The functional trait spectrum of European temperate grasslands

Questions: What is the functional trait variation of European temperate grasslands and how does this reflect global patterns of plant form and function? Do habitat specialists show trait differentiation across habitat types?. Location: Europe. Methods: We compiled 18 regeneration and non-regeneration traits for a continental species pool consisting of 645 species frequent in five grassland types. These grassland types are widely distributed in Europe but differentiated by altitude, soil bedrock and traditional long-term management and disturbance regimes. We evaluated the multivariate trait space of this entire species pool and compared multi-trait variation and mean trait values of habitat specialists grouped by grassland type. Results: The first dimension of the trait space accounted for 23% of variation and reflected a gradient between fast-growing and slow-growing plants. Plant height and SLA contributed to both the first and second ordination axes. Regeneration traits mainly contributed to the second and following dimensions to explain 56% of variation across the first five axes. Habitat specialists showed functional differences between grassland types mainly through non-regeneration traits. Conclusions: The trait spectrum of plants dominating European temperate grasslands is primarily explained by growth strategies which are analogous to the trait variation observed at the global scale, and secondly by regeneration strategies. Functional differentiation of habitat specialists across grassland types is mainly related to environmental filtering linked with altitude and disturbance. This filtering pattern is mainly observed in non-regeneration traits, while most regeneration traits demonstrate multiple strategies within the same habitat type.EL, BJA, MTI, AM, PI and CB acknowledge the research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007–2013 under REA grant agreement no. 607785, as a part of the NAtive Seed Science TEchnology and Conservation (NASSTEC) Initial Training Network (ITN). BJA was further funded by the Marie Curie Clarín‐COFUND program of the Principality of Asturias and the European Union (ACB17‐26). BJA and HB acknowledge support from the German Centre for Integrative Biodiversity Research (iDiv) Halle–Jena–Leipzig funded by the German Research Foundation (DFTG FZT 118) through the sPlot research platform. PI acknowledges support from the Rural & Environment Science & Analytical Services Division of the Scottish Government. KÖ thanks RO1567‐IBB03/2018 for financial support

Global patterns in endemicity and vulnerability of soil fungi

Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

[Fine root nitrogen contents and morphological adaptations of alpine plants].

Nitrogen and carbon contents of fine roots were studied for 92 alpine plant species in the Northwest Caucasus. Nitrogen content ranged from 0.43% (Bromus variegatus) to 3.75% (Corydalis conorhiza) with mean value 1.3%. Carbon content ranged from 40.3% (Corydalis conorhiza) to 51.7% (Empetrum nigrum) with mean value 43.4%. C:N ratio was found to be 34:1 which is higher than the worldwide mean. Eudicot's roots had higher N concentration (1.37 +/- 0.07) than monocot's ones (0.95 +/- 0.09). Among the life forms, carbon content increased in the following order: geophytes < hemicriptophytes < chamaephytes. Specific root length positively correlated with nitrogen root content and negatively--with carbon root content. Species with larger leaves and higher specific root area had more nitrogen and less carbon in roots in comparison with species with small leaves. There were positive correlations between leaf and root nitrogen, as well as carbon, contents. Regrowth rate; seed size, aboveground biomass, and vegetation mobility were not related with root nitrogen content. Our results corroborate the poor and rich soil adaptation syndromes. Species of competitive and ruderal (sensu Grime) strategies are more typical for alpine meadows and snow bed communities. They had higher nitrogen contents in leaves and roots, larger leaves with higher water content and higher rate of seed production. On the other hand, stress-tolerant plants had higher carbon and less nitrogen concentrations in their roots and leaves, smaller leaves and specific leaf area

Is intensity of plant root mycorrhizal colonization a good proxy for plant growth rate, dominance and decomposition in nutrient poor conditions?

Questions: Mycorrhizae may be a key element of plant nutritional strategies and of carbon and nutrient cycling. Recent research suggests that in natural conditions, intensity of mycorrhizal colonization should be considered an important plant feature. How are inter-specific variations in mycorrhizal colonization rate, plant relative growth rate (RGR) and leaf litter decomposability related? Is (arbuscular) mycorrhizal colonization linked to the dominance of plant species in nutrient-stressed ecosystems? Location: Teberda State Biosphere Reserve, northwest Caucasus, Russia. Methods: We measured plant RGR under mycorrhizal limitation and under natural nutrition conditions, together with leaf litter decomposability and field intensity of mycorrhizal colonization across a wide range of plant species, typical for alpine communities of European mountains. We applied regression analysis to test whether the intensity of mycorrhizal colonization is a good predictor of RGR and decomposition rate, and tested how these traits predict plant dominance in communities. Results: Forb species with a high level of field mycorrhizal colonization had lower RGR under nutritional and mycorrhizal limitation, while grasses were unaffected. Litter decomposition rate was not related to the intensity of mycorrhizal colonization. Dominant species mostly had a higher level of mycorrhizal colonization and lower RGR without mycorrhizal colonization than subordinate species, implying that they were more dependent on mycorrhizal symbionts. There were no differences in litter decomposability. Conclusions: In alpine herbaceous plant communities dominated by arbuscular mycorrhizae, nutrient dynamics are to a large extent controlled by mycorrhizal symbiosis. Intensity of mycorrhizal colonization is a negative predictor for whole plant RGR. Our study highlights the importance of mycorrhizal colonization as a key trait underpinning the role of plant species in carbon and nutrient dynamics in nutrient-limited herbaceous plant communities

Do patterns of intra-specific variability and community weighted-means of leaf traits correspond? An example from alpine plants

Intraspecific variability of the traits is usually less than interspecific, but directions of inter-and intraspecific variation along environmental gradients are not well studied. For 17 alpine species we test a hypothesis that the direction of intraspecific variation in leaf traits among different communities along an environmental gradient coincides consistently with community weighted mean (CWM) trait variation at the community level along the same gradient. We obtained two groups of leaf traits according to their response to CWM and topographic (snow depth and snow melt) gradients. For leaf mass and area intraspecific variation corresponded to CWM variation among communities. SLA, water content and leaf thickness patterns within species changed directly among communities according to the toposequence (snowmelt gradient). These results are well expressed for forbs, but mostly they were not significant for graminoids. For leaf area we obtained opposite response of forbs and graminoids to snowmelt gradient. Forbs increased, but graminoids decreased leaf area when snow depth increased. Intraspecific trait variation across natural gradients does not necessarily follow that for interspecific or community-level variation

Global endemics-area relationships of vascular plants

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 104, 105, 106, 107, and 108 km2, 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 km2 (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

Do trade-offs govern plant species’ responses to different global change treatments?

Abstract Plants are subject to trade-offs among growth strategies such that adaptations for optimal growth in one condition can preclude optimal growth in another. Thus, we predicted that a plant species that responds positively to one global change treatment would be less likely than average to respond positively to another treatment, particularly for pairs of treatments that favor distinct traits. We examined plant species’ abundances in 39 global change experiments manipulating two or more of the following: CO₂, nitrogen, phosphorus, water, temperature, or disturbance. Overall, the directional response of a species to one treatment was 13% more likely than expected to oppose its response to a another single-factor treatment. This tendency was detectable across the global data set, but held little predictive power for individual treatment combinations or within individual experiments. Although trade-offs in the ability to respond to different global change treatments exert discernible global effects, other forces obscure their influence in local communities