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The reproductive traits in Gagea are affected by both abiotic and biotic environmental factors. However, further intrinsic drivers, like the ploidy level, could also have a significant influence on the sexual efficiency of these geophytes. Here, we present a comparative study involving the reproductive biology of five species of Gagea occurring in southern Italy, and representing different ploidy levels. The experimental investigations included flower phenology, pollen quality (i.e., morphology, viability, and germination), and stigma receptivity. Such data were then combined with information on seed-set available from previous work. All the studied species showed a gradual pollen presentation, and an early and durable stigma receptivity. Such traits represent effective functional adaptations to prevent pollen limitation under the unpredictable weather dynamics typical of the early blooming season of these plants. The use of a diluted substrate favoured the rate of pollen germination in vitro and, likely, it represents a further adaptation versus adverse environmental conditions (i.e., rain damage on exposed pollen). However, the rates of pollen viability and germination were generally low and appeared related to the ploidy level. Data inherent pollen quality (i.e. morphology, viability and germination) and seedset indicated the hexaploid G. lutea as the most fertile species, while the heptaploid G. fragifera had the lowest scores for all the considered traits. Finally, by considering the isolation and reduced size of the studied population, the unexpected low fertility found in the diploid G. minima was possibly due to inbreeding depression related to the relict status of this species in southern Italy. [ABSTRACT FROM AUTHOR]

Eosinophilic esophagitis (EoE) is increasingly diagnosed in patients with dysphagia. Type-2 immunity can induce EoE histopathology via non-IgE-dependent mechanisms, possibly involving IgG4 and IL-10. To elucidate the contribution of this response to EoE pathogenesis, we examined its association with clinical and histologic endpoints in adult EoE patients given a two-food elimination diet. IgG4- and IL-10-expressing cells were counted in esophageal biopsies and serum food-specific IgG4 measured at baseline and follow-up. Variables were correlated with histologic measures of disease activity. Patients exhibited significant reduction in esophageal eosinophilia and overall histology. A significant decrease in IL-10+-cell frequencies correlated with histologic changes. In contrast, a decline in serum and esophageal IgG4, while substantial, did not correlate with IL-10+-cell frequencies or histologic parameters. These results suggest a critical role of IL-10 in EoE pathogenesis. Conversely, IgG4 expression, while reflecting exposure to food antigens, is not obviously related to EoE histopathology or IL-10 expression. [ABSTRACT FROM AUTHOR]

Abstract Global plant diversity is at risk due to anthropogenic changes to ecosystems, but given severely limited conservation resources, a reliable prioritisation strategy for species and sites is needed. Our objective was to identify key areas for conserving the phylogenetic diversity (PD) of threatened vascular plants in Italy, one of the most species-rich regions in the Mediterranean Basin. We used spatial data and the conservation status of 995 threatened vascular plants and applied a phylogenetically informed spatial planning to minimize conservation costs. We then determined the degree of overlap with existing protected areas and evaluated whether this PD-based prioritisation of areas provides adequate protection for threatened phylogenetically distinctive species (EDGE). The cost-effective procedure identified as priority for conservation 12% of the study territory, while achieving over 90% of conservation targets (total PD). We showed that priority areas and protected areas are moderately spatially mismatched. We also showed that not all top-EDGE species were met by the procedure applied, hence we conclude that the PD-based model indicated key areas for protection, but nevertheless additional attention is needed to protect top-EDGE species. This study represents one of the most comprehensive analyses, to date, for the conservation of the native flora in the Mediterranean, incorporating both spatial distribution and evolutionary relationships. Our work on the prioritisation of threatened plant species across Italy can serve as a guide for future conservation applications. Graphical abstract Unlabelled Image Highlights • We applied a cost-effective phylogenetic diversity (PD) informed spatial planning. • Key areas cover 12% of Italy, while achieving 90% of conservation targets. • Areas with overlap across PD and top-EDGE should receive special attention. • Additional attention is needed to conserve top-EDGE taxa not covered by key PD areas. [ABSTRACT FROM AUTHOR]

Background: Recent studies have evaluated the upper esophageal sphincter (UES) with high-resolution manometry (HRM) in some esophageal diseases, but not eosinophilic esophagitis (EoE). The aim of our study was to evaluate the function of the UES across EoE, gastroesophageal reflux disease (GERD), functional dysphagia (FD), and the relationship with esophageal symptoms, esophageal body contraction, and esophagogastric junction (EGJ) metrics. Methods: HRM was performed on 30 EoE, 18 GERD, and 29 FD patients according to the Chicago Classification 3.0. The study data were exported to the online analysis platform Swallow Gateway. The UES was assessed in terms of UES Resting Pressure (UES-RP), UES Basal Pressure (UES-BP), UES Integrated Relaxation Pressure (UES-IRP), UES Relaxation Time (UES-RT), Basal UES Contractile Integral (Basal UES-CI), Post-Deglutitive UES Contractile Integral (Post-Deglutitive UES-CI), and Proximal Contractile Integral (PCI). Results: ANOVA analysis showed significantly higher values of Post-Deglutitive UES-CI in EoE patients compared with FD patients (p = 0.001). Basal UES-CI and UES-RP showed significantly higher values in EoE (p = 0.002, p = 0.038) and GERD (p < 0.001, p = 0.001) patients compared with FD patients. Correlations between LES-CI and Post-Deglutitive UES-CI, Basal UES-CI, and UES-RP (p ≤ 0.001, p = 0.027, p = 0.017, respectively), and between LES-BP and Post-Deglutitive UES-CI (p = 0.019), independent of diagnosis, were shown. No correlations have been demonstrated between the UES, EGJ metrics, and esophageal symptoms. Conclusions: Some differences in UES metrics in the three different diseases were found. Further studies are needed to confirm the results of our pilot study and possible applications in clinical practice. [ABSTRACT FROM AUTHOR]

The yellow carnation Dianthus guliae Janka is a rare endemic of the Italian peninsula. As numerous extinctions have occurred in the past, very few populations are still present. Two years of field surveys revealed high mortality and an absence of recruitment in the southernmost populations of this species. Work in a botanical garden, under semi-natural conditions, revealed the occurrence of proterandrous hermaphroditism and self-compatibility. The durable flower lifespan, the competitive effects among flowers and the different outcomes from spontaneous and hand-performed pollinations (with both self- and cross-pollen) suggested low pollination rates in the experimental stand. Pollinator exclusion experiments revealed a low frequency of delayed autonomous selfing, suggesting that self-fertilization in D. guliae relies mainly on facilitated selfing and geitonogamy. Studies of inbreeding depression during the early life-history stages revealed significant differences between selfed and crossed progenies in terms of seed mass, germination rates, developmental vigour and mortality rates. Therefore, when pollen delivery is scarce, the plant may fail reproductive assurance via autonomous selfing. The influence of inbreeding depression contributes to a further reduction in recruitment chances in very small D. guliae populations. Experimental reintroductions are urgent to avoid local extinction at the southern periphery of its range. [ABSTRACT FROM AUTHOR]

This paper considers the demography, ecology, and conservation perspectives of the western populations of the clonal dwarf-shrub Sarcopoterium spinosum (L.) Spach. While in the Middle East the species dominates large areas, westwards it is less common and many populations have become extinct since the late 19th century. We highlight the ecological limitations and their implications for the conservation of the species at the periphery of its range. In southern Italy we studied the demographic traits of two populations and the age spatial structure of a third. Ramet density and lifespan appear to be lower than in the Middle East. The floristic analysis of the stands studied and a climatic analysis over the whole range of S. spinosum provide a key for the interpretation of such differences. Given that summer drought stress decreases westwards, both the sprouting vigor and the ecological space available for S. spinosum become limited by increasing competition. This makes the populations more likely to become extinct in changing landscapes, as revealed by the decreasing extent of occurrence and area of occupancy due to habitat loss. Although S. spinosum is not at risk in the Middle East, at the western border of its range it qualifies as an endangered species. [ABSTRACT FROM AUTHOR]

Deceptive orchid species that offer no floral rewards to pollinators often experience pollinator limitation.Serapias vomeraceais considered a particular example of terrestrial orchids using deceptive strategies because its sepals, petals and the lateral lobes of the hypochile form a small tube imitating a little hole that the insects use to rest. The pollination biology and breeding system were investigated in two populations ofS. vomeraceain order to examine the extent of pollinator limitation. Visiting insects were immobile in theSerapiasflowers during the early morning and late evening. The main pollinators were Oedemeridae and Lymexylidae (Coleoptera), but Hymenoptera (Ceratina,Eucera,Osmia) were also observed. Fruit set did not vary in response to floral display size, suggesting that variations in flower number per inflorescence and plant height were not responsible for attracting pollinators and thus reproductive success. AlthoughS. vomeraceais self-compatible, bagged inflorescences produced no fruits. Artificial pollination resulted in 95–100% fruit set by induced autogamy, 95–100% by geitonogamous pollination and 90–95% by xenogamous pollination. Fruit set in the open-pollinated control was 13–18%. Fruit production was not related to the size, number or position of flowers. Pollinator observation and supplemented hand-pollination indicated a positive relationship between fruit set and pollinator visitations in this species. [ABSTRACT FROM AUTHOR]

Italy has a rich natural heritage, which is dangerously under pressure. In recent years, there is an increased awareness of the crucial role of plants in ecosystem functioning and in providing ecosystem services. Consequently, an updated Red List of the Italian vascular flora was compiled in this work, at the request of the Ministry for Environment, Land and Sea Protection, with the scientific support of the Italian Botanical Society. The IUCN Red List criteria were applied to 2,430 Italian native vascular plant taxa to assess their current extinction risk and to highlight the major threats affecting the Italian flora. Our results revealed that 54 taxa (2.2% of the assessed taxa) are extinct or possibly extinct at regional level, while 590 taxa (24.3%) were assigned to a risk category. Moreover, 404 taxa (16.6%) were categorized as Data Deficient. The Italian vascular flora is primarily threatened by habitat modifications due to anthropic disturbance and, especially, to agriculture, tourism and residential development. Coastal areas and lowlands, where anthropogenic impacts and ecosystem destruction are more pronounced, host the greatest number of extinct or declining taxa. Our results represent an important baseline to establish conservation priorities, legislative choices and intervention strategies on a national scale. [ABSTRACT FROM AUTHOR]

Background: The knowledge of the genetic architecture of closely related species and/or populations of a single species can be very useful to shed light on the processes that led to their current distributions. The present study provides a preliminary evaluation of the conservation status of the populations of Cryptotaenia thomasii, a very narrow endemic species occurring in southern Italy. Previous studies showed that C. thomasii was phylogenetically closely related to C. flahaultii, endemic species of Caucasus, and to evaluate its conservation status and the genetic variability of plant species the internal transcribed spacers (ITSs) of nuclear ribosomal DNA were sequenced and the SNPs were analyzed. Results: The restriction analysis of nrDNA with the restriction enzymes allowed to detect the presence of two single mutations (SNPs) among the sequences of two species. Our molecular analysis pointed out that C. thomasii and C. flahaultii, in spite of their geographical disjunction, show a sign of an ancient contact as an extreme case of geographical disjunction Italian-Caucasus. Conclusion: From the evolutionary history of the species and its distribution pattern one can reconstruct a possible scenario with some hypotheses that explain the hypothetical ancestral area where the two species were in contact. We speculate the two species may have originated from fragmentation of a common ancestor widespread in the Western Palearctic zone and have survived in two separated refuge areas limited by important mountain systems. This hypothesis is supported by our molecular analysis, in fact, the analysis of SNPs showed that some C. thomasii populations retain the signs of an ancient link with C. flahaultii. [ABSTRACT FROM AUTHOR]

The selection of resilient cultivars could help stem the losses in forage production due to a changing climate. Secale strictum is a wild grass with interesting potential as a forage crop. We studied the germination requirements of six wild S. strictum populations, representative of the whole species distribution range in Italy and occurring under different osmotic conditions (0 MPa, −0.8 MPa, −1.0 MPa, −1.2 MPa, −1.4 MPa and −1.6 MPa). Our aim was to find beneficial seed and germination traits for the possible use of this species as a crop. Different accessions of domesticated Secale cereale and ×Triticosecale were used as comparison. Some populations of S. strictum were drought tolerant at germination level (final germination > 25% at −1.6 MPa). A great variability was observed among wild populations in traits that currently limit the cultivation of the species as a forage crop (seed size, germinability) and that could improve its usage, especially in arid areas (water stress tolerance, fast germination). A correlation exists between the germination rates of wild populations and the seasonality of the rainfall at their natural growing sites. These results underline the importance of choosing appropriate source lineages when selecting S. strictum populations for crop development. [ABSTRACT FROM AUTHOR]

The results of the 4th National Report for the Italian flora under the 92/43/EEC 'Habitats' Directive are presented. The outcomes showed a general negative conservation status for plant species, with the worst situation being in the Mediterranean bioregion. At the National level, significant monitoring and conservation activities are required. [ABSTRACT FROM AUTHOR]

The bulbous geophyte Fritillaria montana is partially self-compatible and capable of switching gender. Small flowering plants produce only single male flowers, but larger plants produce hermaphrodite or, rarely, male and hermaphrodite flowers. Eight populations in peninsular Italy were sampled to determine the frequency and size distributions of male and hermaphrodite plants, and to determine the relationship of plant size to male and hermaphrodite flower production. Male plants were significantly smaller than hermaphrodites and made up 14.5-47.8% (100% in one small population) of flowering plants within populations. There were no significant differences in male fitness among female-sterile and hermaphrodite flowers, as they both possessed full and comparable fertilizing power. Therefore, the gender variation observed in F. montana is likely to depend on resource-dependent sex allocation. From an evolutionary perspective, we highlight the occurrence of similar mechanisms of gender variation in other representatives of the order Liliales. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168, 323-333. [ABSTRACT FROM AUTHOR]

Effects of climate change are particularly important in the Mediterranean Biodiversity hotspot where rising temperatures and drought are negatively affecting several plant taxa, including endemic species. Assisted colonisation (AC) represents a useful tool for reducing the effect of climate change on endemic plant species threatened by climate change.We combined species distribution models (SDMs) for 188 taxa endemic to Italy with the IUCN red listing range loss threshold under criterion A (30%) to define: (a) the number of AC (measured as 2 × 2 km grid cells that should be occupied by new populations, i.e. grid cells = new populations) required to fully compensate for predicted range loss and to halt the decline below the 30% of range loss; (b) The number of cells necessary to compensate for range loss was calculated as the number of currently occupied cells lost under future climate due to unsuitable conditions. We used two representative concentration pathways, +2.6 and +8.5 W/m2, optimistic and pessimistic scenarios respectively. Availability of suitable areas for AC was also assessed within the current species distribution and within protected areas.Under the optimistic scenario, no taxa would lose more than 30% of their range and AC would not be required. Under the pessimistic scenario, roughly the 90% of taxa showed a cell loss higher than 30%. Eight taxa were predicted to lose >95% of their range. For these species, AC was required from 13 to 16 new populations (=13–16 grid cells) per taxon to cap the range loss at 30%. For currently VU or EN species, an average number of 32–35 AC attempts would be necessary to fully compensate their range loss under a pessimistic scenario. Suitable recipient sites within protected areas falling in their projected range were identified, allowing for short‐distance AC.Synthesis. Combining species distribution models and red listing thresholds under Criterion A has enabled the strategic planning of multiple species assisted colonisation minimising the effort in terms of new populations to be created and maximising the conservation benefit in terms of range loss compensation. [ABSTRACT FROM AUTHOR]

The assessment of the conservation status of a species is the first step in developing a conservation strategy. IUCN Red Lists assessments are an important starting point for conservation actions and the most commonly applied method for assessing the extinction risk of a species. In this study, the global conservation status of the rock rose Helianthemum caput-felis Boiss. (Cistaceae), a perennial Mediterranean plant, was evaluated using the Red List criteria. The distribution of the species was determined by monitoring historical localities and all other suitable sites along the western Mediterranean coasts for 6 years. For each confirmed locality, the ecological and population parameters and the main threats were recorded; these data were used in a quantitative analysis of the species' extinction risk. Our findings indicate there have been several recent extinctions, and there is a continuing decline in the species' area of occurrence, habitat quality and number of reproductive plants. The main threats are related to human activities. Extinction models indicate a probability of quasi-extinction risk of c. 30% in five generations or c. 45% in three generations, with the species likely to become extinct in seven currently known localities within the next 10 years. Application of the Red List criteria indicates H. caput-felis should be categorized as Endangered. This study confirms that legal protection and passive conservation measures are insufficient to guarantee the persistence of a plant species. Active conservation and management actions are needed to protect this and other threatened species of the Mediterranean Basin. [ABSTRACT FROM AUTHOR]

In this contribution, the conservation status assessment of three vascular plants according to IUCN categories and criteria are presented. It includes the assessment of Soldanella calabrella Kress at global level, and the regional assessment of Luzula pindica (Hausskn.) Chrtek & Křísa and Romulea variicolor Mifsud (Italy). [ABSTRACT FROM AUTHOR]

In this contribution, the conservation status assessment of four vascular plants according to IUCN categories and criteria are presented. It includes the assessment of Ophrys normanii J.J.Wood at global level, and the regional assessment of Genista anglica L., Helianthemum lippii (L.) Dum.Cours., and Scrophularia lucida L. (Italy). [ABSTRACT FROM AUTHOR]

Aims: We examined the importance of litter quality and microclimate on early-stage litter mass loss, analysed the importance of interactions among environmental factors in determining key decomposition parameters and compared the variation in decomposition rates in vegetation types and sites with similar climate.Methods: Following the Tea-Bag Index approach, 464 tea-bags were incubated in the soil in 79 sites, distributed across Italy, which included six vegetation types and a broad range of microclimatic conditions.Results: Litter type exerted a stronger control on mass loss compared to climatic factors. The effects of soil moisture were not the same for high and lower quality litter. In addition, the effects of temperature on the decomposition rate depended on soil moisture. The stabilization factor was strongly temperature-dependent, but the influence of temperature differed among vegetation types: those dominated by small-size plants showed a strong decrease in the potential amount of plant material entering into the soil stock under warmer temperatures. The lowest variation in decomposition rate was found in sites characterised by low temperatures, and, among the vegetation types, in alpine snowbeds.Conclusions: The role of litter quality and of the interactions among environmental conditions can potentially determine significant shifts in the expected patterns of ecosystem carbon fluxes. [ABSTRACT FROM AUTHOR]

Taxa endemic to a country are key elements for setting national conservation priorities and for driving conservation strategies, since their persistence is entirely dependent on national policy. We applied the IUCN Red List categories to all Italian endemic vascular plants (1340 taxa) to assess their current risk of extinction and to highlight their major threats. Our results revealed that six taxa are already extinct and that 22.4% (300 taxa) are threatened with extinction, while 18.4% (247; especially belonging to apomictic groups) have been categorized as Data Deficient. Italian endemic vascular plants are primarily threatened by natural habitat modification due to agriculture, residential and tourism development. Taxa occurring in coastal areas and lowlands, where anthropogenic impacts and habitat destruction are concentrated, display the greatest population decline and extinction. The national network of protected areas could be considered effective in protecting endemic-rich areas (ERAs) and endemic taxa, but ineffective in protecting narrow endemic-rich areas (NERAs), accordingly changes to the existing network may increase the effectiveness of protection. For the first time in the Mediterranean Basin biodiversity hotspot, we present a comprehensive extinction assessment for endemic plants under the full responsibility of a single country. This would provide an important step towards the prioritization and conservation of threatened endemic flora at Italian, European, and Mediterranean level. A successful conservation strategy of the Italian endemic vascular flora should implement the protected area system, solve some taxonomical criticism in poorly known genera, and should rely on monitoring threatened species, and on developing species-specific action plans. [ABSTRACT FROM AUTHOR]

In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations and status changes to the Italian administrative regions for taxa in the genera Alchemilla, Arundo, Bupleurum, Clematis, Clinopodium, Cota, Crassula, Cytisus, Euphorbia, Hieracium, Isoëtes, Lamium, Leontodon, Linaria, Lychnis, Middendorfia, Ophrys, Philadelphus, Pinus, Sagina, Sedum, Taeniatherum, Tofieldia, Triticum, Veronica, and Vicia. Nomenclature and distribution updates, published elsewhere, and corrigenda are provided as supplementary material. [ABSTRACT FROM AUTHOR]

Abstract: Questions: Do vascular plant species richness and beta‐diversity differ between managed and structurally complex unmanaged stands? To what extent do species richness and beta‐diversity relate to forest structural attributes and heterogeneity? Location: Five national parks in central and southern Italy. Methods: We sampled vascular plant species composition and forest structural attributes in eight unmanaged temperate mesic forest stands dominated or co‐dominated by beech, and in eight comparison stands managed as high forests with similar environmental features. We compared plant species richness, composition and beta‐diversity across pairs of stands (unmanaged vs managed) using GLMMs. Beta‐diversity was quantified both at the scale of each pair of stands using plot‐to‐plot dissimilarity matrices (species turnover), and across the whole data set, considering the distance in the multivariate species space of individual plots from their centroid within the same stand (compositional heterogeneity). We modelled the relationship between species diversity (richness and beta‐diversity) and forest structural heterogeneity and individual structural variables using GLMMs and multiple regression on distance matrices. Results: Species composition differed significantly between managed and unmanaged stands, but not richness and beta‐diversity. We found weak evidence that plant species richness increased with increasing levels of structural heterogeneity and canopy diversification. At the scale of individual stands, species turnover was explained by different variables in distinct stands, with variables related to deadwood quantity and quality being selected most often. We did not find support for the hypothesis that compositional heterogeneity varies as a function of forest structural characteristics at the scale of the whole data set. Conclusions: Structurally complex unmanaged stands have a distinct herb layer species composition from that of mature stands in similar environmental conditions. Nevertheless, we did not find significantly higher levels of vascular plant species richness and beta‐diversity in unmanaged stands. Beta‐diversity was related to patterns of deadwood accumulation, while for species richness the evidence that it increases with increasing levels of canopy diversification was weak. These results suggest that emulating natural disturbance, and favouring deadwood accumulation and canopy diversification may benefit some, but not all, facets of plant species diversity in Apennine beech forests. [ABSTRACT FROM AUTHOR]

In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records and confirmations to the Italian administrative regions for taxa in the genera Allium, Arabis, Campanula, Centaurea, Chaerophyllum, Crocus, Dactylis, Dianthus, Festuca, Galanthus, Helianthemum, Lysimachia, Milium, Pteris, and Quercus. Nomenclature and distribution updates, published elsewhere, and corrections are provided as supplementary material. [ABSTRACT FROM AUTHOR]

Fluctuating asymmetry ( FA), the deviation from the normal symmetrical condition of a morphological trait having specific morphological symmetry, increases in response to environmental and genetic stress, is related to phenotypic plasticity and is considered a tool for monitoring a species conservation status. However, FA-stress relations are dependent on measured traits or species-specific characteristics such as mating system and habitat. This study investigates the relationships between FA, genetic diversity, population size, density and individual fitness traits (plant height, fruit and seed set), in the endemic A quilegia thalictrifolia, a mixed breeder that is declining, but maintaining high levels of heterozygosity. Leaf and flower FA and other traits were investigated in 10 populations of A. thalictrifolia, the whole species range. As a result, we found similar patterns of FA in leaves and flowers between populations, indicating a homogenous level of stress between populations that differed for other traits. FA and the other traits were not related, including heterozygosity. Heterozygosity was not related to individual fitness traits with the exception of plant height. In accordance with other studies, we found that the role of FA as a tool for assessing the conservation status of a species or population should be reconsidered. However, we conclude that a low level of FA should not automatically be considered an indicator of good conservation status or low level of stress, because in species that evolved in highly stable environments it may indicate a scarce ability to plastically respond to environmental changes, as a consequence of environmental and genetic canalization. Further investigation of this point is needed. [ABSTRACT FROM AUTHOR]

The conservation of species listed in the Bern Convention and European Directive 1992/43/EEC (so-called policy species) is mandatory for European Union (EU) countries. We assessed the conservation status of Italian policy species, based on the IUCN categories and criteria, to evaluate the effectiveness of existing protection measures at the national level. Among the 203 vascular plants, bryophytes and lichens evaluated, 41.9% are categorized as threatened, and one is already extinct, indicating that the protection measures for policy species are inadequate. Our results for the Italian policy species are consistent with those of an assessment at the EU level. Conservation priorities should be established at both the national and regional scales. An effective conservation strategy is needed, and in situ and ex situ actions focused on threatened species should be promoted. [ABSTRACT FROM AUTHOR]

• 3D models allow for a fine above ground biomass (AGB) estimation. • Canopy height-derived AGB estimations are little affected by variations of cloud point density. • A meaningful error level affects the biomass estimates at very low AGB. • Adjusting the volume by the coefficient of density is the best option in order to estimate AGB. Primary productivity is a robust indicator of ecosystem functioning because of its close relationships with the stability of the ecological systems. In ecological research, the above ground biomass (AGB) is the most commonly used proxy of primary productivity. However, despite their ecological relevance, the estimates of primary productivity are not addressed by current protocols for monitoring the conservation status of the habitats of Community interest. In this paper, we analyse the accuracy of AGB measurements obtained by image-derived 3D reconstructions of two contrasting mountain grasslands listed as habitats of Community interest in the Annex I of the Habitats Directive. More specifically, we compared the accuracy of the AGB estimates provided by four models, based on four different predictors (height, volume, volume adjusted, and cover volume), in order to evaluate their robustness against within- and between-community heterogeneity. Our study revealed that AGB measures computed from 3D vegetation reconstructions can be an effective way to evaluate primary productivity in herbaceous communities with complex structure and composition patterns. In particular, the vegetation height showed to have the highest correlation with direct AGB measurements. However, the vegetation volume, once adjusted by the coefficient of density, resulted to be the most effective proxy due to the lowest error level. Therefore, such a parameter could be routinely used as a non-destructive indicator for monitoring habitats of particular conservation concern. As a major limitation for this approach, we detected some loss of predictivity power at very low productivity rates. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about ulcerative colitis.