Responses Of Functional Traits Research Articles

How the fish community structure change with seasons in Zhoushan Fishing Ground, China?

Understanding seasonal variations in fish communities is important for fishery resources conservation and management in fishery economic zones. However, there are still knowledge gaps regarding to the differential responses of fish functional traits to various disturbances. Here, we sampled fish communities of 20 sites during autumn (November 2023) and spring (April 2024) in Zhoushan Fishing Ground. Taxonomic diversity (TD), functional diversity (FD), and functional redundancy (FR) were calculated to investigate the state of the fish communities and their seasonal changes. Beta diversity was calculated based on the pairwise communities of spring and autumn and decomposed into turnover and nestedness proportions, to investigate the dissimilarities of the fish communities between the two seasons and their drive mechanisms. We also applied R-mode linked to Q-mode (RLQ) and fourth-corner methods to test the relationships between fish functional traits and environmental variables (trait-environment relationships). These results showed that the mean values of taxonomic and functional beta diversities were 0.852 and 0.769, respectively, which indicate that taxonomic and functional structures of the fish communities have high dissimilarities between spring and autumn. However, the taxonomic and functional structures showed different ecological processes of seasonal changes with the former were mainly driven by species turnover (occupied 89.9% of the total dissimilarity) and the latter were driven by both functional turnover and nestedness (occupied 57.9% and 42.1% of the total dissimilarity, respectively). Species occurrence, environmental variables, and functional traits matrices were closely correlated, which mainly result from the significant trait-environmental relationships. Combining with TD, FD, and FR, we concluded that the fish communities in autumn had higher resistance to environmental changes than in spring. Our findings are accepted to serve as a basis for fishery management.

Response of Plant Leaf Traits to Environmental Factors in Climax Communities at Varying Latitudes in Karst Regions

Exploring the changes in plant functional traits and their relationship with the environment in karst climax communities across different latitudes can enhance our understanding of how these communities respond to environmental gradients. In this study, we focus on climax karst climax plant communities in Guizhou Province, China. We selected three sample sites located at varying latitudes and analyzed the variations in functional traits of the plant communities at these latitudes. Additionally, we examined the relationship between functional traits and environmental factors, integrating species characteristics and community structure into our analysis. The results indicated that (1) there were significant differences in both the community leaf aspect ratio and the community-specific leaf area. (2) Soil organic carbon content exhibited significant variations across different latitudes, while soil nitrogen content was notably higher in mid-latitude and low-latitude regions compared to high-latitude areas. The distribution of soil factors was more concentrated in high and mid-latitude regions, whereas low-latitude areas displayed more pronounced variability. (3) The primary environmental factors influencing the climax community in the karst study area included soil water content (SPMC), soil bulk density (BD), soil organic carbon content (SOC), soil nitrogen content (SNC), and soil phosphorus content (SPC). Our findings suggest that karst plant communities exhibit specific combinations of functional traits at distinct latitudes. With increasing latitude, the community demonstrated a gradual shift in ecological strategy from conservative to more opportunistic. Most environmental factors imposed limiting effects on plant functional traits, with plants primarily constrained by BD during growth. Among the responses of plant functional traits to environmental factors, community-weighted leaf area and community-weighted chlorophyll content were the most sensitive to soil conditions.

Bryophytes adapt to open-pit coal mine environments by changing their functional traits in response to heavy metal-induced soil environmental changes.

Plants have unique adaptability to heavy metal pollution. However, the adaptation strategies of bryophytes are still unclear. In order to better understand the response of bryophytes to different heavy metal and the adaptation mechanisms of different species to heavy metal pollution, we studied soil physicochemical properties, distribution of heavy metal elements, ecological risk assessment and the community structure, functional characteristics of bryophytes in large open-pit coal mines in Inner Mongolia. The results indicate that: (1) The soil in three open-pit mining areas currently does not pose an ecological risk from the heavy metal pollution, but high concentrations of Zn and Hg are found in most parts of the study area; (2) The presence of a single heavy metal drives the distribution of specific taxa of bryophytes. Apart from Hg, Pb, and Zn, all the other heavy metals significantly impact the community structure of bryophytes; (3) With the exception of Pb and Hg, all the other heavy metals have an influence on the functional traits of bryophytes; 4) Different taxa of bryophytes will adapt to changes in soil environments caused by heavy metal pollution by altering their functional traits (blades, leaf cells, or plant size).

Responses of Local and Non-Local Tropical Plant Seedling Functional Traits to Simulated Drought

Responses of Local and Non-Local Tropical Plant Seedling Functional Traits to Simulated Drought

Functional traits as an indicator of urbanization impact on the scorpion assemblage in Neotropical forest

Currently, natural forests face significant loss of vegetation cover linked to habitat loss due to urban expansion. Therefore, we investigated the effects of changes in different land uses and land cover at the landscape scale resulting from the urbanization process on the functional traits of the body of scorpions in the Brazilian Atlantic Forest. In 10 forest fragments in Paulista, Pernambuco, we observed that forest cover had a statistically significant negative relationship with the average functional body traits of the scorpion assemblage. Distinct functional body traits were associated with the conditions of the surrounding landscape. Forest units with lower forest cover harbored species with higher average functional body traits, indicating adaptation to the urban scenario. Conversely, in areas with greater forest cover, species with smaller functional body traits predominated, suggesting habitat sensitivity and dependence on less disturbed environments. Our results indicate that scorpions may be indicators of changes in functional body traits due to land use change. These findings highlight significant implications for biodiversity conservation in the Atlantic Forest in the face of urban expansion, emphasizing the role of scorpions as key indicators of changes in functional body traits in response to the altered landscape.

Species-specific functional trait responses in two species coexisting along a shore-to-inland dune gradient.

Coastal dunes are characterised by strong gradients of abiotic stress, typically increasing in severity from inland areas towards the shoreline. Thus, dune gradients represent unique opportunities to study intraspecific responses to environmental changes and to investigate which factors drive community change. This study aims to examine functional trait variation in two coexisting species in response to environmental changes along a dune gradient in NW Spain. Trait convergence was also investigated and compared between both ends of the gradient. We measured functional leaf traits related to plant efficiency in the use of light, water and nutrients, also possible stressors (salt content and pH) and availability of limiting resources (water and nutrients) in the soil. Most soil variables showed changes following a non-directional gradient. Differences in soil variables were site specific and depended on growth of the study species. Structural and functional traits depended on species and/or plant position on the gradient, except for effective quantum yield of PSII and leaf δ15N. The pattern of variation was mostly directional for reflectance indices related to leaf physiology. Multivariate analyses showed significant interspecific differences in the set of traits they exhibited along positions in the gradient. Species also differed in the combination of traits selected under given environmental conditions. Coexisting species display a specific set of traits that reflects different strategies to environmental stress. Our study highlights the overly simplistic nature of some previous studies that assume dune gradients are monotonically directional, without considering that these gradients may be differentially modified by species activity.

Response of submerged macrophytes of different growth forms to multiple sediment remediation measures for hardened sediment.

Climate change and intensified human activities have disrupted the natural hydrological regime and rhythm of river-connected lakes, extending the dry season, increasing water loss, and exposing previously submerged lake floors. This exposure has led to significant sediment hardening, which directly impacts submerged macrophytes. However, strategies to mitigate the negative effects of hardened sediments and promote the growth and development of submerged macrophytes remain largely unexplored. In this study, we selected typical hardened sediment from Dongting Lake to investigate the response of different growth forms of submerged macrophytes to multiple sediment remediation measures (loosening and litter addition) using a mesocosm experiment. The results indicated that loosening alone uniformly benefited all submerged macrophytes by increasing total biomass, relative growth rate (RGR), and the root/shoot ratio. Additionally, loosening altered the root traits of submerged macrophytes, promoting maximum root length (MRL) while reducing average root diameter (ARD). Moreover, different submerged macrophytes exhibited species-specific responses to the combination of loosening and litter addition. Notably, the combination of loosening and adding Miscanthus lutarioriparius litter had an antagonistic effect on the growth of Potamogeton wrightii and Myriophyllum spicatum. The response of functional traits of submerged macrophytes with similar growth forms to the same treatment was consistent. Our findings suggest that future sediment remediation efforts should consider matching specific treatments with the growth forms of submerged macrophytes to achieve optimal outcomes.

Balancing the nutrient needs: Optimising growth in Malus sieversii seedlings through tailored nitrogen and phosphorus effects.

The impact of nitrogen (N) and phosphorus (P) on the physiological and biochemical processes crucial for tree seedling growth is substantial. Although the study of plant hydraulic traits in response to N and P is growing, comprehensive research on their combined effects remains limited. Malus sieversii, a key ancestral species of modern apples and a dominant species in Xinjiang's Tianshan wild fruit forest, is witnessing a decline due to climate change, pests and diseases, compounded by challenges in seedling regeneration. Addressing this, a 4-year study was conducted to determine the optimal fertilisation method for it. The experiment explored varying levels of N (N10, N20 and N40) and P (P2, P4 and P8), and their combined effects (N20Px: N20P2, N20P4, N20P8; NxP4: N10P4, N20P4 and N40P4), assessing their impact on gas exchange, hydraulic traits, and the interplay among functional traits in Tianshan Mountains' M. sieversii seedlings. Our study revealed that All N-inclusive fertilisers slightly promoted the net photosynthetic rate. N10 significantly increasing leaf hydraulic conductivity. All P-inclusive fertilisers adversely affected hydraulic conductivity. P8, N20P4 and N20P8 notably increased seedlings' vulnerability to embolism. Seedlings can adaptively adjust multiple functional traits in response to nutrient changes. The research suggests N10 and N20 as the most effective fertilisation treatments for M. sieversii seedlings in this region, while fertilisation involving phosphorus is less suitable. This study contributes valuable insights into the specific nutrient needs of it, vital for conservation and cultivation efforts in the Tianshan region.

Unveiling intra-population functional variability patterns in a European beech (Fagus sylvatica L.) population from the southern range edge: drought resistance, post-drought recovery and phenotypic plasticity.

Understanding covariation patterns of drought resistance, post-drought recovery and phenotypic plasticity, and their variability at the intra-population level are crucial for predicting forest vulnerability to increasing aridity. This knowledge is particularly urgent at the trailing range edge since, in these areas, tree species are proximal to their ecological niche boundaries. While this proximity increases their susceptibility, these populations are recognized as valuable genetic reservoirs against environmental stressors. The conservation of this genetic variability is critical for the adaptive capacity of the species in the current context of climate change. Here we examined intra-population patterns of stem basal growth, gas exchange and other leaf functional traits in response to an experimental drought in seedlings of 16 open-pollinated families within a marginal population of European beech (Fagus sylvatica L.) from its southern range edge. We found a high degree of intra-population variation in leaf functional traits, photosynthetic performance, growth patterns and phenotypic plasticity in response to water availability. Low phenotypic plasticity was associated with higher resistance to drought. Both drought resistance and post-drought recovery of photosynthetic performance varied between maternal lines. However, drought resistance and post-drought recovery exhibited independent variation. We also found intra-population variation in stomatal sensitivity to soil drying, but it was not associated with either drought resistance or post-drought recovery. We conclude that an inverse relationship between phenotypic plasticity and drought resistance is not necessarily a sign of maladaptive plasticity, but rather it may reflect stability of functional performance and hence adaptation to withstand drought. The independent variation found between drought resistance and post-drought recovery should facilitate to some extent microevolution and adaption to increasing aridity. The observed variability in stomatal sensitivity to soil drying was consistent with previous findings at other scales (e.g., inter-specific variation, inter-population variation) that challenge the iso-anisohydric concept as a reliable surrogate of drought tolerance.

Multiple time scale optimization explains functional trait responses to leaf water potential.

Plant response to water stress involves multiple timescales. In the short term, stomatal adjustments optimize some fitness function commonly related to carbon uptake, while in the long term, traits including xylem resilience are adjusted. These optimizations are usually considered independently, the former involving stomatal aperture and the latter carbon allocation. However, short- and long-term adjustments are interdependent, as 'optimal' in the short term depends on traits set in the longer term. An economics framework is used to optimize long-term traits that impact short-term stomatal behavior. Two traits analyzed here are the resilience of xylem and the resilience of nonstomatal limitations (NSLs) to photosynthesis at low-water potentials. Results show that optimality requires xylem resilience to increase with climatic aridity. Results also suggest that the point at which xylem reach 50% conductance and the point at which NSLs reach 50% capacity are constrained to approximately a 2 : 1 linear ratio; however, this awaits further experimental verification. The model demonstrates how trait coordination arises mathematically, and it can be extended to many other traits that cross timescales. With further verification, these results could be used in plant modelling when information on plant traits is limited.

Eurasian watermilfoil (Myriophyllum spicatum) alters its root topology but conserves its root branching in response to freshwater cultural eutrophication

Cultural eutrophication is the main cause of the decline of submerged plants in freshwater ecosystems. While many studies have focused on the nutrient uptake by the roots of these plants, less attention has been given to the effects of eutrophication on root structure. We designed a mesocosm experiment with Eurasian watermilfoil (Myriophyllum spicatum), a submerged plant indigenous to the Eurasian continent. The responses of plant functional traits, including growth traits, morphological traits and root topological indices, to different nitrogen (N) and phosphorus (P) concentrations were elucidated. We found that high P concentrations suppressed all the morphological traits and reduced the root topological traits, whereas N concentrations had a comparatively minor effect. Although the root branching of M. spicatum did not change, its root topology became more dichotomous with fewer exterior root links being formed in nutrient-rich habitats, and the root form changed from deep and thin to shallow and dense with increasing P concentrations. The root nutrient absorption ability of M. spicatum may decrease with cultural eutrophication, and this change most likely reduces its anchoring ability and increases its sensitivity to dislodge from the sediment if disturbed by hydraulic forces.

Explaining the mechanisms behind niche dimensionality and light-driving species diversity based on functional traits

Two prevalent ecological mechanisms, niche dimensionality and light asymmetry, may well explain species loss with fertilization gradients in grassland communities. Although there is still controversy surrounding the two competitive mechanisms that maintain species coexistence, few studies have examined the patterns of change in dissimilarity in species composition (β-diversity) and the relative explanatory contributions of plant functional traits to α- and β-diversity when multiple resources are added. To clarify this knowledge gap, we conducted a 6-year experiment of resource addition in an alpine meadow on the Qinghai-Tibet Plateau to assess how species richness and spatial β-diversity are affected by increasing numbers of added resources (NAR) and light limitation. Our results found that both NAR and light limitation led to decreased species richness, suggesting that niche dimensionality and light asymmetry may contribute equally to species loss, rather than either alone. Moreover, NAR is the primary factor responsible for the increase in β-diversity, which exhibits a negative relationship with species richness. Furthermore, the increase in height is the most likely explanation for β-diversity, while the increase in SLA is the most likely explanation for species richness, thereby indicating the changes in species richness and composition can be effectively explained by the response of certain morphological functional traits with the addition of multiple resources. Future research should focus on the complex interactions of different ecological mechanisms that contribute to the maintenance of biodiversity in grassland ecosystems all over the world.

Different temperature sensitivities of key physiological processes lead to divergent trait response patterns in Arctic phytoplankton

AbstractOcean warming is especially pronounced in the Arctic, and phytoplankton will face thermodynamically driven changes in their physiology, potentially pushing them beyond their thermal optimum. We assessed temperature responses of multiple functional traits over their entire thermal window (growth rates, quotas of particulate organic carbon, nitrogen, and chlorophyll a, as well as photophysiological parameters) in three different Arctic phytoplankton species (Thalassiosira hyalina, Micromonas pusilla, and Nitzschia frigida). Temperature response patterns in growth and biomass production rates indicated that all species exhibit wide thermal windows with highest rates at temperatures that exceed current polar temperatures. Species showed different temperature response patterns in cellular elemental quotas, which originate from the interplay of cell division and biomass production: These processes differ in their temperature sensitivity and optima, resulting in U‐shaped, bell‐shaped, or linear patterns of elemental quotas. Despite unaltered light intensity, higher temperatures increased light acclimation indices in all species while lifetimes of photosystem II reopening decreased in all species, suggesting that warming causes a transition from light saturation to light limitation. Our findings on temperature sensitivities of cell division and biomass production not only indicate that Arctic phytoplankton may benefit from moderate warming, but also highlight that meaningful interpretations of cellular quotas require a consideration of the underlying processes.

Polyploidy and the evolution of phenotypic integration: Network analysis reveals relationships among anatomy, morphology, and physiology.

Most traits are polygenic and most genes are pleiotropic, resulting in complex, integrated phenotypes. Polyploidy presents an excellent opportunity to explore the evolution of phenotypic integration as entire genomes are duplicated, allowing for new associations among traits and potentially leading to enhanced or reduced phenotypic integration. Despite the multivariate nature of phenotypic evolution, studies often rely on simplistic bivariate correlations that cannot accurately represent complex phenotypes or data reduction techniques that can obscure specific trait relationships. We apply network modeling, a common gene co-expression analysis, to the study of phenotypic integration to identify multivariate patterns of phenotypic evolution, including anatomy and morphology (structural) and physiology (functional) traits in response to whole genome duplication in the genus Brassica. We identify four key structural traits that are overrepresented in the evolution of phenotypic integration. Seeding networks with key traits allowed us to identify structure-function relationships not apparent from bivariate analyses. In general, allopolyploids exhibited larger, more robust networks indicative of increased phenotypic integration compared to diploids. Phenotypic network analysis may provide important insights into the effects of selection on non-target traits, even when they lack direct correlations with the target traits. Network analysis may allow for more nuanced predictions of both natural and artificial selection.

Interactive effects of fire and grazing on vegetation structure and plant species composition in subtropical grasslands

AbstractQuestionFire and grazing, and their interaction, are the main drivers of vegetation structure and plant species composition in many grasslands globally. However, for subtropical grasslands in southern Brazil, the interactive effects of fire and grazing on plant community composition characteristics remain relatively understudied, even though this ecosystem is recognized as fire‐dependent with critical importance for livestock grazing.LocationSubtropical grassland in southern Brazil (Santiago, Rio Grande do Sul state).MethodsBeginning in 2017, we established an experiment with three treatments: fire only (F), grazing only (G), and fire and grazing (F + G). Grazing was continuous with ca 1.1 animal unit per hectare annually and prescribed fires were applied annually in winter. We assessed vegetation structure (via percentage of bare soil, height of canopy, and available forage) and plant species composition during spring (November) and summer (March) of 2017, 2018, 2019 and 2020 (only summer season).ResultsDifferences in vegetation structure were found among treatments, wherein bare soil, height of canopy and available forage were higher in F, and lower but similar in F + G and G. Plant species richness was equal among treatments, but cover of C3 grasses was higher in F than in other treatments, and shrub cover was lower in F and F + G in comparison to G. In F + G treatment, available biomass for subsequent burning was limited, resulting in lower amounts of fuel, reduced fire spread, and ultimately less total area burned in the subsequent years.ConclusionsOur findings suggest that interaction of fire and grazing can be a useful vegetation management tool for conserving native plant species, increasing availability of more desirable forage plants, and decreasing shrubs (including toxic Senecio species which contain hepatotoxic pyrrolizidine alkaloids). The singular and interactive effects of fire and grazing suggest the subhumid Río de la Plata grasslands are a fire‐adapted ecosystem with variable plant functional trait responses facilitating differential dominance. There is a need for future work to address spatio‐temporal variability and vegetation heterogeneity.

Responses of Intraspecific and Interspecific Trait Variations to Nitrogen Addition in a Tibetan Alpine Meadow.

A community functional structure may respond to environmental changes such as nitrogen (N) enrichment by altering intraspecific and interspecific trait variations. However, the relative contributions of both components in determining the community response to N enrichment are unclear. In this study, we measured the plant height (H), leaf area (LA), leaf dry matter content (LDMC), and specific leaf area (SLA) based on a nine-year N addition gradient experiment in an alpine meadow on the Tibetan Plateau. We examined the intraspecific and interspecific variations within and among the communities, the responses of traits in terms of community weighted mean (CWM) and non-weighted mean (CM) to N addition, and the effects of these trait variations on aboveground net primary productivity (ANPP). Our results show that N addition increased the interspecific variation in H while decreasing that of LA within the community, whereas it had no significant effects on the intraspecific variations in the four traits within the community. In contrast, N addition significantly increased the intraspecific variation in H and decreased that of LA among the communities. Moreover, the contribution of intraspecific variation was greater than that of the interspecific variation in terms of CWM for all traits, while the opposite contribution was observed in terms of CM, suggesting that the dominant species would have greater resilience while subdominant species would become less resistant to N addition. Further, intraspecific variations of LA and LDMC within the community played an important role in explaining community productivity. Our results highlight the importance of both intraspecific and interspecific variations in mediating functional trait responses to N enrichment, and intraspecific variation within the communities has important implications for community functioning that should be considered to better understand and predict the responses of the alpine grasslands to N enrichment.

Plant functional group interactions intensify with warming in alpine grasslands

Plant–plant interactions regulate plant community structure and function. Shifts in these interactions due to global climate change, mediated through disproportional increases of certain species or functional groups, may strongly affect plant community properties. Still, we lack knowledge of community‐level effects of climate‐driven changes in biotic interactions. We examined plant community interactions by experimentally removing a dominant functional group, graminoids, in semi‐natural grasslands in Southern Norway. To test whether the effect of graminoid removal varied with climate, the experiment was replicated across broad‐scale temperature and precipitation gradients. To quantify community‐level interactions across sites, we tested for changes in the remaining vascular community (i.e. forbs) cover, richness, evenness, and functional traits reflecting leaf‐economic investment and plant size over five years. The effect of graminoid removal on forb community structure and functioning varied over time, and along the climate gradients. Forb cover increased in response to graminoid removal, especially at warmer sites. Species richness increased following removal irrespective of climate, whilst evenness increased under warmer and wetter conditions irrespective of removal. No climate or removal effect was found for species turnover. Functional trait responses varied along the precipitation gradient – compared to controls, forb mean SLA decreased in drier conditions after graminoid removal. Leaf thickness increased under cooler and drier conditions irrespective of removal. These community structure alterations demonstrate stronger competitive interactions between forbs and graminoids under warmer conditions, whilst functional trait responses indicate a facilitative effect of graminoids under drier conditions. This indicates that both competition and facilitation regulate plant communities, suggesting complexity when scaling from populations to communities. Finally, both temperature and precipitation determine the direction and intensity of biotic interactions, with ecosystem‐wide implications for forb persistence and ecosystem functioning under future climates. Further work is needed to generalise the role of changing interactions in mediating community responses to climate change.

Predicting Urban Trees’ Functional Trait Responses to Heat Using Reflectance Spectroscopy

Plant traits are often measured in the field or laboratory to characterize stress responses. However, direct measurements are not always cost effective for broader sampling efforts, whereas indirect approaches such as reflectance spectroscopy could offer efficient and scalable alternatives. Here, we used field spectroscopy to assess whether (1) existing vegetation indices could predict leaf trait responses to heat stress, or if (2) partial least squares regression (PLSR) spectral models could quantify these trait responses. On several warm, sunny days, we measured leaf trait responses indicative of photosynthetic mechanisms, plant water status, and morphology, including electron transport rate (ETR), photochemical quenching (qP), leaf water potential (Ψleaf), and specific leaf area (SLA) in 51 urban trees from nine species. Concurrent measures of hyperspectral leaf reflectance from the same individuals were used to calculate vegetation indices for correlation with trait responses. We found that vegetation indices predicted only SLA robustly (R2 = 0.55), while PLSR predicted all leaf trait responses of interest with modest success (R2 = 0.36 to 0.58). Using spectral band subsets corresponding to commercially available drone-mounted hyperspectral cameras, as well as those selected for use in common multispectral satellite missions, we were able to estimate ETR, qP, and SLA with reasonable accuracy, highlighting the potential for large-scale prediction of these parameters. Overall, reflectance spectroscopy and PLSR can identify wavelengths and wavelength ranges that are important for remote sensing-based modeling of important functional trait responses of trees to heat stress over broad ranges.

Fish assemblage and functional trait responses to small‐dam removal

Abstract Dams are one of the greatest threats to freshwater biodiversity and efforts to remove dams to restore riverine systems are increasing. However, dam‐removal studies have primarily focused on taxonomic responses to large dam removals with little work on the functional trait responses of fish to small‐dam removals; such a focus limits the application of results in regions with different taxonomic compositions. We explored taxonomic and functional trait responses of fish assemblages to two small‐dam removals over 10 years using a Multiple Before After Control Impact design at a dammed and an undammed river. Eight life‐history traits were used to calculate functional diversity (RaoQ) and determine the position of each fish species within a multivariate life‐history space relative to three life‐history strategy endpoints: opportunistic, periodic, and equilibrium. The distance of each species relative to these endpoints was used to calculate community weighted means (CWM), allowing us to examine the shift in life‐history strategy of a given assemblage after dam removal. Based on life‐history theory, we predicted a decrease in the CWM of equilibrium strategists and an increase in the CWM opportunistic strategists after dam removal. For the dammed river, we observed changes in assemblage structure at both the control and impact sites driven primarily by shifts from a lentic to lotic assemblage, with the most apparent change occurring in the formerly impounded sites. These changes tended to occur within 1 year, suggesting rapid colonization by lotic species after habitat change. By contrast, no change in assemblage structure was found for the undammed river, suggesting that dam removal was the primary driver of the shifts in assemblage structure observed in the dammed river. We found no change in the CWM of periodic strategists or RaoQ of all life‐history traits at any site after dam removal. Based on CWM, life‐history strategies shifted in response to dam removal at impounded sites where equilibrium strategists decreased and opportunistic strategists tended to increase after the impounded sites changed from a stable lentic environment to an unstable lotic environment, supporting predictions made by life‐history theory. Our results suggest that small‐dam removal may provide ecological benefits by restoring fish assemblages to a more natural riverine state and reversing the negative effects of dam construction on the ecosystem. We demonstrate that combining both trait‐based and taxonomic approaches can improve our ecological understanding of the impacts of dam removal on fish assemblages and provide relevant data for local management.

Response of Functional Traits of Aquatic Plants to Water Depth Changes under Short-Term Eutrophic Clear-Water Conditions: A Mesocosm Study.

Aquatic plants play a key role in the structuring and functioning of shallow lake ecosystems. However, eutrophication often triggers shifts in plant communities and species diversity, especially in the early stages when the water is still clear. Additionally, water depth is an important factor regulating aquatic plant communities. We conducted a 50-day mesocosm study to investigate how water depth (50 cm and 100 cm) affected the functional traits (vertical expansion versus horizontal colonisation) of 20 aquatic plants under eutrophic clear-water conditions. Among the selected species, the submerged plants Hydrocotyle vulgaris and Limnophila indica exhibited higher plant height or biomass in deeper water, while the emergent plants Myriophyllum aquaticum showed the opposite trend. Additionally, Ludwigia peploides subsp. stipulacea exhibited better vertical growth than the remaining species, and the submerged species Vallisneria denseserrulata had better horizontal colonisation. There was a positive correlation between plant height and rhizome length, indicating the absence of a trade-off between vertical growth and horizontal expansion. Our findings suggest an overall resilience of aquatic plants to varying water depths within our study range and highlight the importance of analysing functional traits when selecting appropriate species in freshwater ecosystem restoration, particularly in the face of climate change-induced water depth fluctuations.