]

Summary: Despite the ecological significance of ericoid mycorrhizal fungi, little is known about the abiotic and biotic factors driving their diversity and community composition.To determine the relative importance of abiotic and biotic filtering in structuring ericoid mycorrhizal fungal communities, we established 156 sampling plots in two highly contrasting environments but dominated by the same Ericaceae plant species: waterlogged bogs and dry heathlands. Plots were located across 25 bogs and 27 dry heathlands in seven European countries covering a gradient in nitrogen deposition and phosphorus availability. Putatively ericoid mycorrhizal fungal communities in the roots of 10 different Ericaceae species were characterized using high‐throughput amplicon sequencing.Variation in ericoid mycorrhizal fungal communities was attributed to both habitat and soil variables on the one hand and host plant identity on the other. Communities differed significantly between bogs and heathlands and, in a given habitat, communities differed significantly among host plant species. Fungal richness was negatively related to nitrogen deposition in bogs and phosphorus availability in bogs and heathlands.Our results demonstrate that both abiotic and biotic filtering shapes ericoid mycorrhizal fungal communities and advocate an environmental policy minimizing excess nutrient input in these nutrient‐poor ecosystems to avoid loss of ericoid mycorrhizal fungal taxa. [ABSTRACT FROM AUTHOR]

The significant impacts of the introduced plant pathogen Phytophthora cinnamomi on native Australian vegetation have been well documented, but there is less knowledge of long-term effects. We assessed long-term (26 years) disease progression and impacts on vegetation floristics and structure at a heathy woodland site in the Great Otway National Park, eastern section. Disease progressed dramatically between 1989 and 2005 and by 2015 only 0.08% of the site was non-diseased. There were significant declines in plant species richness and numbers of susceptible species; and increases in percentage cover of resistant sedges and grasses overall, and in cover of Leptospermum continentale (prickly tea-tree) in post-disease areas. There were significant declines of Xanthorrhoea australis (Austral grass-tree), a keystone species that contributes greatly to vegetation structure and fauna habitat. There is an urgent need to map the distribution of P. cinnamomi affected vegetation and identify floristically important non-diseased vegetation in the national park. It is imperative that quarantine of non-infested areas, phosphite application, track closures and vehicle wash-downs be implemented to reduce disease extension and protect the significant biodiversity of the region including species rich heathlands and nationally listed threatened plant and fauna species and their habitats. Long-term (26-year) impacts of Phytophthora cinnamomi infestation were investigated in heathy woodland in the Great Otway National Park. There was significant disease progression, declines in plant species richness and susceptible species such as Xanthorrhoea australis (Austral grass-tree) a keystone species that contributes greatly to vegetation structure and fauna habitat. [ABSTRACT FROM AUTHOR]

In dry habitats of European lowlands terricolous lichens and bryophytes are almost neglected in conservation practises, even if they may strongly contribute to biodiversity. This study aims at (a) testing the role of heathlands, acidic and calcareous dry grasslands for lichen and bryophyte diversity and conservation in lowland areas of northern Italy characterized by high human impact and habitat fragmentation; (b) detecting the effect of environmental drivers and vegetation dynamics on species richness and composition. Lichens, bryophytes, vascular plants, and environmental variables were recorded in 287 circular plots for 75 sites. Our results indicate that heathlands, acidic and calcareous dry grasslands host peculiar terricolous lichen and bryophyte communities that include several species of conservation concern. Thus, each habitat provides a complementary contribution to lichen and bryophyte diversity in continental lowland landscapes. Furthermore, in each habitat different factors drive species richness and composition with contrasting patterns between lichens and bryophytes. In terms of conservation, our results indicate that management of lowland dry habitats should act at both local and landscape scales. At local scale, vegetation dynamics should be controlled in order to avoid biodiversity loss due to vegetation dynamics and wood encroachment. At the landscape scale, patches of all the three habitats should be maintained to maximize regional diversity. [ABSTRACT FROM AUTHOR]

Aims: Tropical tree lines are often associated with abrupt shifts in vegetation, soils and disturbance regimes, but the underlying mechanisms are poorly understood. We analysed the role of grazing, fuels and fire in maintaining a sharp tree line with flammable heathland above non‐flammable forest. Location: Bale Mountains, Ethiopia. Methods: The study used grazing exclosures, repeated vegetation sampling, soil analyses and burning and sowing experiments along an altitudinal gradient with Hagenia abyssinica forest, Erica trimera forest and Erica heathland; all were heavily grazed, the Erica heathland also burnt on short rotation. Results: Contrary to expectation, livestock exclusion did not increase flammability in the forest, but instead resulted in a dense carpet of non‐flammable herbs. In the heathland, livestock exclusion led to somewhat faster post‐fire fuel recovery, but no major change in vegetation. Seeding of tree species resulted in some seedling establishment, but notably Hagenia grew poorly in the heathland, even when protected from livestock. A bioassay, as well as observations of outpost trees on atypical soil above the tree line, suggests that this poor growth is caused by the acidic soils, rather than harsh climate. Despite frequent fires, heathland soils had lower pH and higher organic matter content than forest soils. Below the tree line, tree seedling establishment was successful only in forest gaps, and if livestock was excluded. In both forest and heathland rapid vegetative regeneration in the ground flora after disturbance restricted major species shifts. Conclusions: These results suggest that the contrasting fire potential between heathland and forest, and thus the sharp tree line would be maintained, or possibly even accentuated, in the absence of livestock grazing, and that Hagenia colonization upwards into the heathland is restricted not only by fire and grazing, but also the acidic soils, which is a legacy of centuries of dominance by Erica. [ABSTRACT FROM AUTHOR]

Blandfordia grandiflora (Blandfordiaceae) is a resprouting perennial herb in wet heathland of coastal and tableland habitats on mainland eastern Australia. It has attractive turbinate flowers of considerable horticultural value. Blandfordia grandiflora is reported to have an enhanced flowering response in the first post-fire flowering season, and management prescriptions advocate frequent fire as beneficial for the species. Nonetheless, the present study appears to be the first to document the flowering response and fate of individual plants exposed to a range of fire frequencies (3-, 6- and 9-year intervals) over an extended period. We also examined the flowering response in unburnt habitat. High survival rates (>95%) were observed for B. grandiflora plants in heathland that had remained unburnt for a minimum of 30 years. Flowering after experimental burns was found to peak in the second post-fire flowering season rather than the first, and there was no clear fire frequency effect. Maximum levels of flowering during the second post-fire season reached 38 to 56% of individuals, although in some years post-fire flowering during this peak season was as low as 23%. Comparatively few plants flowered during the second-year peak season after every fire, and ~34% of individuals in both the 6- and 9-year burn treatments failed to flower at any time. Inter-fire flowering was also observed, and in some instances this flowering was not significantly different to the level achieved during the peak post-fire flowering season. For example, ~9% of individuals flowered 5–7 times over a 12-year period despite being burnt on only four occasions. Flowering after vernalisation (winter-chilling) was observed in unburnt heathland, and the level of this response was not significantly different to peak post-fire flowering in some years. The findings are examined in the context of evolutionary and habitat processes within a climate change framework. Future studies should focus on the complex interactions between climate, fire and soil for not only B. grandiflora , but more importantly for the diverse assemblage of plant species in wet heathland. Blandfordia grandiflora (Christmas bells) is a perennial herb that grows in wet heathlands of eastern Australia. It has attractive flowers of considerable horticultural value, and is reported to flower strongly after fire. This study demonstrated a tendency for flowering to peak in the second post-fire flowering season, irrespective of fire frequency. However, this response was variable: comparatively few plants flowered during the second-year peak season after every fire. Flowering after winter-chilling was also observed. The findings are discussed in the context of climate change. [ABSTRACT FROM AUTHOR]

Context: Fire behaviour research has largely focused on dry ecosystems that burn frequently, with far less attention on wetter forests. Yet, the impacts of fire in wet forests can be high and therefore understanding the drivers of fire in these systems is vital. Objectives: We sought to identify and rank by importance the factors plausibly driving flammability in wet eucalypt forests, and describe relationships between them. In doing so, we formulated a set of research priorities. Methods: Conceptual models of forest flammability in wet eucalypt forests were elicited from 21 fire experts using a combination of elicitation techniques. Forest flammability was defined using fire occurrence and fireline intensity as measures of ignitability and heat release rate, respectively. Results: There were shared and divergent opinions about the drivers of flammability in wet eucalypt forests. Widely agreed factors were drought, dead fine fuel moisture content, weather and topography. These factors all influence the availability of biomass to burn, albeit their effects and interactions on various dimensions of flammability are poorly understood. Differences between the models related to lesser understood factors (e.g. live and coarse fuel moisture, plant traits, heatwaves) and the links between factors. Conclusions: By documenting alternative conceptual models, we made shared and divergent opinions explicit about flammability in wet forests. We identified four priority research areas: (1) quantifying drought and fuel moisture thresholds for fire occurrence and intensity, (2) modelling microclimate in dense vegetation and rugged terrain, (3) determining the attributes of live vegetation that influence forest flammability, (4) evaluating fire management strategies. [ABSTRACT FROM AUTHOR]

Worldwide, regularly recurring wildfires shape many peatland ecosystems to the extent that fire‐adapted species often dominate plant communities, suggesting that wildfire is an integral part of peatland ecology rather than an anomaly. The most destructive blazes are smoldering fires that are usually initiated in periods of drought and can combust entire peatland carbon stores. However, peatland wildfires more typically occur as low‐severity surface burns that arise in the dormant season when vegetation is desiccated, and soil moisture is high. In such low‐severity fires, surface layers experience flash heating, but there is little loss of underlying peat to combustion. This study examines the potential importance of such processes in several peatlands that span a gradient from hemiboreal to tropical ecozones and experience a wide range of fire return intervals. We show that low‐severity fires can increase the pool of stable soil carbon by thermally altering the chemistry of soil organic matter (SOM), thereby reducing rates of microbial respiration. Using X‐ray photoelectron spectroscopy and Fourier transform infrared, we demonstrate that low‐severity fires significantly increase the degree of carbon condensation and aromatization of SOM functional groups, particularly on the surface of peat aggregates. Laboratory incubations show lower CO2 emissions from peat subjected to low‐severity fire and predict lower cumulative CO2 emissions from burned peat after 1–3 years. Also, low‐severity fires reduce the temperature sensitivity (Q10) of peat, indicating that these fires can inhibit microbial access to SOM. The increased stability of thermally altered SOM may allow a greater proportion of organic matter to survive vertical migration into saturated and anaerobic zones of peatlands where environmental conditions physiochemically protect carbon stores from decomposition for thousands of years. Thus, across latitudes, low‐severity fire is an overlooked factor influencing carbon cycling in peatlands, which is relevant to global carbon budgets as climate change alters fire regimes worldwide. [ABSTRACT FROM AUTHOR]

Aims: In riverine ecosystems, variations in disturbance and stress intensities along the flood gradient shape vegetation community structure. However, human modifications to the flood regime may change the magnitude of disturbance and stress, leading to different species distribution patterns along environmental gradients. We aimed to study the effects of local‐ and broad‐scale environmental gradients on riparian plant CSR (Competitors–Stress tolerators–Ruderals) strategies along a highly regulated river. Location: Rhône River, France. Methods: We assessed how changes in elevation, fine sediment and temperature influenced CSR strategies of riparian plant communities, by studying variations in the community‐weighted means and the functional dispersion of the CSR values, on gravel bars along a 250 km north–south river corridor. Results: Species with contrasting ecological strategies co‐occurred less on gravel bars subject to fine sediment deposition, leading to patterns of biotic homogenization along the flood gradients. Furthermore, a shift in CSR strategies from ruderal to stress‐tolerant communities occurred along the elevation gradient on bars with low proportions of fine sediments and from stress‐tolerant to ruderal communities along the elevation gradient on bars with high proportions of fine sediments. Regarding the climatic gradient, the mean value of ruderals increased with temperatures. Also, for stress tolerators, the dispersion value diverged between the northern and southern gravel bars when the proportion of fine sediments was low and converged when the proportion of fine sediments was high. Conclusions: Overbank fine sedimentation alleviates the intensity of stress along not only the elevation gradient but also the climatic gradient. By homogenizing the functional composition of communities, this process may have detrimental consequences for riparian plant diversity, especially of ruderal plants in the littoral zone. In regulated river systems, restoration measures should therefore promote an increase in the intensity of: (a) disturbance through the reactivation of bedload supply and transport; and (b) stress through increased flow dynamics. [ABSTRACT FROM AUTHOR]

Over the past few decades the Arctic has warmed up more than the lower latitudes. Soil organic carbon (SOC) in the Arctic is vulnerable to climate change, and carbon dioxide (CO2) produced via SOC decomposition can amplify atmospheric temperature increase. Although SOC composition is relevant to decomposability, studies on its compositional changes with warming are scarce, particularly in the Arctic. Therefore, we investigated the responses of SOC and the bacterial community to climate manipulation under Cassiope and Salix heath vegetation communities in permafrost‐affected soil in Zackenberg, Greenland. After 8–9 years of experimental warming, we evaluated changes in SOC quantity and quality of three density fractions of soil: free light fraction (FLF), occluded light fraction (OLF) and heavy fraction (HF). The SOC content at 0–5‐cm depth was significantly reduced with warming under Cassiope, and it was accompanied by decreased FLF content, attributed to accelerated decomposition of the FLF by warming. However, SOC molecular composition and bacterial community composition were not affected by warming. By contrast, there was no warming effect on SOC under Salix, which could be partially due to smaller temperature increases caused by higher moisture levels associated with larger silt and clay contents, or to different responses of the dominant plant species to temperature. In both soils, more than 55% of SOC was associated with minerals, and its molecular composition indicated microbial decomposition. Our results suggested that long‐term warming in the high Arctic could induce the loss of SOC, particularly in the FLF; however, the response could vary with vegetation type and/or soil properties, that is, soil texture. Highlights: We show decreased SOC with long‐term (8‐year) warming of heath soils in the high ArcticParticularly, the free light fraction of SOC in topsoil decreased with warming in a Cassiope heath siteMineral‐associated SOC content was more than 55% and showed signs of microbial processingEffects of warming differed according to soil properties and/or plant community composition [ABSTRACT FROM AUTHOR]

Automated recording units (ARUs) are an integral instrument in a broad range of applications such as invasive species management, behavioural studies, and environmental impact assessments. They have become particularly important in conservation programmes for a range of cryptic threatened bird species. While the fundamental issues of signal attenuation and degradation are well known, understanding how environmental factors influence detectability of calls on ARU recordings in particular circumstances is essential for the accurate interpretation of their results. Using five transects spaced at equal angles running from a central playback source we tested the detectability of Pezoporus flaviventris (Western Ground Parrot) and Atrichornis clamosus (Noisy Scrub-bird) calls on Wildlife Acoustics SM2 and SM4 devices. Both species call from on or near the ground in moderately dense heathlands. Detectability of calls was affected by wind direction: fewer calls were detected on an ARU that was up-wind of the broadcast source compared with another on a down-wind unit. More calls were detected on ARUs deployed at higher relative elevation, and detectability decreased with increased distance from the playback source. Calls were detected at a greater distance from the playback source when using SM4 ARUs, compared to SM2 ARUs. Inconsistency in the detection of bird calls through space and time could lead to errors in metrics calculated from acoustic data. Further investigation is required to determine how environmental factors such as wind direction can be accounted for in data analysis. [ABSTRACT FROM AUTHOR]

Climate change is altering disturbance regimes and recovery rates of forests globally. The future of these forests will depend on how climate change interacts with management activities. Forest managers are in critical need of strategies to manage the effects of climate change.We co‐designed forest management scenarios with forest managers and stakeholders in the Klamath ecoregion of Oregon and California, a seasonally dry forest in the Western US subject to fire disturbances. The resultant scenarios span a broad range of forest and fire management strategies. Using a mechanistic forest landscape model, we simulated the scenarios as they interacted with forest growth, succession, wildfire disturbances and climate change. We analysed the simulations to (a) understand how scenarios affected the fire regime and (b) estimate how each scenario altered potential forest composition.Within the simulation timeframe (85 years), the scenarios had a large influence on fire regimes, with fire rotation periods ranging from 60 years in a minimal management scenario to 180 years with an industrial forestry style management scenario. Regardless of management strategy, mega‐fires (>100,000 ha) are expected to increase in frequency, driven by stronger climate forcing and extreme fire weather.High elevation conifers declined across all climate and management scenarios, reflecting an imbalance between forest types, climate and disturbance. At lower elevations (<1,800 m), most scenarios maintained forest cover levels; however, the minimal intervention scenario triggered 5 × 105 ha of mixed conifer loss by the end of the century in favour of shrublands, whereas the maximal intervention scenario added an equivalent amount of mixed conifer.Policy implications. Forest management scenarios that expand beyond current policies—including privatization and aggressive climate adaptation—can strongly influence forest trajectories despite a climate‐enhanced fire regime. Forest management can alter forest trajectories by increasing the pace and scale of actions taken, such as fuel reduction treatments, or by limiting other actions, such as fire suppression. [ABSTRACT FROM AUTHOR]

Recent advances in wearable sensor technology and smartphones enable simple and affordable collection of personal analytics. This paper reflects on the lessons learned in the SWELL project that addressed the design of user-centered ICT applications for self-management of vitality in the domain of knowledge workers. These workers often have a sedentary lifestyle and are susceptible to mental health effects due to a high workload. We present the sense–reason–act framework that is the basis of the SWELL approach and we provide an overview of the individual studies carried out in SWELL. In this paper, we revisit our work on reasoning: interpreting raw heterogeneous sensor data, and acting: providing personalized feedback to support behavioural change. We conclude that simple affordable sensors can be used to classify user behaviour and heath status in a physically non-intrusive way. The interpreted data can be used to inform personalized feedback strategies. Further longitudinal studies can now be initiated to assess the effectiveness of m-Health interventions using the SWELL methods. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In the Nama-Karoo, South Africa, rainfall and grazing by livestock are two important drivers of botanical composition. Summer rains are advantageous particularly to the grass layer, whereas the characteristic dwarf shrubs survive better than grasses during drought, and benefit from rainfall during cool months. Heavy grazing by livestock during summer reduces the abundance of grasses, whereas winter grazing increases it. This study examined the influences of season of grazing (summer vs winter) and rainfall on botanical composition at two long-term grazing trials at Grootfontein in the eastern Karoo from 1949 to 1967. Severe summer grazing strongly reduced grass abundance and slightly increased the abundance of both palatable and unpalatable dwarf shrubs. High previous-season rainfall strongly promoted short-lived grasses. Dwarf shrubs and grasses declined in response to a decline in annual rainfall over the study period, except for the creeping grass Tragus koelerioides that increased in abundance, possibly in response to decreased competition and an increase in available gaps in the vegetation layer. Results indicate that grazing systems that exclude repeated summer-only grazing maintain ecological health, and that rainfall is the main driver of composition unless extreme grazing systems are employed. [ABSTRACT FROM AUTHOR]

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Northern Eurasia is highly sensitive to climate change. Fires in this region can have significant impacts on regional air quality, radiative forcing and black carbon deposition in the Arctic to accelerate ice melting. Using a MODIS-derived burned area data set, we report that the total annual area burned in this region declined by 53 % during the 15-year period of 2002-2016. Grassland fires dominated the trend, accounting for 93 % of the decline of the total area burned. Grassland fires in Kazakhstan contributed 47 % of the total area burned and 84 % of the decline. Wetter climate and increased grazing are the principle driving forces for the decline. Our findings: 1) highlight the importance of the complex interactions of climate-vegetation-land use in affecting fire activity, and 2) reveal how the resulting impacts on fire activity in a relatively small region such as Kazakhstan can dominate the trends of burned areas across a much larger landscape of northern Eurasia. Our findings may be used to improve the prediction of future fire dynamics and associated fire emissions in northern Eurasia. [ABSTRACT FROM AUTHOR]

Question: Herbivores exert strong influences on vegetation through activities such as trampling, defoliation, and fertilization. The combined effect of these activities on plant performance may cause dramatic vegetation shifts. Because herbivore pressures and the relative importance of their different activities are not equally distributed across the landscape, it is important to understand their isolated effect. One example of an herbivore‐induced vegetation shift is the reindeer‐driven transition from a subarctic tundra vegetation dominated by dwarf shrubs into a more productive, graminoid‐dominated state. Here, we asked how each of the grazing activities by reindeer separately and combined shape vegetation composition. Location: Nordreisa, Norway. Methods: We used a field experiment over six summers to study the separate and interacting effects of reindeer trampling, defoliation, addition of faeces and removal of moss on tundra heath vegetation, and to identify which of these factors were most important in driving the plant community towards a graminoid‐dominated state. Results: The combination of all treatments resulted in the strongest changes in vegetation, but trampling was the single most important factor altering the vegetation composition by reducing the abundance of both evergreen and deciduous dwarf shrubs. In contrast to what was expected, none of our treatments, separate or combined, resulted in an increased abundance of graminoids in 5 years, although such rapid vegetation changes have been observed in the field in similar environmental conditions. Conclusions: Trampling is the key process by which reindeer influence the abundance of functional groups, but only many processes combined result in strong changes in community composition. Moreover, additional factors not included in this experiment, such as urine, may be important in causing a state shift to a graminoid‐dominated community. [ABSTRACT FROM AUTHOR]