The last two decades have seen steadily increasing interest in plant functional ecology, and an orders-of-magnitude improvement in the scope and availability of data on plant traits and ecosystem processes. These developments have been propelled in part by a perceived need for a more solid scientific foundation for global vegetation and land-surface models, which are used to explore terrestrial carbon cycling and to represent the interactions of ecosystems and climate. However, this need remains substantially unfulfilled. I will argue that a key reason is the absence of any agreed theoretical framework for the analysis of trait-environment relationships. One consequence of this ‘theory gap’ is the continued reliance of models on plant functional types (PFTs) with fixed trait values – long after it became clear that most traits vary more within PFTs than between them. Another is the prevalence in the ecological literature of statistical analyses marred by arbitrary choices of environmental predictors, and misattribution of cause and effect in the controls of plant traits. Fortunately, eco-evolutionary optimality hypotheses are now helping to fill the theory gap, and have shown striking success in generating realistic predictions from universal, PFT-independent rules. The emerging ‘optimal trait theory’ has the potential to underpin a new, unified understanding of photosynthesis, respiration, transpiration, carbon allocation and nutrient acquisition at leaf, plant and ecosystem levels. Such understanding is a pre-requisite for next-generation models that will be more robust and reliable than those currently in use.
How to cite: Prentice, I. C.: Optimal trait theory: an emerging route towards better land ecosystem models, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2158, https://doi.org/10.5194/egusphere-egu25-2158, 2025.
Traits are fundamental to understanding plant function and represent key variables for ecosystem modelling. An expanding class of models based on eco-evolutionary optimality (EEO) theory shows great potential in predicting trait–trait and trait–environment relationships at both leaf and whole-plant levels, via universal formulations that apply equally to all plant functional types. According to this theory gross primary production (GPP), the basis of the terrestrial carbon cycle, is jointly determined by the ratio of intercellular to ambient CO₂ concentrations (χ), leaf-level photosynthetic capacity (Vcmax) and absorbed light, which depends on incident solar radiation and leaf area index (LAI). The effect of nitrogen (N) supply on GPP is mediated by the allocation of carbon (C) to leaves, while leaf-level photosynthetic traits (e.g. χ and Vcmax), morphological traits (e.g leaf mass per area, LMA) and biomass allocation (to roots, shoots and stems) are shaped by climate and light. The amount of N per unit area of leaf (Narea) is related in part to the quantity of photosynthetic enzymes, indexed by carboxylation capacity at standard temperature (Vcmax25), and in part to LMA. Plant N isotope ratios (δ15N) are sensitive to the partitioning of N loss from soil between the gaseous and leaching pathways (a balance that is strongly under climatic control), and also to plants’ N uptake strategy (mycorrhizal type, or symbiotic N-fixation).
This study tested quantitative trait predictions derived from EEO principles using published and unpublished data from the Northeast China Transect (NECT), which spans a precipitation gradient from moist forest to semi-desert. Predicted and observed (or inferred) values of χ, LAI, GPP and biomass decreased with dryness, while LMA and leaf nitrogen per unit area (Narea) increased. Plant δ15N increased with dryness and soil temperature. This implied fraction of N lost in gaseous forms (fgas) increased strongly towards the dry end of the transect. By reproducing observed patterns of trait variation along the NECT, these findings provide empirical support for an emerging, optimality-based theory for the coupling of C, N and water cycles in terrestrial ecosystems.
How to cite: Ding, R., Dong, N., Ni, J., Harrison, S. P., and Prentice, I. C.: Optimality-based modelling of plant traits and primary production along the Northeast China Transect, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3853, https://doi.org/10.5194/egusphere-egu25-3853, 2025.
Improved whole-plant cost:benefit understanding of allocation and activities of leaf versus wood tissues should in principle yield better understanding of differences among species in growth rates and differences among sites in vegetation productivity. To this end we measured whole-plant allocation to sapwood versus leaves in terms of mass and area for 180 woody species sampled from 11 sites arrayed across broad precipitation and temperature gradients in Australia (10-28 oC range in mean annual temperature; 380-2600 mm range in annual precipitation). Physiological rates (photosynthesis, sapwood respiration) and other standard traits were also measured. We quantified coordination between tissue-level traits and whole-plant allocation to leaf versus wood, and the role of site climate and soil properties in driving trait variation. Most but not all observed trait–trait and trait–environment relationships were consistent with predictions based on optimality theory and prior knowledge. Sapwood respiration, expressed at a standard temperature, showed clear patterning with site climate and soil nutrients. Mass-basis sapwood:leaf allocation showed clear patterning with site climate but area-basis allocation far less so. Wide variation and clear taxonomic patterning was observed among co-occurring species in key properties suggesting that cost:benefit considerations should include trait coordination and competitive effects as well as environmental drivers. Taken together, our findings suggest a fresh direction for understanding links between plant traits, environmental adaptation and – appropriately scaled up – ecosystem-scale processes.
How to cite: Wright, I., Chhajed, S., and Westerband, A.: Ecological implications of variation in whole-plant leaf:wood allocation, allometry, costs and benefits., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3398, https://doi.org/10.5194/egusphere-egu25-3398, 2025.
Observations of drought-driven damage to vegetation are widespread but, until recently, large-scale terrestrial models used to study climate-vegetation interactions did not capture the contrasting sensitivities of plants to drought. This is changing with the advent of a generation of models that consider plant hydraulics. Plant hydraulics link plant water status to pedoclimatic conditions; as such, explicit consideration of plant hydraulics should make models more mechanistic and predictive. Models, however, diverge in how they represent the plant water transport pathway and relate it to other plant functions (e.g., photosynthesis), so they further diverge in their parameterisation approach for hydraulic processes. Only at the most basic level do plant hydraulic implementations converge on a common set of measurable traits or parameters: two that describe a hydraulic vulnerability curve (e.g., P12 and P50, the water potentials at which 12% and 50% of a plant’s hydraulic conductivity are lost, respectively), and one that quantifies the efficiency of water movement within the plant (e.g., maximum hydraulic conductance). Regrettably, we do not yet know how to obtain regional- or global-scale hydraulic parameters from local-scale measurements, nor how to connect them to other plant traits. In this study, we propose strategies to leverage cross-species hydraulic diversity when scaling traits from the species level into model parameters. We also emphasise the importance of accounting for (i) within-species trait variability across space (e.g., interactions between hydraulic traits and their environment) and (ii) cross-functional trait covariation (i.e., interactions – or lack thereof – among traits that characterise different functional axes). Beyond advancing regional and global plant hydraulic modelling, efforts to address the suggested strategies would ready models for simulations that capture the resilience of vegetation communities worldwide.
How to cite: Sabot, M., De Kauwe, M., Pitman, A., Gallagher, R., Verhoef, A., Martin-StPaul, N., Cochard, H., de Cáceres, M., Flo, V., Hu, P.-H., Medlyn, B., Papastefanou, P., Ukkola, A., Zaehle, S., and Zeng, Y.: Challenges and opportunities in building a global model of plant hydraulics, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12285, https://doi.org/10.5194/egusphere-egu25-12285, 2025.
Over the past centuries, human activities have profoundly reshaped global plant migration patterns, accelerating the movement of species across vast distances. These new arrivals—whether deliberately introduced or transported unintentionally—often possess distinct functional traits that transform local community trait spaces and, in turn, ecosystem processes. Despite these widespread changes, the extent of functional conversions remains poorly understood.
In this study, we combine crowd-sourced plant occurrence data with naturalized species lists to reconstruct global trait distributions for two scenarios: (i) considering all species observed in a region and (ii) excluding neophyte species. By comparing these distributions, we estimate how neophyte introductions have reconfigured ecosystem functional spaces.
Our findings suggest distinct, region-specific shifts in functional traits along the global spectrum of plant form and function. These shifts are particularly evident in principal component 1 (PC1), which is associated with size-related traits such as plant height, rooting depth, and seed mass, and principal component 2 (PC2), which reflects traits like specific leaf area (SLA) and leaf nitrogen per area. For instance, in the Mediterranean, communities appear to have shifted toward larger trait values on PC1, while in Eastern and Central North America, shifts tend toward smaller values. In Western North America, the primary shift occurs along PC2, with increases in SLA and declines in leaf nitrogen per area. In Southern Australia, trait space shifts along both PC1 and PC2, combining smaller size traits with higher SLA values.
These results highlight the significant and varied impacts of Anthropocene plant migration on ecosystem functional properties worldwide, while also identifying gaps and biases in the extensive yet heterogenous crowd-sourced observation data. Moreover, the set of current and past trait patterns may open new opportunities to model the anthropogenic impact on ecosystem processes and properties.
How to cite: Wolf, S., Svidzinska, D., Mahecha, M., and Kattenborn, T.: Anthropocene Plant Migration: Regional Shifts in Trait Patterns and Functional Diversity, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17721, https://doi.org/10.5194/egusphere-egu25-17721, 2025.
CO2 fluxes from wood decomposition represent an important source of carbon from forest ecosystems to the atmosphere, which are determined by both wood traits and climate influencing the metabolic rates of decomposers. Previous studies have quantified the effects of moisture and temperature on wood decomposition, but these effects were not separated from the potential influence of wood traits. Indeed, it is not well understood how traits and climate interact to influence wood CO2 fluxes. Here, we examined the responses of CO2 fluxes from dead wood with different traits (angiosperm and gymnosperm) to drought and nutrient enhancement across seasonal temperature gradients. Our results showed that drought significantly decreased wood CO2 fluxes, but its effects varied with both taxonomical group and drought intensity. Drought-induced reduction in wood CO2 fluxes was larger in angiosperms than gymnosperms for the 35% rainfall reduction treatment, but there was no significant difference between these groups for the 70% reduction treatment. This is because wood nitrogen density and carbon quality were significantly higher in angiosperms than gymnosperms, yielding a higher moisture sensitivity of wood decomposition. Further, nutrient additions significantly increased wood CO2 fluxes via fungal composition, but effects varied with nutrient types and taxonomic groups. Specifically, phosphorus addition significantly increased wood CO2 fluxes (65%) through decreased acid phosphatase activity and increased abundance of fast-decaying fungi (e.g., white rot), while nitrogen addition marginally increased it (30%). Phosphorus addition caused a greater increase in CO2 fluxes in gymnosperms than in angiosperms (83.3% vs. 46.9%), which was associated with an increase in Basidiomycota:Ascomycota operational taxonomic unit abundance in gymnosperms but a decrease in angiosperms. Our results highlight the key role of wood traits in regulating moisture and nutrient response of wood CO2 fluxes. Given that the range of angiosperm species may expand under climate warming and forest management, our data suggest that expansion will increase drought effects but decrease nutrient effects on forest carbon cycling in forests previously dominated by gymnosperm species.
How to cite: Hu, Z., Zhou, G., and Fernandez-Martínez, M.: Traits mediate global change effects on wood carbon fluxes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21911, https://doi.org/10.5194/egusphere-egu25-21911, 2025.
Understanding global biodiversity patterns and the impacts of climate change on these patterns remains a critical challenge in Earth system science. Shifts in plant functional diversity are pivotal drivers of ecosystem processes, including the carbon cycle. Fundamental plant traits—governing photosynthesis, carbon storage, and water/nutrient uptake—directly influence vegetation function. Therefore, high-resolution global maps of these traits are essential for studying ecosystem dynamics, identifying environmental threats, and guiding conservation strategies. However, existing trait maps are limited by sparse, regionally biased observations and reliance on statistical extrapolations, leading to low explanatory power and ecological inconsistencies across diverse environments.
The VESTA (Vegetation Spatialization of Traits Algorithm) project addresses these challenges by integrating a trait-based dynamic global vegetation model (DGVM) with Earth observation (EO) data to produce global maps of above- and below-ground plant traits for both current and future scenarios. Trait-based DGVMs offer process-based approaches that directly link environmental factors to plant ecology and vegetation patterns. The VESTA model is initialized with data from comprehensive global trait databases, while EO data are used to calibrate and optimize the model. This calibration adjusts trait-relationship curves to align model outputs with satellite-derived measurements of vegetation structure and productivity.
A critical aspect of VESTA is accounting for the distinctiveness of plant functional types (PFTs) in trait-relationship modeling. Analysis of global plant trait databases confirms that relationships between traits, such as specific leaf area (SLA) and carbon-to-nitrogen ratios (C:N), vary significantly across PFTs. Grouping these relationships by functional type enhances explanatory power compared to assuming a single global relationship. For example, plots of trait relationships grouped by PFT reveal distinct patterns, with PFT-specific ranges and correlations that are essential for improving model accuracy.
Preliminary global simulations at a 0.5° resolution using climatic data from the CRUJRA dataset and fixed global trait relationships reproduce general SLA spatial patterns, such as lower values in boreal regions. However, comparisons with reference SLA maps highlight the limitations of the fixed-relationship approach, underscoring the need for VESTA’s optimization methods. By addressing these limitations, the VESTA project aims to provide robust, ecologically consistent trait maps that enhance our understanding of global biodiversity patterns and support effective ecosystem management under changing environmental conditions.
How to cite: Dantas de Paula, M. and Hickler, T.: Integrating a Dynamic Global Vegetation Model (LPJ-GUESS-NTD) and Earth Observation data for mapping functional traits of vegetation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5663, https://doi.org/10.5194/egusphere-egu25-5663, 2025.
Nitrogen (N) and phosphorus (P) are considered the most significant limiting factors for plant growth in natural ecosystems. While Vcmax and Jmax can be predicted reasonably well based on N content, as included in some existing models, predictions improve when P content is taken into account. However, the evidence supporting the role of P in relation to Vcmax and Jmax mainly in tropical ecosystems and the relationship between leaf nutrient traits (both N and P) and photosynthetic parameters across global biomes and climate zones remains unclear due to a lack of data from temperate and boreal regions. In this study, we analyze observations from species across 21 plant functional types (PFTs), 7 biomes, and 4 climate zones, encompassing both broadleaf and needle-leaf temperate and boreal species, to investigate how these N and P influence photosynthetic parameters while considering the variations among different PFTs. The results show that the interaction between leaf nitrogen and phosphorus content significantly affects Vcmax for different plant functional types. Additionally, the explanatory power of N and P as individual variables varies among the different functional types. For most temperate and boreal PFTs, the relationship between Jmax and Vcmax is significantly influenced by the inclusion of N or P. Our analysis highlights the importance of differentiating the relationships between photosynthetic capacity and nutrients across various plant functional types, providing a quantitative framework for understanding the constraints of N and P on photosynthesis.
How to cite: Lin, X., Wang, F., Guo, L., Xiao, Z., and Fang, J.: Nitrogen and phosphorus constraints to photosynthetic capacity across different plant functional types, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9389, https://doi.org/10.5194/egusphere-egu25-9389, 2025.
Increasing frequency and intensity of droughts and heatwaves worldwide cause reductions in forest productivity, threatening the ecosystem services that forests provide and their carbon sequestration potential. A better understanding of the trait variability in space and time would improve the predictability of models on individual and ecosystem scale. We looked at the acclimation potential of drought and heat tolerance in three important tree species in Sweden: Picea abies, Betula pendula and Quercus robur. We hypothesized that i) tree species can acclimate to warming and drought leading to better resistance to heatwaves, and ii) heat and drought tolerance are coupled and that acclimation to drought would lead to increased heat tolerance and vice versa. In a climate chamber experiment in southern Sweden, seedlings of the three species were planted in pots and exposed to two different temperatures, and a well-watered and drought treatment. After a three-month acclimation phase, the trees were exposed to two consecutive heat waves with a two-week recovery period. Before and after acclimation and heatwaves, drought and heat tolerance indicators were measured, such as turgor loss point (ψTLP) and leaf thermal tolerance (T50). Leaf drought and heat tolerance acclimated to respective treatments, with different magnitudes depending on species. The three species also had different survival strategies to heatwaves. The results reveal the acclimation potential of tree species to drought, warming and the combination. They underline the importance to consider trait acclimation and the combined effects of drought and heat on tree physiology in plant and ecosystem models.
How to cite: Schönbeck, L., Bergstrand, K.-J., and Löf, M.: Acclimation to drought and warming alters stress response to heatwaves in tree seedlings, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9557, https://doi.org/10.5194/egusphere-egu25-9557, 2025.
Plant traits connect individual organisms to ecosystem functions and offer a valuable perspective on ecosystem responses to rapid global change. This talk highlights the potential of flexible-trait modelling to advance our understanding of trait ecology and forest stability.
The flexible-trait model LPJmL-FIT, which was built upon data from the TRY Plant Trait Database, enables us to explore how key plant traits and their interactions over space and time. By integrating process-based vegetation models with machine learning and advanced statistics, we demonstrate how this approach can complement observations to uncover links between biodiversity, plant traits, and ecosystem functioning.
The talk will share key insights from studies on the role of functional diversity in enhancing forest resilience to climate change (Billing et al., 2022, 2024; Sakschewski et al., 2015; Thonicke et al., 2020). Our findings demonstrate that functional trait diversity supports long-term forest biomass, particularly through mechanisms such as functional complementarity. However, the benefits of diversity diminish under extreme warming and vary across site conditions, underscoring the context-dependent nature of these dynamics and the need for continued model development. Further progress in trait-based modelling depends on broader datasets, particularly for belowground traits, which remain underrepresented in current measurements. These efforts might bridge key gaps and refine our understanding of future plant dynamics.
Billing, M., Sakschewski, B., Werner Von Bloh, , Vogel, Johannes, & Thonicke, K. (2024). ‘How to adapt forests?’—Exploring the role of leaf trait diversity for long-term forest biomass under new climate normals. Global Change Biology, 30(4), e17258. https://doi.org/10.1111/GCB.17258
Billing, M., Thonicke, K., Sakschewski, B., von Bloh, W., & Walz, A. (2022). Future tree survival in European forests depends on understorey tree diversity. Scientific Reports, 12(1), 1–12. https://doi.org/10.1038/s41598-022-25319-7
Sakschewski, B., von Bloh, W., Boit, A., Rammig, A., Kattge, J., Poorter, L., Peñuelas, J., & Thonicke, K. (2015). Leaf and stem economics spectra drive diversity of functional plant traits in a dynamic global vegetation model. Global Change Biology, 21(7), 2711–2725. https://doi.org/10.1111/gcb.12870
Thonicke, K., Billing, M., von Bloh, W., Sakschewski, B., Niinemets, Ü., Peñuelas, J., Cornelissen, J. H. C., Onoda, Y., van Bodegom, P., Schaepman, M. E., Schneider, F. D., & Walz, A. (2020). Simulating functional diversity of European natural forests along climatic gradients. Journal of Biogeography, 47(5), 1069–1085. https://doi.org/10.1111/jbi.13809
How to cite: Billing, M., Sakschewski, B., von Bloh, W., Bereswill, S., Priesner, J., and Thonicke, K.: Towards Resilient Forests: Uncovering the Role of Plant Traits and Functional Diversity, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11638, https://doi.org/10.5194/egusphere-egu25-11638, 2025.
Understanding global patterns of functional diversity is essential for exploring ecosystem functioning, yet our current knowledge is limited to specific regions and geographically restricted datasets.. Meanwhile, rapidly growing citizen science initiatives, such as iNaturalist or Pl@ntNet, have generated millions of ground-level species observations across the globe. Despite citizen science species observations being noisy and opportunistically sampled, previous studies have shown that integrating them with large functional trait databases enables the creation of global trait maps with promising accuracy. However, aggregating citizen science data only allows for the generation of relatively sparse and coarse trait maps, e.g. at 0.2 to 2.0 degree spatial resolution.
Here, by using such citizen science data in concert with vegetation surveys and high-resolution Earth observation data, we extend this approach to model the relationships between functional traits and their structural and environmental determinants, providing global trait maps with globally continuous coverage and high spatial resolution (up to 1km). This fusion of ground-based citizen science and continuous satellite data allows us not only to map more than 30 ecologically relevant traits but also to derive crucial functional diversity metrics at a global scale. These metrics—such as functional richness and evenness—provide new opportunities to explore the role of functional diversity in ecosystem processes, particularly in areas previously lacking in data availability.
Our approach presents a scalable framework to advance understanding of plant functional traits and diversity, opening the door to new insights on how ecosystems may respond to an increasingly variable and extreme climate.
How to cite: Lusk, D., Wolf, S., Svidzinska, D., Kattge, J., Maria Sabatini, F., Bruelheide, H., Damasceno, G., Moreno Martinez, Á., and Kattenborn, T.: From satellites to smartphones: harnessing citizen science and Earth observation to unlock global perspectives on plant functional diversity, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11749, https://doi.org/10.5194/egusphere-egu25-11749, 2025.
Plants are a key interface in the Earth system, modulating hydrology, nutrient cycles, and surface properties such as albedo through their physiological activity, growth, and development. Because evolution has shaped these plant properties, the representation of geological-age-appropriate vegetation in ecosystem and climate models is critically important for the examination of environmental change over geologic time. The last >400 million years of plant evolution has recorded paradigm shifts in plant anatomical traits in response to adaptation to environmental conditions. The disparity between extinct traits and living traits challenges the validity of extrapolating past ecosystem function from observations made using living plants. Major plant environmental resistances (i.e., to drought and frost) can be opaque to reconstruct in deep-time ecosystems because extinct organisms contained anatomical features with no living analog, but these properties are related to plant traits and can be derived directly from fossilized plant anatomy.
Recent advances integrate measurements of plant fossils containing anatomical detail with process-based ecosystem models. This approach allows quantitative plant traits to be derived for extinct plants and the effects of these paleo-traits to be simulated in the context of age-appropriate environments. Key measurements of plant vascular anatomy from fossilized wood, branches, and leaves are made from field-collected plant fossils or material already present in museum collections using minimally destructive techniques. These measurements are transformed using biophysical, biochemical, or statistical models of plant function into quantitative or qualitative traits, or are used directly as parameters in the process-based ecosystem model Paleo-BGC.
Application of this linked anatomy-trait-model approach across Earth history shows that appropriate modeling of traits may have profound effects on simulated biogeochemical cycles. For example, the replacement of one plant type—a sphenopsid—by another closely related plant within the same taxonomic group with different traits likely had significant effects on the collapse of the Carboniferous rainforest during the Carboniferous-Permian transition (~303 Ma). Likewise, exploring the effect of ecosystem replacement across a singular environmental event (the Triassic-Jurassic mass extinction, ~201 Ma) illustrates how changes in plant community composition, by modifying vegetation traits present in ecosystems, transformed the relative magnitude of plant carbon and water cycle effects in response to Earth system events. Linking deep-time plant anatomy to ecosystem function through quantitative and qualitative paleo-traits is an underutilized, accessible, and informative approach to identifying vegetation response through time. Applying these methods across the evolutionary history of land plants, as recorded in the fossil record, will yield a better understanding of the feedbacks between vegetation and climate and a more complete picture of how the evolution of plant traits influenced plant-environment feedbacks through time.
How to cite: Wilson, J., Matthaeus, W., White, J., Peppe, D., Jones, W., Cross, O., Hametz-Berner, R., Hornum, S., and Mattison, W.: Linking vegetation to ecosystem function through plant paleo-traits, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13693, https://doi.org/10.5194/egusphere-egu25-13693, 2025.
Climate change is expected to impact the distribution of invasive plants, with certain species forecasted to expand, contract and/or shift their invasive ranges. However, the mechanisms and associated species traits driving these distinct biogeographical responses are not well understood. In this study, we investigate the relationships between functional and niche traits of invasive plant species and their forecasted range responses to climate change. We leveraged previously published species distribution models for invasive terrestrial plants in the United States, as well as a comprehensive invasive traits database, to assemble a dataset of current and future ranges (based on average projected climate in 2040-2060) of 476 invasive plants. We also compiled functional and niche traits for these species, such as specific leaf area, dispersal vectors and environmental tolerances. Our findings indicate that species with larger current ranges, moderately thick, resource-efficient leaves, and long-distance animal dispersal capabilities showed smaller range centroid shifts. Conversely, changes in range area were smaller for species with broad hardiness zone ranges, a preference for higher elevations, and tolerance to extreme precipitation regimes. Minimum hardiness zone emerged as the strongest predictor of range expansion or contraction within the U.S., with species adapted to warmer climates and with restricted current ranges more likely to expand. This work provides valuable insights into the mechanisms underlying invasive plant range responses to climate change and offers a framework for integrating trait-based approaches with predictive modeling to inform management strategies.
How to cite: Nunez-Mir, G., Tovar, E., Allen, J., and Suzi-Simmons, A.: Invasive winners and losers: the influence of traits on climate-driven invasive plant range changes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14001, https://doi.org/10.5194/egusphere-egu25-14001, 2025.
The eucalyptus forests of Tasmania, Australia are some of the most productive and carbon dense in the world. Of the eucalypt species that are native to Tasmania, messmate stringybark (Eucalyptus obliqua, Euob) dominates 20% of the forested landscape. Moreover, Euob is distributed across both dry and wet forests that exhibit vastly different microclimates and subdominant vegetation communities. However, warming temperatures and increasingly stochastic precipitation events threaten their fate. Here, we reconstruct historical growth and physiology to characterize the sensitivity and timing of Euob tree responses to climate in two contrasting forest types (i.e. wet versus dry). We then combine these data with stand-level surveys and total carbon inventories to scale our findings within their respective geographical footprints. Finally, we develop a novel modeling framework to contextualize differences in the growth potential of trees in each environment under current and future projected environmental conditions. We found Euob tree growth in dry forests is highly sensitive to climate in the late spring, while growth in wet forests is more complacent and driven to a greater extent by mean climate over the course of a growing season. Moreover, intrinsic water use efficiency, the ratio of net photosynthesis to stomatal conductance to water, remains constant across a range of soil moisture in wet Euob forests, but declines with increasing water availability in dry forests. Our data suggest Euob growth, and subsequently carbon uptake and allocation to stem wood, is energy-limited in wet forests and water-limited in dry forests. Growth modeling revealed that, even under ideal conditions (i.e. maximum realized growth potential), stand-level carbon stocks in dry Euob forests achieve only 90% of those currently observed in wet forests. Our results suggest Euob trees in energy-limited wet forests could benefit under future climate, as Tasmania is expected to become warmer in most regions, while dry forests may be particularly vulnerable.
How to cite: Mathias, J., Stephenson, T., Moon, C., Jones, M., Hudiburg, T., and Lynch, L.: Climate sensitivity and carbon dynamics of Eucalyptus obliqua within wet and dry Tasmanian forests: Implications for future growth under climate change, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14210, https://doi.org/10.5194/egusphere-egu25-14210, 2025.
Mixed-species forests have the potential to enhance ecosystem resilience and productivity in the context of global change. While plant traits are increasingly being used to extend the scope of Earth observations to the organismal level and to link them to ecosystem functioning, intraspecific trait variability and plasticity are often neglected - models often rely on species-level means from databases. Furthermore, studies of species interactions and trait dynamics often overlook belowground plasticity. We investigated how competitive interactions influence growth and functional traits of four temperate deciduous tree species. We hypothesized that (1) growth effects in mixtures occur not only at the level of wood biomass, but also at the level of leaves and fine roots, resulting in overyielding effects at the stand level, (2) competitive interactions in mixed-species communities increase trait dissimilarity at the community level, and (3) species acclimation to intra vs. interspecific competition follows different types of reaction norms, including changes in trait mean and/or variability, depending on competitive status.
A forest inventory was conducted in planted monocultures, 2-species and 4-species mixtures of European Acer, Tilia, Quercus and Carpinus, representing a spectrum from acquisitive to conservative tree species. Competition effects were assessed with linear mixed effects models at the level of biomass and space acquisition, including leaf, canopy, stem and fine root traits. Using monocultures and 4-species mixtures, we analysed trait dissimilarity, means and variability of traits related to resource acquisition and use, including an extended ectomycorrhizal trait space, using kernel density-based metrics and generalised linear mixed models.
Most diverse stands, especially those with acquisitive Acer, exhibited aboveground overyielding, 1.5 to 1.9 times higher than monocultures. Fine roots showed significant overyielding in 4-species stands. Biomass allocation were highly species-specific and varied significantly at the diversity level. At the community level, aboveground traits other than specific leaf area showed limited plasticity, but belowground there was a marked difference between competitive superior and inferior species. Reaction norms of aboveground traits were dominated by shifts in mean and variability, whereas root traits were dominated by increases in variability in mixture. Trait dissimilarities, as a measure of plasticity across diversity levels, differed markedly between species, competitive dominance, and above and below ground. Overall, dominant Acer acclimated least to interspecific competition, whereas inferior Tilia and Carpinus showed variability-driven plasticity above and below ground. Quercus showed mean-driven reaction norms below ground, with minimal changes in trait variability in the mixture.
Our data highlights the need to increasingly consider effects at the whole-plant level, as both above- and belowground components contribute significantly to overyielding in mixed-species environments. Our results further underscore how species mixing and competitive hierarchies drive trait plasticity at the level of mean and/or variability, highlighting distinct above- and belowground strategies (i.e. reaction norms) that may drive resource complementarity and thus govern longer-term coexistence and biogeochemical cycling in mixed-species stands.
How to cite: Rewald, B., Sandén, H., Godbold, D. L., and Werner, R.: Beyond Mean Reaction Norms: Trait Plasticity and Growth of Trees under Interspecific Competition Above and Below Ground, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18957, https://doi.org/10.5194/egusphere-egu25-18957, 2025.
Leaves and trunk bark are the main parts of woody species burned in canopy and surface fires, yet lack of knowledge of flammability of different plant parts and their coordination have impeded the understanding of plant flammable strategies to fire disturbance, and the ecological feedbacks between fire and vegetation.
We sampled 271 common woody species in subtropical semi-humid forest, then measured 10 flammability traits of leaves and bark using the cone calorimeter (including heat release, time to ignition, flame height, smoke production). Bark and leaf flammability showed large difference across woody species. Leaves were generally more ignitable, consumable and combustible, but the sustainability was lower than that of the bark. Moreover, we show that bark flammability and leaf flammability are decoupled because they were driven by size-related traits and economics-related traits, respectively.
According to the decoupling between leaves and bark, we defined plant flammability syndromes based on the different combinations of flammability strategies of leaves and bark, and assessed the impact of fire frequency on different flammability syndromes. Furthermore, the results also indicated that 40.0%, 39.1% and 20.9% woody plant species had hot-, fast-, and low-flammable leaves, respectively; and 28.2%, 35.7% and 36.1% species had hot-, fast- and low- flammable bark. Tree species (47.5%) had a higher percentage of flammability strategy separation between leaves and bark than large shrub (19.7%) and shrub species (18.2%). Community-level evidence showed that species with fast- or hot- flammable leaves and bark may gain a notable advantage with repeated fires. Structural equation models indicated that more frequently burned forests were associated with infertile soil, shrub enrichment and lower species richness, subsequently leading to a favor on flammable plant species.
Therefore, the difference and coordination between leaves and bark flammability, might help to well characterize the flammability strategies of plants. The positive feedback loop would generate between the dominance of flammable species in the plant communities and the fire frequency, fostering the characteristics of fire regimes in the semi-humid evergreen broadleaved forests.
How to cite: Luo, C.: Bark and leaf flammability in subtropical semi-humid forest in China, and plant flammable syndromes how to respond to fire frequency, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16656, https://doi.org/10.5194/egusphere-egu25-16656, 2025.
Liana abundance increases with the seasonality of rainfall in tropical forests, and evergreen lianas and trees may compete for water during the dry season. Several studies suggest functional divergence of water use strategies between lianas and trees, with lianas experiencing less water stress and exhibiting growth advantage over trees during the dry season.
Our aim was to test the hypothesis that evergreen lianas are less drought tolerant and more water spending than evergreen trees. If so, we expected that, compared to trees, lianas should have (i) less sclerophyllous leaves, (ii) larger but fewer xylem vessels in their branches, (iii) higher predawn and midday water potentials, (iv) lower water use efficiency, (v) access to deeper water sources.
We tested our hypothesis in a seasonally dry tropical forest on a white-sand hill in Ankarafantsika National Park, north-western Madagascar (MAP, 1600 mm; dry season, April to November). We studied three liana and three tree species in June 2023, and seven liana and eight trees species in September 2024. We measured leaf mass per area, nitrogen content and δ13C, leaf predawn and midday water potentials, diameter and density of xylem vessels of branches, and δ18O of xylem water.
We found that lianas had lower leaf mass per area, higher leaf predawn water potentials, larger and fewer xylem vessels, and lower δ18O of xylem water than trees. Overall, our results confirm that evergreen trees are more drought tolerant than lianas while evergreen lianas are more water spending than trees but not consistently across families.
How to cite: Epron, D., Sakaue, Y., Fujimoto, Y., Sunayama, S., Rakotomamonjy, A. H., Noyori, W., Razanaparany, T., Razafiarison, Z. L., Sato, H., and Kitajima, K.: Do stem and leaf functional traits explain differences in water use between tropical evergreen trees and lianas during the dry season?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4643, https://doi.org/10.5194/egusphere-egu25-4643, 2025.
How to cite: Bérangère, L., Leydet, M., Meineri, E., Saatkamp, A., and Violle, C.: Functional responses of Mediterranean flora to fire: a community-scale perspective, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21106, https://doi.org/10.5194/egusphere-egu25-21106, 2025.
Plant functional traits provide a link to scale from organism to community and ecosystem levels, making it critical to understand how traits will mediate ecosystem responses to climate change. Combinations of these functional traits, which are likely to shift under climate change, also provide insight into plant resource use strategies, determining whether plants have resource-use acquisitive or conservative growth strategies. In this study, we used meteorological and eddy covariance tower data from the Niwot Ridge Long Term Ecological Research site (Colorado, USA) to run point-scale Community Land Model (CLM; the terrestrial component of the Community Earth System Model) simulations with plant functional trait observations. We modified plant traits and parameters–including foliar traits, phenological characteristics, and hydraulic traits–to represent tundra growth strategies and to configure dry, moist, and wet tundra communities driven by differences in snow accumulation. After validating our simulations with local observations, we quantified the relative contributions of plant trait and climate change scenario uncertainties to future productivity outcomes by modifying parameters to represent more resource-use conservative or acquisitive communities under two climate change scenarios. We found that using foliar trait observations from each plant community significantly improved productivity estimates compared to overestimates in the default simulation. In addition, the relative contributions of plant trait and climate scenario uncertainties varied among communities and over time in future simulations. Overall, uncertainty in plant functional trait shifts had a larger effect on ecosystem carbon-cycle responses than uncertainty in the forced response from medium and high emissions scenarios. Our findings demonstrate the importance of plant functional traits in shaping ecosystem responses to climate change and the value of incorporating site-level observations into ecosystem models as a means to predict climate change impacts on ecosystem function.
How to cite: Jay, K., Wieder, W., Elmendorf, S., Spasojevic, M., and Suding, K.: Uncertainty in tundra plant functional traits outweighs climate scenario uncertainty, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7741, https://doi.org/10.5194/egusphere-egu25-7741, 2025.
Buttress roots are iconic features of tropical rainforests, yet the mechanisms underlying their global distribution remain poorly understood. Two prevailing hypotheses, mechanistic support and nutrient acquisition, have been explored through numerous studies, but no global consensus has emerged. To address this gap, we conducted a global biogeographic analysis, identifying 847 tree species capable of generating buttress roots and integrating this data with forest inventory datasets worldwide. Our findings reveal that while buttress root species are associated with higher canopy heights, they are not adapted to high wind speeds or shallow soils, challenging the mechanistic support hypothesis. Instead, we found that soil phosphorus limitations and relatively acidic soils enhance the presence of buttress roots, supporting their role in nutrient acquisition. Climatic factors, including the lowest temperature of the coldest month and site water balance, also appear to constrain the distribution of buttress root species, potnetially due to photosynthesis-related trait limitations. Our geospatial models estimate that buttress root species cover approximately 21% of global tropical forests, emphasizing their ecological significance in tropical forest structure. These findings highlight the critical role of buttress roots in forest ecosystems and their importance for global conservation efforts.
How to cite: Ma, H., Brun, P., Maynard, D., van den Hoogen, J., Luo, Y., Karger, D., Mo, L., Ding, W., Plekhanova, E., Popp, M., and Zimmermann, N.: The biogeography and functional understanding of buttress roots in tropical forests, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4326, https://doi.org/10.5194/egusphere-egu25-4326, 2025.
Terrestrial plants maintain carbon reserves to support their functions during periods when metabolic demand exceeds carbon supply, such as during the dormant season (Carbone et al. 2013). Urban trees may differ in the size and age of these carbon pools due to their specific environmental conditions, especially more stressful environment and occasional lack of water. In order to better understand the carbon storage strategy of urban trees, tree-ring core samples were collected in a medium-sized Hungarian city, Debrecen, from Celtis occidentalis trees located in different urban areas, such as downtown and suburban sampling points. In addition to the tree rings, bud samples were also collected to determine the age of carbon used for the production of new plant tissue during spring. The accelerator mass spectrometry-based bomb-radiocarbon approach was used determine the age of the carbon stored in the plant and bud samples (Richardson et al. 2015, Richter et al. 2009.). The results show that fresh carbon was used to produce new spring buds and the results show that the possible fossil contribution in urban areas can shift the age of fresh plant material. In contrast, our previous study showed that non-urban trees use much older carbon to produce buds (Varga et al. 2024). Although the trees studied used fresh carbon to build new tissues, the sugar and starch concentrations and their radiocarbon ages show that there is a low but considerable amount of stored carbon in the urban trees. The 14C measurement reveals the turnover time and mixing of old and fresh carbon in the tree, and shows a declining trend in the stored carbon concentration by the years.
References
Carbone et al. 2013., Age, allocation and availability of nonstructural carbon in mature red maple trees. New Phytologist 200(4): 1145–1155.
Richardson et al., 2015. Distribution and mixing of old and new nonstructural carbon in two temperate trees. New Phytologist 206(2): 590–597.
Richter et al., 2009. Preparation of starch and soluble sugars of plant material for the analysis of carbon isotope composition: a comparison of methods. Rapid Commun. Mass Spectrom. 23, 2476–2488.
Varga, et al., 2024. Spring buds of European woody plants have old 14C age. Heliyon 10.
How to cite: Varga, T., Nagy, D., Molnár, M., Jull, T. A. J., Futó, I., Sierra, C. A., Hilman, B., Vargas, D., and Lisztes-Szabó, Z.: Assessing Carbon Storage and Age in Urban Trees Using Radiocarbon Analysis, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7360, https://doi.org/10.5194/egusphere-egu25-7360, 2025.
Root phosphatase activity (RPA) is an important physiological root trait, serving as hydrolyzing soil organic phosphorus into bioavailable orthophosphate and reflecting plants’ ability to acquire phosphorus. However, the global variation and its link with other root traits remains uncertain. By synthesizing the first global dataset of RPA comprising 607 observations across 258 species, we found that while RPA varies tremendously among species, N-fixers exhibited significantly higher RPA than non-fixers. However, RPA showed minimal variation across different growth forms and mycorrhizal types. Moreover, our results revealed globally widespread coordination and trade-offs between RPA and root morphology, architecture, and mycorrhizal symbiosis that are directly linked to phosphorus acquisition. However, there are few exceptions in certain groups, likely due to outlier species that employ unique strategies. Additionally, root nutrients are good predictors of RPA. RPA aligns closely with the collaboration dimension of the root economics space globally. We suggest that plants employ a range of phosphorus acquisition strategies, which could explain species coexistence in phosphorus-limited soils.
How to cite: Ao, G. and Zhu, B.: Linking root phosphatase activity to root chemical and morphological traits across species – a global synthesis., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7832, https://doi.org/10.5194/egusphere-egu25-7832, 2025.
Biogeochemical cycling and properties of ecosystems depend, in part, on the assimilation of carbon and uptake of mineral nutrients and water by plants. Belowground, these processes can be studied with the root economic spectrum (RES) which describes plant resource acquisition strategies along a spectrum of fast (e.g., longer and thinner roots) to slow acquisition (e.g., shorter and thicker roots). However, plant-mediated controls on ecosystem functions have often been studied aboveground, leaving the belowground processes largely understudied. This is especially true for water-saturated wetlands, such as peatlands, where drivers of root resource acquisition strategies may be very different than in upland soils. In order to reliably predict peatland plant responses to environmental change and the subsequent shifts in biogeochemical cycles, we need a better understanding of plant fine root trait plasticity under climate warming.
We investigated RES trait-environment linkages at a peatland whole-ecosystem climate change experiment (SPRUCE, Minnesota, USA). We collected shrub and tree (spruce and larch) fine root samples from root ingrowth cores installed in enclosures (n=10) with warming (+0 ℃ to +9 ℃) and elevated CO2 (ambient and +500 ppm above ambient) treatments, and plots without enclosure (n=2), over five years (2014-2017 and 2022-2023). We obtained root economic trait data, such as specific root length (SRL) and root tissue density (RTD), from the samples using a root scanning software, as well as root chemistry using an isotope-ratio mass spectrometer. In addition, we collected root exudation rate data from trees and shrubs in each enclosure in 2022. To estimate the contribution of increased soil temperature and elevated CO2 on RES traits, we will build linear mixed effect models for each root trait (response variables) with soil temperature, soil moisture and elevated CO2 treatment as fixed effects and year and microtopography (hummock and hollow) as random effects.
Preliminary results suggest that shrubs respond to warming by shifting to a stronger resource acquisition strategy, as indicated by increasing SRL by soil temperature and slightly decreasing RTD. Tree SRL did not change along the warming and elevated CO2 treatments, but RTD seems to decrease, particularly in the 9 ℃ warming treatment, in general indicating a slow resource acquisition strategy. We also found indications of an increasing nutrient-mining strategy with warming for shrubs, where increasing root exudation rates in higher soil temperature may lead to increasing plant-available N and increased root N uptake.
How to cite: Määttä, T., Chari, N., Childs, J., Iversen, C., Salmon, V., Schwaner, G., Weber, S., and Malhotra, A.: Peatland shrub roots increase resource acquisition with warming, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11448, https://doi.org/10.5194/egusphere-egu25-11448, 2025.
Arbuscular mycorrhizal fungi (AMF) as symbiotic microorganisms mediate carbon allocation between plants and soil by acting as a pathway of carbon to soil organic matter and between soil and atmosphere through mycorrhizal respiration. In 2022 an experiment focusing on the contribution of mycorrhizal fungi to soil respiration was set up in a Central-Hungarian dry sandy grassland. In this drought prone area drought events occur throughout the year and the limited water availability causes seasonal changes in plant growth, carbon uptake and thus in soil respiration as well.
During this study CO2 gas exchange was monitored by two different systems: eddy covariance (EC) and automated soil respiration measuring system (ASRS). In case of the ASRS four treatments were separated using the collar deployment method: i) undisturbed, root and AMF included, ii) disturbed, root and AMF included, iii) root excluded and iv) root and AMF excluded.
Here we present our results from two consecutive, yet - regarding water availability - dissimilar years (2023 and 2024).
How to cite: De Luca, G., Fóti, S., Mészáros, Á., Pintér, K., Nagy, Z., and Balogh, J.: How seasonal drought events alter carbon allocation and mycorrhizal respiration in a Central-Hungarian dry grassland, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12647, https://doi.org/10.5194/egusphere-egu25-12647, 2025.
As the major carbon sources of soil respiration (Rs) are the soil organic carbon content (SOC) and the belowground carbon allocation, we aimed to reveal their effects on actual CO2 efflux from soil. For that reason, we measured soil respiration and additional variables in a dry grassland site in Hungary in the same spatial grid (78 points, 0.54 ha) during 23 campaigns in eight years covering a broad range of environmental conditions. The measuring positions at the study site had high spatial variability of topsoil organic carbon content (range was 2-14%, 0-10 cm). The source of belowground carbon allocation is plant photosynthesis, therefore we used gross primary productivity (GPP) as a predictive variable of Rs. GPP was derived from eddy-covariance measurements and downscaled to the measuring positions by using above-ground biomass and vegetation index data. To visualize the multidimensional data, principal component analysis was performed. To describe the partial effects of the measured variables general additive models (GAM) were fitted and the relative importance of predictor variables in GAM models was estimated. According to the results, GPP had similar importance in the models as soil temperature (Ts) and soil water content (SWC), while the importance of SOC was negligible. GPP was the most important predictor variable in the middle of the vegetation period, while SWC was the most important in the first part of the vegetation period and Ts in the late season. The overall relative importance of SWC, GPP and Ts were 35.7%, 31.8% and 29.2%, respectively. The shape of the partial effect of GPP was linear suggesting that the whole range of GPP could be an important factor in soil respiration models.
How to cite: Balogh, J., de Luca, G., Pintér, K., Nagy, Z., Koncz, P., Süle, G., Kardos, L., Cserhalmi, D., Gelybó, G., Kampfl, G., and Fóti, S.: Belowground carbon allocation has stronger influence on soil respiration than soil organic carbon content in a dry temperate grassland , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16006, https://doi.org/10.5194/egusphere-egu25-16006, 2025.
Plant hydraulic traits are critical in regulating plant–water interactions and essential for understanding vegetation responses to environmental stress. Building on our earlier methodology for mapping global plant functional traits, we now incorporate a newly-available dataset of hydraulic traits for 55,779 tree species. This integrated framework leverages remotely sensed imagery, crowdsourced biodiversity data, and trait databases to estimate and map key hydraulic parameters, including maximum stomatal conductance (gsMAX), xylem pressure at 50% and 88% conductance loss (P50, P88), and photosynthetic water use efficiency (WUE).
The tree trait data underlying our study accounts for the large phylogenetic signals inherent in these hydraulic traits by leveraging phylogenetically-informed machine learning models and novel trait imputation methods. These enhanced predictions of hydraulic traits are subsequently integrated into our trait-mapping workflow, which has previously demonstrated high accuracy (r > 0.5; rME < 6%; rRMSE < 11%) for leaf-level traits at a 1 km spatial resolution. While the hydraulic trait maps have not yet been validated due to a lack of independent validation data, the observed patterns are consistent with a meta-analysis based on recent literature.
We also capture the full distribution of hydraulic traits (standard deviation, skewness, and kurtosis) at the grid-cell level to reflect the non-Gaussian variability of community-level traits. This added detail helps elucidate the ecological strategies of species assemblages and refines our understanding of ecosystem vulnerability to climate extremes. Overall, this work offers a new avenue for improving global ecosystem models and Earth system simulations by providing spatially explicit community-level hydraulic trait estimates at large scales. Our results highlight the importance of merging global remote sensing data with state-of-the-art trait imputation and phylogenetic information to advance research on plant functioning and ecosystem dynamics.
How to cite: Moreno-Martínez, Á., Muñoz-Marí, J., Adsuara, J., Knighton, J., Sanchez-Martinez, P., Anderegg, L., Dechant, B., Schneider, F. D., Kattge, J., Katternborn, T., Lusk, D., Koppa, A., Miralles, D., Piles, M., Mencuccini, M., Chaparro, D., and Camps-Valls, G.: Mapping Tree Hydraulics and Assemblages at Continental Scale, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17820, https://doi.org/10.5194/egusphere-egu25-17820, 2025.
Ecological stoichiometry studies the chemical balance and their coupling relationships of carbon (C), nitrogen (N), phosphorus (P) and other elements in ecological processes, and plays an important role in revealing the mechanisms underlying biogeochemical cycles and ecosystem functions. This study focused on cold temperate coniferous forests, i.e. larch forests, and explored its stoichiometry character in China and how plant community structure and environmental factors affect the CNP stoichiometry of its soil and different organs of constructive species. The results following: (1) The needle and twig N:P ratios of larch species were less than 10, and the N:P ratio of cone was less than 14, indicating that constructive species growth was limited by N in Chinese larch forest. There were significant differences in the CNP stoichiometry characteristics among different organs of the constructive species. Although CNP stoichiometric characteristics of cone were significantly correlated with the C and N contents and C:N ratio of shallow soils, the reproductive organs had greater internal stability of the element stoichiometry than needle and twig, which were more easily affected by soil stoichiometry. (2) Altitude is an important factor affecting soil CNP stoichiometry in larch forests. And, the C and N contents, and C:N, C:P and N:P ratios in different soil layers significantly increased with the stand age, indicating that the growth of larch forests is conducive to the accumulation of soil nutrients. (3) Climatic factors were the main factors for the C content of twig, the N content of cone, and the N:P ratios of all organs in larch forests. Topographic factors were the main factors affecting needle C and N contents. The larch forest type was the main factor affecting cone C content, C:N and C:P ratios. Community factors were the main factors affecting the C:N ratio of soil and P content of cone. The relationships between CNP stoichiometric characteristics of different organs of constructive species and community factors were mainly reflected in average tree height and stand density, while the relationships between soil CNP stoichiometric characteristics and community factors were mainly reflected in stand age. This study elucidated the CNP stoichiometric characteristics of larch forests in China, and revealed the important influence of community factors on the stoichiometry of larch forests. These results will help to understand the adaptation and evolution process of alpine forest ecosystem to nutrient environment.
How to cite: Fang, W.: Stoichiometry character of larch forests in China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20925, https://doi.org/10.5194/egusphere-egu25-20925, 2025.
Natural regeneration is important for the study of vegetation dynamics under the background of global climate change, as well as for forest production management. Fagus species are an important component of temperate forests in the Northern Hemisphere and also have significant socio-economic value. However, large-scale studies on the regeneration of Fagus populations are currently insufficient. This study, based on community survey data from 150 natural Fagus forest plots, explores the large-scale pattern of Fagus population regeneration in China and analyzes the impacts of various factors, including natural disturbances, stand age, community structure, climate, soil physicochemical properties, and topography. The results showed that the density of Fagus seedlings generally exhibited a geographical pattern of being higher in the north and lower in the south, higher in the west and lower in the east, and increasing with elevation. Multiple regression analysis indicated that the density of standing dead trees (indicating disturbances), average tree height, and the density of Fagus trees in the canopy layer have relatively greater positive effects on the density of Fagus seedlings, while stand age and annual average temperature have relatively greater negative effects. Structural equation modeling further showed that the impact of mean annual temperature on the density of Fagus seedlings was mainly a direct negative effect. Stand age, on the one hand, had a directly negative impact on the density of Fagus seedlings, and on the other hand, had a indirectly opposite effect by reducing the density of Fagus trees in the canopy layer and increasing the average tree height. The density of standing dead trees had a direct promoting effect on the density of Fagus seedlings. The study results emphasize the importance of spatial scale in regeneration research, as well as the potential application of using the quantity of dead wood to represent small-scale disturbances in large-scale regeneration studies. They also provide a theoretical reference for the protection and utilization of Fagus resources in China.
How to cite: Cai, Q.: Large-scale patterns of Fagus regeneration in China, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20941, https://doi.org/10.5194/egusphere-egu25-20941, 2025.
Biodiversity and community functional traits are critical to preserving the lake ecosystem stability under global environmental changes, which is essential for sustaining the vital ecosystem services we depend on. However, how species diversity and the key functional trait affect the multiple dimensions (temporal stability, resistance, resilience and recovery) and facets (function, composition, diversity and functional trait) of stability of macrophyte communities to algal bloom disturbances in freshwater lakes remains unclear. Here, based on sediment nutrient gradient experiments and three-year seasonal monitoring of macrophyte communities in Erhai Lake before and after the occurrence of algal blooms, we found that species diversity and stoichiometric homeostasis of phosphorus (HP) have positive relationships with functional and compositional temporal stability, resistance, and recovery, indicating that ecosystems with high species diversity and community HP are more resistant and stable in response to external algal bloom disturbances. However, species diversity and community HP have no positive or even negative relationships with resilience, suggesting that high biodiversity with high-HP species-dominated ecosystems is not beneficial for the rapid recovery from disturbances, probably due to the slow growth and reproduction rate of high-HP species. In addition, we found strong positive correlations between functional and compositional stability across the four dimensions of stability, while stability of species diversity and the key functional trait (HP) exhibit complex relationships, implying the difficulty of optimizing multiple dimensions and facets of stability simultaneously. Our results highlight the importance of macrophyte species diversity and community HP in determining the multiple dimensions and facets of stability in response to disturbances, which provides new insights for predicting the responses of macrophyte-dominated lake ecosystems to the current increasing frequency of algal blooms.
How to cite: Su, H.: Linking macrophyte species diversity and community stoichiometric homeostasis with multidimensional stability under algal bloom disturbances, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20958, https://doi.org/10.5194/egusphere-egu25-20958, 2025.
Posters virtual: Wed, 30 Apr, 14:00–15:45 | vPoster spot A
EGU25-17774 | ECS | Posters virtual | VPS4
Trouble follows the needy: more severe leaf herbivory in the resource-poorer temperate oak forest than in the birch forestWed, 30 Apr, 14:00–15:45 (CEST) | vPA.7
Plant-insect herbivore interactions are essential in shaping forest ecosystem health. The resource availability hypothesis (RAH) and the leaf economics spectrum (LES) theory predict that species in high-resource environments tend to adopt a "fast" strategy but are more susceptible to herbivory. However, this contradicts reports of increased insect herbivory in the context of global drought intensification, and hinders accurate prediction about how different plant species respond to herbivorous insect feeding.
To fill this knowledge gap, we conducted an observational study in two temperate forests dominated by Quercus mongolica and Betula platyphylla in eastern China to compare their leaf herbivory patterns and explore possible mechanisms. We measured three leaf herbivory proxies (consumed leaf area, percent consumed, and herbivory frequency), some leaf traits (leaf area, specific leaf area, leaf water content, leaf nitrogen, phosphorus and non-structural carbohydrate contents), and soil properties (pH, soil water content, soil organic carbon content, soil nitrogen and phosphorus contents).
We found that Q. mongolica, growing in poorer soil environments with lower water and nutrient contents, experienced higher leaf herbivory than B. platyphylla. Regarding leaf traits, Q. mongolica had a higher leaf area and non-structural carbohydrate content, but lower specific leaf area, leaf nutrient and water contents than B. platyphylla. At the leaf level, leaf area, rather than specific leaf area, of both tree species was positively correlated with leaf herbivory. At the tree level, species-specific patterns emerged, i.e., leaf herbivory of B. platyphylla was positively related to leaf area and negatively related to leaf nitrogen and water contents and soil phosphorus content, whereas that of Q. mongolica was only positively affected by soil phosphorus content.
These findings challenge the predictions of RAH and LES theory, as Q. mongolica that grows in resource-poorer soil environments with a conservative strategy suffers higher leaf herbivory than B. platyphylla, shedding some light on the proverb that trouble follows the needy. Moreover, water-related factors (i.e., leaf and soil water contents) and leaf area showed an important effect on driving interspecific and intraspecific leaf herbivory variations here, implying that climate-induced droughts may exacerbate herbivore pressure in temperate forests.
How to cite: Zhao, C. and Tian, D.: Trouble follows the needy: more severe leaf herbivory in the resource-poorer temperate oak forest than in the birch forest, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17774, https://doi.org/10.5194/egusphere-egu25-17774, 2025.
EGU25-13963 | ECS | Posters virtual | VPS4
Ecological interactions in dioecious plants: implications for soil fungi and arthropodsWed, 30 Apr, 14:00–15:45 (CEST) | vPA.8
Many dioecious plants are dominant foundational species (e.g., grasses, poplars, ginkgoes) that structure ecosystems and provide essential resources for diverse ecological communities. Due to their higher nutrient demands and reproductive costs, female plants generally appear more sensitive to environmental changes, such as increased temperatures and drought conditions. The soil ecosystem is critical for providing the substrate, nutrients, and habitat for terrestrial plant communities to exist. Male and female plants are likely to interact with the soil environment differently, with implications for ecosystem functioning. Recent research has shown that female and male plants differ in their soil microbial diversity and community composition. However, how plant sex affects soil communities is still unknown. This study investigated how female and male plants of Ilex vomitoria differ in fungal diversity and composition and subsequent cascading effects on soil arthropods. Fungal operational taxonomic units (OTUs) were identified from DNA sequencing data, and arthropods were extracted and identified from 91 soil samples collected under the canopies of female and male Ilex vomitoria individuals across three locations in southeastern Texas, USA. We found that male plants of I. vomitoria exhibit higher fungal diversity compared to female plants, with both sexes associating with distinct fungal communities. Conversely, soil arthropod diversity and community composition were affected by location but not plant sex. Our results provide valuable insights into the ecological interactions of dioecious plants, emphasizing the role of plant sex as a key trait that influences soil biodiversity and the associated functioning of ecosystems.
How to cite: Bradley Jimenez, R.: Ecological interactions in dioecious plants: implications for soil fungi and arthropods, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13963, https://doi.org/10.5194/egusphere-egu25-13963, 2025.
EGU25-6451 | Posters virtual | VPS4
Plant Trait-Based Modeling of Forest SuccessionWed, 30 Apr, 14:00–15:45 (CEST) | vPA.9
Gap dynamics is one of the key drivers of forest succession in temperate forests. The primary successional trajectory involves the transition from early to late successional species, each with distinct trait characteristics. I will present a modeling approach to forest successional dynamics based on scaling plant traits from individual to community levels. In this work, the shade tolerance index is statistically linked with plant traits that characterize early and late successional species using the U.S. Forest Inventory dataset. Discrete and continuous mathematical models, represented by Markov chains and autoregressive models, are employed to predict forest dynamics. An individual-based model is also used to assess the robustness of this scaling approach under different disturbance regimes. Overall, modeling forest successional dynamics based on the scaling of shade tolerance-related functional traits from the individual to the ecosystem level addresses major limitations of models based on the traditional stand age metric.
How to cite: Strigul, N.: Plant Trait-Based Modeling of Forest Succession, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6451, https://doi.org/10.5194/egusphere-egu25-6451, 2025.
EGU25-14964 | ECS | Posters virtual | VPS4
Getting Out from Under: The Belowground Response of a Restored Grassland to Soil Disturbance and Resource AdditionWed, 30 Apr, 14:00–15:45 (CEST) | vPA.10
Disturbances resulting from anthropogenic global change pose ongoing threats to plant biodiversity. Functional trait-based approaches enable ecologists to observe species-level stress responses with implications for community-level adaptations to disturbances. DRAGNet (Disturbance and Resources Across Global Grasslands) leverages grassland restoration to explore the mechanisms driving disturbance recovery and community assembly. In this single-site study, we examine how plant composition and traits vary across disturbance (tillage) and soil resource (NPK+) gradients. Plant composition will be surveyed in 28 plots, with root and soil samples extracted for trait analysis and soil nutrient testing. We predict that plants in disturbed, nutrient-enriched plots will exhibit divergent functional traits, including reduced root biomass and specific root length, alongside changes in above-ground traits. Preliminary data illustrates the impact disturbance can have on community composition, particularly by promoting invasive species (PERMANOVA, p = 0.0576). This finding underscores the influence of disturbance on plant community assembly and highlights the potential vulnerability of restored grasslands to invasive species proliferation under human-induced disturbances. This study aims to uncover the root functional traits driving the recovery of a restored grassland across both soil disturbance and resource gradients.
How to cite: Campbell, A., Sullivan, L., Celestin, M., and McCary, M.: Getting Out from Under: The Belowground Response of a Restored Grassland to Soil Disturbance and Resource Addition, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14964, https://doi.org/10.5194/egusphere-egu25-14964, 2025.
EGU25-14991 | ECS | Posters virtual | VPS4
Plant litter trait variation between native and nonnative species across steep climate gradient in Hawaiian IslandsWed, 30 Apr, 14:00–15:45 (CEST) | vPA.11