Specific Leaf Area Research Articles

Introduction Leaf functional traits are pivotal indicators of plant ecological strategies, reflecting adaptations to environmental conditions. However, the patterns of intraspecific trait variation along environmental gradients and their underlying drivers remain inadequately explored, particularly in fragile ecosystems like karst landscapes. Methods We investigated 12 leaf functional traits (encompassing morphological and chemical characteristics) of Pinus armandii along an elevational transect (2128 to 2509 m) in the Karst mountainous region of southwestern China. Using correlation and redundancy analyses, we examined altitudinal trends in trait variation and their relationships with key soil factors. Results Our results revealed substantial intraspecific variability in all leaf traits, with coefficients of variation ranging from 3.24% to 28.15%. Specific leaf area, leaf length, thickness, area, carbon content, potassium content, and the ratios of C:N, C:P, and N:P decreased significantly with increasing elevation. Conversely, leaf dry matter content, nitrogen content, and phosphorus content increased significantly. We found notable coordination and trade-offs among traits, forming an integrated network centered on the C:N ratio. Soil factors—specifically soil organic carbon, pH, and available potassium—were identified as the primary drivers of this trait variation. Discussion P. armandii in karst mountainous regions adapts to elevational changes through coordinated adjustments in leaf functional traits, thereby optimizing resource acquisition and use strategies. These findings advance our understanding of plant adaptation mechanisms in such fragile environments.

Tree species mixing has been widely recognized as an effective silvicultural strategy for enhancing both stand productivity and biodiversity. Nevertheless, its effects on branch radial growth and the underlying physiological mechanisms remain inadequately understood. In this study, we measured branch ring widths and 22 functional traits of pure and mixed plantations of Pinus massoniana and Castanopsis hystrix to investigate the effects of species mixing on branch radial growth, to assess potential variations between even- and uneven-aged forest mixtures, and to elucidate the underlying physiological mechanisms. Our results demonstrated that tree species mixing generally promoted branch radial growth, as indicated by the basal area increment for both studied species. The effect of species mixing on branch radial growth was not significantly different between even- and uneven-aged mixtures for C. hystrix; however, it diminished with increasing age of P. massoniana. Our findings indicated that the radial branch growth of P. massoniana was related to larger tracheid radial diameter and higher hydraulic conductance. In contrast, increased branch radial growth of C. hystrix was more related to higher specific leaf area and thinner leaves in mixed plantations, which potentially improved the light capture efficiency and leaf carbon turnover rate. Our results also indicated that tree species mixture is an effective strategy for enhancing branch growth. The positive mixing effect could diminish as P. massoniana reaches an over-mature age in the mixed-species stand, implying that species mixing practices during the early stages of stand development provide more benefit. The findings provide valuable insights for formulating reasonable forest management strategies and improving the understanding of the eco-physiology of species mixing effects on tree growth.

Tree species differ in their ability to use light efficiently, affecting carbon gain, establishment and survival in highly heterogeneous environments. This efficiency relies on the maintenance of the photosynthetic induction state, regulated by structural, biochemical, photochemical and stomatal processes that vary along the leaf economics spectrum (LES). Slow return species, such as shade-tolerant species (often late successional), are thought to sustain higher photosynthetic induction state, while quick return species, like light-demanding species (often early successionals) would have lower shade acclimation and shade-tolerant species lower acclimation to high light. Yet, results often deviate from these predictions. Moreover, most LES traits reflect steady state performance, not dynamic responses. Here, we investigated photosynthetic induction responses in four widely distributed Brazilian tree species representing contrasting successional groups and LES positions, grown under 10% light, 50% light and Full sun. We quantified induction dynamics in terms of CO2 assimilation, stomatal conductance, electron transport rate, as well as chlorophyll content, and leaf mass per area (LMA). Acclimation to distinct light environments was assessed using a shade adjustment coefficient and a novel metric based on Principal Component Analysis (PCA), Relative Plasticity (RP). RP suggests an asymmetrical bell-shaped relationship with LES position: the slow return Hymenaea courbaril showed low plasticity and little change in resource allocation (LMA), photosynthetic rates or induction times; the fast-return Schinus terebinthifolia, displayed moderate plasticity but unexpectedly high shade acclimation showing high induction state and CO2 assimilation rates; and the intermediate strategists Cecropia pachystachya and Handroanthus impetiginosus exhibited the highest plasticity, with coordinated increases in LMA, CO2 assimilation, conductance and photosynthetic induction under increasing light conditions. These findings highlight the importance of integrating photosynthetic dynamics into ecophysiological frameworks for species selection in reforestation, particularly in heterogeneous light environments, where adaptive flexibility can play a critical role on the resilience of an ecosystem.

Abstract Low light is a characteristic of coffee agroforestry systems, yet the optimal shade level for establishing such systems remains unclear. Furthermore, the effects of reduced light on the growth and physiology of juvenile Coffea arabica F1 hybrids have not been fully explored. This study examined gene-by-environment interactions among coffee hybrids and their parental lines across a controlled shade gradient in a greenhouse. The tested C. arabica included landrace accessions ( i.e. ‘ET531’, ‘MS’, ‘T4905’, and ‘Rume Sudan’), pure lines ( i.e. ‘Caturra’,‘T5296’, ‘Marsellesa’ and ‘IAPAR59’), and F1 hybrids ( i.e. ‘H1’, ‘H3’, ‘Mariana’, and ‘Starmaya’). Plants were grown under five shade treatments intercepting 0, 35, 58, 73, and 88% of ambient light (ranging from ~10 to 800 μmol m −2 s −1 ) to simulate agroforestry light environments. Shade significantly influenced all measured traits, including photosynthetic parameters, chlorophyll a fluorescence, aboveground biomass, specific leaf area, total leaf area, growth rate and leaf count. Notably, the line varieties ‘Caturra’ and ‘Marsellesa’ and hybrid ‘Starmaya’ demonstrated comparatively enhanced vegetative performance when grown under shade ( i . e , shade level of 35 – 88%), particularly in leaf count ( ca. 75 % more), plant height ( ca. 75 % taller), and stem dry mass (50 % greater). Wild Ethiopian accessions ‘ET531’ and ‘Rume Sudan’ exhibited distinctive plant height responses, reflecting their unique genetic adaptation patterns to shade, with plant height and apical dominance increasing, as a photomorphogenetic response to avoid the shade. These findings offer preliminary insights to inform the selection of C. arabica genotypes suitable for coffee agroforestry systems based on juvenile plants.

Rice ranks among the most significant staple crops worldwide. Precise and dynamic monitoring of specific leaf area (SLA) provides essential information for evaluating rice growth and yield. While previous remote sensing studies on SLA estimation have primarily focused on crops such as wheat and soybeans, studies on rice SLA remain limited. This study aims to evaluate the predictive potential of several machine learning algorithms for estimating rice SLA across different growth stages, planting densities, and nitrogen treatments at the pre-flowering stage. By utilizing UAV-based multispectral remote sensing data, a high-precision rice SLA monitoring model was developed. The feasibility of using vegetation indices (VIs), texture indices (TIs), and their combinations to predict rice SLA was explored. VIs and TIs were derived from UAV imagery, and the recursive feature elimination was conducted on these indices individually as well as their combined fusion (VIs + TIs). Four machine learning algorithms were employed to predict SLA values. The results indicate that random forest-based models utilizing VIs, TIs, and their fusion can all predict rice SLA effectively with high accuracy. Among these models, the RF model utilizing the combined variables (VIs + TIs) exhibited the highest performance, with R2 = 0.9049, RMSE = 0.0694 m2/g, RRMSE = 0.1042, and RPD = 3.2419. This study demonstrates that individual VIs can provide effective spectral information for SLA estimation, especially during the crucial pre-flowering growth phase of rice. The fusion of VIs and TIs enhances the model’s adaptability to complex field conditions by integrating both canopy biochemical and structural characteristics, thus improving model stability. This technology offers a swift and efficient approach for monitoring crop growth in the field, offering a theoretical foundation for subsequent crop yield estimation.

Integrating leaf morphological traits can improve the predictive capacity of flux-based ozone metrics for ecophysiological responses in ornamental plant species.

Intensity and duration of urbanisation drive adaptive divergence of functional traits and ecological strategies in Youngia japonica.

Fruit sunburn is a major abiotic stress limiting apple production worldwide, with losses potentially reaching 50% due to climate change-driven heat events. This study aimed to evaluate sustainable strategies to mitigate or reduce sunburn on ‘Gala Galaxy Selecta’ apple trees. Field trials conducted in summer 2021 compared eight treatments: silicon-based application (Eckosil®), foliar fertilization with algae extracts, macro- and micronutrients, and amino acids, increased irrigation (+35% ETc), mineral particle films (Surround®, Vegepron Sun®, Agrowhite®, Sunstop®), and an untreated control. Randomized block designs with replicates were used. Agronomic parameters, including particle film coverage, trunk cross-sectional area, yield, and fruit quality (color, sunburn incidence, firmness, soluble solids content, dry matter, starch), were measured at harvest. Physiological responses, such as net photosynthesis, maximum quantum yield of Photosystem II, specific leaf area, fruit surface temperature, photoprotective pigments, antioxidants, and heat shock protein gene expression, were also assessed. Foliar fertilization, Agrowhite®, and water reinforcement produced the highest yield per trunk cross-sectional area, with increased soluble solids content and enhanced red pigmentation. Surround® minimized sunburn incidence but reduced photosynthetic activity, as did Vegepron Sun®. Agrowhite® balanced sunburn protection with maintenance of fruit quality and physiological function. These findings provide practical guidance for growers to select effective treatments, balancing sunburn mitigation, fruit quality, and tree physiological performance, while offering researchers insights into integrating agronomic and physiological strategies for climate-resilient apple production.

Excessive light intensity, often resulting from anthropogenic disturbances, poses a threat to light-sensitive Liquidambar formosana seedlings. This study examined the effects of five light intensity levels and three silicon (Si) application rates on photosynthetic performance, oxidative stress responses, and seedling growth. Results indicated that full sunlight significantly reduced ground diameter, chlorophyll content, specific leaf area, and stomatal conductance. Meanwhile, it increased the activities of superoxide dismutase and peroxidase, and led to higher accumulation of malondialdehyde (MDA). Application of Si enhanced seedling height, biomass accumulation, and antioxidant enzyme activity under high-light conditions, while reducing MDA content, stomatal CO2 conductance, and transpiration rate, and maintaining a stable net photosynthetic rate. However, excessive Si (3000 mg·kg−1) led to decreased catalase activity, chlorophyll content, and leaf area under intense light. These findings suggest that L. formosana seedlings perform best under moderate shade (11,000–46,000 lx) and moderate Si application (1000–2000 mg·kg−1), which together mitigate photoinhibition damage. Optimal physiological responses thus require balanced Si concentrations. Further investigation is warranted to elucidate the mechanisms underlying the interactive effects of shading and Si application for improved seedling resilience.

Global forests are currently facing significant anthropogenic disturbances. Previous research on plant functional traits has predominantly focused on relatively intact forests, often overlooking those that have experienced such disturbances. This oversight has lead to a scarcity of relevant data regarding disturbed forests in the global and Chinese plant functional trait databases, thereby limiting our understanding of the life history strategies employed by plants inhabiting these altered environments. This study presents data on 12 morphological traits and 24 ecological stoichiometry traits for 62 common species in disturbed forests and 43 species in conserved forests in East China. We analyzed the variability characteristics of these functional traits, explored functional trait differences between disturbed and conserved forests, and examined relationships among various functional traits to investigate disparities in life history strategies between the two forest types. The results indicated that the variability of plant functional traits was generally lower in disturbed forests compared to conserved ones. Most functional traits exhibited significant differences between the two forest types (P < 0.05). Additionally, stronger correlations among functional traits were noted in disturbed forests. From a functional trait perspective, plants in disturbed forests displayed high trait correlations and formed trait combinations indicative of a resource conservative strategy characterized by low specific leaf area, high dry matter content and tissue density across leaves, twigs, barks and stems; alongside heightened carbon investment but reduced al locations for nitrogen and phosphorus. A comprehensive investigation of plant functional traits in both disturbed and conserved forests will enrich the global and Chinese trait databases, providing insights into how forest plants adapt to disturbances and informing ecological restoration in degraded areas.

Common bean (Phaseolus vulgaris L.) is a legume crop cultivated and consumed extensively around the world due to its superfood composition and its social-economic impact on farmers. Thus, an experiment with a synthetic cytokinin 6-benzylaminopurine (6-BAP) was conducted in order to assess its effect on the morphological root and shoot traits of the Bayo variety. For that, a Random Complete Block Design (RCBD) was used with 6 treatments (T1: 10 ppm BAP + Drench; T2: 10 ppm BAP + Foliar; T3: 20 ppm BAP + Drench; T4: 20 ppm BAP + Foliar; T5: 30 ppm BAP + Drench; T6: 30 ppm BAP + Foliar and T7: control) and four repetitions. The parameters evaluated were plant height, stem diameter, leaf area, specific leaf area, root length, specific root length, specific root area, root tissue density, dry, and fresh weight matter of root and foliage, and the whole plant. Therefore, no significant differences were found for most parameters, indicating that root and shoot development was not impaired by 6-BAP application, whether applied foliarly or by drenching. The only exception was a reduction in root dry weight at 30 ppm under soil drenching. Nevertheless, root soil exploration and overall plant growth remained unaffected under the tested conditions.

Studying the response of plant leaf functional traits to elevation helps us understand plant adaptation to the environment and their distribution trends under global climate change. Currently, how plant leaf functional traits respond to elevation across different scales or among different species remains controversial. Quercus rehderiana Hand.-Mazz. is widely distributed across various altitude ranges in southwestern China, making it an ideal species to address this question. Therefore, this study established three 20 × 20 m quadrats at each of five altitude gradients (2000, 2200, 2400, 2600, and 2800 m). By measuring morphological and nutrient indicators in leaves from five individuals of Quercus rehderiana in each quadrat, we analyzed the response of leaf functional traits to elevation. The results showed that leaf thickness (LT), specific leaf area (SLA), phosphorus (P), potassium (K) concentrations, carbon phosphorus ratio (C:P ratio), and nitrogen phosphorus ratio (N:P ratio) of Quercus rehderiana varied significantly across different elevations. Regression analysis revealed that leaf area (LA), K concentration, and carbon nitrogen ratio (C:N ratio) decreased with increasing elevation, while LT and nitrogen (N) concentration increased. Correlation analysis indicated that LA was significantly negatively correlated with LT and leaf P concentration, but positively correlated with carbon (C) concentration and stoichiometric ratios (C:N, C:P, N:P). Leaf thickness (LT) was significantly negatively correlated with K and calcium (Ca) concentration. Specific leaf area (SLA) and K concentration were significantly negatively correlated with leaf dry matter content (LDMC). The leaves of Quercus rehderiana mainly adapt to different elevations through trade-offs among different morphological and chemical traits. These findings can support the conservation of germplasm resources and forest management.

Introduction White pine blister rust (WPBR) disease, caused by an invasive fungal pathogen ( Cronartium ribicola J.C. Fisch), has long been the primary biotic threat to eastern white pine in Canada. A hybridization program initiated in Ontario, Canada in the 1950s aimed to transfer blister rust resistance from Himalayan blue pine to eastern white pine, resulting in WPBR-resistant interspecific hybrids. Metabolic adjustments related to disease resistance may cause trade-offs with tolerance to abiotic stress (e.g., frost, heat, drought). To evaluate the adaptive potential of WPBR-resistant hybrids, it is crucial to understand how morphological and physiological traits change during multi-generation backcrossing, as these shifts may influence both growth performance and resilience to climate change. Methods We assessed changes in photosynthetic-related traits, as well as needle morphology and resistance to xylem cavitation of eastern white pine and Himalayan blue pine, and their hybrids with varying levels of white pine parentage ranging from 50 to 87.5%. Results and discussion Needle length and specific leaf area ( SLA ) decreased linearly by increasing eastern white pine parentage; inversely, needle density increased by increasing eastern white pine parentage. Variations in needle morphology were not translated into variations in light-saturated photosynthesis (Amax), mesophyll conductance (g m ), maximum rate of carboxylation (V cmax ), and maximum rate of electron transport (J max ). Photosynthetic nitrogen use efficiency ( PNUE ) decreased, while water use efficiency ( WUE i ) increased with increasing eastern white pine parentage. Increasing needle density and declining PNUE reflect greater investment in structural tissue, which is commonly associated with frost and drought tolerance. Also, Himalayan blue pine and hybrids were more resistant to xylem cavitation than eastern white pine. Hybrid pines recovered most of their eastern white pine morpho-physiological characteristics after two rounds of backcrossing. Consequently, WPBR-resistant interspecific hybrids should have integrated stress tolerance traits of eastern white pine enabling them to adapt to abiotic and biotic stresses in Canadian boreal forests.

Sexual dimorphism in dioecious species can shape divergent hydraulic strategies in response to environmental stress, yet integrative studies linking anatomical and physiological traits across different plant organs remain scarce. We investigated sex-specific water-use strategies in two Mediterranean shrubs, Pistacia lentiscus L. and Rhamnus alaternus L., by analyzing leaf and wood anatomy, leaf functional traits, gas exchange, and chlorophyll fluorescence. Male plants of both species exhibited conservative morpho-anatomical traits, including smaller, thicker leaves, lower specific leaf area (SLA), higher dry matter content, and reduced intercellular spaces, traits typically associated with drought resistance strategies. In P. lentiscus, these traits correlated with higher photosynthetic rates and Fv/Fm values, alongside greater stomatal density and vessel frequency, suggesting coordinated investment in carbon gain and hydraulic efficiency/safety. Conversely, females displayed acquisitive traits (higher SLA, wider intercellular spaces, lower vessel frequency), potentially enhancing photosynthesis under mesic conditions but increasing vulnerability to drought-induced embolism. In R. alaternus, female individuals maintained higher net photosynthesis and iWUE, while males exhibited greater Fv/Fm and a decoupled leaf-wood coordination. These findings suggest that males may adopt safer hydraulic architectures, while females, potentially constrained by reproductive demands, pursue efficiency-driven strategies, still maintaining vessel redundancy in wood. As aridity intensifies in Mediterranean regions, such dimorphism may influence population dynamics, sex ratios, and species resilience. Our results underscore the ecological significance of species-specific sex-based hydraulic variation and the necessity of incorporating sex into trait-based models of plant responses to climate change.

Trait-based research considerably increased our comprehension of various fields related to ecology and evolution. As measuring traits can be time-consuming and costly, analyses regularly use trait data from databases instead of carrying out new measurements. However, intraspecific trait variability can cause substantial differences between trait values of different populations and regions. Here we evaluated whether intraspecific trait variability causes considerable differences in trait values measured in two regions of Europe. We tested whether regionally measured trait values from the Pannonian Ecoregion differ from trait values for the same species originating from northwestern Europe by comparing data from the Pannonian Database of Plant Traits (PADAPT) and the LEDA Traitbase. We evaluated six traits: thousand-seed mass (TSM), seed bank persistence index (SBPI), leaf area (LA), leaf dry matter content (LDMC), specific leaf area (SLA), and leaf dry mass. We found that trait data from the two databases significantly differed for TSM, SBPI, SLA, and LDMC. We can assume that the markedly different climates of the two regions can be the reason behind the observed intraspecific trait differences; therefore, the geographical origin of trait data matters in trait-based analyses. The findings support the assumption that regionally measured trait data are essential for reliable regional-scale trait-based studies, and compiling these data into regional databases is the most efficient way to facilitate their use. We conclude that for studies analysing traits in the Pannonian Ecoregion (and possibly in eastern and central Europe in general), it is advisable to use PADAPT instead of databases compiling data from regions with markedly different climatic conditions.

Abstract Phosphorus (P) is vital for plant responses to climate change, influencing primary productivity. However, the seasonal variations of foliar phosphorus fractions (FPFs) in deep-rooted desert species are not well understood, especially in hyper-arid ecosystems with P-impoverished soils. Therefore, we investigated seasonal dynamics of Alhagi sparsifolia seedlings under four P-supply gradients (0, 1, 3, and 5 g P m-2 y-1) in a two-year open-air pot experiment. We quantified concentrations and proportions of key functional phosphorus forms (FPFs)—metabolic P, structural P, nucleic acid P, and residual P—alongside leaf traits and soil properties across spring, summer, and autumn. Findings showed notable seasonal variations: soil available P concentration decreased by 48.8% in summer compared to spring and autumn, while leaf total P concentration increased by 1.9%. Autumn exhibited higher specific leaf area, leaf P content per unit area, and mass compared to spring and summer. Additionally, metabolic, structural, and residual P concentrations rose significantly with increasing soil P supply, while nucleic acid P decreased. FPF allocation varied seasonally, with summer showing increases in metabolic P (1.6% concentration, 1.9% allocation), nucleic acid P (5.0%, 4.2%), and structural P (4.0%, 2.9%) compared to spring. Similar comparisons with autumn revealed greater summer increases of 3.3% (0.4%), 7.7% (2.7%), and 5.5% (2.5%) respectively. FPF dynamics correlated more strongly with leaf traits than soil properties in spring and summer, but autumn weakened these associations. This study highlights the seasonal allocation patterns and their role in the adaptation of desert plants to poor-P conditions.

Deficit soil moisture is one of the most critical limiting factors affecting crop growth and overall productivity. Because of its low membrane integrity, high stomatal conductance and increased transpiring leaf surface, the essential solanaceous crop chilli is highly vulnerable to drought. One crucial stress management technique for combating water stress is seed priming. Chilli seeds were subjected to different priming agents 2.5 % potassium nitrate (KNO3), 3 % silicon dioxide (SiO2) and unprimed seeds with distilled water for 24 hours. Prior to the flowering stage, the crop was subjected to moisture stress by withholding irrigation in both greenhouse and field conditions. Results of both experiments revealed that seed priming with 2.5 % KNO3, resulted in enhanced physiological traits like relative water content, specific leaf area, total chlorophyll and biochemical traits like malonaldehyde, H2O2, trehalose, α-amylase activity, superoxide dismutase, total soluble sugars and total soluble protein, followed by quality traits like capsaicin, vitamin C and yield traits viz., plant height, number of flowers plant-1, number of fruits plant-1 and fruit yield plant-1, whereas 3 % SiO2 primed seeds recorded significantly higher values for total proline content and cell membrane stability index compared to unprimed seeds. Seeds primed with 3 % SiO2 recorded early flowering, whereas seeds primed with 2.5 % KNO3 recorded the first fruiting stage. The results showed that seeds with 3% SiO2 can be recommended for seed formation in cases of water shortage and seeds primed with 2.5 % KNO3 demonstrated high antioxidant levels and the maximum capacity to absorb water.

Phosphorus (P) allocation as dependent on a plant's age is a critical yet understudied factor in the adaptive strategies of shade-tolerant plants. We investigated how Coptis chinensis, a perennial medicinal plant species, allocates leaf P fractions and exhibits leaf structural modifications in response to the understory light environment. By analyzing leaf P fractions, chlorophyll concentrations, photosynthetic parameters, and leaf anatomical traits in juvenile (two- and three-year-old) and adult (five-year-old) plant, we uncovered age-dependent shifts in leaf P fractions that balanced photoprotection and growth. Leaves of juvenile plant allocated a greater proportions of P to nucleic acid P (PN), exhibited higher photoprotective pigment-to-chlorophyll ratios, and maintained greater specific leaf area (SLA) with thinner tissue structures. The proportion of PN was positively correlated with photoprotective pigment-to-chlorophyll ratios, indicating that enhanced PN allocation contributes to light-stress resilience and early-stage growth. In contrast, as plants progressed to the adult stage, leaves showed a marked shift toward higher allocation to metabolite P (PM), which correlated with higher photosynthetic rates, higher chlorophyll concentrations, and increased Rubisco enzyme activity. Concurrent structural modifications, including thicker palisade mesophyll and reduced SLA, further supported enhanced photosynthetic performance. This developmental transition from PN-dominant to PM-dominant allocation thus reflects a physiological acclimation that sustains photosynthesis and improves photosynthetic P-use efficiency under shaded conditions. Our findings highlight a dynamic interplay between P allocation and structural acclimations in C. chinensis leaves, revealing an adaptive strategy that balances photoprotection and growth across different ages. By demonstrating how resource allocation shifts with age in a shade-adapted perennial, this study offers novel insights into the evolutionary strategies that underpin long-term survival and productivity in understory environments.

Abstract. Temperate semi-natural grassland plant communities are expected to shift under global change, mainly due to land use and climate change. However, the interaction of different drivers on diversity and the influence of diversity on the provision of ecosystem services are not fully understood. To synthesize the knowledge of grassland dynamics and to be able to predict community shifts under different land-use and climate change scenarios, we developed the GrasslandTraitSim.jl model. In contrast to previously published grassland models, we link morphological plant traits to species-specific processes via transfer functions, thus avoiding a large number of species-specific parameters that are difficult to measure and calibrate. This allows any number of species to be simulated based on a list of commonly measured traits: specific leaf area, maximum height, leaf nitrogen per leaf mass, leaf biomass per plant biomass, above-ground biomass per plant biomass, root surface area per below-ground biomass, and arbuscular mycorrhizal colonization rate. For each species, the dynamics of the above- and below-ground biomass and its height are simulated with a daily time step. While the soil water content is simulated dynamically, the nutrient dynamics are kept simple, assuming that the nutrient availability depends on total soil nitrogen, yearly fertilization with nitrogen and the total plant biomass. We present a model description – which is complemented by online documentation with tutorials, flow charts, and interactive graphics – and calibrate and validate the model with two different datasets. We show that the model replicates the seasonal dynamics of productivity for experimental sites of the grass species Lolium perenne across Europe satisfactorily well. Furthermore, we demonstrate that the model can be used to simulate the productivity and functional composition of grassland sites with different numbers of mowing events and grazing intensity in three regions in Germany. Therefore, the GrasslandTraitSim.jl model is presented as a useful tool for predicting the plant biomass production and plant functional composition of temperate grasslands in response to management under climate change.

Urban expansion alters environmental conditions, influencing tree physiology and performance. Urban trees provide cooling, sequester carbon, support biodiversity, filter contaminants, and enhance human health. This study examines how two common urban trees—Norway Maple (Acer platanoides L.) and Little-leaved Linden (Tilia cordata Mill.)—respond to urban site conditions by assessing leaf morphology, stomatal, and gas exchange traits across street and urban park sites in Chicago, IL. Street trees exhibited structural trait adjustments, including smaller leaf area, reduced specific leaf area, and increased stomatal density, potentially reflecting acclimation to more compact and impervious conditions. Norway Maple showed stable photosynthetic assimilation (A), stomatal conductance (gs), and transpiration (E) across sites, alongside higher intrinsic water-use efficiency (iWUE), indicating a conservative water-use strategy. In contrast, Little-leaved Linden maintained A and gs but showed elevated E and iWUE at street sites, suggesting adaptive shifts in water-use dynamics under street microenvironments. These findings highlight how species-specific physiological strategies and local site conditions interact to shape tree function in cities and underscore the importance of incorporating functional traits into urban forestry planning to improve ecosystem services and climate resilience.