Senckenberg Institute for Plant Form and Function Jena

Abstract Arable fields and mesic meadows have been affected by intensifying agricultural management and nutrient input during the 20th century, but direct evidence for the long‐term impact of intensification on plant nutrient contents remains scarce. Non‐destructive novel spectroscopic methods can produce such data from herbarium specimens, making it possible to investigate how contents of leaf nutrient traits, especially nitrogen and phosphorus, changed over the last century, and what role habitat type and management practices play. We carried out a resurvey study of functional traits in arable field and mesic meadow communities. We used specimens from two German herbaria with a high coverage of their local floras: the herbaria Senckenberg Görlitz and Senckenberg Haussknecht in Jena. Following specimen information, the same plant species were resampled in the field in 2022 at the same locations. We employed near‐infrared spectroscopy to predict leaf nitrogen, phosphorus and carbon content of herbarium and field specimens. Nutrient content changes over time were compared with public records of regional P and N fertilization. Overall, 1270 specimens of 76 species from both herbarium and field were studied, the oldest from the 19th century. Leaf nitrogen and the leaf nitrogen:phosphorus ratio increased significantly through time, while leaf phosphorus and carbon content decreased significantly over time. Arable field species showed a stronger response in leaf phosphorus content and leaf nitrogen:phosphorus ratio than mesic meadow species. The total amount of nitrogen or phosphorus fertilizer applied per year on a regional scale was found to be significantly correlated with the respective leaf nutrient content levels. Synthesis : Our study shows a long‐term increase of leaf nitrogen in the studied habitats, paralleling increased chemical fertilizer applications in Germany. Our data indicate a shift from predominantly N‐limited towards more P‐limited growth conditions. The stronger response of species from arable fields compared to species from mesic meadows could indicate a faster adjustment to environmental pressures. This study thus also serves to showcase the potential of the combination of herbarium collections and NIR spectroscopy.

An increasing number of studies in botanical gardens are investigating species' responses to climate change. However, the influence of local environmental or habitat conditions such as soil nutrient status or microclimate on phenology and the link between morpho-physiological functional traits and phenological stages are poorly understood, making it difficult to extrapolate patterns from botanical gardens to natural environments. Therefore, we selected herbaceous species growing in two semi-natural habitats, namely, semi-dry grasslands (SDGs) and mesophilic grasslands (MGs) and the botanical garden of Jena (Germany) to investigate the influence of habitat conditions on interspecific and intraspecific patterns in phenology, functional traits and their associations. For 16 species, we monitored leaf and flowering phenology weekly for 133 populations from the three habitats, measured morpho-physiological traits (i.e., whole plant, leaf and reproductive traits), as well as habitat conditions and compared the measurements across habitats. Multivariate analyses revealed that morpho-physiological traits conspicuously showed stronger differences between habitats compared to phenological traits. Populations on MG showed temporal niche segregation, whereas populations on SDG showed flowering synchrony. Boosted Regression Trees showed that morpho-physiological traits, especially reproductive traits, strongly influenced phenological traits and that the trait-phenology relationships were highly habitat-specific. We conclude that species phenology is broadly similar between botanical gardens and local habitats. However, phenological responses to the environment may be constrained by a certain suite of correlated traits due to ecological plant strategies that vary across habitats. The effect of habitat conditions on morpho-physiological functional traits and phenology-trait relationships is important and should not be neglected at local scales, implying consequences at larger scales.

Bryophyte research is severely underrepresented compared to vascular plant research, even though we know that bryophytes are crucial components of ecosystems and contribute significantly to ecosystem functions and processes, and thus to ecosystem services. This underrepresentation creates many hurdles and barriers that Early Career Researchers (ECRs) must first overcome to establish in this field, which significantly hinders research now and in the future. Therefore, this work deals with the future of bryophyte research, and bryophyte ecology in particular, which is reflected in the perspectives of ECRs in this scientific field. By listing the many barriers that bryophyte researchers and especially ECRs face, including underrepresentation, funding and publishing, but also possible solutions, we want to raise awareness for and advocate to raise the profile of bryophyte research. We here identify multiple barriers that bryophyte-focused ECRs face and what is needed to overcome them. We address different structural and institutional levels, ranging from early education in schools to academia, funding and publishing. Raising the profile of bryophyte research works on many different levels simultaneously. To improve the prospects of bryophytes and thus increase scientific interest in, and ultimately understanding of, this important group of plants, we need to raise awareness now.

Abstract The concept of growing degree days (GDDs) is commonly used to predict phenological events in plants, assuming that plants develop proportionally to the accumulated temperature. Two species‐specific parameters, T Base and t 0 (minimum temperature above which and start date when GDDs begin to accumulate), are considered for the calculation. However, species‐specific optimised thresholds of wild herbaceous species remain sparse, and therefore the reliability of the models is questionable. By employing several modelling approaches using phenological records of leaf unfolding and flowering onset of 87 wild herbaceous species collected in six European botanical gardens between 2019 and 2024, we assessed the reliability of GDD models across a diverse array of species. We further examined whether thresholds of T Base and t 0 for calculating GDD can be optimised for a large set of species and for single species. We aimed to estimate and evaluate these thresholds and the reliability of GDD models using species' temporal niche and bud traits to see whether for specific groups of species, specific GDD models work better. Our analyses revealed that GDD models for leaf unfolding and flowering onset performed better than the null model (i.e. mean date across years and species) for 84% and 70% of the species, respectively. Our results showed that species with intermediate temporal niches were less dependent on the selection of T Base and t 0 . Overall, we found better performance of the models using a T Base around 4°C for most of the species. By considering optimised thresholds, we found that predictions of leaf unfolding dates were more accurate in early‐growing species, and regarding the start date for temperature accumulation, we found that larger values for t 0 are suitable for predictions for species with later leaf unfolding or flowering onset. Our results emphasise that simple temperature accumulating GDD models can be optimised by using the temporal niches of the studied species to approximate the underlying model parameters or by applying thresholds that are valid for many species. The use of simple but optimised GDD models can be advantageous for small datasets that would otherwise be overfitted with more complex models. Read the free Plain Language Summary for this article on the Journal blog.

Large-scale disturbances like fire, bark beetle outbreaks, and windstorms increasingly affect forest ecosystems . Rather than salvage logging, retaining deadwood may support tree species regeneration. This systematic review summarizes the role of deadwood in creating microsites to facilitate tree regeneration. We conducted an English-language literature search in the Web of Science and Scopus. After the title-abstract screening, we classified studies that met our eligibility criteria into three subtopics: deadwood as (1) substrate, (2) browsing protection, and (3) microclimate improvement. We then performed a snowball sampling using the literature search tool ResarchRabbit. The final qualitative synthesis included 161 studies (browsing: n = 34, microsite: n = 64, substrate: n = 68; five studies occurred in two subtopics). Our review revealed the importance of coarse woody debris (CWD) as a regeneration substrate, particularly for small-seeded conifers, which preferred CWD over the forest floor. Establishment success depended on the decomposition stage, CWD species, stem diameter, and moss cover. Deadwood reduced browsing pressure, where fallen trees formed barriers limiting ungulate browsing access and individual logs or branch piles protected seedlings. Logs enhanced tree species regeneration on open sites by improving seedling survival and growth, especially on the north and nearby sides. Deadwood, including logs, snags, and logging slash, significantly influenced the microclimate by moderating soil temperatures. The effects on soil moisture were variable. In conclusion, deadwood retention has the potential to serve as a modular toolbox in post-disturbance forest management.

Bryophytes form an integral component in numerous ecosystems. They impact ecosystem processes by regulating water, carbon, and nutrient input into the soil, making them an ecologically significant but understudied group of plants. To understand ecosystem processes, functional traits offer a suitable tool as they reflect plant performance and strategies that respond to changes in the environment. Functional traits, however, have been hardly studied and are still poorly understood in bryophytes, limiting the understanding of functional responses to environmental variability and future change. Therefore, we here measured 10 functional traits related to water balance (e.g., leaves per cm, branching density, water uptake capacity) and productivity (e.g., shoot length, in situ fluorescence, specific shoot area) and related them to environmental variability for eight common forest floor bryophyte species in two temperate coniferous forests. We tested how well these traits respond to small-scale variability in water, light, and nutrient availability. Multivariate analyses showed a large variation in trait composition of the investigated species, mainly driven by growth form (pleurocarpous vs. acrocarpous), while the impact of forest type (Norway spruce vs. Scots pine) on trait composition seemed less important. Mixed effects models across all species revealed that traits were very sensitive to within-forest small-scale variability; for example, leaves per cm or in situ fluorescence were positively related to increasing plot-level characteristics such as leaf area index and throughfall, again with growth form-specific responses. We further found intraspecific trait variation for the most dominant bryophyte species, indicating considerable phenotypic plasticity. We conclude that moss trait variability is more linked to growth form than to forest type, and that both bryophyte communities and individual species are functionally sensitive to small-scale environmental variability. We therefore emphasize including bryophytes and growth form as a functional group more specifically in functional response studies.

ABSTRACT Aims The community composition of native and alien plant species is influenced by the environment (e.g., nutrient addition and changes in temperature or precipitation). A key objective of our study is to understand how differences in the traits of alien and native species vary across diverse environmental conditions. For example, the study examines how changes in nutrient availability affect community composition and functional traits, such as specific leaf area and plant height. Additionally, it seeks to assess the vulnerability of high‐nutrient environments, such as grasslands, to alien species colonization and the potential for alien species to surpass natives in abundance. Finally, the study explores how climatic factors, including temperature and precipitation, modulate the relationship between traits and environmental conditions, shaping species success. Location In our study, we used data from a globally distributed experiment manipulating nutrient supplies in grasslands worldwide (NutNet). Methods We investigate how temporal shifts in the abundance of native and alien species are influenced by species‐specific functional traits, including specific leaf area (SLA) and leaf nutrient concentrations, as well as by environmental conditions such as climate and nutrient treatments, across 17 study sites. Mixed‐effects models were used to assess these relationships. Results Alien and native species increasing in their abundance did not differ in their leaf traits. We found significantly lower specific leaf area (SLA) with an increase in mean annual temperature and lower leaf Potassium with mean annual precipitation. For trait–environment relationships, when compared to native species, successful aliens exhibited an increase in leaf Phosphorus and a decrease in leaf Potassium with an increase in mean annual precipitation. Finally, aliens' SLA decreased in plots with higher mean annual temperatures. Conclusions Therefore, studying the relationship between environment and functional traits may portray grasslands' dynamics better than focusing exclusively on traits of successful species, per se.

Artificial intelligence (AI) surpasses human accuracy in identifying ordinary objects, but it is still challenging for AI to be competitive in pollen grain identification. One reason for this gap is the extensive trait variation in pollen grains. In classical textbooks, pollen size relies on only 25-50 pollen grains, mostly for one plant and site. Lack of variation in pollen databases can cause limited application of machine learning approaches to real-world samples. Therefore, our study aims to investigate sources of spatial and temporal pollen trait variation for pollen morphology and fluorescence. For this purpose, 64,001 pollen grains from the four herbaceous and insect-pollinated plant species Achillea millefolium L., Lamium album L., Lathyrus vernus (L.) Bernh., and Lotus corniculatus L. sampled across four years and seven locations across Central Germany were measured using multispectral imaging flow cytometry. Observed trait variations were very species-specific; however, for most species, significant differences in spatial as well as temporal variation were found for at least one pollen trait. We could also show that this variability and the identity of a particular sample influence the accuracy of AI classifications and that multiple measurements of different origins provide the most robust AI-based identifications.

Global biodiversity is changing at unprecedented rates during the Anthropocene. Whereas current biodiversity patterns can be observed directly, information from the recent past is far less easily retrieved yet urgently needed to understand present observations and predict future developments. For plants, herbaria offer such a unique glimpse into the past. Evaluation of plant specimens allows determining a wide range of attributes like species identity, morphological and phenological traits and even signs of biotic interactions. Specimen’s labels convey data such as species identity (and identification history), date and locality of collection, as well as the surrounding biotic and abiotic environment. Current methodological developments in sensor technology and computer vision increasingly enable us to extract this information in a high throughput and automated way. Equally vast developments in data science allow to integrate data from other sources for much more comprehensive analyses than before. With millions of specimens already digitized and digitization schemes running in many institutions, we will be increasingly able to determine characteristics of species and link them via distribution records to large-scale climate change scenarios. This allows us to better predict species’ threat levels, and to develop scenarios on the consequences of biodiversity change for ecosystem functioning. The present contribution reviews recent herbaria research and describes potential avenues with respect to Museomics and the Extended Specimen, and we propose Collectomics as a new framework to unravel, understand, and cope with the Anthropocene biodiversity change.

This dataset contains bird detections from eleven private gardens in Gütersloh, North Rhine-Westphalia, Germany, collected via passive acoustic monitoring across spring and early summer of 2024, along with additional environmental variables describing the sites. The recordings were made as part of the interdisciplinary project gARTENreich (www.gartenreich-projekt.de), which studied drivers and barriers of biodiversity-friendly garden design. gARTENreich was a joint project between the Institut für ökologische Wirtschaftsforschung (iöw) Berlin GmbH, the Friedrich-Schiller-Universität Jena, NABU e.V., Hochschule für Wirtschaft und Recht Berlin, NaturGarten e.V., the City of Gütersloh, and the municipality of Aumühle. It was funded by the German Federal Ministry of Education and Research in the Research Initiative for the Conservation of Biodiversity (FEdA). The eleven gardens where these recordings were made took part in the project as volunteers. The recordings were made using Olympus recorders and analysed with BirdNET. For a more detailed description of the methods, please see the README. The “gardenbirds_csv” table contains the species detections per garden and month. The “gardenbirds_additional_info.csv” file contains additional data for each garden, including potentially relevant characteristics.

Abstract Species delimitation in liverworts, such as Metzgeria , is hampered by their limited morphology and hence morphologically determined specimens often turn out to belong to other taxa using molecular data. Metzgeria is a simple thalloid liverwort genus with over 100 species and a worldwide distribution. Seven species are listed to occur in Europe. We used three plastid markers ( trnL‐F , rps4 , rpl16 ) and 126 Metzgeria specimens to test the phylogenetic position of European Metzgeria species and to re‐evaluate morphological traits used in species circumscriptions in an integrative manner. We confirmed five taxa, Metzgeria conjugata , M. furcata (with two varieties), M. leptoneura (for Madeira and the Azores only), M. pubescens , M. simplex (as a variety of M. conjugata ) and formally introduce M. curviseta , M. scyphigera and M. azorica sp. nov. for the European flora. Specimens morphologically determined as M. temperata fall either in the M. scyphigera clade or form a well‐separated clade. Further, we tackle the long‐standing nomenclatural issue of M. fruticulosa auct. non (O.F.Müll.) A.Evans by providing the new name Metzgeria aeruginosa comb. & stat. nov. Metzgeria thus includes nine species in Europe, for which an updated identification key is provided, which should aid in morphological species determination of this simple thalloid liverwort in Europe.

Using this dataset, we examined how various plant characteristics, both above- and belowground, respond to different climatic and soil conditions. We did this by growing the same five types of perennial herbaceous plants in the same conditions at five botanical gardens in Central Europe. We measured above- and belowground traits after up to four growing seasons, and then analysed their relationships to differences in climatic conditions, soil chemistry and nutrient availability.

Abstract One of silviculture's primary objectives is converting monospecific into diverse forest stands comprising climate-tolerant species, aiming to mitigate global change. In practice, this is often achieved by enrichment planting or seeding of species, currently not occurring in the specific area. Silver fir ( Abies alba ) is considered one of the European native species regarded as climate tolerant. The species, therefore recently received increasing attention in research and forestry in the context of climate change adaptation. The intra-specific variation in drought tolerance has been intensively studied in Abies alba adult trees, but not in seedlings. Here, we explore the potential of Abies alba seedlings to withstand simulated summer droughts in central Europe. A climate chamber experiment was conducted, examining the resistance to and recovery from drought of silver fir seedlings of four provenances representing a geographic West–East gradient in Europe. Seedlings were exposed to two 30-day drought scenarios of differing severity under controlled conditions. We measured biomass partitioning patterns and individual photosynthetic efficiency. Growth and maximum photosynthetic efficiency were unaffected by intermediate drought. Intense drought significantly reduced the maximum photosynthetic efficiency of all provenances. Seedlings of the easternmost provenance showed the greatest biomass across all treatments; however, they failed to recover from drought. Our findings show that differences in drought susceptibility of emerging Abies alba seedlings do not follow geographic gradients.

ABSTRACT Aim Phenological shifts are regarded to be the most pronounced indicators of global climate change. Worldwide, native species pools are being increasingly colonised by non‐native species, thus shaping novel communities. Here, we investigate whether, and how, phenology varies between native and non‐native species. We also examine whether functional traits and/or phylogeny can explain these phenological variations. Location Europe and Asia. Time Period 2022. Major Taxa Studied Perennial herbs. Methods We studied multiple phenophases and functional traits of 427 plant species across 13 botanical gardens using the PhenObs monitoring protocol. We used linear mixed models to test for phenology and functional trait differences between native and non‐native species. Boosted regression trees were employed to identify the functional trait predictors of phenology variance between native and non‐native species. To test the effect of phylogeny on these phenological variations, we estimated phylogenetic signal using Pagel's λ. Results Native and non‐native species exhibited distinct phenological patterns and functional traits. Native species started vegetative phenophases earlier than non‐native species and senesced later. Similarly, reproductive phenophases varied, with native species flowering earlier and having longer flowering and fruiting durations. Native species also had higher specific leaf area, while non‐native species had higher seed mass and larger leaf area. The variations in phenology were explained by garden location, leaf area, plant height, and leaf nitrogen. Most phenophases and functional traits showed low phylogenetic conservatism, suggesting a more important role of local environmental factors in driving these variations. Main Conclusions Our findings suggest that the phenological differences between native and non‐native species, both in timing and magnitude, may change the community composition and structure under global change. Non‐native species likely occupy a subset of native phenological niches, and this overlap may alter biotic interactions and ecosystem functioning. Future research needs to substantiate our findings under natural field conditions.

Despite widespread concern over global biodiversity loss, the balance between gains and losses within local plant communities remains contentious, largely due to a scarcity of integrative, long-term and large-scale analyses across different habitats and multiple facets of biodiversity. Here, we analyse 57,390 vegetation-plot time series of vascular plants across Europe to quantify the average and habitat-specific trends in taxonomic, functional, phylogenetic, and gamma diversity, alongside with changes in threatened Red List, non-native, and specialist versus generalist species. We find that, over the last 100 years, plant communities gained on average 0.7% in vegetation cover and 0.2% in species number per year, associated with gains in functional and phylogenetic diversity, non-native, Red List, and generalist species. Diversity changes are most pronounced in mire and wetland communities. Differences among habitat types and habitat-change trajectory (stable, successional, disturbed), together with the most recent observation year, explain 2.1%-36.6% of the variation in diversity trends. Habitat-specific gamma diversity showed no general trends and only increased in stable grasslands and successional sparsely vegetated habitats. By integrating habitat types and change trajectories, we reconcile some of the conflicting narratives on local biodiversity change in favour of a more nuanced understanding of the observed variation in local biodiversity change.

Forest management affects forest-dwelling taxa, such as birds, which play diverse roles in ecosystem functioning. While birds are frequently studied, surveys typically are conducted during the breeding season, overlooking non-breeding periods during which birds may have different resource requirements. Understanding year-round dynamics of habitat use is essential to inform management practices that support bird communities. We used passive acoustic monitoring to study bird assemblages across a gradient from deciduous broadleaved to coniferous forest stands around the city of Jena (Thuringia, Germany). We investigated how season, forest type, and environmental variables influence species taxonomic diversity, community composition, and functional diversity. Birds were monitored in 30-day periods during winter, spring, summer, and autumn 2024 using AudioMoth recorders and BirdNET for species identification. Species diversity varied significantly by season, peaking in spring and summer and declining in autumn and winter; forest type had no effect. Community composition was primarily driven by season, but within seasons, birds clustered by forest type. Season influenced functional dispersion and dissimilarity, but not evenness; forest type influenced only functional dispersion. Overall, seasonality, especially migration dynamics, most strongly impacts bird diversity. Within seasons, forest type structures community composition but does not affect taxonomic or functional diversity. Persistent functional diversity despite taxonomic shifts suggests functional redundancy, indicating resilience to habitat change. Coniferous stands emerged as harbouring distinct, but equally diverse bird species compared to deciduous stands. Forest managers should prioritise a mix of forest types to sustain rich bird communities and ensure long-term ecosystem functionality.

Correction to: Communications Earth & Environment https://doi.org/10.1038/s43247-026-03668-9 , published online 25 May 2026

Abstract Climate stress impacts on the Amazon Forest highlight the need to understand tree resilience mechanisms. Dry-season leaf turnover in this forest may have evolved to alleviate drought and herbivory stress, and volatile isoprenoid production protects against abiotic and biotic stresses, motivating investigation of their joint responses. We measured temperature and light responses of volatile isoprenoid emissions and photochemical activity traits in 12 brevideciduous and evergreen central Amazon Forest trees. Brevideciduous trees showed stronger increases in sesquiterpene and highly reactive monoterpene emissions with temperature. Brevideciduous isoprene emitters showed superior baseline photosynthetic performance, while evergreen non-emitters had the highest baseline stomatal conductance and thermal stability. By neglecting variability in leaf turnover strategies, a global isoprene emission model consistently overestimated isoprene fluxes. These findings reveal overlooked phenological controls on Amazonian volatile isoprenoid fluxes, challenging standard model parameterization and emphasizing leaf-level data to improve predictions of atmospheric chemistry and climate-vegetation feedback.

The dataset contains three sequence alignment files with Sanger-sequences stemming mainly from European taxa of the simple thalloid liverwort genus Metzgeria (Jungermanniopsida). A focus is on the following Metzgeria taxa: M. leptoneura, M. curviseta, M. pubescens, M. conjugata, M. furcata, M. temperata, M. aeruginosa, M. scyphigera, and M. azorica sp. nov. Three alignment files in nexus format are available: 1) a file with sequences from the trnL-trnF region (including the trnL group I intron, trnL 3′exon, trnL-F intergenic spacer IGS), 2) a file with sequences from the rps4 gene including the trnS-rps4 IGS, and 3) a file with sequences from the rpl16 intron (partially including parts of the rpl16 3′exon). All three files were used in molecular phylogenetic analyses and integrative taxonomy of Metzgeria and serve as a baseline for further phylogenetic and taxonomic studies on this genus.

Abstract Overwintering below‐ground buds and organs determine spring regrowth of perennial herbs in temperate regions. This effect could also manifest further in the timing and duration of plant growth and flowering and has been documented in some species and organ types. However, to what extent this applies across the entire spectrum of below‐ground organs, bud types and temperate herbs remains unclear. Here we measured the timing of spring growth and flowering pattern (first flowering day, day of peak growth, growth rate and flowering length) in a phylogenetically representative set of 243 species of temperate perennial herbs grown in semi‐natural conditions of a botanical garden. These phenological traits were linked with data on bud traits (flower and leaf preformation, bud volume and bud scale coverage differentiation) as proximate drivers of species phenology and with whole plant traits (plant height, below‐ground storage volume and bud bank traits) and analysed using non‐phylogenetic and phylogenetic regression models and structural equation modelling. We showed that the timing of flowering and growth of perennial herbs was mainly determined by bud traits, namely flower and leaf preformation together with primordia volume. The often‐reported link between smaller plant size and early flowering seems largely indirect and rather stemming from size constrains in flower‐preforming species. Growth rate was predicted both directly by bud bank depth and indirectly through the association between storage volume and bud volume. Our study shows how the interplay between bud traits and whole plant traits determines herbaceous spring phenology. By identifying bud traits as the proximate drivers of spring phenology, we demonstrate that incorporating them into phenological studies will make possible more mechanistic understanding of how species phenology responds to external drivers such as temperature. This approach can enhance our understanding of species phenological shifts in response to global environmental changes. Read the free Plain Language Summary for this article on the Journal blog.