Bernhard Schmid

Biodiversity–ecosystem functioning (BEF) relationships are increasingly recognized as an important aspect of ecosystem research and management thanks to knowledge gained from long-term grassland and, more recently, forest experiments. However, to what extent the behavior of non-experimental systems corresponds to the relationships discovered in BEF experiments remains controversial. We investigated the relationship between trait-based diversity and drought response using data from forests in northern Switzerland, which experienced an extremely hot and dry summer in 2018. We used Sentinel-2 satellite data to assess trait diversity and quantified drought response in terms of resistance, recovery, and resilience from 2017 to 2020. We then analyzed the BEF relationship between trait-based diversity and drought response for different aggregation levels of richness and evenness. Forests with greater richness were more resistant and resilient to the drought event, and the relationship of evenness with resistance or resilience was hump-shaped or negative, respectively. These results suggest that trait-based diversity supported forest drought response via a mixture of complementarity and dominance effects, the first indicated by positive richness effects and the second by negative evenness effects. Our results link ecosystem functioning and biodiversity at large scales and provide new insights into the BEF relationships in real-world forest ecosystems.

Plant diversity effects on community productivity often increase over time. Whether the strengthening of diversity effects is caused by temporal shifts in species-level overyielding (i.e., higher species-level productivity in diverse communities compared with monocultures) remains unclear. Here, using data from 65 grassland and forest biodiversity experiments, we show that the temporal strength of diversity effects at the community scale is underpinned by temporal changes in the species that yield. These temporal trends of species-level overyielding are shaped by plant ecological strategies, which can be quantitatively delimited by functional traits. In grasslands, the temporal strengthening of biodiversity effects on community productivity was associated with increasing biomass overyielding of resource-conservative species increasing over time, and with overyielding of species characterized by fast resource acquisition …

Extreme weather events are occurring more frequently, and research has shown that plant diversity can help mitigate the impacts of climate change by increasing plant productivity and ecosystem stability. Although soil temperature and its stability are key determinants of essential ecosystem processes, no study has yet investigated whether plant diversity buffers soil temperature fluctuations over long-term community development. Here we have conducted a comprehensive analysis of a continuous 18-year dataset from a grassland biodiversity experiment with high spatial and temporal resolutions. Our findings reveal that plant diversity acts as a natural buffer, preventing soil heating in hot weather and cooling in cold weather. This diversity effect persists year-round, intensifying with the aging of experimental communities and being even stronger under extreme climate conditions, such as hot days or dry years. Using …

It is well known that biodiversity positively affects ecosystem functioning, leading to enhanced ecosystem stability. However, this knowledge is mainly based on analyses using single ecosystem functions, while studies focusing on the stability of ecosystem multifunctionality (EMF) are rare. Taking advantage of a long‐term grassland biodiversity experiment, we studied the effect of plant diversity (1–60 species) on EMF over 5 years, its temporal stability, as well as multifunctional resistance and resilience to a 2‐year drought event. Using split‐plot treatments, we further tested whether a shared history of plants and soil influences the studied relationships. We calculated EMF based on functions related to plants and higher‐trophic levels. Plant diversity enhanced EMF in all studied years, and this effect strengthened over the study period. Moreover, plant diversity increased the temporal stability of EMF and fostered …

The associations of arbuscular mycorrhizal (AM) or ectomycorrhiza (EcM) fungi with plants have sequentially evolved and significantly contributed to enhancing plant nutrition. Nonetheless, how evolutionary and ecological forces drive nutrient acquisition strategies of AM and EcM woody plants remains poorly understood. Our global analysis of woody species revealed that, over divergence time, AM woody plants evolved faster nitrogen mineralization rates without changes in nitrogen resorption. However, EcM woody plants exhibited an increase in nitrogen mineralization but a decrease in nitrogen resorption, indicating a shift towards a more inorganic nutrient economy. Despite this alteration, when evaluating present‐day woody species, AM woody plants still display faster nitrogen mineralization and lower nitrogen resorption than EcM woody plants. This inorganic nutrient economy allows AM woody plants to …

Tree growth is a key component of forest ecosystem functioning and is wellknown to be limited by water availability [1]. It is acknowledged that composition and diversity of co-occurring tree species can mitigate the influence of drought on treegrowththroughtheresourcecomplementarity for water use via niche partitioning and facilitation between different species [2, 3]. However, direct evidence on the role of water use in diversityproductionrelationshipsremainslimited. For individual trees, species interactions at the neighbourhood scale play a major role in water supply and growth [4], which provide insights into the emerging net effects of biodiversity at the community scale. Such effects might be achieved by differences in species’ functional traits. These differences in functional trait composition can be quantified at the neighbourhood scale in several ways to provide mechanistic insights into the processes underlying …

Cultivar mixtures have been proposed as a way to increase diversity and thereby improve plant production, but our understanding of the effects of mixing cultivars on crop diseases and resource-use efficiency remains fragmentary. We performed a meta-analysis to assess the effects of cultivar mixtures on crop yield, yield stability, resource-use efficiency, and disease severity compared with monocultures of twelve major crops. We found that, overall, mixing of cultivars increased crop yield by 3.82%. Yield gains from mixing cultivars were highest in rice (+16.1%), followed by maize (+8.5%), and were lowest in barley (+0.9%) and sorghum (no increase). Temporal yield stability increased with the number of cultivars in the mixtures. Overall, mixing cultivars increased crop biomass, leaf area index, photosynthetic rate, and Water-use efficiency by 5.1, 7.2, 8.5 and 4.3%, respectively, and decreased disease incidence by 24 …

The density of wood is a key indicator of trees’ carbon investment strategies, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here, we analyze information from 1.1 million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially-explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical dry forests being up to twice as dense as that in boreal forests. In both angiosperms and gymnosperms, temperature and water availability emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems.

The global biodiversity crisis has stimulated decades of research on three themes: species coexistence, biodiversity–ecosystem functioning relationships (BEF), and biodiversity–ecosystem functional stability relationships (BEFS). However, studies on these themes are largely independent, creating barriers to an integrative understanding of the causes and consequences of biodiversity. Here we review recent progress towards mechanistic integration of coexistence, BEF, and BEFS. Mechanisms underlying the three themes can be linked in various ways, potentially creating either positive or negative relationships between them. That said, we generally expect positive associations between coexistence and BEF, and between BEF and BEFS. Our synthesis represents an initial step towards integrating causes and consequences of biodiversity; future developments should include more mechanistic approaches and …

Author Correction: Multitrophic arthropod diversity mediates tree diversity effects on primary productivity Author Correction: Multitrophic arthropod diversity mediates tree diversity effects on primary productivity Nat Ecol Evol. 2024 Feb;8(2):352. doi: 10.1038/s41559-024-02324-9. Authors Yi Li 1 , Bernhard Schmid 2 , Andreas Schuldt 3 , Shan Li 1 , Ming-Qiang Wang 4 5 , Felix Fornoff 6 , Michael Staab 7 , Peng-Fei Guo 8 , Perttu Anttonen 9 10 , Douglas Chesters 4 , Helge Bruelheide 9 10 , Chao-Dong Zhu 4 11 , Keping Ma 12 13 14 15 , Xiaojuan Liu 16 17 18 Affiliations 1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China. 2 Department of Geography, Remote Sensing Laboratories, University of Zurich, Zurich, Switzerland. 3 Forest Nature Conservation, University of Göttingen, Göttingen, Germany. 4 Key Laboratory of Zoological Systematics …

Foliar herbivory is known to directly affect phyllosphere microbiomes through altering plant phenotypes. However, how plant evolutionary responses to herbivory shape phyllosphere microbiomes is unclear. Here we use different invasive populations of the plant Ambrosia artemisiifolia that vary in reassociation timespan with a native specialist herbivore, to test whether renewed selection imposed by the herbivore is accompanied by evolutionary shifts in leaf chemistry and correlated changes in phyllosphere microbial communities. In common garden experiments we found directional changes in phyllosphere fungal communities with increasing duration of reassociation, accompanied by increased phyllosphere fungal alpha diversity and community complexity. These changes were associated with shifts in concentrations of plant metabolites, expression levels of their underlying biosynthetic genes, and increased …

Forest biodiversity is critical for many ecosystem functions and services. Yet, it remains uncertain how plant functional diversity influences ecosystem functioning across environmental gradients and contiguous larger areas. We integrated remote sensing and terrestrial biosphere modeling to explore functional diversity–productivity relationships at multiple spatial scales for a heterogeneous forest ecosystem in Switzerland. We initialized forest structure and composition in the ecosystem demography model (ED2) through a combination of ground‐based surveys, airborne laser scanning and imaging spectroscopy for forest patches at 10 × 10‐m spatial grain. We derived morphological and physiological forest traits and productivity from model simulations at patch‐level to relate morphological and physiological aspects of functional diversity to the average productivity from 2006 to 2015 at 20 × 20 to 100 × 100‐m …

Carbon‐focused climate mitigation strategies are becoming increasingly important in forests. However, with ongoing biodiversity declines we require better knowledge of how much such strategies account for biodiversity. We particularly lack information across multiple trophic levels and on established forests, where the interplay between carbon stocks, stand age, and tree diversity might influence carbon–biodiversity relationships. Using a large dataset (>4600 heterotrophic species of 23 taxonomic groups) from secondary, subtropical forests, we tested how multitrophic diversity and diversity within trophic groups relate to aboveground, belowground, and total carbon stocks at different levels of tree species richness and stand age. Our study revealed that aboveground carbon, the key component of climate‐based management, was largely unrelated to multitrophic diversity. By contrast, total carbon stocks—that is …

Ecosystem management aims at providing many ecosystem services simultaneously. Such ecosystem service multifunctionality can be limited by tradeoffs and increased by synergies among the underlying ecosystem functions (EF), which need to be understood to develop targeted management. Previous studies found differences in the correlation between EFs. We hypothesised that correlations between EFs are variable even under the controlled conditions of a field experiment and that seasonal and annual variation, plant species richness, and plot identity (identity effects of plots, such as the presence and proportion of functional groups) are drivers of these correlations. We used data on 31 EFs related to plants, consumers, and physical soil properties that were measured over 5 to 19 years, up to three times per year, in a temperate grassland experiment with 80 different plots, constituting six sown plant species …

A major feature of humans is that they can attain much higher population densities than any non-domestic animal species of similar body size (Damuth 1987). This is most likely due to the invention of agriculture (Herrera and Garcia-Bertrand 2018), which allowed humans to manage ecosystems in such a way that as much biomass as possible is converted into food (Vitousek et al. 1986). Early farmers developed a large diversity of crops in different regions of the world and grew them in various arrangements and rotations (Tariq et al. 2019; Teran and Rasmussen 1995). With the advent of the industrial revolution and ‘chemical’agriculture in the 19th century in Europe (Liebi g 1840), focus shifted on growing fewer high-yielding species over larger areas and time spans. This was made possible by managing soil nutrients (eg explored in long-term experiments at Rothamsted in the UK; Jenkinson 1991), controlling …

Remote sensing enhances large-scale biodiversity monitoring by overcoming temporal and spatial limitations of ground-based measurements and allows assessment of multiple plant traits simultaneously. The total set of traits and their variation over time is specific for each individual and can reveal information about the genetic composition of forest communities. Measuring trait variation among individuals of one species continuously across space and time is a key component in monitoring genetic diversity but difficult to achieve with ground-based methods. Remote sensing approaches using imaging spectroscopy can provide high spectral, spatial, and temporal coverage to advance the monitoring of genetic diversity, if sufficient relation between spectral and genetic information can be established.We assessed reflectance spectra from individual Fagus sylvatica L. (European beech) trees acquired across eleven …

Woody plant encroachment in arid grasslands may reduce plant uptake and soil storage of carbon (C) with consequences for the global C cycle, yet multi-site comparative studies have not been done so far and experiments are not feasible due to the long time needed for soil organic C (SOC) to accumulate. We selected multiple grassland sites with ≥50 % or 0 % woody plant aboveground biomass in each of six vegetation types representing a gradient of increasing aridity, resulting in a comparative study design with a total of 178 pure and 106 wooded grasslands distributed over the large geographic area of Xinjiang, China. Differences between wooded and pure grasslands in SOC stocks in the top 100 cm of the soil changed from positive to negative with increasing aridity. This effect was strongest in the upper soil layers, suggesting that woody plants had perhaps not been present for long enough to leave a …

Extreme weather events are occurring more frequently, and research has shown that plant diversity can help mitigate impacts of climate change by increasing plant productivity and ecosystem stability,. Although soil temperature and its stability are key determinants of essential ecosystem processes related to water and nutrient uptake as well as soil respiration and microbial activity, no study has yet investigated whether plant diversity can buffer soil temperature fluctuations. Using 18 years of a continuous dataset with a resolution of 1 minute (∼795,312,000 individual measurements) from a large-scale grassland biodiversity experiment, we show that plant diversity buffers soil temperature throughout the year. Plant diversity helped to prevent soil heating in hot weather, and cooling in cold weather. Moreover, this effect of plant diversity increased over the 18-year observation period with the aging of experimental communities and was even stronger under extreme conditions, i.e., on hot days or in dry years. Using structural equation modelling, we found that plant diversity stabilized soil temperature by increasing soil organic carbon concentrations and, to a lesser extent, by increasing the plant leaf area index. We suggest that the diversity-induced stabilization of soil temperature may help to mitigate the negative effects of extreme climatic events such as soil carbon release, thus slow global warming.

Transformative sustainability research aspires to expand problem framing and knowledge production beyond the boundaries of academic disciplines to contribute to real-world change. Transdisciplinarity has emerged as a key approach to such research and in the meantime is openly promoted in international reports and funding initiatives like Horizon Europe. Behind these developments are vibrant communities of researchers and practitioners–a part of which is gathered in the Special Focus of this GAIA issue–who have formed to advance method, content, and the institutionalization of transdisciplinary research. This is realized, amongst others, by regular gatherings like the International Transdisciplinarity Conference (ITD) and the recent inauguration of a Society for Transdisciplinary and Participatory Research in Germany.GAIA has supported this type of research and its community from its outset and provided a …

Biodiversity loss presents a growing threat to the global environment and requires systematic and spatially contiguous monitoring. Monitoring of within-species genetic variation, a key factor when assessing biodiversity loss, is laborious and could be complemented by observations of phenotypes allowing inferences about genetic variation. We studied genetic and phenotypic variations in the common European beech (Fagus sylvatica L.) derived from whole-genome sequences and spectral phenotypes of more than 200 individuals at 22 sites across the species’ natural range. The spectral phenotypes were collected under standardized illumination/observation conditions from the same top-of-canopy leaves used for nuclear DNA extraction. We found that spectral and environmental information explains 77.7% of the variance along the first two Principal Coordinates representing genetic structure among sampled individuals. Information from spectral phenotypes contributed 12.1% to predictions of between-site genetic structure. We therefore conclude that future remote observations having sufficient spectral and spatial resolution could improve our ability to rapidly and continuously monitor genetic diversity in trees.HighlightsGenetic diversity underpins biodiversity which loss requires systematic monitoringSpectral phenotypes acquired in situ are indicative of genetic variationIntraspecific spectral and genomic variation correlate across a species rangeSpectral phenotypes improve prediction of the between-site genetic structureRemote observations may contribute to monitoring genetic diversity within species