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Aim: Mountains shelter high biological diversity and constitute both important barriers and confluence areas for species. They often contain species whose populations occur at their range limit (peripheral species), which according to the "Centre‐Periphery" hypothesis (CPH) are expected to occur in marginal environments, exhibit low abundance and consequently high vulnerability. Our study investigates this hypothesis for the flora of the Pyrenees, a biogeographical crossroads containing a large proportion of the total European plant diversity. Location: Pyrenees. Methods: We determined whether more than 2600 native plant species were endemic to the Pyrenees or found at the centre or periphery of their whole distribution range within the mountain chain. We then compared the ecological preferences, local and regional abundance, and conservation status among central, peripheral and endemic species. Results: A quarter of the flora was found at its geographic range limit within the Pyrenees. Endemic and peripheral species were more likely to be soil specialists in alpine grasslands and rocks, and exhibited smaller regional ranges than central species, but their local abundance did not tend to differ. Peripheral species at their southern range edge were more widespread regionally than at their northern range edge. Peripheral taxa were more prevalent in the Pyrenean red list of threatened species (55%) compared to national and regional protection lists (40% and 31%, respectively). Main conclusions: Peripheral species contribute substantially to the diversity of the Pyrenean flora. They follow the predictions of the CPH given their occurrence in scarce habitats, their low regional abundance and their high vulnerability according to the Pyrenean red list, although they tend to show similar local abundances as other species and are infrequent in protection lists. Integrative and cross‐border assessments of the ecology and rarity of mountain floras provide better estimates of their vulnerability and ensure more efficient prioritization of their conservation. [ABSTRACT FROM AUTHOR]

With the advent of flexible electronics, the old fashioned and conventional solid‐state technology will be replaced by conductive inks combined with low‐cost printing techniques. Graphene is an ideal candidate to produce conductive inks, due to its excellent conductivity and zero bandgap. The possibility to chemically modify graphene with active molecules opens up the field of responsive conductive inks. Herein, a bioresponsive, electroactive, and inkjet‐printable graphene ink is presented. The ink is based on graphene chemically modified with selected enzymes and an electrochemical mediator, to transduce the products of the enzymatic reaction into an electron flow, proportional to the analyte concentration. A water‐based formulation is engineered to be respectful with the enzymatic activity while matching the stringent requirements of inkjet printing. The efficient electrochemical performance of the ink, as well as a proof‐of‐concept application in biosensing, is demonstrated. The versatility of the system is demonstrated by modifying graphene with various oxidoreductases, obtaining inks with selectivity toward glucose, lactate, methanol, and ethanol. [ABSTRACT FROM AUTHOR]

Long‐term monitoring of biodiversity is a fundamental part of environmental management, and Citizen Science (CS) approaches are increasing their contribution to such endeavour. CS plant monitoring programmes, however, almost exclusively report on the species presence, which can be used to detect changes in distribution or occupancy areas, but not to assess their local extinction risk. To anticipate the collapse of local populations, we need information on population sizes, trends, temporal fluctuations and threats. This is particularly important in the case of priority species (threatened, endangered and those that need special protection).Here we describe the working protocol of the 'Adopt a plant' programme, a collaborative network that is currently monitoring 332 populations of 204 plant taxa (threatened, of community interest, common, rare and habitat indicators) across a heterogeneous landscape in NE Spain. Coordinated by scientists, participants estimate population sizes, record disturbances and follow scientifically rigorous sampling methods to track plant abundances year after year in fixed representative areas within populations. Two simple indices are estimated from that information: the overall trend (mean population abundance change, as percentage; PAch) and temporal fluctuations (standard deviation of annual changes; PAchsd).The potential of this ongoing high‐quality dataset is demonstrated through the analysis of 242 populations monitored over 3–10 years. Stability is the dominant trend (mean PAch: +0.14%), with priority species having similar PAch and lower PAchsd than non‐priority ones. Regardless of the priority status, small populations performed worse than large ones. Only 8% of studied populations faced direct human threats.Synthesis and applications. The 'Adopt a plant' collaborative monitoring programme was launched in NE of Spain to produce standardized indices of abundance change and other early‐warning signals of concern or risk of population collapse. Such information is crucial to report the conservation status of threatened plants, and plants of Community interest (Habitats Directive). By analysing hundreds of populations, we found that priority plants experienced few threats and did not perform worse than non‐priority ones. This unexpected finding evidences the importance of gathering massive demographic information to refine conservation priorities and to achieve a more comprehensive assessment of flora's vulnerability. [ABSTRACT FROM AUTHOR]

Hutchinson defined the ecological niche as a hypervolume shaped by the environmental conditions under which a species can ‘exist indefinitely’. Although several authors further discussed the need to adopt a demographic perspective of the ecological niche theory, very few have investigated the environmental requirements of different components of species’ life cycles (i.e. vital rates) in order to examine their internal niche structures. It therefore remains unclear how species’ demography, niches and distributions are interrelated. Using comprehensive demographic data for two well‐studied, short‐lived plants (Plantago coronopus, Clarkia xantiana), we show that the arrangement of species’ demographic niches reveals key features of their environmental niches and geographic distributions. In Plantago coronopus, opposing geographic trends in some individual vital rates, through different responses to environmental gradients (demographic compensation), stabilize population growth across the range. In Clarkia xantiana, a lack of demographic compensation underlies a gradient in population growth, which could translate in a directional geographic range shift. Overall, our results highlight that occurrence and performance niches cannot be assumed to be the same, and that studying their relationship is essential for a better understanding of species’ ecological niches. Finally, we argue for the value of considering the assemblage of species’ demographic niches when studying ecological systems, and predicting the dynamics of species geographical ranges. [ABSTRACT FROM AUTHOR]

The 'centre-periphery hypothesis' ( CPH) is a long-standing postulate in ecology that states that genetic variation and demographic performance of a species decrease from the centre to the edge of its geographic range. This hypothesis is based on an assumed concordance between geographical peripherality and ecological marginality such that environmental conditions become harsher towards the limits of a species range. In this way, the CPH sets the stage for understanding the causes of distribution limits. To date, no study has examined conjointly the consistency of these postulates. In an extensive literature review we discuss the birth and development of the CPH and provide an assessment of the CPH by reviewing 248 empirical studies in the context of three main themes. First, a decrease in species occurrence towards their range limits was observed in 81% of studies, while only 51% demonstrated reduced abundance of individuals. A decline in genetic variation, increased differentiation among populations and higher rates of inbreeding were demonstrated by roughly one in two studies (47, 45 and 48%, respectively). However, demographic rates, size and population performance less often followed CPH expectations (20-30% of studies). We highlight the impact of important methodological, taxonomic, and biogeographical biases on such validation rates. Second, we found that geographic and ecological marginality gradients are not systematically concordant, which casts doubt on the reliability of a main assumption of the CPH. Finally, we attempt to disentangle the relative contribution of geographical, ecological and historical processes on the spatial distribution of genetic and demographic parameters. While ecological marginality gradients explain variation in species' demographic performance better than geographic gradients, contemporary and historical factors may contribute interactively to spatial patterns of genetic variation. We thereby propose a framework that integrates species' ecological niche characteristics together with current and past range structure to investigate spatial patterns of genetic and demographic variation across species ranges. [ABSTRACT FROM AUTHOR]

A new miniaturized flow injection analysis (FIA) system for developing electrochemiluminescence (ECL)-based assays is presented. Novel thin-layer flow−cell (TLFCL) screen-printed carbon electrodes integrated in one-channel flow cells were used as the electrode surface. These TLFCL electrodes, combined with miniaturized electrochemical and optical instrumentation, allowed a high degree of automation and simplicity of the assay. The performance of this high-throughput flow system was corroborated with a proof-of-concept centered on H2O2 detection. For that purpose, an ECL transduction chemistry mechanism based on a electrochemiluminescence resonance energy transfer (ECL-RET) donor−acceptor strategy, between an electro-oxidized luminophore (luminol) to a fluorophore (fluorescein), in the presence of the analyte of interest, was carried out. The results showed that fluorescein ECL-RET luminescent response increases the sensitivity of H2O2 detection by up to one order of magnitude, in comparison with a luminol−H2O2 fluorescein-free assay. All experiments were performed in a decentralized, small-sized, easy-to-use FIA system coupled to ECL detection instrumentation. [ABSTRACT FROM AUTHOR]

Aim To assess the spatial congruence between hotspots based on taxonomic, phylogenetic and functional diversity, after accounting for the correlation between diversity metrics, and the spatial scale and sampling completeness of data. Location The Ordesa and Monte Perdido National Park (Central Pyrenees, Spain), a species-rich area subjected to intensive botanical sampling. Methods We selected hotspots using different diversity metrics and two different data sources (~49,000 occurrence records of 1379 vascular plants in 1 × 1 km grid cells and 1218 inventories of plant communities containing a total of 859 taxa) and compared their spatial congruence. The effect of sampling completeness of data was explicitly assessed. Phylogenetic diversity and functional diversity (measured with richness-dependent and richness-independent metrics) were based on a molecular phylogeny, and a functional dendrogram, respectively. The effectiveness of different types of hotspots in representing other diversity components was tested with permutation tests. Results We found that spurious correlations between diversity metrics explained the congruence between taxonomic, phylogenetic and functional hotspots. When richness-independent metrics were used, diversity hotspots were no longer congruent regardless of the source of data. Hotspots were biased towards intensively sampled grid cells, and the amount of diversity they captured was exaggerated due to the coarse spatial scale of species-occurrence data. The efficiency of hotspots in terms of integrating different diversity components was lower at community scale and not significantly higher than expected at random, regardless of the sampling completeness. Main conclusions Our results stress that the arbitrary use of diversity metrics and the scale of analyses along with the sampling bias in data can distort the true location of hotspots, and exaggerate their spatial congruence. After accounting for such methodological issues, we found a clear mismatch between diversity components that questions the utility of hotspots as a conservation tool of multiple diversity components. [ABSTRACT FROM AUTHOR]

Most species are exposed to significant environmental gradients across their ranges, but vital rates (survival, growth, reproduction and recruitment) need not respond in the same direction to those gradients. Opposing vital rate trends across environments, a phenomenon that has been loosely called 'demographic compensation', may allow species to occupy larger geographical ranges and alter their responses to climate change. Yet the term has never been precisely defined, nor has its existence or strength been assessed for multiple species. Here, we provide a rigorous definition, and use it to develop a strong test for demographic compensation. By applying the test to data from 26 published, multi-population demographic studies of plants, we show that demographic compensation commonly occurs. We also investigate the mechanisms by which this phenomenon arises by assessing which demographic processes and life stages are most often involved. In addition, we quantify the effect of demographic compensation on variation in population growth rates across environmental gradients, a potentially important determinant of the size of a species' geographical range. Finally, we discuss the implications of demographic compensation for the responses of single populations and species' ranges to temporal environmental variation and to ongoing environmental trends, e.g. due to climate change. [ABSTRACT FROM AUTHOR]

Aim The 'centre-periphery hypothesis' ( CPH) predicts that species performance (genetics, physiology, morphology, demography) will decline gradually from the centre towards the periphery of the geographic range. This hypothesis has been subjected to continuous debate since the 1980s, essentially because empirical studies have shown contrasting patterns. Moreover, it has been proposed that species performance might not be higher at the geographic range centre but rather at the environmental optimum or at sites presenting greater environmental stability in time. In this paper we re-evaluate the CPH by disentangling the effects of geographic, climatic and historical centrality/marginality on the demography of three widely distributed plant species and the genetic diversity of one of them. Location Europe and North America. Methods Based on a species distribution modelling approach, we test whether demographic parameters (vital rates, stochastic population growth rates, density) of three plant species of contrasting life-forms, and the genetic diversity of one of them, are higher at their geographic range centres, climatic optima or projected glacial refugia. Results While geographic, climatic and historical centre-periphery gradients are often not concordant, overall, none of them explain well the distribution of species demographic performance, whereas genetic diversity responds positively only to a historical centrality, related to post-glacial range dynamics. Main conclusions To our knowledge, this is the first assessment of the response of species performance to three centrality gradients, considering all the components of different species life cycles and genetic diversity information across continental distributions. Our results are inconsistent with the idea that geographically, climatically or historically marginal populations generally perform worse than central ones. We particularly emphasize the importance of adopting an interdisciplinary approach in order to understand the relative effects of contemporary versus historical and geographic versus ecological factors on the distribution of species performance. [ABSTRACT FROM AUTHOR]

The effects of the present biodiversity crisis have been largely focused on the loss of species. However, a missed component of biodiversity loss that often accompanies or even precedes species disappearance is the extinction of ecological interactions., Here, we propose a novel model that (i) relates the diversity of both species and interactions along a gradient of environmental deterioration and (ii) explores how the rate of loss of ecological functions, and consequently of ecosystem services, can be accelerated or restrained depending on how the rate of species loss covaries with the rate of interactions loss., We find that the loss of species and interactions are decoupled, such that ecological interactions are often lost at a higher rate. This implies that the loss of ecological interactions may occur well before species disappearance, affecting species functionality and ecosystems services at a faster rate than species extinctions. We provide a number of empirical case studies illustrating these points., Our approach emphasizes the importance of focusing on species interactions as the major biodiversity component from which the 'health' of ecosystems depends. [ABSTRACT FROM AUTHOR]

Anthropogenic changes in landscape structure, such as habitat loss, habitat subdivision and edge increase, can strongly affect the performance of plants, leading to population declines and extinctions. Many studies to date have focused on single characteristics of landscape structure or single life-cycle phases, but they poorly discern the different pathways through which landscape change influences plant population dynamics via different vital rates. In this study, we evaluated the effect of two structural characteristics (habitat quantity and edge length) on vital rates and population growth rates of a perennial forest plant ( Primula vulgaris) in a historically managed landscape. Areas with higher amounts of forest habitat had higher population growth rates due to higher recruitment, survival and growth of seedlings, while increased forest edge length was positively associated with population growth rates primarily due to a higher survival of reproductive individuals. Effects were stronger during the first of the two transition intervals studied. The results demonstrate that changes in different landscape structural characteristics may result in opposing effects acting via different vital rates, and highlight the need for integrative analyses to evaluate the effects of rapid landscape transformation on the current and long term plant population dynamics. [ABSTRACT FROM AUTHOR]

Analyzing intraspecific variation in population dynamics in relation to environmental factors is crucial to understand the current and future distributions of plant species. Across ranges, peripheral populations are often expected to show lower and more temporally variable vital rates than central populations, although it remains unclear how much any differences in vital rates actually contribute to differences in population growth rates. Moreover, few demographic studies accounting for environmental stochasticity have been carried out both at continental and regional scales. In this study we calculated stochastic growth rates in five central and six northern peripheral populations of the widespread shortlived herb Plantago coronopus along the Atlantic Coast in Europe. To evaluate at two spatial scales how mean values and variability of vital rates (i.e., fecundity, recruitment, survival, growth, and shrinkage) contributed to the differences in stochastic growth rates, we performed Stochastic Life Table Response Experiment (SLTRE) analyses between and within central and peripheral regions. Additionally, we searched for correlations between vital rate contributions and local environmental conditions. Lower mean values and greater variability for some vital rates in peripheral than in central populations had an overall negative but nonsignificant effect on the stochastic growth rates in the periphery. Different life cycle components accounted for differences in population growth depending on spatial scale, although recruitment was the vital rate with the highest influence both between and within regions. Interestingly, the same pattern of differentiation among populations was found within central and peripheral areas: in both regions, one group of populations displayed positive contributions of growth and shrinkage and negative contributions of recruitment and survival; the opposite pattern was found in the remaining populations. These differences in vital rate contributions among populations within regions were correlated with precipitation regime, whereas at the continental scale, differences in contribution patterns were related to temperature. Altogether, our results show how populations of F. coronopus exhibit life cycle differences that may enable the species to persist in locations with widely varying environmental conditions. This demographic flexibility may help to explain the success of widespread plants across large and heterogeneous ranges. [ABSTRACT FROM AUTHOR]

In animals, age-associated disorders are believed to be connected to shifts in the antioxidant/pro-oxidant balance in favour of oxidative stress. However, the contribution of oxidative stress to ageing in long-lived perennials has not been explored to date., Here, we tested age- and sex-related changes in several photo-oxidative stress markers in Borderea pyrenaica, a small dioecious geophyte relict of the Tertiary with one of the longest life spans ever recorded for a non-clonal herb (more than 300 years). Given that survival increases with age in B. pyrenaica, we hypothesized that oxidative stress does not increase with ageing because the species develops improved anti-oxidant defence., In three field samplings performed during 2008, 2010 and 2011 in the Central Pyrenees ( NE Spain), we examined the effects of ageing and sex on photosynthetic pigment levels, PSII integrity ( F v /F m ratio), lipid peroxidation, and the extent of photo and anti-oxidant protection in chloroplasts. Furthermore, we explored whether age and sex affect plant response to severe natural desiccation., Both male and female plants maintained chlorophyll levels intact, as well as the F v/ F m ratio and the levels of lipid peroxidation, irrespective of age. This finding suggests the absence of age-associated oxidative stress at the organismal level. Furthermore, photoprotection mechanisms were found to be similarly efficient in the oldest individuals as in juvenile plants, in terms of xanthophyll cycle de-epoxidation and accumulation of low-molecular-weight antioxidants (carotenoids and tocopherols). Indeed, females over 100 years of age were the most resistant to severe desiccation, maintaining higher leaf hydration levels, less chlorophyll degradation and better PSII integrity under stress than females below 100 years, males below or above 100 years, and juveniles., Synthesis. Neither males nor females of the extraordinarily long-lived B. pyrenaica show age-dependent signs of oxidative stress. This observation suggests that age-induced oxidative stress is not a universal feature of ageing in perennial plants. Indeed, females older than 100 years showed signs of negative senescence, in that they registered improved physiological performance with increasing age. [ABSTRACT FROM AUTHOR]

Peripheral populations have long been predicted to show lower vital rates, higher demographic fluctuations, and lower densities than central populations. However, recent research has questioned the existence of clear patterns across species' ranges. To test these hypotheses, we monitored five central and six northern peripheral populations of the widespread herb Plantago coronopus along the European Atlantic coast during 5 yr. We estimated population density, and calculated mean values and temporal variability of four vital rates (survival, individual growth, fecundity and recruitment) in hundreds of plants in permanent plots. Central populations showed higher fecundity, whereas peripheral populations had higher recruitment per reproductive plant, indicating a higher overall reproductive success in the periphery. Central populations showed a marginally significant tendency for higher growth, and there were no differences between range positions in survival. Fecundity and growth were affected by intraspecific competition, and recruitment was affected by precipitation, highlighting the importance of local environmental conditions for population performance. Central and peripheral populations showed no significant differences in temporal variability of vital rates. Finally, density was significantly higher in peripheral than in central populations, in discrepancy with the abundant-centre model. Density was correlated to seedling recruitment, which would counterbalance in peripheral populations the lower fecundity and the tendency for lower growth of established plants. Such compensations among vital rates might be particularly common in widespread plants, and advise against simplistic assumptions of population performance across ranges. The whole species' life cycle should be considered, since different arrangements of vital rates are expected to maximize fitness in local environments. Our results show also the importance of discerning between geographical periphery and ecological marginality. In a context of climate-induced range shifts, these considerations are crucial for the reliability of niche-models and the management of plant peripheral populations. [ABSTRACT FROM AUTHOR]

Populations at the margin of geographic ranges of distribution have been considered more vulnerable than central ones, but recent reviews have caste doubt on this generalization. We examined the reproductive and demographic performance of a rare Euroasiatic orchid (Cypripedium calceolus) at its southwesterly range limit and compared our findings with those of previous studies of nine central populations at the center of the orchid's range. We sought to test the central-marginal model and to evaluate factors involved in long-term performance of forest Eurosiberian species with peripheral populations in southern European mountains. We characterized (structure, temporal fluctuations, herbivory, reproductive success, and recruitment at different habitats) four Pyrenean populations of C. calceolus of different sizes (5-3500 ramets) and monitored three of them for up to 13 years. Two quantitative stochastic models (count data and matrix models) were used to assess population trends and viability and the effect of herbivory. Contrary to expectations, and despite the negative effect of sporadic events of herbivory, the peripheral populations we studied (except the smallest one) performed similarly or better than populations occurring in central part of the species' range in terms of reproductive success and population growth rates. Landscape changes over the last 50 years suggest that natural reforestation could be involved in the success of this plant at its southern limit. Forest expansion in the mountain regions of southern Europe may provide new opportunities for plants with geographic distributions centered mainly at higher latitudes and give some hope for their recovery in future scenarios dominated by biodiversity loss. [ABSTRACT FROM AUTHOR]

A central tenet of conservation biology is that population size affects the persistence of populations. However, many narrow endemic species combine small population ranges and sizes with long persistence, thereby challenging this tenet. I examined the performance of three different-sized populations of Petrocoptis pseudoviscosa (Caryophyllaceae), a palaeoendemic rupicolous herb distributed along a small valley in the Spanish Pyrenees. Reproductive and demographic parameters were recorded over 6 years, and deterministic and stochastic matrix models were constructed to explore population dynamics and extinction risk. Populations differed greatly in structure, fecundity, recruitment, survival rate, and life span. Strong differentiation in life-history parameters and their temporal variability resulted in differential population vulnerability under current conditions and simulated global changes such as habitat fragmentation or higher climatic fluctuations. This study provides insights into the capacity of narrow endemics to survive both at extreme environmental conditions and at small population sizes. When dealing with species conservation, the population size–extinction risk relationship may be too simplistic for ancient, ecologically restricted organisms, and some knowledge of life history may be most important to assess their future. [ABSTRACT FROM AUTHOR]

In addition to human-caused changes in the environment, natural stochasticity may threaten species persistence, and its impact must be taken into account when priorities are established and management plans are designed. Borderea chouardii is a Tertiary relict at risk of extinction that occurs in only one location in the world, where the probability of human disturbance is low. Its persistence, therefore, is mainly linked to its response to natural threats such as stochasticity. Over 8 years I monitored up to 25% of this rupicolous small geophyte. The population had an unbalanced size structure and 90% failure in seed arrival at appropriate microhabitats, which suggests a problem with recruitment. I used matrix models to describe its population dynamics, conducted hand sowings, and performed stochastic simulations to investigate the effect of environmental stochasticity on population trend and viability. I modeled several scenarios to represent a variety of ecological situations, such as population reduction, episodic or persistent disease, and enhancement or decrease of recruitment. Population growth rate (λ) was never significantly different from unity over the study period. The risk of extinction was null over the next five centuries under current conditions. Increase of mortality and decrease of recruitment reduced stochastic population growth rate, but no factor except a persistent increase of 10% mortality resulted in extinction. These results are the consequence of the plant's extremely long life span (over 300 years) and low temporal variability of key vital rates. Even though hand sowing significantly increased the stochastic population growth rate, other approaches may be more important for the persistence of this species. The extremely slow capacity for recovery following disturbances renders habitat preservation essential. In addition, the founding of new populations would reduce the risk associated with habitat destruction. [ABSTRACT FROM AUTHOR]

This meeting report discusses the challenges and importance of monitoring plants and pollinators in a changing world. It emphasizes the need for systematic surveys and monitoring using plot-based methods to gather quantitative data on abundance and distributions. The report highlights the scarcity of monitoring data, lack of support for monitoring programs in many countries, and the need for coordinated efforts and improved statistical tools. It also mentions the development of a standardized EU pollinator monitoring scheme and the potential for technological innovations. The report concludes by emphasizing the importance of policy and international collaboration in conservation efforts, particularly in relation to the EU's Nature Restoration Law. The text acknowledges the funding sources and contributions of citizen scientists to monitoring efforts. [Extracted from the article]