Invasive species pose a significant threat to biodiversity, particularly in freshwater ecosystems. While temperate climates often act as filters, thermally stable environments such as thermal springs can serve as refugia for tropical non-native species by providing conditions similar to their native habitats. The large natural thermal lake of Lake Hévíz in Hungary and its outflow have facilitated the establishment of several allochthonous species from tropical and subtropical regions. This study investigated whether physiological or morphological differentiation exists between Vallisneria australis populations at upper (warmer) and lower (cooler) sites that were 7 km apart. Results showed that temperature difference between the upper and lower parts of the outflow of 4.6 °C significantly affected the photophysiology of V. australis. Lower photophysiological parameters related to primary production (ETRmax and Ik) were recorded at the upper site compared to the lower site. Significant differences between sites were found for most photochemical parameters, while seasonal variations were observed. Correlation patterns between water temperature and photophysiological parameters also differed between the two sites, suggesting different response strategies, while the complementary laboratory transplant experiments at controlled temperatures (19 °C and 24 °C) mirrored the field differences in photochemical parameters, supporting the hypothesis of physiological differentiation. These results suggest that the variations are not just short-term plastic responses, but reflect a more established physiological divergence. The thermal gradient is likely to exert selective pressure, possibly leading to local acclimation or even adaptation, although genetic evidence for this differentiation is not presented. The potential escape into nearby Lake Balaton poses a significant ecological risk. The results support the application of the precautionary principle in managing the spread of V. australis.

Study region: The Pannonian Basin, Hungary. Study focus: Macrophytes are essential components of freshwater ecosystems, influencing aquatic bacterial communities. This study investigated the impact of macrophytes on bacterioplankton abundance, metabolic activity and diversity across 12 shallow lakes in the Pannonian Basin. We assessed the interplay between macrophyte coverage and physicochemical parameters in structuring microbial communities using 16S rRNA gene metabarcoding and the most probable number (MPN) method. New hydrological insights for the region: While macrophyte presence appeared to influence the distribution of certain bacterial groups, most operational taxonomic units (OTUs) exhibited sitespecific patterns. Notably, Rhodocyclaceae and the genus Limnohabitans were more abundant in macrophyte- and reed-covered areas. 'Candidatus Patescibacteria' and Epsilonbacteraeota were found almost exclusively in certain samples, reaching 41.6% and 32.3% relative abundance, respectively. In contrast, freshwater SAR11 bacteria, particularly the LD12 clade, were present in nearly all sampled waters, with the highest observed relative abundance of 14.2% of total sequences. MPN values of heterotrophic bacteria (103-106 MPN mL-1) were highest in open water and submerged macrophyte samples; however, the abundance of other bacterial functional groups was linked with environmental factors such as dissolved oxygen levels. These findings suggest that beyond macrophyte coverage, other environmental parameters, such as hydrological conditions and surrounding land use, may exert a more deterministic effect on bacterioplankton in shallow lakes, even within a relatively small geographical area.

The littoral zones of shallow lakes are critical transitional habitats and emergent macrophytes, such as common reed (Phragmites australis), frequently dominate these margins. The potential effects of urbanisation on the common reed in the littoral zone of Lake Balaton were investigated. Elevated artificial night light levels were detected along the shoreline, reflecting extensive human activity, with littoral zones exhibiting significantly higher illumination than pelagic areas. No statistically significant correlations were observed between artificial night light and most vegetative parameters, while reproductive biomass and the proportion of flowering individuals were found to be significantly negatively correlated with it. Furthermore, a statistically significant positive correlation was identified between artificial night light and the timing of the start of the season, indicating a delayed initiation of seasonal growth in more urbanised sites. The findings reveal that urbanisation does not uniformly impair plant performance but acts as a complex environmental filter, shaping specific functional traits. Generative traits and the onset of seasonal growth appear more sensitive to urban pressures compared to vegetative growth, also emphasising the importance of integrating indicators for a more holistic assessment of urban impacts on aquatic vegetation.

The regulation of water levels in recreational lakes restrains the natural hydrological variability to which littoral organisms have adapted. This study examined the morphological and photophysiological responses of Phragmites australis to water levels and fluctuations in Lake Balaton, Hungary. Morphological measurements were conducted annually between 2000 and 2024, while chlorophyll fluorescence parameters were recorded at two sites from 2012 onwards. The annual average water level was negatively correlated with aboveground biomass (rho =-0.706), whereas annual water level fluctuation was positively associated with biomass (rho = 0.742). Autocorrelation analysis revealed substantial temporal dependence in the morphological series, which reduced the significance of the correlations. However, the correlations in the photophysiological data remained statistically robust after correction: the annual average water level was negatively correlated with the photosynthetic capacity proxy, the maximum electron transport rate (ETRmax; rho =-0.743), while the annual water level fluctuation was positively associated (rho = 0.795) with ETRmax. The study years were classified into four hydrological categories based on long-term averages. Thirteen of the 25 years fell within the HS category, reflecting the sustained hydrological oversaturation imposed by water management that had significant affect on plant morphology and physiology. The exploratory composite Phragmites Vigour Score (PVS), integrating morphological and photophysiological plant responses, showed strong Spearman correlations with both annual mean water level (rho =-0.752) and annual water level fluctuation (rho = 0.852), with water level variability emerging as the stronger and more relevant predictor within this system. These results suggest that prolonged periods of high water levels and low variability are associated with the suppression of the the structural development and photosynthetic capacity of Phragmites plants, whereas periods of plant vigour coincide with intermittent hydrological variability. Water level fluctuation is proposed as a candidate ecological indicator for emergent macrophyte functional status in regulated shallow lakes, although its system-specific adaptation is likely required. These findings support the incorporation of controlled water level fluctuations into the management of regulated shallow lakes, where ecological and recreational objectives must be reconciled.

This study investigated the effect of epiphyton on foliar traits of a submerged rooted macrophyte, Potamogeton perfoliatus, in a shallow freshwater lake, highlighting its influence on the ecological dynamics of littoral zones in aquatic ecosystems. It was shown that the limnological characteristics of the sampling sites (water chlorophyll-a, total suspended matter and coloured dissolved organic matter content) had no significant effect on the average values of epiphytic algal content found on pondweed leaves, while influencing the plasticity of these data. The responses of morphological and physiological traits of submerged macrophytes to accumulated epiphyton demonstrate the complexity of their relationship: epiphyton colonisation had no relevant effect on leaf morphology (except leaf length) and leaf pigment content (except Chl-a/Chl-b ratio), however, this study highlights the significant influence of epiphytic algal biomass on photophysiological traits of submerged macrophyte leaves, as 5 out of 6 photophysiological traits were affected. The results highlight the importance of considering epiphyte colonisation when seeking to understand the ecological functioning of littoral aquatic ecosystems. Furthermore, the complex interactions between epiphytes and submerged rooted macrophytes should be considered in integrated lake management and environmental protection policies. These interactions play an important, though ambiguous role in shaping habitat variability and overall ecosystem health in littoral zones.

Lake Balaton, a large shallow freshwater lake in Hungary, exhibits diverse bacterioplankton communities influenced by various environmental factors. This study aims to evaluate the bacterial diversity in Lake Balaton using the long-read approach to 16 S rRNA gene sequencing. Water samples were collected from a wide network of 33 locations across the lake’s four basins and analyzed for bacterial community composition. Sequencing results revealed a high taxonomic diversity with significant zonal variations. Dominant families included Comamonadaceae, Burkholderiaceae, and Methylophilaceae. Environmental parameters such as temperature, pH, and CDOM were found to significantly correlate with bacterial abundance and diversity. The study underscores the utility and portability of using the long-read sequencing technology in assessing microbial diversity and provides insights into the ecological dynamics of bacterioplankton in freshwater lakes.

Shallow lakes worldwide face escalating pressures from eutrophication and climate change, yet comprehensive monitoring of Chlorophyll-a (Chl-a) spatiotemporal dynamics remains challenging due to the high costs and logistical constraints of traditional sampling approaches across large, heterogeneous water bodies. Lake Balaton, a large shallow lake system (80 km long, 7 km wide, 3.7 m mean depth) in Central Europe, exemplifies these monitoring challenges while serving as a representative system for understanding climate-driven changes in temperate shallow lakes. Despite decades of in-situ measurements along the lake's centerline, fine-scale spatial patterns and long-term temporal trends in Chl-a remain poorly characterized due to sparse samplings. Using a machine-learning-derived optical remote sensing dataset (1984-2023) at 30 m spatial resolution, we conducted comprehensive spatiotemporal analysis of Chl-a dynamics and examined relationships with bathymetry, nutrient loading, and light availability features. Our analysis reveals an exponential west-to-east decline in Chl-a concentrations with distance from the primary nutrient source, characterized by a consistent decay rate of 0.04-0.06 km-1 (typically 0.05 km-1). Littoral zones consistently exhibited 1.3-2.8 times higher optical Chl-a concentrations than pelagic zones, reflecting integrated signals from phytoplankton, benthic algae, and submerged macrophytes. Phenological analysis demonstrated significant climate-driven shifts, with peak Chl-a timing advancing by 20 days over the study period and growing season onset occurring 10 days earlier, consistent with regional warming trends. These findings provide a transferable framework for satellite-based water quality monitoring in shallow lake systems and demonstrate the critical importance of accounting for spatial heterogeneity and climate-driven temporal shifts in lake management strategies globally.

Chlorophyll-a (Chl-a) is one of the critical water quality indicators that shows the eutrophication status of aquatic ecosystems. As the largest lake and a well-known attraction in middle Europe, Lake Balaton contributes 70 % or more of local economy through tourism, while also maintaining a unique biodiversity. Therefore, long-term monitoring of water quality is essential for its effective management. With the longest global environmental record and a preferable spatial resolution, the satellite constellation Landsat is used for retrieving Chl-a in this study. However, the common low-frequent in-situ samplings and similar to 16-day revisit of Landsat have limited both the quality and applicability of Landsat to Chl-a retrieval. Initially, we trained both linear and several machine learning models using matchups between in-situ measurements and satellite data from Landsat 4-9 missions during 1984 and 2023. To address the imbalanced data problem, which lacks high concentration samples due to the rare blooming events, we extend the time tolerance, incorporate temporal information, which connotes the phenology information, and apply an oversampling technique during the training process. Validated on Lake Balaton, which has a spatiotemporal amplitude of Chl-a concentration ranging from 5 to 260 mu g/L since 1980s, Random Forest model has the best accuracy, which shows an R-square 0.86 and RMSE 8.16 mu g/L. The over-sampling technique improves the accuracy by 9.5 % than the non-oversampled. Leveraging all strategies improves overall accuracy by 21 %. The result also shows a reasonable trade-off via increasing the number of matchups 3 to 8 times by extending the time tolerance from the same day to 3 days regardless of the high variability of Chl-a due to the sinking and floating movement of algae. The enhancement framework can be applied to other lakes, especially for lakes with coarse samplings and wide Chl-a fluctuations. We present an open-source online tool for historical and real-time Chl-a mapping, designed for both experts and the public. With customizable code for global lakes, results are continuously showcased on the HUN-REN Balaton Limnological Research Institute's website and social media.

Common reed (Phragmites australis) is a cosmopolitan species, though its dieback is a worldwide phenomenon. In order to assess the evolutionary role of phenotypic plasticity in a successful plant, the values and plasticity of photophysiological traits of Phragmites australis were investigated in the Lake Fertő wetlands at 5 sites with different degrees of reed degradation and along a seasonal sequence. On the one hand, along the established ecological degradation gradient, photophysiological traits of Phragmites changed significantly, affecting plant productivity, although no consistent gradient-type trends were observed. Gradual changes within a season in the values of photosynthetic traits were observed that were recorded in both degraded and stable stands, suggesting a universal response to seasonally changing environmental conditions that could not be overridden by the ecological gradient. On the other hand, reed plants exposed to different levels of degradation showed comparable physiological plasticity; there was no difference in trait variability between stable and degraded stands. This relatively uniform plasticity is likely to contribute to the resilience of reed plants by providing a wider range of adaptive traits under different conditions. In contrast, the 150-200% gradual change in photophysiological trait plasticity with senescence in Phragmites was also demonstrated, reflecting a more dynamic response of the photosynthetic apparatus to seasonal changes. Senescence affected the plasticity of plant traits independently of their degradation status, suggesting a more universal nature of seasonal changes. This research shows that under conditions of conservative resource use determined by stressful habitats, trait values respond to conditions, while trait plasticity shows minimal changes. Furthermore, phenological sequence significantly influenced both the values and the plasticity of the photosynthetic traits studied. Our results underline the impact of ecological degradation on reed physiology and highlight the importance of understanding both trait values and plasticity in plant responses to environmental and seasonal change.

The influence of macrophytes on the optical environment of the littoral zone was assessed by studying the effect of monospecific Potamogeton perfoliatus on the quantitative and qualitative properties of light and the response of plants to this altered environment. P. perfoliatus was shown to alter the optical environment and consequently its own architecture: in high-density pondweed patches, 67 percent of incident light was absorbed in the top 10 cm, while spectral properties of light was significantly altered. Leaf morphology and photophysiology adapted to these changes, with photosynthetically active biomass concentrated in the upper water layer and stem biomass increasing in the basal parts due to self-shading. This study highlights the importance of submerged macrophytes in shaping the optical environment and ecological dynamics of littoral zones. Not only do pondweed plants from different sites show very similar vertical patterns of morphological and physiological parameters, but they also contribute to similar vertical spatial variability in water optics, thus increasing habitat complexity. This added optical heterogeneity not only increases the diversity of the littoral zone, but also enriches the entire aquatic ecosystem of shallow lakes by providing additional optical ecological niches.

Water temperature is a key parameter that needs to be closely monitored since it has a great impact on the physical, chemical, and biological effects on water bodies. As the largest lake in Central Europe, Lake Balaton provides important recreational and ecological values that the water temperature of which could be affected by global warming and anthropogenic activities, which lacks comprehensive investigation. Our study leverages multisource data on Google Earth Engine (GEE) to conduct a temperature variation analysis over two decades and detailed spatial variations across different parts of the lake, with in-situ data serving as both auxiliary and validation source. With an accuracy of 1.6 degrees C and a seasonal quantile difference within 1 degrees C, the satellite-based observations are in good agreement with the in-situ measurements. In the inter-annual analysis, water temperature increases at 0.7 degrees C/decade with more notable warming in annual minimum and winter temperatures, particularly in the shallowest basin. For intra-annual temperature analysis, examining monthly cumulative temperature anomalies indicates that during warming months, the western and shallower regions demonstrate relatively higher temperatures, with a 0.62 degrees C and 0.35 degrees C increase per 1 m decrease in water depth for spring and summer, respectively. Conversely, in cooling months, the deeper, eastern areas exhibit elevated temperatures, with an increase of 0.05 degrees C and 0.11 degrees C per 1 m increase in water depth for autumn and winter, respectively. Surface water temperatures near the coast are predominantly influenced by factors such as wind speed and water depth, inducing cooling effects, while artificial surfaces contribute to warming effects. These discoveries deepened our understanding of the detailed temporal variations and spatial heterogeneity of water temperature in aquatic ecological environment of Lake Balaton, providing valuable insights for effective monitoring and management strategies amid climate change and human activities.

The biological synchrony of neighbouring lakes in Central Europe was evaluated by analysing the concurrent time series of algal biomass variables using long-term (1999–2019) satellite (Landsat 7) derived chlorophyll-index data. The synchrony between the hydrologically connected and disconnected lakes was estimated and compared. Although the hydrologically connected lakes showed a low but significant synchrony (0.21 ± 0.07), the synchrony of phytoplankton phenological events in two hydrologically separated lakes was higher (0.50 ± 0.07). All data indicated a robust spatial correlation: the closer the compared lake regions were to each other, the higher the degree of similarity was. These data suggest that hydrological connectivity between lakes is not necessary and that the geological, geomorphological and mesoclimatic characteristics of the region may have a greater influence on the occurrence of biological processes in the lakes. Proximity of the lakes studied suggests that large-scale, integrating factors affecting all three studied lakes override the idiosyncrasies of these lakes, and therefore clustered management of neighbouring lakes may be useful to consider.

A multidisciplinary approach demonstrates how submerged macrophytes generate high phenological variability in Hungary's Lake Balaton. A 239-month time series of water chlorophyll indices derived from Landsat 7 imagery from 1999 to 2019 was used. These data facilitated the generation of area-based phenological patterns, which allowed an assessment of phenological variability by correlating chlorophyll index sequences with spatially adjacent values. The results showed that phenological variability was consistently low (below 5%) at the farthest points from the shore, indicating uniform phenological processes in the pelagic zone of Lake Balaton. Conversely, the littoral zone showed almost eight times higher variability, indicating increased diversity in shallow water areas. In particular, extensive macrophyte biomass datasets revealed a direct relationship between increased phenological variability in the littoral zone and macrophyte biomass (Spearman rank correlation: 0.893). This research highlights contrasting phenological patterns between phytoplankton and macrophyte communities, driven by different life cycles, and the possibility of effectively using satellite data to delineate phenological separation within lakes.

Study region: Pannonian Ecoregion, Hungary. Study focus: Bridging the gap between atmospheric influences and aquatic environments, this study embarked on a comprehensive reconstruction of daily surface water temperatures across lakes and rivers within the Pannonian Ecoregion over an extensive period of 150 years (1870–2021). New hydrological insights for the region: The analysis revealed a clear warming trend in waters over the past 150 years, and majority of this warming occurred in recent three to four decades (average warming rate: 0.317 °C/decade). Seasonal patterns indicated that winter and spring exhibited faster warming rates, followed by autumn and summer. There has been a significant increase in the number, duration, and intensity of heatwaves in both lakes and rivers, particularly pronounced in the last 30–40 years, and with the rise of air temperatures, river and lake heatwaves tend to intensity. These findings underscore the escalating impact of climate change on freshwater systems in the Pannonian Ecoregion, emphasizing the urgent need for mitigation measures. As the first study on river and lake heatwaves in Hungary and one of the few studies on river heatwaves worldwide, this study will provide reference for analysing extreme thermal events in aquatic systems.

Conflicts and natural disasters affect entire populations of the countries involved and, in addition to the thousands of lives destroyed, have a substantial negative impact on the scientific advances these countries provide. The unprovoked invasion of Ukraine by Russia, the devastating earthquake in Turkey and Syria, and the ongoing conflicts in the Middle East are just a few examples. Millions of people have been killed or displaced, their futures uncertain. These events have resulted in extensive infrastructure collapse, with loss of electricity, transportation, and access to services. Schools, universities, and research centers have been destroyed along with decades' worth of data, samples, and findings. Scholars in disaster areas face short- and long-term problems in terms of what they can accomplish now for obtaining grants and for employment in the long run. In our interconnected world, conflicts and disasters are no longer a local problem but have wide-ranging impacts on the entire world, both now and in the future. Here, we focus on the current and ongoing impact of war on the scientific community within Ukraine and from this draw lessons that can be applied to all affected countries where scientists at risk are facing hardship. We present and classify examples of effective and feasible mechanisms used to support researchers in countries facing hardship and discuss how these can be implemented with help from the international scientific community and what more is desperately needed. Reaching out, providing accessible training opportunities, and developing collaborations should increase inclusion and connectivity, support scientific advancements within affected communities, and expedite postwar and disaster recovery.

Lake Balaton is the largest lake (~587 km 2 ) in middle Europe but very shallow with an average depth of 3 m, whose abundant fauna and flora have irreplaceable ecological values. Its natural beaches and artificial facilities attract millions of tourists all over the world. To facilitate long-term monitoring and management of water quality, Landsat satellites, the longest and most consistent spectral archive of earth observation, are used for Chl-a concentration retrieval. Based on the cloud-based geospatial data platform Google Earth Engine (GEE), this study integrates satellite spectral bands with temporal information to improve Chl-a concentration retrieval with Landsat. Results show that the proposed method has an RMSE 6.41 mg/m 3 . The yearly mean Chl-a shows a good consistency with in-situ measurements and can capture key variability between years and discover the years with high Chl-a concentration. Therefore, this work can benefit exploring long-term spatio-temporal patterns of water quality in Lake Balaton. An online interface has also been developed with GEE for the easy access and visualization of Chl-a variations.

Lake Balaton, a shallow polymictic freshwater lake in Central Europe, became eutrophic in the 1970s. To retain the inorganic nutrients from the main tributary River Zala, a semi-artificial system called the Kis-Balaton Water Protection System (KBWPS) was constructed in the early 1980s. In 2015, the system was reconstructed and modernised, thus offering the opportunity to evaluate the effectiveness of the functional connection between the KBWPS and Lake Balaton over the past 20 years and to compare its impact before and after the reconstruction. To this end, time series data of algal biomass in Lake Balaton between 1999 and 2019 based on Landsat 7 satellite data were analysed. Over the last 20 years, the algal biomass in Lake Balaton showed an increasing trend (0.009 ± 0.011% increase per year), with territorial specificities also observed. No change was noted in the western part, while an increase was recorded in the eastern part of the lake. A significant difference in the rate of algal biomass accumulation was noticed before (annual increase of 0.008 ± 0.019%) and after (0.240 ± 0.306% per year) the KBWPS reconstruction. Given that the largest increase in algal biomass after reconstruction was observed in the outermost KBWPS basin of Lake Balaton, it appears that mesoscale environmental, water balance, or other factors affecting the lake are playing a role in this increase, rather than the KBWPS reconstruction. This research highlights the potential to study aquatic ecosystems using Earth observation techniques, and how mesoscale factors such as changes in the local climate regime or shifts in lake management can greatly impact the trophic state of a large shallow lake. Effectively identifying these factors is crucial in maintaining the proper status of aquatic ecosystems.

This dataset includes leaf samples from six floating and emergent macrophyte species common in temperate areas, covering different phenological stages, seasons, and environmental conditions, and measured leaf reflectance (400-2500 nm) and leaf traits (dealing with photophysiology, pigments, and structure). Data were collected along three years (2016-2018) from three temperate shallow lakes surrounded by wetlands and hosting abundant macrophyte communities, located in central and southern Europe: Lake Hídvégi or Kis-Balaton (Hungary), Mantua lakes system (Italy), and Lake Varese (Italy). Leaf photophysiological parameters derived from chlorophyll fluorescence measured with a PAM-2500 chlorophyll fluorometer (Heinz Walz GmbH, Germany). Leaf pigments were derived from spectrophotometric readings of absorbance of leaf extracts in acetone 80%.

Photomorphogenesis is a process by which photosynthetic organisms perceive external light parameters, including light quality (color), and adjust cellular metabolism, growth rates and other parameters, in order to survive in a changing light environment. In this study we comprehensively explored the light color acclimation of Cyanobium gracile, a common cyanobacterium in turbid freshwater shallow lakes, using nine different monochromatic growth lights covering the whole visible spectrum from 435 to 687 nm. According to incident light wavelength, C. gracile cells performed great plasticity in terms of pigment composition, antenna size, and photosystem stoichiometry, to optimize their photosynthetic performance and to redox poise their intersystem electron transport chain. In spite of such compensatory strategies, C. gracile, like other cyanobacteria, uses blue and near far-red light less efficiently than orange or red light, which involves moderate growth rates, reduced cell volumes and lower electron transport rates. Unfavorable light conditions, where neither chlorophyll nor phycobilisomes absorb light sufficiently, are compensated by an enhanced antenna size. Increasing the wavelength of the growth light is accompanied by increasing photosystem II to photosystem I ratios, which involve better light utilization in the red spectral region. This is surprisingly accompanied by a partial excitonic antenna decoupling, which was the highest in the cells grown under 687 nm light. So far, a similar phenomenon is known to be induced only by strong light; here we demonstrate that under certain physiological conditions such decoupling is also possible to be induced by weak light. This suggests that suboptimal photosynthetic performance of the near far-red light grown C. gracile cells is due to a solid redox- and/or signal-imbalance, which leads to the activation of this short-term light acclimation process. Using a variety of photo-biophysical methods, we also demonstrate that under blue wavelengths, excessive light is quenched through orange carotenoid protein mediated non-photochemical quenching, whereas under orange/red wavelengths state transitions are involved in photoprotection.

Abstract Background Macrophytes are key players in aquatic ecosystems diversity, but knowledge on variability of their functional traits, among and within species, is still limited. Remote sensing is a high-throughput, feasible option for characterizing plant traits at different scales, provided that reliable spectroscopy models are calibrated with congruous empirical data, but existing applications are biased towards terrestrial plants. We sampled leaves from six floating and emergent macrophyte species common in temperate areas, covering different phenological stages, seasons, and environmental conditions, and measured leaf reflectance (400–2500 nm) and leaf traits (dealing with photophysiology, pigments, and structure). We explored optimal spectral band combinations and established non-parametric reflectance-based models for selected traits, eventually showing how airborne hyperspectral data could capture spatial–temporal macrophyte variability. Results Our key finding is that structural—leaf dry matter content, leaf mass per area—and biochemical—chlorophyll-a content and chlorophylls to carotenoids ratio—traits can be surrogated by leaf reflectance with normalized error under 17% across macrophyte species. On the other hand, the performance of reflectance-based models for photophysiological traits substantively varies, depending on macrophyte species and target parameters. Conclusions Our main results show the link between leaf reflectance and leaf economics (structure and biochemistry) for aquatic plants, thus envisioning a crucial role for remote sensing in enhancing the level of detail of macrophyte functional diversity analysis to intra-site and intra-species scales. At the same time, we highlighted some difficulties in establishing a general link between reflectance and photosynthetic performance under high environmental heterogeneity, potentially opening further investigation directions.