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Ruderal plant species typically occur and prevail in frequently disturbed areas especially in sites with pronounced direct or indirect human activity. In Greece ruderal taxa (both exclusive and non-exclusive) account for 23.9% of all recorded plant taxa. This study presents an analysis of the ruderal plant diversity patterns in the 13 floristic regions of Greece and different aspects of ruderal diversity related to alien taxa and to taxa of conservation interest. Although many ruderal plant taxa are common and widespread, their contribution to the diversity of each floristic region ranges between 27.8% in the North Central and 41.6% in the Cyclades region. Spatial distribution analysis revealed that the ruderal flora presents higher frequency of occurrence in major urban areas, in coastal and low to medium elevation mainland and island areas. The total number of ruderal taxa per floristic region is strongly correlated with the total number of taxa per region. The richness in exclusive ruderal taxa is highly correlated with surface area proportions of settlements and other built-up areas, as well as with artificial land, wetlands, sparsely vegetated land and shrublands. Ruderals account for a greater proportion of taxa in species-poor regions than in species-rich ones. Patterns of ruderal taxa diversity proved to be rather complicated and different spatial scales must be considered if ruderal biodiversity of the cultural landscapes in Greece is to be preserved.

The EU Water Framework Directive foresees the ecological assessment of surface waters against identified pressures. Nutrient loading is the main pressure impairing the ecological quality of lake ecosystems, and aquatic macrophytes are considered good indicators of ecological response. In this study, we statistically assessed different aspects of aquatic plant (macrophyte) diversity in response to different trophic levels in Mediterranean lakes. We used 5690 relevés of aquatic vegetation, distributed over 305 transects, sampled in 18 freshwater lake ecosystems during 2013–2016. Our results show a significant decrease in taxonomic alpha diversity in lakes with a total phosphorus content above 100 μg/L. Syntaxonomic diversity followed the species richness pattern as well. Functional richness decreased along the trophic gradient, while functional dispersion was higher in lakes with high trophic levels. Taxonomic and functional beta partitioning presented changes in assembly processes leading to greater community homogeneity in lakes with higher trophic levels. In summary, we found no redundancy between taxonomic and functional diversity indices. These results provide novel insights into aquatic plant assembly processes of impacted freshwater lakes needed to forward conservation and restoration practices.

Patterns of phylogenetic diversity and structure of flora in refugial areas may be very complex due to habitat heterogeneity and legacies of various historical processes. Revealing these patterns can help understand the nature of the refugia. Here we study phylogenetic patterns of the flora in one of the main putative Pleistocene refugia of temperate forest biota in Europe through a community-level analysis for the main types of forests. For this purpose, a database of vegetation plots from deciduous and mountain coniferous forests of northern and central Greece was created. The plots were classified into floristically and ecologically interpretable community types. Faith’s phylogenetic diversity, mean phylogenetic distance and mean nearest taxon distance, as well as their standardized equivalents, were used to characterize the mean phylogenetic diversity and structure of each community type. All analyses were applied both for all the vascular plant taxa and for angiosperm taxa only. We related the measures of phylogenetic diversity and structure to ecological factors and compared them among community types. The 25 identified community types differed in their phylogenetic diversity and structure. The observed patterns were significantly different when old evolutionary lineages, such as gymnosperms and ferns, were taken into account. A random or overdispersed phylogenetic structure was observed for most of the community types, while only two oak-dominated community types were clustered. The highest phylogenetic diversity and a notably high proportion of plots with an overdispersed phylogenetic structure were observed in two mesic ravine forest community types (one of these transitional to beech forests). Phylogenetic metrics correlated with ecological conditions, in particular, overdispersion was more common in shaded, cool and moist forests. The high phylogenetic diversity and overdispersed structure of the two ravine community types can be related to the putative refugial role of these forest habitats.

Phylogenetic diversity aims to quantify the evolutionary relatedness among the species comprising a community, using the phylogenetic tree as the metric of the evolutionary relationships. Could these measures unveil the evolutionary history of an area? For example, in a speciation hotspot (biodiversity cradle), we intuitively expect that the species in the community will be more phylogenetically clustered than randomly expected. Here, using a theoretical simulation model, we estimate the ability of phylogenetic metrics of current diversity to detect speciation history. We found that, in the absence of dispersal, if the incipient species do not coexist in the region of speciation (as expected under allopatric speciation), there was no clear phylogenetic clustering and phylogenetic diversity failed to detect speciation history. But if the incipient species coexisted (sympatric speciation), metrics such as standardized effect size of Faith’s Phylogenetic Diversity (PD) and of Mean Nearest Taxon Distance (MNTD) were able to identify areas of high speciation, while Mean Pairwise Distance (MPD) was a poor indicator. PD systematically outperformed MNTD. Dispersal was a game-changer. It allowed species to expand their range, colonize areas, and led to the coexistence of the incipient species originating from a common ancestor. If speciation gradient was spatially contiguous, dispersal strengthened the associations between phylogenetic clustering and speciation history. In the case of spatially random speciation, dispersal blurred the signal with phylogenetic clustering occurring in areas of low or no speciation. Our results imply that phylogenetic clustering is an indicator of speciation history only under certain conditions.

Human activities like urbanization and agriculture affect spatial biodiversity patterns. The presence and activities of humans richly benefit alien species, but native species usually decline in human-impacted areas. Considering that the richness of alien and native species are inter-related, we explored the effect of human population density, human-related land uses (agricultural and urban), and natural land area on avian (alien and native) species richness of Massachusetts for two time periods using Generalized Additive Models. Avian alien species richness increased with native species richness in both time periods. Despite the predominant role of native species richness as a major driver of alien species richness, human activities play an important additional role in shaping species richness patterns of established aliens. Human-related land uses (urban and agricultural) and human population favored alien species richness in both time periods. Counter to expectations, human activities were also positively associated to native avian species richness. Possible explanations of these patterns may include habitat heterogeneity, increased availability of resources, and reduced predation risk.

Understanding the ecological mechanisms behind biological invasions remains a major focus of conservation biology and ecosystem management. Several hypotheses highlight that different facets of native biodiversity affect the establishment and spread of alien species. Here, we approach this question by examining the spatiotemporal relationship between alien bird species richness and different facets of biodiversity (taxonomic, functional, and phylogenetic) using breeding bird atlases for three U.S. states and for two time periods in each state. We associated native species richness, and functional and phylogenetic diversity with alien species richness, using generalized least squares models. Our results show that, consistently, across the three states and two time periods examined, alien species richness is positively associated with native diversity, and particularly with phylogenetic diversity. The relative importance of biodiversity metrics reflecting the functional or phylogenetic range occupied by the assemblage seems to advocate in favor of the importance of resource diversity as a main driver of both native and alien diversity. The secondary importance of biodiversity facets reflecting species functional or phylogenetic similarity, along with the lack of importance of functional or phylogenetic clustering or overdispersion, implies that if this relationship is shaped by biotic interactions, then biotic interactions facilitating coexistence (including even processes like predator‐mediated coexistence) are far more important than adversarial interactions like competition, at least at the scale of our analysis. Finally, the dominance of phylogenetic metrics over functional ones highlights the adaptive potential of a community accumulated over long lineage history may play an additional role as a source of information on evolutionary processes driving diversity patterns.

Monitoring of habitat types conservation status is an essential task in the frame of the European policy for biodiversity conservation. The parameters to be assessed for the purposes of habitat types’ conservation status assessment are described in several European documents, but the methodology for their determination has not yet been standardized or optimized. This study presents methods for the assessment of the actual status and the future prospects of structure and functions of habitat types. Specifically, it presents a bottom–up approach for the assessment of these two parameters at different spatial scales. In the proposed method, conservation status assessment is based on a classification of habitat types to subtypes, with the latter representing the basic monitoring entities. The conservation status is assessed by recording: (i) the presence/absence of specific indicators of structure and functions per habitat type, and (ii) the presence/absence, abundance, and vitality of the typical species of the habitat subtypes. The typical species are determined objectively using algorithms and fidelity coefficient values. The conservation status and future prospects of structure and functions (including the typical species) are estimated quantitatively with the help of numerical methods and algorithms, but their assignment to conservation status classes is based on thresholds defined by experts. Assessments are made at the local scale, but can be upscaled to coarser ones (up to the national level). The proposed methods have been applied in Greece and were effective both in terms of results obtained and costs needed.

Europe’s Natura 2000 network (N2K), based on the EU Birds and Habitat Directives, has rapidly expanded protected areas targeting species and habitat types. In Greece, 52.4% of native freshwater fish are considered as species of EU community interest within the Habitats Directive (HD). However, 31.3% of all threatened fish species at a global level and 32.0% at a national level, are not included in the Habitat Directives Annex lists. Fishes in Greece’s rivers are understudied, precise knowledge of their distributions is poor for most species. We utilize a large set of site-based electrofishing samples to explore the coverage of these species by the country’s Natura 2000 sites. Field surveys recorded 102 species inhabiting rivers within 645 sampling sites. Although the majority of the HD listed, threatened and endemic freshwater fish species exist within the current N2K network, important gaps are evident and four HD species were not found within any Natura 2000 sites. In analyzing fish densities from field sampling, only two upland-stream species, Salmo farioides and Barbus strumicae, show significantly higher abundance inside N2K sites. Applying a Combined Index utilizing IUCN vulnerability status, species rarity and richness, we identified 161 hotspot sites for riverine fishes; 50.9 % of all hotspots are located outside of N2K network, especially in lowland areas. Unprotected areas with a high concentration of hotspots are mapped; the river basins with the highest number of such unprotected hotspots belong to the Strymonas, Pinios, Evrotas and Aoos rivers. With concern for the EU’s revised biodiversity conservation strategy, our screening level assessment provides insights for unmet conservation needs and the method is readily transferable to other states and protected area jurisdictions.

We studied the differentiation among plant communities of deciduous broadleaved and mountain coniferous forests in terms of functional diversity and identity at a regional scale (northern and central Greece). We asked if patterns of functional differentiation among communities are consistent between the overstorey and understorey layers and if they can be influenced by deep past environmental conditions. Functional Richness (FRic) and Functional Dispersion (FDis), as well as their standardized effect sizes, were employed to assess the multivariate functional diversity of the community types. In contrast, single-trait Community Weighted Means (CWMs) were used as surrogates of functional identity. The aforementioned indices were calculated for three datasets, namely all the vascular plant taxa found in individual vegetation plots (total community), all phanerophyte (tree and shrub) taxa (overstorey) and all non-phanerophyte vascular plant taxa (understorey). We found that community types and especially four broad forest types (beech, ravine, pine and oak forests) are well differentiated in terms of functional composition (identity), as indicated by Non-Metric Multidimensional Scaling (NMDS). After conducting an NMDS for the three datasets, functional identity based on the total floristic composition was found to be the best discriminator of the studied communities. However, contrasting patterns were found for some specific traits or their categories between overstorey and understorey layers. The patterns of functional diversity of the community types (based on multivariate indices), revealed by calculating the standardized effect sizes of FRic and FDis based on the richness null model, did not differ substantially from random expectations for most of the studied community types when the dataset of all the vascular plant taxa was analyzed. However, the patterns revealed for the overstorey layer differed from those for the understorey layer. For the latter layer, the clustered structure was revealed in many community types based on the ses.FDis metric. Indications of deep past influence on the functional composition were found for certain community types (i.e. ravine forests) based on single-trait metrics, but no indication of such influence was found based on multivariate indices. Our findings highlight the complementarity and the additive explanatory value of the simultaneous use of single- and multi-trait approaches and their application to different layers in forests.

The delineation of Quiet Areas (QAs) forms nowadays a national obligation of EU countries. Nevertheless the variable applications of QAs among Member-States have highlighted the need for an international common approach for the preservation of Quietness. The objective of this paper is to identify and thus protect QAs of EU. Our methodological design consisted of the implementation of a coarse scale distance-based methodology regarding the identification of QAs among different countries, environmental and altitudinal zones with a view to investigating the spatial pattern of QAs as well as their spatial relation to other protected areas. QAs cover 56.09% of EU territory with most of the sites comprising an area larger than 100 km 2 indicating that Quietness provides a valuable ecosystem service for human well-being. Central Europe demonstrates lower percentages of Quietness whereas Mediterranean and Scandinavian areas contain higher percentages of Quietness. Also our findings regarding the spatial overlap of QAs with Natura 2000 network suggest that QAs actually indicate sites of environmental quality, and could thus be incorporated into environmental policy initiatives.

Native-alien species relationship is one of the potential mechanisms to explain alien species' success. Most approaches have so far focused on species richness, but species-centric approaches alone are of limited explanatory ability. We utilized the breeding bird atlases of Great Britain at three time points, to examine the temporal patterns of alien bird species assemblages' richness and composition and analyze the spatio-temporal relationship between them and native species functional and phylogenetic diversity. Alien birds were successful in increasing their average local richness and range from the 1970s to the 2010s, without high values of the replacement component of β-diversity in most assemblages and with increasing richness in the majority of atlas cells. Communities with higher native diversity were positively associated with higher alien species richness and overall, our results showed that native biodiversity metrics can act as reliable predictors of alien species richness patterns. Native phylogenetic diversity emerged as an important predictor of alien species richness, whereas functional diversity was not as successful. Phylogenetic diversity may have captured native species' functional differences more effectively and/or the added layer of phylogenetic information increased phylogenetic diversity's ability to predict alien species richness patterns and may be indicative of evolutionary processes reflecting the mechanisms shaping native-alien species' relationship. If we were to predict where these alien birds may spread within the next 20 years, our results point to phylogenetically rich communities. This is likely a reflection of habitat heterogeneity and/or resource availability in these communities. In any case, a multifaceted approach is preferable, as different measures highlight different mechanisms driving communities' invasibility.

© 2017 German Botanical Society and The Royal Botanical Society of the Netherlands Plant–pollinator network structure is the outcome of ecological and evolutionary processes, and although the importance of environmental factors is beyond doubt, our knowledge of how abiotic factors (e.g. climate) shape plant–pollinator networks remains limited. This knowledge gap is critical, as climate change poses a major threat to ecosystems, especially in the Mediterranean. This study focuses on one of the hottest parts of the Mediterranean Basin, the Aegean Archipelago, Greece, and examines how climate affects species richness and network properties (e.g. nestedness, modularity and specialisation) – either directly or indirectly through species richness. We sampled systematically 39 local plant–pollinator networks on eight islands along a north–south climate gradient in the Aegean. All plant–pollinator material used in the analyses was collected in 2012 and identified to species level. Aspects of climate used in the models were expressed as average conditions (mean temperature and annual precipitation) or as seasonal variability (isothermality and temperature seasonality). Structural properties of plant–pollinator networks were found to be strongly associated with species richness, which was in turn affected by climate, implying that pollination network structure is driven indirectly by climate. In addition, climate had a direct effect on network structure, especially on modularity and specialisation. Different aspects of climate affected network properties in different ways. We highlight that even in a relatively narrow latitudinal gradient, such as within the Aegean Sea region, climate constitutes a significant driver of plant–pollinator interactions.

Often climatic niche models predict that any change in climatic conditions will impact species abundance or distribution. However, the accuracy of models that just incorporate climatic information to predict future species habitat use is widely debated. Alternatively, environmental conditions may simply need to be above some minimum threshold of climatic suitability, at which point, other factors drive population size. Using the example of nesting sites of loggerhead sea turtles (Caretta caretta) in the Mediterranean (n = 105), we developed climatic niche models to examine whether a climatic suitability threshold could be identified as a climatic indicator in order for large populations of a widespread species to exist. We then assessed the climatic suitability of sites above and below this threshold in the past (∼1900) and future (∼2100). Most large sites that are currently above the climatic threshold were above the threshold in the past and future, particularly when future nesting seasonality shifted to start 1–2 months earlier. Our analyses highlight the importance of future phenological shifts for maintaining suitability. Our results provide a positive outlook for sea turtle conservation, suggesting that climatic conditions may remain suitable in the future at sites that currently support large nesting populations. Our study also provides an alternative way of interpreting the outputs of climatic niche models, by generating a threshold as an index of a minimum climatic suitability required to sustain large populations. This type of approach offers the possibility to benefit from information provided by climate-driven models, while reducing their inherent uncertainties.

Marine protected areas (MPAs) represent the main tool for halting the loss of marine biodiversity. However, there is increasing evidence concerning their limited capacity to reduce or eliminate some threats even within their own boundaries. Here, we analysed a Europe-wide dataset comprising 31,579 threats recorded in 1692 sites of the European Union's Natura 2000 conservation network. Focusing specifically on threats related to marine species and habitats, we found that fishing and outdoor activities were the most widespread threats reported within MPA boundaries, although some spatial heterogeneity in the distribution of threats was apparent. Our results clearly demonstrate the need to reconsider current management plans, standardise monitoring approaches and reporting, refine present threat assessments and improve knowledge of their spatial patterns within and outside MPAs in order to improve conservation capacity and outcomes.

Biodiversity hotspots (BH) cover a small fraction of the Earth&rsquo, s surface, yet host numerous endemics. Human-induced biodiversity loss has been increasing worldwide, despite attempts to halt the extinction crisis. There is thus an urgent need to efficiently allocate the available conservation funds in an optimised conservation prioritization scheme. Identifying BH and endemism centres (EC) is therefore a valuable tool in conservation prioritization and planning. Even though Greece is one of the most plant species-rich European countries, few studies have dealt with the identification of BH or EC and none has ever incorporated phylogenetic information or extended to the national scale. Consequently, we are unaware of the extent that Special Areas of Conservation (SAC) of the Natura 2000 network efficiently protect Greek plant diversity. Here, we located for the first time at a national scale and in a phylogenetic framework, the areas serving as BH and EC, and assessed the effectiveness of the Greek SAC in safeguarding them. BH and EC are mainly located near mountainous areas, and in areas supposedly floristically impoverished, such as the central Aegean islands. A critical re-assessment of the Greek SAC might be needed to minimize the extinction risk of the Greek endemics, by focusing the conservation efforts also on the BH and EC that fall outside the established Greek SAC.

Fire affects diversity and structure of flower-visitor communities. We explored the effect of fire history on the diversity patterns and structure of the flower-visitor guilds (bees, beetles, flies, sawflies, and wasps), across a post-fire regeneration sequence of pine forests in Rhodes Island, Greece. Fire history was defined by fire frequency and post-fire age of sites. We did not find significant differences in species richness and abundance per guild between fire-history regimes except for the abundance of flies, sawflies and the entire flower-visitor community. Fire strongly affected the community structure of bees, beetles, and sawflies. Some of the most abundant and common species responded significantly to fire in terms of abundance; yet, we observed no significant variation in the abundance of the common species of bees, the most prominent pollinator group, implying that provision of pollination services may not be considerably affected by fire. Long-unburnt sites displayed higher heterogeneity in species composition compared to recently-burnt sites (either burnt once or twice). This pattern deviated significantly from null expectations when analyzing the abundance-based metric of β-diversity and was obscure in the case of the presence/absence-based metric, indicating that fire affected mainly the spatial distribution of individuals, i.e. the main change is not due to species turnover but to changes in relative abundance. Furthermore, the species composition in recently-burnt sites (burnt once in 2008) were more similar than in twice-burnt sites (including areas burnt once between 1984 and 1992, and in 2008), indicating that fire frequency affected post-fire heterogeneity of species composition.

Understanding the patterns of species richness and their environmental drivers, remains a central theme in ecological research and especially in the continental scales where many conservation decisions are made. Here, we analyzed the patterns of species richness from amphibians, reptiles and mammals at the EU level. We used two different data sources for each taxon: expert-drawn species range maps, and presence/absence atlases. As environmental drivers, we considered climate and land cover. Land cover is increasingly the focus of research, but there still is no consensus on how to classify land cover to distinct habitat classes, so we analyzed the CORINE land cover data with three different levels of thematic resolution (resolution of classification scheme ˗ less to more detailed). We found that the two types of species richness data explored in this study yielded different richness maps. Although, we expected expert-drawn range based estimates of species richness to exceed those from atlas data (due to the assumption that species are present in all locations throughout their region), we found that in many cases the opposite is true (the extreme case is the reptiles where more than half of the atlas based estimates were greater than the expert-drawn range based estimates). Also, we detected contrasting information on the richness drivers of biodiversity patterns depending on the dataset used. For atlas based richness estimates, landscape attributes played more important role than climate while for expert-drawn range based richness estimates climatic variables were more important (for the ectothermic amphibians and reptiles). Finally we found that the thematic resolution of the land cover classification scheme, also played a role in quantifying the effect of land cover diversity, with more detailed thematic resolution increasing the relative contribution of landscape attributes in predicting species richness.

Fire is an important and frequent disturbance in Mediterranean-type ecosystems affecting the structure and dynamics of bee communities. We explored the effect of fire history on taxonomic and functional composition of wild bees on Rhodes Island, Greece, using UV-bright pan trap sampling. We carried out a fourth-corner analysis based on Generalized Linear Models to identify significant interactions between functional traits (nesting preferences, trophic specialization, and body size) and fire history, defined by fire frequency and post-fire age of sites. Our analysis showed that species diversity and abundance at various taxonomic levels did not display significant differences among different fire history regimes (twice-burnt, recently-burnt, old-burnt, and unburnt). The effect of fire was detected when focusing on functional traits rather than species. Ground nesting bees were positively associated with recently-burnt sites, which provide bare soil and therefore nesting sites for this group of bees. Polylectic bees were positively associated with twice-burnt sites, indicating the dominance of generalist bee species. Larger bees were positively associated with post-fire age, probably due to the larger foraging range of larger bees that enables a more efficient exploitation of aggregated resources. Our results show that responses of wild bee species to fire are driven by nesting preference, trophic specialization, and body size.

In the western part of the Arabian/Persian Gulf, coastal habitats such as intertidal wetlands and mangroves are scarce and poorly studied. We conducted a rapid assessment survey of bird species richness and abundance at the Fuwairit khor lagoon in northern Qatar, using a line transect count scheme to collect data from six different generic habitat types, repeated during five consecutive days in late April 2013. To further analyze the ecological requirements of the surveyed bird assemblage per habitat type, we assigned ecological guild categories to each species and distinguished among migrants, local, and regional breeders. Mangrove and intertidal mudflats hosted the highest bird densities and the most distinctive assemblages, while the beach habitat had high concentrations of birds but relatively few species. In contrast to the wetland habitats, near-shore marine areas and dune habitats had very limited numbers of birds and a relatively depauperate species assemblage. Employing a habitat perspective in a quantitative bird survey method shows that birds are effective biodiversity indicators for a rapid survey of coastal features in a poorly-studied region of the Arabian/Persian Gulf.

Trait selection is a critical step of functional diversity (FD) studies and is often hampered by the limited availability of trait data for large sets of species. Thus, most studies examine FD using traits determined primarily by the availability of data rather than a specific function. This practice implicitly assumes that the subset of functional traits available will be representative of the trait data of interest. Here, we test whether the different functional trait groups (FTGs-distinct axes of ecological niches of the species e.g. morphological, reproductive, physiological) show congruent FD spatial patterns and if one FTG could act as a surrogate for another FTG. We used data on the 85 amphibian species of Europe and 12 traits to estimate three aspects of FD (richness, evenness and dispersion) for three different FTGs (Morphological, Reproductive and Habitat-related) and the complete set of traits. Our results challenge the surrogacy value of one set of FTGs for another set of FTGs. We further found that this has an impact on identifying hotspots (different functions will have different hotspots). So the argument that FD is easier to preserve in less area due to the redundancy of traits may hold true for a specific function, but will not necessarily be the same for different functions. Finally, our results reveal that, for any given community, FD is not characterized by a single spatial pattern, but by many depending on the function analyzed.

© 2019 by the Ecological Society of America Fire, a frequent disturbance in the Mediterranean, affects pollinator communities. We explored the response of major pollinator guilds to fire severity, across a fire-severity gradient at different spatial scales. We show that the abundance of all pollinator groups responded to fire severity, and that bees and beetles showed in addition a significant species-diversity response. Bees, sawflies, and wasps responded to fire severity at relatively small spatial scales (250–300 m), whereas flies and beetles responded at larger spatial scales. The response of bees, sawflies, and wasps was unimodal, as predicted by the intermediate disturbance hypothesis, whereas flies and beetles showed a negative response. A possible explanation is that the observed patterns (spatial scale and type of response) are driven by taxa-specific ecological and life-history traits, such as nesting preference and body size, as well as the availability of resources in the postfire landscape. Our observational study provides an insight into the effect of fire severity on pollinators. However, future research exploring the explicit link between the pre- and postfire landscape structure and pollinator traits and responses is required for further establishment and understanding of cause–effect relationships.

Changes in species diversity following volcanic eruptions have been studied extensively, but our knowledge on functional diversity and community assembly under such conditions is very limited. Here, we study the processes following the destruction of vegetation after a volcanic eruption. Specifically, we investigate (1) the temporal patterns of taxonomic and functional diversity over time since a previous eruption (alpha diversity) and beta diversity, (2) the temporal patterns of 26 individual traits (vegetative characteristics, plant taxa ecological preferences, and regenerative characteristics) providing more detailed information on species strategies at the initial and later stages of succession, and (3) the processes driving species assembly and whether they changed over time since the eruption an eruption. We analyzed data recorded during five floristic censuses that took place between 1911 and 2011, calculated alpha and beta facets of taxonomic and functional diversity and examined how community structure changed over time, using 26 functional characteristics, based on their ability to discern primary from later colonists, including longevity, growth form, Ellenberg's indicator values, seed production and weight, flower size and sex, pollination type, and dispersal mode. Null model analysis was used to test whether the observed functional diversity deviates from random expectations. Alpha diversity, both taxonomic and functional, increased over time after an eruption, while beta diversity did not display a clear trend. This finding indicates that mainly abiotic processes determine species assembly over time after an eruption (at least for the time span studied here), contrary to theoretical expectations. It is most interesting that, simultaneously, some aspects of diversity indicated the effect of biotic interactions (facilitation and competition) on the assembly of species a few years after an eruption. This finding implies a legacy effect, since a high percentage of perennial species was noticed in the assemblage right after the eruption, as well as the effect of the harsh environmental conditions on the assembly of the plant communities. In conclusion, our results indicate the role of legacy effects in succession (most probably through the survival of underground plant parts) and underline the importance of disturbance history in providing the context needed for understanding effects of past events on succession.

AimTo project the potential European distribution of seven broad habitat categories (needle-leaved, broad-leaved, mixed and mediterranean forest, urban, grassland and cropland) in order to assess effects of land use, climate change and increase in CO2 on predicted habitat changes up to the year 2050. LocationEurope. MethodWe modelled the response of European vegetation to changes in land use, climate and CO2 by combining the land-use model Dyna-CLUE (based on the CORINE land-cover data) and the dynamic vegetation model LPJ-GUESS. Two reforestation options were explored: maintaining the current range of tree species (EFI) or promoting naturally occurring tree species (NAT). Climate data from two general circulation models and two SRES scenarios (A2 and B1) were used. The broad habitat types were classified according to a combination of land use and the dominant plant species. ResultsOur models predicted that croplands and grasslands are expected to decrease due to land-use change. Although climate change has a negative effect on needle-leaved forest, it is expected to maintain its area or even increase in the EFI reforestation option while mediterranean, broad-leaved and mixed forests are expected to increase markedly. All investigated drivers have shown some effect, but land use is the dominant contributor to broad habitat change except for needle-leaved and mixed which are mainly influenced by climate change. Main conclusionsLand use is predicted to have the greatest effect on broad habitat distribution according to our simulations. Hence in most parts of Europe mitigating actions should focus on land-use change rather than climate change. According to our simulation, the effects of the different drivers are not in general additive. In some cases they act synergistically and in some cases antagonistically. The projected habitat changes are a valuable tool for species distribution modelling and are available online. (Less)

Questions Do the mechanisms driving community assembly differ between two islands of different age and history of vegetation development? How does sampling scale affect the strength that each assembly mechanism poses on the assembly of plant communities? Location Volcanic islands (Palea Kameni and Nea Kameni) of Santorini Archipelago, Greece. Methods Functional diversity has been proposed as a framework for discriminating among mechanisms of community assembly, such as habitat filtering, limiting similarity and random assembly. We investigated four plant communities in two sea-born volcanic islands. We recorded plant diversity at scales from 1 m2 to 64 m2. We calculated three indices of functional diversity: functional richness, functional evenness and functional divergence, using 26 functional traits (including vegetative characteristics, ecological preferences and regenerative characteristics). We used null model analysis to test for two different assembly mechanisms: habitat filtering and limiting similarity or random assembly. Results The assemblage of the four communities was complex and did not follow a single mechanism. In most cases, finer-scale patterns indicated randomness, while coarser scales revealed more structured communities. In the older island, the scrub community was mainly defined by limiting similarity. The therophytic community displayed a limited range of functional traits, indicating mainly habitat filtering, but within this range, the evenness of the distribution indicated limiting similarity. On the younger island, the range of traits did not differ from random. However, within this range of traits, one therophytic community showed signs of limiting similarity, while the second therophytic community displayed uneven functional trait distribution, indicating mainly habitat filtering. The three indices reflected different facets of functional diversity and were not correlated, thus we may argue that they are not redundant, and we even detected different mechanisms of assembly within the same community. Conclusions The functional diversity of the therophytic communities in the younger island implied no specific assembly mechanism; perhaps due to its age, the community is still at the early stages of colonization (i.e. stochastic processes, such as arrival of new species, prevail). In the older island, the lack of disturbances for a long period allowed the establishment of communities assembled by specific mechanisms, such as competition and habitat filtering.

EU conservation policy is primarily based on the Natura 2000 network of protected areas (PAs). We analyzed the land-cover changes between 2000 and 2006 inside 25,703 Natura 2000 sites in 24 EU Member States, and compared them with those observed outside the PAs. At the EU level, ‘Artificial surfaces’ and ‘Agricultural areas’ exhibit lower rates of transformation within PAs than outside. ‘Forests and semi-natural areas’ marginally increased inside PAs, while they marginally decreased outside. In States that joined the EU before 2000, landscape transformation rates were low, and inside PAs ‘Forest’ preservation was accompanied with a shift from intensive agricultural practices ‘Permanent arable land’ to more diverse ‘Agricultural mosaics’. In new Member States (most of them located in Eastern Europe), there was agricultural abandonment, with conversion to ‘Artificial surfaces’ or ‘Natural vegetation’, both within and outside PAs. Broad scale EU policies (like the Common Agricultural Policy) and socio-economic drivers (like the transition from planned to market economy) seem to be dominant factors in explaining land-cover transformations, while conservation policies may moderate these trends inside PAs.

The species–area relationship (SAR) is one of the few generalizations in ecology. However, many different relationships are denoted as SARs. Here, we empirically evaluated the differences between SARs derived from nested-contiguous and non-contiguous sampling designs, using plants, birds and butterflies datasets from Great Britain, Greece, Massachusetts, New York and San Diego. The shape of SAR depends on the sampling scheme, but there is little empirical documentation on the magnitude of the deviation between different types of SARs and the factors affecting it. We implemented a strictly nested sampling design to construct nested-contiguous SAR (SACR), and systematic nested but non-contiguous, and random designs to construct non-contiguous species richness curves (SASRs for systematic and SACs for random designs) per dataset. The SACR lay below any SASR and most of the SACs. The deviation between them was related to the exponent f of the power law relationship between sampled area and extent. The lower the exponent f, the higher was the deviation between the curves. We linked SACR to SASR and SAC through the concept of “effective” area (Ae), i.e. the nested-contiguous area containing equal number of species with the accumulated sampled area (AS) of a non-contiguous sampling. The relationship between effective and sampled area was modeled as log(Ae) = klog(AS). A Generalized Linear Model was used to estimate the values of k from sampling design and dataset properties. The parameter k increased with the average distance between samples and with beta diversity, while k decreased with f. For both systematic and random sampling, the model performed well in predicting effective area in both the training set and in the test set which was totally independent from the training one. Through effective area, we can link different types of species richness curves based on sampling design properties, sampling effort, spatial scale and beta diversity patterns.

EU biodiversity conservation policy is based on the Habitats Directive (92/43/EC), which aims that habitat types and species of Community interest should reach ‘favourable conservation status’. To this end, Member States are obliged to perform periodic assessment of species and habitat conservation status through biodiversity monitoring, which, in almost all cases, was performed by experts implementing standardized field protocols. Here, we examine the quality of data collected in the field by non-experts (citizen scientists) for the conservation status assessment of habitat types, and specifically for the criteria ‘typical species’, ‘specific structures and functions’, and ‘pressures and threats’. This task is complicated and demands different types of field data. We visited two Natura 2000 sites and investigated four habitat types (two in each site) with non-experts and compared their data to the data collected by experts for accuracy, completeness and spatial arrangement. The majority of the non-expert data were accurate (i.e. non-experts recorded information they observed in the field), but they were incomplete (i.e. non-experts detected less information than the experts). Also, non-experts chose their sampling locations closer to the edge of the habitat, i.e. in more marginal conditions and thus in potentially more degraded conditions, than experts.

This paper presents the establishment and the first outcomes of the Hellenic Ecosystem Services Partnership (HESP), a scientific-technical committee aiming at the guidance and coordination of the Ecosystem Services (ES) assessment in Greece. HESP consists of experts from different disciplines (ecology, marine biology, socio-ecological system science) and aims to: i) coordinate ES assessment efforts under a shared framework; ii) promote the ES approach in Greece; iii) support the European implementation of ES at the national level (Mapping and Assessment of Ecosystem and their Services initiative), and iv) fulfill priority actions regarding the ES implementation and the obligations derived from the National Biodiversity Strategy. In this paper, we present the first drafting of the National Agenda including short- and long-term objectives towards the national implementation of MAES, we outline the HESP Action Plan to 2020, as well as the timeline of the basic steps to be taken, to achieve decision making on the basis of ES maintenance and enhancement. It will also serve as a call for action to encourage more ES assessments at the national level, but also as a primer for the inclusion of protected areas and other areas of special importance for ES assessments at the EU level.

Recent anthropogenic climate change is strongly associated with average shifts toward earlier seasonal timing of activity (phenology) in temperate-zone species. Shifts in phenology have the potential to alter ecological interactions, to the detriment of one or more interacting species. Recent models predict that detrimental phenological mismatch may increasingly occur between plants and their pollinators. One way to test this prediction is to examine data from ecological communities that experience large annual weather fluctuations. Taking this approach, we analyzed interactions over a four-year period among 132 plant species and 665 pollinating insect species within a Mediterranean community. For each plant species we recorded onset and duration of flowering and number of pollinator species. Flowering onset varied among years, and a year of earlier flowering of a species tended to be a year of fewer species pollinating its flowers. This relationship was attributable principally to early-flowering species, suggesting that shifts toward earlier phenology driven by climate change may reduce pollination services due to phenological mismatch. Earlier flowering onset of a species also was associated with prolonged flowering duration, but it is not certain that this will counterbalance any negative effects of lower pollinator species richness on plant reproductive success. Among plants with different life histories, annuals were more severely affected by flowering–pollinator mismatches than perennials. Specialized plant species (those attracting a smaller number of pollinator species) did not experience disproportionate interannual fluctuations in phenology. Thus they do not appear to be faced with disproportionate fluctuations in pollinator species richness, contrary to the expectation that specialists are at greatest risk of losing mutualistic interactions because of climate change.

The role of nature in tourism is widely acknowledged; yet, information remains limited about the determinants of green tourism development within conservation areas. Here, we aimed to provide a framework for exploring the supportive role of quietness in green tourism development. Because natural quietness is expected to facilitate conservation and promote environment-friendly tourism, we tested whether quiet areas within conservation sites in Greece indicate “hotspots” of green tourism . We found that the percentage of quietness was related to environment-friendly tourism, indicating that the acoustic value of a site contributes towards driving the pattern of green tourism . When more than 30% of the surface area of a conservation site was quiet, activities supporting green tourism were significantly higher. This threshold implies that both the conservation and acoustic value of a site are important in environment-conscious tourism destinations. Overall, we suggest that the acoustic quality of a site might function as a tool for management, facilitating the identification of green tourism “hotspots”.

Historical fire records and meteorological observations spanning over one century (1894–2010) were assembled in a database to collect long-term fire and weather data in Greece. Positive/negative events of fire occurrence on an annual basis were considered as the years where the annual values of the examined parameters were above (positive values) or below (negative values) the 95% confidence limits around the trend line of the corresponding parameter. To analyse the association of positive/negative events of fire occurrence with meteorological extremes, we proceeded with a cross-tabulation analysis based on a Monte Carlo randomization. Positive/negative values of total annual precipitation were randomly associated with the corresponding values of burned areas, and significant associations were observed for seasonal precipitation totals (spring and fire season). Fire season precipitation is the dominant factor coinciding with negative values of area burned, while years with high spring precipitation coincide with years with large areas burned. These results demonstrate the dual role of precipitation in controlling a fire's extent through fuel build-up and dryness. Additionally, there is a clear outperformance of precipitation-related variables compared with temperature-related weather revealing that, at least in Greece, total area burned at the national scale is controlled by precipitation totals rather than air temperature. This analysis improves our understanding of the underlying mechanisms of fire regimes and provides valuable information concerning the development of models relating fire activity to weather parameters, which are essential when facing a changing climate that may be associated with shifts in various aspects of the typical fire regimes of ecosystems. Our results may allow fire managers to more easily incorporate the effect of extreme weather conditions into long-term planning strategies. They contribute to the exploration of fire–climate relationships and may become more important if climate change scenarios are used to predict the occurrence of future extreme weather taking into consideration that climate change is discussed on the basis of changes of extremes rather than changes in means.

Elevational gradients provide a unique opportunity to explore species responses to changing environmental conditions. Here, we focus on an elevational gradient in Crete, a climate-vulnerable Mediterranean plant biodiversity hotspot and explore the diversity patterns and underlying mechanisms of different plant life forms. We found that the significant differences in life forms&rsquo, elevational and environmental ranges are reflected in &alpha, diversity (species richness at local scale), &gamma, diversity (species richness at regional scale) and &beta, diversity (variation in species composition). The &alpha, and &gamma, diversity decreased with elevation, while &beta, diversity followed a hump-shaped relationship, with the peak varying between life forms. However, &beta, deviation (deviation from null expectations) varied significantly with elevation but was life formindependent. This suggests that species composition is shaped by the size of the available species pool which depends on life form, but also by other deterministic or stochastic processes that act in a similar way for different life forms. The strength of these processes varies with elevation, with hotter&ndash, drier conditions and increased human activities filtering species composition at lowlands and large-scale processes determining the species pool size overriding local ecological processes at higher elevations.

Modern water resource management requires biomonitoring of the structure and functioning of freshwater ecosystems, which may be better illuminated by functional trait distribution patterns and responses across human-induced pressure gradients. In this study, we applied the RLQ, the fourth-corner and their novel combination methods, in order to assess the relationship between the distribution of 30 aquatic macrophyte functional traits and 14 indicators of anthropogenic pressures across 16 freshwater lakes. Our findings showed that there is a statistically significant relationship between the distribution of specific functional traits and anthropogenic pressures. Eutrophication was the dominant pressure and the shift from a submerged-macrophyte dominated vegetation community to an emergent one was the most important functional response. Aerial reproduction and dispersal traits were found to replace water-related ones under higher nutrient concentrations. Trophic and light preferences of macrophytic species increased, while their leaf morphology was found to change from tubular/capillary leaf types with low leaf area values to entire leaf types with greater leaf area. These results provide hints on the changes in ecosystem functioning occurring as a response to human-induced drivers. Therefore, this assessment approach could provide important support to the tasks of biomonitoring, conservation and management planning in freshwater ecosystems.

SummaryEnvironmental policy integration is an acknowledged principle of sustainable development. Spatial planning may be a useful means of integrating two policies with differing objectives. The Birds and Habitats Directives of the European Union (EU) aim at preserving biodiversity through the conservation of the Natura 2000 protected areas network, while the EU's Environmental Noise Directive aims at improving human health and wellbeing by controlling environmental noise, through the preservation of Quiet Areas (QAs). Using Greece as an example, an integrated network of Natura 2000 sites and QAs permitted the identification of potential spatial overlaps. The established Natura 2000 network incorporates more than 30% of the QAs located in the open countryside of Greece, and the combined network includes 17 out of the 19 conservation priority habitat types. Flagship species (like bear, wolf and wild goat) show a preference for sites containing QAs. It may be possible to combine these two EU policies efficiently, as protected and quiet areas appear to be mutually beneficial.

The Natura 2000 network represents the largest conservation network in the world that has been established under common directives adopted by all member states of European Union. The Greek state, in the context of implementing the directives and managing the Natura 2000 sites, selected only a part of the network (83 sites) to be under a specific management scheme, forming a “sub-network” of managed sites. To assess the potential decision-making criteria and principles which underlie the selection process of this sub-network, we applied a multi-criteria approach including ecological, socioeconomic and management history criteria. We found that the sub-network of managed sites performed better than random for some criteria and worse than random for other criteria. Our results demonstrate that the sub-network was close to optimal for management history related criteria and better than random for ecological factors. On the other hand, human activities, population density and land value were undervalued in the prioritization process. Several sites, however, consistently scored high for all criteria and approximately half of them are included in the sub-network of managed sites. The prioritization of conservation efforts on these sites is important in the post-financial crisis era when public funding for conservation is rapidly decreasing and conservation administration is being gradually dismantled. Our study emphasizes the intricacy involved in conservation planning by highlighting that the selection of the managed sites of the Greek Natura 2000 network was primarily based on scientific reasoning and political motivations whereas a more integrative approach, such as considering socioeconomic factors, appears to be absent from the process.