Biodiversity loss poses a significant threat to ecosystem functioning. However, much of the empirical evidence for these effects is based on artificial experiments that often fail to simulate the structure of natural communities. Hence, it is still unclear whether natural diversity losses would significantly affect the functioning of "real-world" ecosystems. As subordinate and rare species constitute most of the diversity in natural communities and are often more vulnerable to local extinction, we evaluated their contribution to ecosystem functioning in a naturally species-rich grassland. We focused on two mechanisms by which they can support ecosystem functions: redundancy and complementarity. We conducted two long-term field experiments (>6 years) simulating contrasting biodiversity loss scenarios through the manual removal of plant species and measured the consequences of species loss on various ecosystem functions related to carbon dynamics. The latter were examined seasonally to explore diversity effects outside the typical peak of vegetation. We found that dominant removal led to substantial reductions in aboveground phytomass and litter production and altered the annual carbon fixation capacity of the vegetation, highlighting the pivotal role of dominant species in driving ecosystem functioning. Despite high species diversity, other species could not fully compensate for the loss of a single dominant even after more than 25 years, challenging assumptions about redundancy. Complementarity effects were not detected at the peak of vegetation but were evident in early spring and autumn when subordinate and rare species enhanced ecosystem functions. Surprisingly, belowground phytomass, soil organic carbon content, and litter decomposition were unaffected by species removal, suggesting complex interactions in belowground processes. These findings underscore the importance of dominant species in maintaining ecosystem functioning and emphasize the need for nuanced approaches to studying biodiversity loss in real-world communities. Comprehensive seasonal measurements are essential for accurately discerning the effects of biodiversity on ecosystem dynamics and informing effective conservation strategies that maintain ecosystem functioning.

• Klíčová slova
• aboveground biomass, belowground biomass, biodiversity loss, dominant species, ecosystem functioning, litter decomposition, net ecosystem C exchange, phenological complementarity, seasonal carbon dynamics, soil organic carbon,
• MeSH
• biodiverzita * MeSH
• časové faktory MeSH
• koloběh uhlíku * MeSH
• pastviny * MeSH
• roční období * MeSH
• rostliny * klasifikace   MeSH
• uhlík * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• uhlík * MeSH

Understanding how land use affects temporal stability is crucial to preserve biodiversity and ecosystem functions. Yet, the mechanistic links between land-use intensity and stability-driving mechanisms remain unclear, with functional traits likely playing a key role. Using 13 years of data from 300 sites in Germany, we tested whether and how trait-based community features mediate the effect of land-use intensity on acknowledged stability drivers (compensatory dynamics, portfolio effect, and dominant species variability), within and across plant and arthropod communities. Trait-based plant features, especially the prevalence of acquisitive strategies along the leaf-economics spectrum, were the main land-use intensity mediators within and across taxonomic and trophic levels, consistently influencing dominant species variability. Functional diversity also mediated land-use intensity effects but played a lesser role. Our analysis discloses trait-based community features as key mediators of land-use effects on stability drivers, emphasizing the need to consider multi-trophic functional interactions to better understand complex ecosystem dynamics.

• MeSH
• biodiverzita * MeSH
• členovci fyziologie   MeSH
• ekosystém * MeSH
• potravní řetězec MeSH
• rostliny MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Německo MeSH

Theories explaining community assembly assume that biotic and abiotic filters sort species into communities based on the values of their traits and are thus based on between-species trait variability (BTV). Nevertheless, these filters act on individuals rather than on species. Consequently, the selection is also influenced by intraspecific trait variability (ITV) and its drivers. These drivers may be abiotic (e.g., water availability) or biotic (e.g., competition). Although closely related species should have similar traits, many of them coexist. We investigated the relative magnitudes of BTV and ITV in coexisting closely related species and how their individual traits differ under different drivers of ITV. We manipulated conditions in a greenhouse pot experiment with four common Carex species, where individuals of each species originated from four source localities. Individuals were grown in factorial combinations of two moisture levels, with and without a competitor (grass species Holcus lanatus, a frequent competitor). We analyzed the variability of six morphological traits on individuals in the greenhouse and three morphological traits in the source localities. Species identity was the main determinant of differences in most traits. Competition exerted a greater effect than water availability. For leaf dry matter content (LDMC) and vegetative height, competition's effect even exceeded the variability among species. On the contrary, for specific leaf area (SLA) and clonal spread, the interspecific differences exceeded ITV induced by experimental treatments. SLA measured in the greenhouse closely correlated with values measured in field populations, while LDMC did not. The variability caused by source locality of ramets in the greenhouse was small, although sometimes significant. Closely related species differ in their traits, but for some traits, ITV can exceed BTV. We can expect that ITV can modify the processes of community assembly, particularly among coexisting closely related species.

• Klíčová slova
• Carex species, closely related species, competition, functional traits, greenhouse experiment, interspecific trait variability, intraspecific trait variability, water availability,
• Publikační typ
• časopisecké články MeSH

Ecological theory posits that temporal stability patterns in plant populations are associated with differences in species' ecological strategies. However, empirical evidence is lacking about which traits, or trade-offs, underlie species stability, especially across different biomes. We compiled a worldwide collection of long-term permanent vegetation records (greater than 7000 plots from 78 datasets) from a large range of habitats which we combined with existing trait databases. We tested whether the observed inter-annual variability in species abundance (coefficient of variation) was related to multiple individual traits. We found that populations with greater leaf dry matter content and seed mass were more stable over time. Despite the variability explained by these traits being low, their effect was consistent across different datasets. Other traits played a significant, albeit weaker, role in species stability, and the inclusion of multi-variate axes or phylogeny did not substantially modify nor improve predictions. These results provide empirical evidence and highlight the relevance of specific ecological trade-offs, i.e. in different resource-use and dispersal strategies, for plant populations stability across multiple biomes. Further research is, however, necessary to integrate and evaluate the role of other specific traits, often not available in databases, and intraspecific trait variability in modulating species stability.

• Klíčová slova
• acquisitive, conservative, dispersal, long-term studies, temporal patterns, variability,
• MeSH
• ekosystém * MeSH
• fenotyp MeSH
• fylogeneze MeSH
• listy rostlin MeSH
• rostliny * MeSH
• semena rostlinná MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

The stability of ecological communities is critical for the stable provisioning of ecosystem services, such as food and forage production, carbon sequestration, and soil fertility. Greater biodiversity is expected to enhance stability across years by decreasing synchrony among species, but the drivers of stability in nature remain poorly resolved. Our analysis of time series from 79 datasets across the world showed that stability was associated more strongly with the degree of synchrony among dominant species than with species richness. The relatively weak influence of species richness is consistent with theory predicting that the effect of richness on stability weakens when synchrony is higher than expected under random fluctuations, which was the case in most communities. Land management, nutrient addition, and climate change treatments had relatively weak and varying effects on stability, modifying how species richness, synchrony, and stability interact. Our results demonstrate the prevalence of biotic drivers on ecosystem stability, with the potential for environmental drivers to alter the intricate relationship among richness, synchrony, and stability.

• Klíčová slova
• climate change drivers, evenness, species richness, stability, synchrony,
• MeSH
• ekosystém MeSH
• klimatické změny MeSH
• půda chemie   MeSH
• rostliny klasifikace   metabolismus   MeSH
• sekvestrace uhlíku MeSH
• vývoj rostlin MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• půda MeSH