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Here, we investigate Mid- to Late-Holocene vegetation changes in low-lying coastal areas in Tonga and how changing sea levels and recurrent volcanic eruptions have influenced vegetation dynamics on four islands of the Tongan archipelago (South Pacific). To investigate past vegetation and environmental change at Ngofe Marsh (‘Uta Vava’u), we examined palynomorphs (pollen and spores), charcoal (fire), and sediment characteristics (volcanic activity) from a 6.7-m-long sediment core. Radiocarbon dating indicated the sediments were deposited over the last 7700 years. We integrated the Ngofe Marsh data with similar previously published data from Avai’o’vuna Swamp on Pangaimotu Island, Lotofoa Swamp on Foa Island, and Finemui Swamp on Ha’afeva Island. Plant taxa were categorized as littoral, mangrove, rainforest, successional/ disturbance, and wetland groups, and linear models were used to examine relationships between vegetation, relative sea level change, and volcanic eruptions (tephra). We found that relative sea level change has impacted vegetation on three of the four islands investigated. Volcanic eruptions were not identified as a driver of vegetation change. Rainforest decline does not appear to be driven by sea level changes or volcanic eruptions. From all sites analyzed, vegetation at Finemui Swamp was most sensitive to changes in relative sea level. While vegetation on low-lying Pacific islands is sensitive to changing sea levels, island characteristics, such as area and elevation, are also likely to be important factors that mediate specific island responses to drivers of change.

Current models of island biogeography treat endemic and non-endemic species as if they were functionally equivalent, focussing primarily on species richness. Thus, the functional composition of island biotas in relation to island biogeographical variables remains largely unknown. Using plant trait data (plant height, leaf area and flower length) for 895 native species in the Canary Islands, we related functional trait distinctiveness and climate rarity for endemic and non-endemic species and island ages. Endemics showed a link to climatically rare conditions that is consistent with island geological change through time. However, functional trait distinctiveness did not differ between endemics and non-endemics and remained constant with island age. Thus, there is no obvious link between trait distinctiveness and occupancy of rare climates, at least for the traits measured here, suggesting that treating endemic and non-endemic species as functionally equivalent in island biogeography is not fundamentally wrong.

Aim Adaptive radiation, in which successful lineages proliferate by exploiting untapped niche space, provides a popular but potentially misleading characterization of evolution on oceanic islands. Here we analyse the respective roles of members of in situ diversified vs. non-diversified lineages in shaping the main ecosystems of an archipelago to explore the relationship between evolutionary and ecological ‘success’. Location Canary Islands. Taxon Vascular plants. Methods We quantified the abundance/rarity of the native flora according to the geographical range (number of islands where present and geographical extent of the range), habitat breadth (climatic niche) and local abundance (cover) using species distribution data based on 500 × 500 m grid cells and 2000 vegetation inventories located all over the archipelago. Results Species of diversified lineages have significantly smaller geographic ranges, narrower climatic niches and lower local abundances than those of non-diversified lineages. Species rarity increased with the degree of diversification. The diversified Canarian flora is mainly comprised by shrubs. At both archipelagic and island level, the four core ecosystems (Euphorbia scrub, thermophilous woodlands, laurel forest and pine forest) were dominated by non-diversified lineages species, with diversified lineages species providing

Aim: Biological invasions are likely determined by species dispersal strategies as well as environmental characteristics of a recipient region, especially climate and human impact. However, the contribution of climatic factors, human impact, and dispersal strategies in driving invasion processes is still controversial and not well embedded in the existing theoretical considerations. Here, we study how climate, species dispersal strategies, and human impact determine plant invasion processes on islands distributed in all major oceans in the context of directional ecological filtering. Location: Six mountainous, tropical, and subtropical islands in three major oceans: Island of Hawai'i and Maui (Pacific), Tenerife and La Palma (Atlantic), and La Réunion and Socotra (Indian Ocean). Taxon: Vascular Plants. Methods: We recorded 360 non-native species in 218 plots along roadside elevational transects covering the major temperature, precipitation and human impact (i.e., road density) gradients of the islands. We collected dispersal strategies for a majority of the recorded species and calculated the environmental niche per species using a hypervolume approach. Results: Non-native species’ generalism (i.e., mean community niche width) increased with precipitation, elevation and human impact but showed no relationship with temperature. Increasing precipitation led to environmental filtering of non-native species resulting in more generalist species under high precipitation conditions. We found no directional filtering for temperature but an optimum range of most species between 10 and 20°C. Niche widths of non-native species increased with the prevalence of certain dispersal strategies, particularly anemochory and anthropochory. Main conclusions: Plant invasion on tropical and subtropical islands seems to be mainly driven by precipitation and human impact, while temperature seems to be of little importance. Furthermore, anemochory and anthropochory are dispersal strategies associated with large niche widths of non-native species. Our study allows a more detailed look at the mechanisms behind directional ecological filtering of non-native plant species in non-temperature-limited ecosystems.

Assessing extinction risk from climate drivers is a major goal of conservation science. Few studies, however, include a long-term perspective of climate change. Without explicit integration, such long-term temperature trends and their interactions with short-term climate change may be so dominant that they blur or even reverse the apparent direct relationship between climate change and extinction. Here we evaluate how observed genus-level extinctions of arthropods, bivalves, cnidarians, echinoderms, foraminifera, gastropods, mammals and reptiles in the geological past can be predicted from the interaction of long-term temperature trends with short-term climate change. We compare synergistic palaeoclimate interaction (a short-term change on top of a long-term trend in the same direction) to antagonistic palaeoclimate interaction such as long-term cooling followed by short-term warming. Synergistic palaeoclimate interaction increases extinction risk by up to 40%. The memory of palaeoclimate interaction including the climate history experienced by ancestral lineages can be up to 60 Myr long. The effect size of palaeoclimate interaction is similar to other key factors such as geographic range, abundance or clade membership. Insights arising from this previously unknown driver of extinction risk might attenuate recent predictions of climate-change-induced biodiversity loss. Using extinction data from the geological past, the authors compare the effects of synergistic palaeoclimate interactions, where short- and long-term trends are aligned, with antagonistic ones, where they are not, finding that the former can increase extinction risk by up to 40%.

Insular woodiness (IW)—the evolutionary transition from herbaceousness toward woodiness on islands—is one of the most iconic features of island floras. Since pioneering work by Darwin and Wallace, a number of drivers of IW have been proposed, such as 1) competition for sunlight requiring plants with taller and stronger woody stems and 2) drought favoring woodiness to safeguard root-to-shoot water transport. Alternatively, IW may be the indirect result of increased lifespan related to 3) a favorable aseasonal climate and/or 4) a lack of large native herbivores. However, information on the occurrence of IW is fragmented, hampering tests of these potential drivers. Here, we identify 1,097 insular woody species on 375 islands and infer at least 175 evolutionary transitions on 31 archipelagos, concentrated in six angiosperm families. Structural equation models reveal that the insular woody species richness on oceanic islands correlates with a favorable aseasonal climate, followed by increased drought and island isolation (approximating competition). When continental islands are also included, reduced herbivory pressure by large native mammals, increased drought, and island isolation are most relevant. Our results illustrate different trajectories leading to rampant convergent evolution toward IW and further emphasize archipelagos as natural laboratories of evolution, where similar abiotic or biotic conditions replicated evolution of similar traits. publishedVersion

Aim Functional traits can help us to elucidate biogeographical and ecological processes driving assemblage structure. We analysed the functional diversity of plant species of different evolutionary origins across an island archipelago, along environmental gradients and across geological age, to assess functional aspects of island biogeographical theory. Location Canary Islands, Spain. Major taxa studied Spermatophytes. Time period Present day. Methods We collected data for four traits (plant height, leaf length, flower length and fruit length) associated with resource acquisition, competitive ability, reproduction and dispersal ability of 893 endemic, non-endemic native and alien plant species (c. 43% of the Canary Island flora) from the literature. Linking these traits to species occurrences and composition across a 500 m × 500 m grid, we calculated functional diversity for endemic, non-endemic native and alien assemblages using multidimensional functional hypervolumes and related the resulting patterns to climatic (humidity) and island biogeographical (geographical isolation, topographic complexity and geological age) gradients. Results Trait space of endemic and non-endemic native species overlapped considerably, and alien species added novel trait combinations, expanding the overall functional space of the Canary Islands. We found that functional diversity of endemic plant assemblages was highest in geographically isolated and humid grid cells. Functional diversity of non-endemic native assemblages was highest in less isolated and humid grid cells. In contrast, functional diversity of alien assemblages was highest in arid ecosystems. Topographic complexity and geological age had only a subordinate effect on functional diversity across floristic groups. Main conclusions We found that endemic and non-endemic native island species possess similar traits, whereas alien species tend to expand functional space in ecosystems where they have been introduced. The spatial distribution of the functional diversity of floristic groups is very distinct across environmental gradients, indicating that species assemblages of different evolutionary origins thrive functionally in dissimilar habitats. publishedVersion

Climbing activities affect cliff site species. With cliff sites harbouring unique species communities, the rise in popularity of outdoor climbing activities is a major threat. In this study, we assessed a previously unclimbed boulder before, during and after 500 climbing ascents. We observed an overall reduction in lichen cover by 4.2–9.5%, located around the footholds and combined foot- and handhold but not the handhold. We found the reduction in lichen cover to be strongest at the very start of the climbing treatment and to lessen over time. Therefore, management should focus on directing climbing activities to selected sites, while protecting sites with high conservation value where climbing is prohibited entirely. publishedVersion

Limestone–marl alternations are commonly used for high‐resolution cyclostratigraphic studies and palaeoenvironmental reconstructions, but diagenetic studies indicate that not all limestone–marl alternations reflect genuine differences in the initial sediment composition driven by environmental changes. Differences in the ratios of diagenetically inert trace elements between limestones and marls indicate changes affecting the terrigenous fraction of the precursor sediment. Contrarily, limestone–marl alternations without these differences can be the product of: (i) variations in CaCO3 input (aragonite, calcite); (ii) distortion of the latter by diagenetic CaCO3 redistribution; or (iii) diagenetic CaCO3 redistribution in a homogeneous precursor sediment. The aim of this study is to provide a method to differentiate these cases and to identify variations in the proportion of calcite and aragonite in the precursor sediment composition. The model of differential diagenesis assumes that the concentration of diagenetically inert elements is inversely proportional to the amount of redistributed CaCO3. Consequently, the difference between ratios of diagenetically inert elements from two adjacent beds is a measure for CaCO3 redistribution. This is quantifiable by the vector length between ratios from two adjacent beds. The approach is illustrated here by evaluation of a case study from the Silurian of Gotland, Sweden. Trace elements were compared according to their solubility during diagenesis. All elements bound to clay minerals or calcite show similar patterns of vector length, while vector length of elements which fit into the aragonite lattice, and are diagenetically mobile, differ. The vector length approach provides a tool to test the diagenetic origin of limestone–marl alternations, to identify initial variations in CaCO3 input and to test a limestone–marl alternation’s suitability for cyclostratigraphic analyses., Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659, Research Foundation of Flanders

Description, Anthropogenic extinctions and alien establishments cause an overall loss of functional diversity of island bird communities., Human impacts reshape ecological communities through the extinction and introduction of species. The combined impact of these factors depends on whether non-native species fill the functional roles of extinct species, thus buffering the loss of functional diversity. This question has been difficult to address, because comprehensive information about past extinctions and their traits is generally lacking. We combine detailed information about extinct, extant, and established alien birds to quantify historical changes in functional diversity across nine oceanic archipelagos. We found that alien species often equal or exceed the number of anthropogenic extinctions yet apparently perform a narrower set of functional roles as current island assemblages have undergone a substantial and ubiquitous net loss in functional diversity and increased functional similarity among assemblages. Our results reveal that the introduction of alien species has not prevented anthropogenic extinctions from reducing and homogenizing the functional diversity of native bird assemblages on oceanic archipelagos.

[Aim]: Environmental niche tracking is linked to the species ability to disperse. While well investigated on large spatial scales, dispersal constraints also influence small-scale processes and may explain the difference between the potential and the realized niche of species at small scales. Here we test whether niche size and niche fill differ systematically according to dispersal syndrome within isolated oceanic islands. We expect that species with higher dispersal abilities (anemochorous or endozoochorous) will have a higher niche fill, despite their environmental niche size., [Location]: Azores archipelago., [Taxon]: Native seed plants., [Methods]: We combined a georeferenced database of the species distribution within the archipelago (Azorean Biodiversity Portal/GBIF) with an expert-based dispersal syndrome categorization and a high-resolution climatic grid (CIELO model). Using four climatic variables (Annual Mean Temperature, Mean Diurnal Range, Annual Precipitation, Precipitation Seasonality), we calculated a four-dimensional hypervolume to estimate the niche size of each species. Niche fill was quantified as the suitable climatic space of the island that was occupied by the focal species., [Results]: We found a significant relationship between dispersal syndromes and niche size, and also between dispersal syndromes and niche fill. Such relationships presented no phylogenetic signal. Endozoochorous species display higher niche fill compared to epizoochorous and hydrochorous species, and larger niches than anemochorous and epizoochorous. Differences among the remaining groups are not significant for either niche size or for niche fill., [Main conclusions]: The ability of a species to track its niche at small scales is not tightly related to its dispersal syndrome, although endozoochorous species track their niche more efficiently than the rest of groups. Despite being intuitively appealing, dispersal syndrome classifications might not be the most appropriate tools for understanding dispersal processes at small scales., ML was funded by a scholarship supporting faculty-specific gender equality targets at (FAU) and by the Spanish Ministry of Economy and Competitivity (BES-2016- 077655; project CGL2015-67865-P) and AEI/FEDER, UE (project UNITED, CGL2016-78070-P,). AMCS was funded by the Portuguese Fundação para a Ciência e a Tecnología (contract CEEIND/03425/2017). The climatic models of EBA were developed in the framework of the project PROAAcXXIs–Projecções das Alterações Climáticas nos Açores para o século XXI. (PO_Açores 2020–Eixo Prioritário 1–Açores-01-0145–FEDER—000037).Biodiversity data comes from the project AZORESBIOPORTAL–PORBIOTA (AÇORES-01-0145-FEDER-000072), which was financed by FEDER in 85% and by Azorean Public funds by 15% through the Operational Program Azores 2020.

Biodiversity dynamics are shaped by a complex interplay between current conditions and historic legacy. The interaction of short- and long-term climate change may mask the true relationship of evolutionary responses to climate change if not specifically accounted for. These paleoclimate interactions have been demonstrated for extinction risk and biodiversity change, but their importance for origination dynamics remains untested. Here, we show that origination probability in marine fossil genera is strongly affected by paleoclimate interactions. Overall, origination probability increases by 27.8% [95% CI (27.4%, 28.3%)] when a short-term cooling adds to a long-term cooling trend. This large effect is consistent through time and all studied groups. The mechanisms of the detected effect might be manifold but are likely connected to increased allopatric speciation with eustatic sea level drop caused by sustained global cooling. We tested this potential mechanism through which paleoclimate interactions can act on origination rates by additionally examining a proxy for habitat fragmentation. This proxy, continental fragmentation, has a similar effect on origination rates as paleoclimate interactions, supporting the importance of allopatric speciation through habitat fragmentation in the deep-time fossil record. The identified complex nature of paleoclimate interactions might explain contradictory conclusions on the relationship between temperature and origination in the previous literature. Our results highlight the need to account for complex interactions in evolutionary studies both between and among biotic and abiotic factors.

Terceira Island (Azores archipelago, central Atlantic Ocean) presents a unique but poorly studied Quaternary palaeobotanical record. Among the sites referenced in the literature, Fanal Bay, within Angra do Heroismo city, is known at least since the 1940s. Field prospection in the summer of 2016 revealed two layers of leaf fossils with an unexpected fossil abundance. The preliminary results showed that these represented autochthonous or para-autochthonous (T0) fossil assemblages, preserved by the emplacement of ash or lapilli layers by volcanic events, in a leaf litter of a laurel palaeoforest. Unfortunately, in 2018, the site was destroyed due to development works to consolidate and requalify the Fanal Bay cliff from further sea erosion. This prevented a detailed study and the ex situ preservation of an important palaeontological site, within the Azores UNESCO Global Geopark. With this work, we hope to call the attention to the need of implementing geoconservation strategies in order to prevent the destruction of important geoheritage within the Azores Islands and to transpose this warning to other geoconservationists in oceanic islands worldwide.

Ecosystem services such as food provisioning, climate regulation, nutrient cycling, or recreation in open landscapes underpin human wellbeing. They are highly dependent on land use, land cover and utilization pattern as well as environmental factors like climate, topography and soil. In consequence, ecosystem services supply shows a high spatial variability. However, it is less clear if the perception of the importance of ecosystem services is similarly heterogeneous in space and amongst societal actors. The aim of this large-scale study was to explore whether land cover and climate gradients as well as socio-cultural factors influence the perceptions of ecosystem services of four groups of societal actors: citizens, farmers, foresters and nature managers. Spatially explicit survey data of 3018 respondents allowed to gain insight into the distribution of perceived importance of 21 ecosystem services in the federal state of Bavaria, Germany together with the respondents’ socio-cultural characterisation (e.g. gender, education and hobbies in nature). Responses were analysed through descriptive statistics, redundancy analysis, and Generalized Linear Models. Results reveal that the perceived importance of many ecosystem services was consistently high across groups, although perception differed for some ecosystem services (e.g. production of energy plants and timber as well as recreation in urban green space). Compared to other actor groups, farmers attributed slightly lower importance to all ES except provisioning services. Socio-cultural factors better explained variability in perceived importance of ecosystem services than land cover and climate gradients. This might be either explained by the fact that the environmental gradients vary not strong enough in our case study or that they do not shape the perceptions of respondents. A limitation of the study is that the sample of respondents obtained is not representative for the population, but biased towards persons interested in the topics of the survey. Still the consensus indicated by the overall positive perception of ecosystem services among respondents highlights the integrative potential of ecosystem services when included in decision-making.

QUESTIONS: Which environmental factors influence fine-grain beta diversity of vegetation and do they vary among taxonomic groups? LOCATION: Palaearctic biogeographic realm. METHODS: We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database, covering a wide range of different grassland and other open habitat types. We derived extensive environmental and structural information for these series. For each series and four taxonomic groups (vascular plants, bryophytes, lichens, all), we calculated the slope parameter (z-value) of the power law species–area relationship (SAR), as a beta diversity measure. We tested whether z-values differed among taxonomic groups and with respect to biogeographic gradients (latitude, elevation, macroclimate), ecological (site) characteristics (several stress–productivity, disturbance and heterogeneity measures, including land use) and alpha diversity (c-value of the power law SAR). RESULTS: Mean z-values were highest for lichens, intermediate for vascular plants and lowest for bryophytes. Bivariate regressions of z-values against environmental variables had rather low predictive power (mean R² = 0.07 for vascular plants, less for other taxa). For vascular plants, the strongest predictors of z-values were herb layer cover (negative), elevation (positive), rock and stone cover (positive) and the c-value (U-shaped). All tested metrics related to land use (fertilization, livestock grazing, mowing, burning, decrease in naturalness) led to a decrease in z-values. Other predictors had little or no impact on z-values. The patterns for bryophytes, lichens and all taxa combined were similar but weaker than those for vascular plants. CONCLUSIONS: We conclude that productivity has negative and heterogeneity positive effects on z-values, while the effect of disturbance varies depending on type and intensity. These patterns and the differences among taxonomic groups can be explained via the effects of these drivers on the mean occupancy of species, which is mathematically linked to beta diversity. The Bavarian Research Alliance (via the BayIntAn scheme) and the Bayreuth Center of Ecology and Environmental Research (BayCEER) funded the initial GrassPlot workshop during which the database was established and the current paper was initiated (grants to JDe). WU acknowledges support from the Polish National Science Centre (grant 2017/27/B/NZ8/00316). IB, JAC and IG-M were funded by the Basque Government (IT936-16). GF carried out the research in the frame of the MIUR initiative "Department of excellence" (Law 232/2016). SBa was supported by the GINOP-2.3.2-15-2016-00019 project. CM was supported by the Czech Science Foundation (grant no. 19-28491X) and the Basque Government (IT936-16). ID was supported by the Polish National Science Centre (grant DEC-2013/09/N/NZ8/03234) and by a Swiss Government Excellence Scholarship for Postdocs (ESKAS No. 2019.0491). MJ was supported by the Slovak Academy of Sciences (grant VEGA 02/0095/19). AN was supported by a " Master Plan Project" in the University of Mazandaran, Iran. DS was supported by the Czech Science Foundation (grant no. 20-29554X). AK, IV and DV were supported by the National Research Foundation of Ukraine (project no. 2020.01/0140). JDo was supported by the Czech Science Foundation (GA17-19376S) and LTAUSA18007 info:eu-repo/semantics/publishedVersion

Aim Trait-based approaches are increasingly important in ecology and biogeography, but progress is often hampered by the availability of high-quality quantitative trait data collected in the field. Alternative sources of trait information include scientific floras and taxonomic monographs. Here we test the reliability and usefulness of trait data acquired from scientific floras against trait values measured in the field, and those in TRY, the most comprehensive global plant trait database. Location Tenerife and La Palma, Canary Islands, Spain. Methods We measured leaf area and specific leaf area (SLA) in the field for 451 native vascular plant species and compared them with equivalent trait data digitised from the most recent and comprehensive guide of the Canarian flora, and data sourced from TRY. We regressed the field-measured traits against their equivalents estimated from the literature and used the regression models from one island to predict the trait values on the other island. Results For leaf area, linear models showed good agreement between values from the scientific flora and those measured in the field (r2 = 0.86). These models were spatially transferable across islands. In contrast, for SLA we found a weak relationship between field-measured values and the best estimates from the scientific flora (r2 = 0.11). Insufficient data were available in the TRY database for our study area to calculate trait correlations with other data sources. Conclusions Scientific floras can act as useful data sources for quantitative plant trait data for some traits but not others, whilst the TRY database contains many traits, but is incomplete in species coverage for our study region, and oceanic islands in general. publishedVersion

Dynamics in the rate of compositional change (rate-of-change; RoC), preserved in paleoecological sequences, are thought to reflect changes due to exogenous (climate and human forcing) or endogenous (local dynamics and biotic interactions) drivers. However, changes in sedimentation rates and sampling strategies can result in an uneven distribution of time intervals and are known to affect RoC estimates. Furthermore, there has been relatively little exploration of the implications of these challenges in quantifying RoC in paleoecology. Here, we introduce R-Ratepol – an easy-to-use R package – that provides a robust numerical technique for detecting and summarizing RoC patterns in complex multivariate time-ordered stratigraphical sequences. First, we compare the performance of common methods of estimating RoC and detecting periods of high RoC (peak-point) using simulated pollen-stratigraphical data with known patterns of compositional change and temporal resolution. In addition, we propose a new method of binning with a moving window, which shows a more than 5-fold increase in the correct detection of peak-points compared to the more traditional way of using individual levels. Next, we apply our new methodology to four representative European pollen sequences and show that our approach also performs well in detecting periods of significant compositional change during known onsets of human activity, early land-use transformation, and changes in fire frequency. Expanding the approach using R-Ratepol to open-access paleoecological datasets in global databases, such as Neotoma, will allow future paleoecological and macroecological studies to quantify major changes in biotic composition or in sets of abiotic variables across broad spatiotemporal scales. publishedVersion

Accelerating ecosystem disruption Oceanic islands are among the most recent areas on Earth to have been colonized by humans, in many cases in just the past few thousand years. Therefore, they are important laboratories for the study of human impacts on natural vegetation and biodiversity. Nogué et al. provide a quantitative palaeoecological study of 27 islands around the world, focusing on pollen records of vegetation composition before and after human arrival. The authors found a consistent pattern of acceleration of vegetation turnover after human invasion, with median rates of change increasing by a factor of six. These changes occurred regardless of geographical and ecological features of the island and show how rapidly ecosystems can change and how island ecosystems are set on new trajectories. Science , this issue p. 488

Dynamics in the rate of compositional change beyond the time of human observation are uniquely preserved in palaeoecological sequences from peat or lake sediments. Changes in sedimentation rates and sampling strategies result in an uneven distribution of time intervals within stratigraphical data, which makes assessing rates of compositional change and the detection of periods with a high rate-of-change (RoC) or "peak-points" challenging. Despite these known issues and their importance, and the frequent use of RoC in palaeoecology, there has been relatively little exploration of differing approaches to quantifying RoC. Here, we introduce R-Ratepol (an easy to use R package) that provides a robust numerical technique for detecting and summarising RoC patterns in complex multivariate time-ordered stratigraphical sequences. We compare the performance of common methods of estimating RoC using simulated pollen-stratigraphical data with known patterns of compositional change and temporal resolution. In addition, we apply our new methodology to four representative European pollen sequences. Simulated data show large differences in the successful detection of known patterns in RoC peak-point detection depending on the smoothing methods and dissimilarity coefficients used, and the level density and their taxonomic richness. Building on these results, we propose a new method of binning with a moving window in combination with a generalised additive model for peak-point detection. The method shows a 22% increase in the correct detection of peak-points and 4% lower occurrence of false positives compared to the more traditional way of peak selection by individual levels, as well as achieving a reasonable compromise between type I and type II errors. The four representative pollen sequences from Europe show that our methodological combination also performs well in detecting periods of significant compositional change including the onset of human activity, early land-use transformation, and changes in fire frequency. Expanding the approach using R-Ratepol to the increasingly available stratigraphical data on pollen, chironomids, or diatoms will allow future palaeoecological and macroecological studies to quantify, and then attribute, major changes in biotic composition across broad spatial areas through time.

Aim: Plant life‐forms characterize key morphological strategies that enable large‐scale comparisons of plant communities. This study applies Raunkiær's plant life‐form concept that was developed for temperate climate to a subtropical island flora, in parts, dominated by summer aridity. We quantify how plant life‐form patterns as well as patterns of important plant functional traits (PFTs) relate to important climate and topographic characteristics. Location: La Palma, Canary Islands. Taxon: Flora of La Palma. Methods: We assigned each native plant species a plant life‐form, that is, phanerophyte, chamaephyte, hemicryptophyte, geophyte and therophyte, as well as PFTs (succulence and N‐fixer). We used stacked species distribution models to assess occurrence probability for each species using the Atlantis database (500 m × 500 m grid). We related richness and percentage values for each plant life‐form and PFT to climate and topography. Results: Plant life‐forms and PFTs showed a clear pattern within geographic but also climate space, while topography had a minor effect. Phanerophytes mainly contributed to the flora in humid areas. Chamaephytes and hemicryptophytes most strongly contributed to the summit scrub flora and, to some degree, also to the arid coastal regions. Geophytes and therophytes were mainly found in dry coastal regions. N‐fixers contributed mainly to warm‐arid and cool‐arid regions, while succulent species were mainly found in arid coastal regions. Main conclusions: Raunkiær's plant life‐form concept can be comprehensively transferred to a subtropical island flora by adapting to local unfavourable growing conditions, that is, aridity. Using the strong environmental gradients offered by our study island, we identify substantial climate‐driven variation in patterns of plant life‐forms and PFTs that might be used for large‐scale comparisons in macroecological studies. The growth strategies reflected in Raunkiær's plant life‐forms suggest differences in species establishment and coexistence dynamics within different parts of the island's climate space.

The origin of carbonatic rhythmically alternating lithologies, called limestone-marl alternations (LMA), is a lively debated topic. LMA are commonly used as high-resolution cyclostratigraphic record, but diagenetic studies indicate that not all LMA reflect genuine differences in the original composition driven by environmental changes. LMA with a clear difference between limestones and marls in their ratios of diagenetically inert elements such as Al2O3/TiO2 can be identified as the product of primary sedimentary differences, i.e. variation affecting the terrigenous compound of the precursor sediment. In contrast, LMA without these differences could be the product of (1) variations in the carbonate compounds of the precursor sediment, i.e. aragonite and calcite input, or of (2) the distortion of the latter by diagenetic carbonate redistribution, or of (3) diagenetic carbonate redistribution in a homogenous precursor sediment. The problem of differentiating these three cases is known as the diagenetic dilemma. The question is, how can the composition in the original CaCO3 compound (aragonite, calcite) of the precursor sediment be reconstructed? This study provides a new approach to tackle the diagenetic dilemma. According to the model of differential diagenesis, the concentration of trace elements is inversely proportional to the amount of diagenetically redistributed carbonate. Consequently, the difference between the ratios of diagenetically inert elements from two adjacent beds is a measure for carbonate redistribution between them. This is quantifiable by calculating the vector length between these ratios for two adjacent beds. The new approach is illustrated here by evaluating 75 contiguous limestone and marl beds from the Högklint Formation (Silurian) on Gotland, Sweden. To test the new method, trace elements in these beds were compared according to their relative solubility during diagenesis. All elements which are either bound to clay minerals or fit into the calcite lattice show the same pattern of vector lengths (

AimRecent studies increasingly use statistical methods to infer biotic interactions from co-occurrence information at a large spatial scale. However, disentangling biotic interactions from other factors that can affect co-occurrence patterns at the macroscale is a major challenge.ApproachFindingsWe present a set of questions that analysts and reviewers should ask to avoid erroneously attributing species association patterns to biotic interactions. Our questions relate to the appropriateness of data and models, the causality behind a correlative signal, and the problems associated with static data from dynamic systems. We summarize caveats reported by macroecological studies of biotic interactions and examine whether conclusions on the presence of biotic interactions are supported by the modelling approaches used.Irrespective of the method used, studies that set out to test for biotic interactions find statistical associations in species' co-occurrences. Yet, when compared with our list of questions, few purported interpretations of such associations as biotic interactions hold up to scrutiny. This does not dismiss the presence or importance of biotic interactions, but it highlights the risk of too lenient interpretation of the data. Combining model results with information from experiments and functional traits that are relevant for the biotic interaction of interest might strengthen conclusions.Main conclusionsMoving from species- to community-level models, including biotic interactions among species, is of great importance for process-based understanding and forecasting ecological responses. We hope that our questions will help to improve these models and facilitate the interpretation of their results. In essence, we conclude that ecologists have to recognize that a species association pattern in joint species distribution models will be driven not only by real biotic interactions, but also by shared habitat preferences, common migration history, phylogenetic history and shared response to missing environmental drivers, which specifically need to be discussed and, if possible, integrated into models.

Globally accelerating trends in societal development and human environmental impacts since the mid-twentieth century 1–7 are known as the Great Acceleration and have been discussed as a key indicator of the onset of the Anthropocene epoch 6 . While reports on ecological responses (for example, changes in species range or local extinctions) to the Great Acceleration are multiplying 8, 9 , it is unknown whether such biotic responses are undergoing a similar acceleration over time. This knowledge gap stems from the limited availability of time series data on biodiversity changes across large temporal and geographical extents. Here we use a dataset of repeated plant surveys from 302 mountain summits across Europe, spanning 145 years of observation, to assess the temporal trajectory of mountain biodiversity changes as a globally coherent imprint of the Anthropocene. We find a continent-wide acceleration in the rate of increase in plant species richness, with five times as much species enrichment between 2007 and 2016 as fifty years ago, between 1957 and 1966. This acceleration is strikingly synchronized with accelerated global warming and is not linked to alternative global change drivers. The accelerating increases in species richness on mountain summits across this broad spatial extent demonstrate that acceleration in climate-induced biotic change is occurring even in remote places on Earth, with potentially far-ranging consequences not only for biodiversity, but also for ecosystem functioning and services.

Space requirements by winter sports and accelerating global warming are usually perceived as stressors for mountain meadow plant communities. Cross-country ski track preparation (i.e. grooming), however, might retard effects of climate change and, being limited in space requirements, might increase abiotic heterogeneity. The effect of cross-country ski tracks on meadow vegetation was quantified along a representative ski track that had been operated for 30 years in the Fichtelgebirge, a low mountain range in central Europe. Paired sampling was implemented to assess the effect of skiing operations on snow and soil properties, plant phenology, biomass production and species composition. Additionally, boosted regression tree analyses were used to quantify the relative importance of the cross-country ski track compared to other environmental conditions. The cross-country ski track strongly increased snow density, enhanced soil frost, and retarded snowmelt, thereby delaying flower phenology (by 2.1 days) and the early development stages of plant species on the track. However, biomass, species richness and species composition were unaffected by skiing operations except for one species (Leontodon autumnalis) showing exclusive occurrence on the track while four others showed reduced relative occurrence on the track. While snow and soil properties were influenced by cross-country ski track preparation, natural environmental variability was more influential for species composition and biomass production than the ski track. We therefore conclude that the ski track – without artificial snow – did not negatively affect species composition. By delaying flower phenology, effects of the ski track even counteracted global warming to some degree. Due to their small spatial extent in the landscape, these ski tracks may add to environmental heterogeneity and thus support sustaining diverse species compositions during environmental changes.

The number of people riding mountain bikes (MTBs) with electrical assistance (eMTB) is growing rapidly, creating a substantial switch from conventional mountain biking to electrically assisted mountain biking. Electrical support has the potential to alter riding behaviour on mountain bikes, associated with a change in destination choice and physiological demand. Hence, this study conducted test rides with 10 sport science students riding on conventional and electrically assisted mountain bikes with the purpose to examine how electrical assistance affects the spatio-temporal riding parameters mean speed, total distance, total climb and surface type. In addition, we recorded the physiological parameter heart rate and calculated the energy expenditure when riding conventional MTBs and eMTBs. We found higher speed associated with longer distance and elevated climb on eMTBs, combined with a higher percentage in the use of singletrails. At the same time, participants riding mountain bikes with electrical assistance showed lower heart rates and lower energy expenditure. Moreover, our results indicate that e-assisted participants are able to reach higher altitudes despite a lower endurance performance. Accordingly, the increasing use of eMTBs is leading to an augmentation of the movement capacity of people in natural mountain areas and thus, promoting physical activity and nature experiences on the one hand. However, a higher number of people in sensitive natural systems is also related to increasing risks for flora and fauna, particularly when riding gets “faster - higher – farther”. Informing people about the risks to increase awareness and promote appropriate behaviour in combination with the setting of a proper trail management, is of crucial importance to successfully merge recreation and nature protection in mountain systems. Management implications This study reveals clear differences in riding behaviour, trail choice and physiological response when riding conventional mountainbikes and mountainbikes with electrical assistance in mountain systems. With electrical assistance allowing less restricted access to physically demanding terrain, an increasing number of mountain bikers may reach sensitive ecosystems in high altitudes. To minimise ecological consequences such as vegetation damage and disturbance of wildlife, it is vital to adequately adjust management solutions. Our results highlight the need for clear regulations and informing of people, translating into a considerate and sustainable behaviour and trail choice and hence the prevention of conflicts with nature conservation and human stakeholders like recreationists or farmers.

AIM: Mountains and islands are both well known for their high endemism. To explain this similarity, parallels have been drawn between the insularity of "true islands" (land surrounded by water) and the isolation of habitats within mountains (so-called "mountain islands"). However, parallels rarely go much beyond the observation that mountaintops are isolated from one another, as are true islands. Here, we challenge the analogy between mountains and true islands by re-evaluating the literature, focusing on isolation (the prime mechanism underlying species endemism by restricting gene flow) from a dynamic perspective over space and time. FRAMEWORK: We base our conceptualization of "isolation" on the arguments that no biological system is completely isolated; instead, isolation has multiple spatial and temporal dimensions relating to biological and environmental processes. We distinguish four key dimensions of isolation: (a) environmental difference from surroundings; (b) geographical distance to equivalent environment [points (a) and (b) are combined as "snapshot isolation"]; (c) continuity of isolation in space and time; and (d) total time over which isolation has been present [points (c) and (d) are combined as "isolation history"]. We evaluate the importance of each dimension in different types of mountains and true islands, demonstrating that substantial differences exist in the nature of isolation between and within each type. In particular, different types differ in their initial isolation and in the dynamic trajectories they follow, with distinct phases of varying isolation that interact with species traits over time to form present-day patterns of endemism. CONCLUSIONS: Our spatio-temporal definition of isolation suggests that the analogy between true islands and mountain islands masks important variation of isolation over long time-scales. Our understanding of endemism in isolated systems can be greatly enriched if the dynamic spatio-temporal dimensions of isolation enter models as explanatory variables and if these models account for the trajectories of the history of a system. Department of Biodiversity, Macroecology & Biogeography at University of Gottingen; The Netherlands Organization for Scientific Research (NWO, no. 2012/13248/ALW to H. Hooghiemstra); European Research Council (ERC) Advanced Grant (no. 741413, Humans on Planet Earth (HOPE); Marie Sklodowska-Curie grant agreement (no. 707968); Danish National Research Foundation for support of the Center for Macroecology, Evolution and Climate (no. DNRF96); Austrian Science Foundation (Fonds zur Forderung der wissenschaftlichen Forschung, FWF, no. I 3757-B29); Portuguese National Funds, through Fundação para a Ciência e a Tecnologia (FCT), within the project UID/BIA/00329/2013 and the research Fellowship PD/BD/114380/2016; Horizon 2020 research and innovation programme (no. 641762). info:eu-repo/semantics/publishedVersion

Topography influences evolutionary and ecological processes by isolating populations and enhancing habitat diversity. While the effects of large-scale topography on patterns of species richness and endemism are increasingly well documented, the direct effect of local topography on endemism is less understood. This study compares different aspects of topographic isolation, namely the isolating effect of deep barrancos (ravines) and the effect of increasing isolation with elevation in influencing patterns of plant endemism within a topographically diverse oceanic island (La Palma, Canary Islands, Spain). We collected plant presence–absence data from 75 plots in 8 barrancos on the northern coast of La Palma, spanning an elevation gradient from 95 to 674m a.s.l. Using mixed-effects models, we assessed the effect of barranco depth and elevation on the percentage of single-island endemics, multi-island endemics, and archipelago endemics. We found that percent endemism was not significantly correlated with barranco depth and correlated negatively with elevation within barrancos (rather than the expected positive relationship). The topographic barriers associated with the deep island barrancos thus appear insufficient to drive speciation through isolation in oceanic island plants. The decrease in endemism with elevation contradicts findings by previous broader-scale studies and it may reflect local influences, such as high habitat heterogeneity at low elevations.

The importance of understanding biotic patterns in managed tropical landscapes is increasingly recognised. Bangladesh is a country with a long human land-use history and constitutes almost a blind spot in vegetation science on the landscape scale. Here, we analyse patterns and drivers of plant species richness and community composition along a land use intensity gradient in a forest landscape including tea gardens, tree plantations and nature reserves (Satchari Reserved Forest) based on multivariate approaches and variation partitioning. We find richness as well composition of tree and understory species to directly relate to a disturbance gradient that reflects protection status and elevation. This is astonishing, as the range in elevation is with 70 m really small. Topography and protection remain significant drivers of biodiversity after correcting for human disturbances. While tree and non-tree species richness were positively correlated, they differ considerably in their relation to other environmental or disturbance variables as well as in the spatial richness pattern. The disturbance regime particularly structures tree species richness and composition in protected areas. We conclude highlighting the importance of explicitly integrating human-biosphere interactions in any nature protection strategy for the study region.

Aim The general dynamic model (GDM) proposed by Whittaker et al. (2008) has become a widely accepted theoretical framework in island biogeography. In this study, we explore whether GDM predictions hold when overall plant diversity is deconstructed into major plant families. Location 101 islands from 14 oceanic archipelagos world-wide. Methods Occurrence data for all species of nine large, cosmopolitan flowering plant families were used to test predictions derived from the GDM. We analysed the effects of island area and age on species richness as well as number and percentage of single-island endemic species per family using mixed-effect models. Results Total species and endemic richness as well as the percentage of endemic species showed the predicted hump-shaped relationship with island age. The overall pattern was mainly driven by few species-rich plant families. Varying patterns were found for individual families, some of them opposing the general trend. In most cases, native and endemic species richness peaked much earlier in the island life cycle than suggested by the GDM. The contribution of area to the explained variation of all dependent variables was much higher than that of island age. Main conclusions The results suggest that biodiversity-age relationships reported for large taxonomic groups like plants are driven by only a few species-rich clades. The way these families influence the overall patterns of species richness and endemism is related to family-specific properties, such as evolutionary history or dispersal strategies. Deviances from the GDM predictions can hence largely be explained by family characteristics and considering taxon-specific traits may help to further improve the explanatory power of the GDM. Families not following the expectations, like Orchidaceae, may be particularly valuable candidates to unveil so far neglected drivers of island biogeographical patterns.

Additional co-authors: Jose Maria Fernandez-Palacios, Rosalina Gabriel, Roy E. Gereau, Rosemary G. Gillespie, Josef Greimler, David E.V. Harter, Tsurng-Juhn Huang, Severin D.H. Irl , Daniel Jeanmonod, Anke Jentsch, Christoph Kueffer, Sandra Nogue, Rudiger Otto, Jonathan Price, Maria M. Romeiras, Dominique Strasberg, Tod Stuessy, Jens-Christian Svenning, Ole R. Vetaas, Carl Beierkuhnlein

The general dynamic model of oceanic island biogeography (GDM) has added a new dimension to theoretical island biogeography in recognizing that geological processes are key drivers of the evolutionary processes of diversification and extinction within remote islands. It provides a dynamic and essentially non-equilibrium framework generating novel predictions for emergent diversity properties of oceanic islands and archipelagos. Its publication in 2008 coincided with, and spurred on, renewed attention to the dynamics of remote islands. We review progress, both in testing the GDM's predictions and in developing and enhancing ecological-evolutionary understanding of oceanic island systems through the lens of the GDM. In particular, we focus on four main themes: (i) macroecological tests using a space-for-time rationale; (ii) extensions of theory to islands following different patterns of ontogeny; (iii) the implications of GDM dynamics for lineage diversification and trait evolution; and (iv) the potential for downscaling GDM dynamics to local-scale ecological patterns and processes within islands. We also consider the implications of the GDM for understanding patterns of non-native species diversity. We demonstrate the vitality of the field of island biogeography by identifying a range of potentially productive lines for future research.

Endemics–Area Relationships (EARs)are fundamental in theoretical and applied biogeography for understanding distribution patterns and promoting biodiversity conservation. However, calculating EARs for vascular plant species from existing data is problematic because of biased knowledge of endemic species distributions and differences between taxonomies. We aimed to overcome these challenges by developing a new standardized global dataset based on expert knowledge to produce a set of global EARs. We developed a nested circle design, with grain sizes of 10 4 , 10 5 , 10 6 , 10 7 , and 10 8 km 2 , respectively, and a global distribution of plots based on a stratified random scheme. The number of vascular plant species endemic to each circle was then estimated independently by five experts randomly chosen from a pool of 23, as both a minimum and a maximum value (lower and upper bounds of the estimation), taking into account the limitations of current knowledge and varied species concepts in existing taxonomies. This procedure resulted in a dataset of 3000 expert estimates. Based on the data, we produced three global EARs for endemic species richness using minimum, maximum and average estimates. As a validation, we used all three models to extrapolate to the entire world, producing estimates of 284,493 (minimum), 398,364 (maximum)and 312,243 (average)vascular plant species. These figures conform to the range of taxonomists’ estimates. From the models, we calculated the average area needed to harbour a single endemic species as 12,875 km 2 (range 9675–20,529). The global vascular plant EARs we calculated represent the first standardized, quantitative expectations of plant endemism at any given scale (sampling unit size). These EARs allow us to provide a clear answer to a long-standing but elusive biogeographical question: how to assess whether any area on the surface of the Earth is rich or poor in endemics relative to the average.

Aim Species-area relationships (SARs) are fundamental scaling laws in ecology although their shape is still disputed. At larger areas, power laws best represent SARs. Yet, it remains unclear whether SARs follow other shapes at finer spatial grains in continuous vegetation. We asked which function describes SARs best at small grains and explored how sampling methodology or the environment influence SAR shape. Location Palaearctic grasslands and other non-forested habitats. Taxa Vascular plants, bryophytes and lichens. Methods We used the GrassPlot database, containing standardized vegetation-plot data from vascular plants, bryophytes and lichens spanning a wide range of grassland types throughout the Palaearctic and including 2,057 nested-plot series with at least seven grain sizes ranging from 1 cm(2) to 1,024 m(2). Using nonlinear regression, we assessed the appropriateness of different SAR functions (power, power quadratic, power breakpoint, logarithmic, Michaelis-Menten). Based on AICc, we tested whether the ranking of functions differed among taxonomic groups, methodological settings, biomes or vegetation types. Results The power function was the most suitable function across the studied taxonomic groups. The superiority of this function increased from lichens to bryophytes to vascular plants to all three taxonomic groups together. The sampling method was highly influential as rooted presence sampling decreased the performance of the power function. By contrast, biome and vegetation type had practically no influence on the superiority of the power law. Main conclusions We conclude that SARs of sessile organisms at smaller spatial grains are best approximated by a power function. This coincides with several other comprehensive studies of SARs at different grain sizes and for different taxa, thus supporting the general appropriateness of the power function for modelling species diversity over a wide range of grain sizes. The poor performance of the Michaelis-Menten function demonstrates that richness within plant communities generally does not approach any saturation, thus calling into question the concept of minimal area. We thank all vegetation scientists who carefully collected multi‐ scale plant diversity data from Palaearctic Grasslands available in GrassPlot. The Eurasian Dry Grassland Group (EDGG) and the International Association for Vegetation Science (IAVS) sup‐ ported the EDGG Field Workshops, which generated a core part of the GrassPlot data. The Bavarian Research Alliance (grant BayIntAn_UBT_2017_58) and the Bayreuth Center of Ecology and Environmental Research (BayCEER) funded the initial GrassPlot workshop during which the database was established and the cur‐ rent paper was initiated. A.N. acknowledges support by the Center for International Scientific Studies and Collaboration (CISSC), Iran. C.M., I.B., I.G.‐M and J.A.C. were funded by the Basque Government (IT936‐16). D.V. carried out the research supported by a grant of the State Fund For Fundamental Research Ф83/53427. G.F. carried out the research in the frame of the MIUR initiative ‘Department of excellence' (Law 232/2016). I.D. was supported by the Polish National Science Centre (grant DEC‐2013/09/N/NZ8/03234). J.Do. was supported by the Czech Science Foundation (GA 17‐19376S). M.J. was supported by grant by Slovak Academy of Sciences (VEGA 02/0095/19). W.U. ac‐ knowledges support from the Polish National Science Centre (grant 2017/27/B/NZ8/00316).

Climatic seasonality drives ecosystem processes (e.g. productivity) and influences plant species distribution. However, it is poorly understood how different aspects of seasonality (especially regarding temperature and precipitation) affect growth continuity of trees in climates with low seasonality because seasonality is often only crudely measured. On islands, exceptionally wide elevational species distribution ranges allow the use of tree rings to identify how growth continuity and climate–growth relationships change with elevation. Here, we present a novel dendroecological method to measure stem growth continuity based on annual density fluctuations (ADFs) in tree rings of Pinus canariensis to indicate low climatic seasonality. The species ranges from 300 to >2000 m a.s.l. on the trade wind-influenced island of La Palma (Canary Islands), where we measured three decades of tree-ring data of 100 individuals distributed over 10 sites along the entire elevational range. The successfully implemented ADF approach revealed a major shift of stem growth continuity across the elevational gradient. In a remarkably clear pattern, stem growth continuity (percentage of ADFs) showed a hump-shaped relationship with elevation reaching a maximum at around 1000 m a.s.l. Low- to mid-elevation tree growth was positively correlated with the Palmer Drought Severity Index (PDSI; indicating aridity) and sea surface temperature (indicating trade wind-influenced moderation of water supply), while high-elevation tree growth was positively correlated with winter temperature (indicating a cold-induced dormancy period). We conclude that ADFs are a useful method to measure stem growth continuity in low-seasonality climates. Growth of P. canariensis on the Canary Islands is more frequently interrupted by winter cold at high elevations and by summer drought at low elevations than in the trade wind-influenced mid elevations, where growth sometimes continues throughout the year. Climate change-associated alterations in trade wind cloud formation might cause non-analogue growth limitations for many unique island species., Climatic seasonality drives ecosystem processes, but it is poorly understood how different aspects of seasonality affect growth continuity of trees in climates with low seasonality. On islands, exceptionally wide elevational species distribution ranges allow the use of tree rings to identify how growth continuity changes with elevation. Here, we present a novel dendroecological method to measure stem growth continuity based on annual density fluctuations (ADFs) in tree rings of Canary Islands pine on La Palma. We find a remarkably clear pattern that trees most often continue to grow year-round in the humid mid-elevation cloud forests of La Palma.

Within-species and among-species differences in growth responses to a changing climate have been well documented, yet the relative magnitude of within-species vs. among-species variation has remained largely unexplored. This missing comparison impedes our ability to make general predictions of biodiversity change and to project future species distributions using models. We present a direct comparison of among- versus within-species variation in response to three of the main stresses anticipated with climate change: drought, warming, and frost. Two earlier experiments had experimentally induced (i) summer drought and (ii) spring frost for four common European grass species and their ecotypes from across Europe. To supplement existing data, a third experiment was carried out, to compare variation among species from different functional groups to within-species variation. Here, we simulated (iii) winter warming plus frost for four grasses, two nonleguminous, and two leguminous forbs, in addition to eleven European ecotypes of the widespread grass Arrhenatherum elatius. For each experiment, we measured: (i) C/N ratio and biomass, (ii) chlorophyll content and biomass, and (iii) plant greenness, root (15) N uptake, and live and dead tissue mass. Using coefficients of variation (CVs) for each experiment and response parameter, a total of 156 within- vs. among-species comparisons were conducted, comparing within-species variation in each of four species with among-species variation for each seed origin (five countries). Of the six significant differences, within-species CVs were higher than among-species CVs in four cases. Partitioning of variance within each treatment in two of the three experiments showed that within-species variability (ecotypes) could explain an additional 9% of response variation after accounting for the among-species variation. Our observation that within-species variation was generally as high as among-species variation emphasizes the importance of including both within- and among-species variability in ecological theory (e.g., the insurance hypothesis) and for practical applications (e.g., biodiversity conservation).