Search Results (80)

Arundo donax L. has been introduced in markets worldwide due to its economic value. However, it is listed in the world’s 100 worst alien invasive species because it easily escapes from cultivation, and forms dense monospecific stands in riparian areas, agricultural areas, and grassland areas along roadsides, including in protected areas. This species grows rapidly and produces large amounts of biomass due to its high photosynthetic ability. It spreads asexually through ramets, in addition to stem and rhizome fragments. Wildfires, flooding, and human activity promote its distribution and domination. It can adapt to various habitats and tolerate various adverse environmental conditions, such as cold temperatures, drought, flooding, and high salinity. A. donax exhibits defense mechanisms against biotic stressors, including herbivores and pathogens. It produces indole alkaloids, such as bufotenidine and gramine, as well as other alkaloids that are toxic to herbivorous mammals, insects, parasitic nematodes, and pathogenic fungi and oomycetes. A. donax accumulates high concentrations of phytoliths, which also protect against pathogen infection and herbivory. Only a few herbivores and pathogens have been reported to significantly damage A. donax growth and populations. Additionally, A. donax exhibits allelopathic activity against competing plant species, though the allelochemicals involved have yet to be identified. These characteristics may contribute to its infestation, survival, and population expansion in new habitats as an invasive plant species. Dense monospecific stands of A. donax alter ecosystem structures and functions. These stands impact abiotic processes in ecosystems by reducing water availability, and increasing the risk of erosion, flooding, and intense fires. The stands also negatively affect biotic processes by reducing plant diversity and richness, as well as the fitness of habitats for invertebrates and vertebrates. Eradicating A. donax from a habitat requires an ongoing, long-term integrated management approach based on an understanding of its invasive mechanisms. Human activity has also contributed to the spread of A. donax populations. There is an urgent need to address its invasive traits. This is the first review focusing on the invasive mechanisms of this plant in terms of adaptation to abiotic and biotic stressors, particularly physiological adaptation. Full article

Soil saline–alkaline stress and water stress, exacerbated by anthropogenic activities and climate change, are major drivers of wetland vegetation degradation, severely affecting the function of wetland ecosystems. In this study, we conducted a simulation experiment with three water levels and four saline–alkaline concentration levels as stress factors to assess eight key functional traits of Phragmites australis and Bolboschoenus planiculmis, dominant species in the salt marsh wetlands in the western region of Jilin province, China. The study aimed to evaluate how these factors influence the functional traits of P. australis and B. planiculmis. Our results showed that the leaf area, root biomass, and clonal biomass of P. australis significantly increased, and the leaf area of B. planiculmis significantly decreased under low and medium saline–alkaline concentration treatments, while the plant height, ramet number, and aboveground biomass of P. australis and the root biomass, clonal biomass, and clonal/belowground biomass ratio of B. planiculmis were significantly reduced and the ratio of belowground to aboveground biomass of B. planiculmis significantly increased under high saline–alkaline concentration treatment. The combination of drought conditions with medium and high saline–alkaline treatments significantly reduced leaf area, ramet number, and clonal biomass in both species. The interaction between flooding water level and medium and high saline–alkaline treatments significantly suppressed the plant height, root biomass, and aboveground biomass of both species, with the number of ramets having the greatest contribution. These findings suggest that the effects of water levels and saline–alkaline stress on the functional traits of P. australis and B. planiculmis are species-specific, and the ramet number–plant height–root biomass (RHR) strategy may serve as an adaptive mechanism for wetland clones to environmental changes. This strategy could be useful for predicting plant productivity in saline–alkaline wetlands. Full article

The re-establishment of submerged macrophytes is crucial for the ecological restoration of eutrophic lakes. Water depth (light intensity) and sediment nutrient levels are key factors influencing the growth of these macrophytes. Although their individual impacts have been extensively studied, their interactive effects remain unclear. We conducted a two-factor experiment to investigate the interactive effects of different water depths (50 cm and 190 cm) and sediment nutrient levels (fertile and infertile) on the growth and morphological traits of Vallisneria denseserrulata. We found that biomass, relative growth rate, below/above-ground biomass, ramet number, and leaf number significantly increased with decreasing water depth in fertile sediments, while no significant or less pronounced changes occurred for infertile sediments. The absence or weak responses to increased light intensity in infertile sediments are likely due to photoinhibition, which may be alleviated at higher nutrient levels in fertile sediments. Additionally, V. denseserrulata, in adapting to low-light environments (deeper water), increased plant height at the cost of decreased leaf number and below-ground biomass as water depth increased in fertile sediments. Our study demonstrated significant interactive effects between water depth (light intensity) and sediment nutrient levels on the growth and morphological traits of V. denseserrulata, indicating that their response to water depth (light intensity) strongly depends on sediment fertility. Full article

Examining the ramet system in bamboo forests can provide an important theoretical basis for strategic management. Moso bamboo is an economically important species in China, and implementing the correct management measures can play a key role in improving bamboo productivity. However, the dynamics of the Moso bamboo ramet system under timber vs. shoot forest management remain underexplored. In this study, we investigated the underground rhizome growth, bud bank structures, branch growth, and distribution patterns of bamboo ramet systems in the two main bamboo cultivation types. Shoot forest ramet systems exhibited stable early-stage rhizome renewal but instability in later stages, characterized by thin, elongated rhizomes. The opposite was observed in the timber forests. The underground bud bank of the ramet system in the shoot forest had a strong renewal ability with stable lateral bud input. However, shoot harvesting disturbed the bud bank balance. The lateral bud input in the timber forest was unstable, with the lateral buds being prone to death. The variation range and quantity of branch types in the ramet system in the shoot forest were greater than those in the timber forest. The number of branches in different parts of the ramet system was in the order of rhizome tip (RT) > middle of rhizome (RM) > rhizome base (RB). The range of variation was greater in the shoot forest. Different management methods led to growth differences in the examined bamboo ramet systems. Bamboo forest management resulted in a correlation between bud banks and ramet system renewal. Operations such as bamboo shoot harvesting significantly impacted branch growth and distribution. These findings not only provide a better understanding of the growth and management strategy of bamboo ramet systems worldwide but also provide a universal theoretical reference for the sustainable management of bamboo forests in other countries. Full article

Climate warming and nitrogen (N) deposition have already occurred and will continue to occur, profoundly affecting exotic plant invasion. Most studies on the effects of climate change focus on plant growth, biomass, and leaf traits, with limited reports on reproductive responses. We selected Solidago canadensis from North America and China as focal species and conducted a long-term common garden experiment simulating climate warming and N deposition to examine how climate warming, N addition, and plant origin influence its reproductive traits. Chinese Solidago canadensis exhibited significantly greater ramet height, more robust ramet diameters, longer and wider inflorescences, and higher seed mass compared to North American Solidago canadensis. Long-term warming and plant origin alone or in combination significantly influenced reproductive traits, while N addition did not influence these traits. The vegetative propagation of a native population was sensitive to warming and N addition, while the generative propagation of an invasive population was sensitive to their combined effects. These findings suggest that the reproductive strategies of Solidago canadensis varied with their origin, and plant origin might be important in mediating climate change effects on their reproduction under plant invasion. Full article

Indian mock strawberry (Duchesnea indica, syn. Potentilla indica), a clonal invasive plant native to Asia, has rapidly spread in Europe, where its ecological adaptation allows it to thrive under varying environmental conditions. It is mostly found in urban habitats such as lawns, parks, and urban and peri-urban forests, where it thrives in various plant communities. It can become dominant in certain communities, indicating its competitive advantage over native plants. Due to similar habitat preferences, it often coexists with the native species Glechoma hederacea, with which it shares other characteristics such as clonal growth. This study investigates the effects of light, nutrients, and competition on the growth, morphology, and physiology of D. indica. A controlled pot experiment exposed plants to combinations of sunlight and shade, optimal and increased nutrient levels, and competitive scenarios with the native plant G. hederacea. The plant traits of biomass, leaf and ramet number, stolon and flower production, leaf greenness, the photosynthetic efficiency of Photosystem II, and stomatal conductance were assessed. Results revealed that light and nutrient availability significantly enhanced growth metrics. In shaded conditions, D. indica adapted with elongated petioles and increased specific leaf area. Competition significantly reduced growth, with G. hederacea outperforming D. indica. These findings highlight the complex interplay between abiotic and biotic factors in influencing invasive species impact, providing essential insights for ecosystem management. Full article

In this work, metabolite profiling of seeds and antioxidant analysis of fragments of two marine seagrasses, Posidonia oceanica and Cymodocea nodosa, were carried out to identify metabolite signature involved in seed viability and to evaluate the potential of fragments as a source of bioactive compounds. Using HILIC/QTOF-MS, UHPLC-MS and spectrophotometric analysis, seed metabolites and polyphenols and antioxidant activities, such as those of radical scavenging (RSA), reduction (FRAP, CUPRAC) and complexation (CCA), of rhizome fragments were evaluated. Metabolite comparison between seeds revealed differences across development stages (germinated and non-germinated) and seed types (dormant and non-dormant), providing insights into metabolic activity potentially associated with germination processes and seed viability. Furthermore, polyphenol analysis showed the highest content of caffeic acid in mature leaves (17.00 ± 0.02 μg g⁻¹ dw for P. oceanica and 98.00 ± 0.03 μg g⁻¹ dw for C. nodosa). Total phenolic content was correlated with flavonoids and with reduction and complexation activities. The combination of radical scavenging activity and t_1/2 was higher in P. oceanica than C. nodosa and also surpassed the commercial synthetic antioxidant BHA. We conclude P. oceanica and C. nodosa exhibit distinct seed metabolite profiles related to germination and type of seeds, and that fragments are rich in antioxidants, with potential as sustainable sources of bioactive compounds. Full article

Heavy metals (HMs) or/and polycyclic aromatic hydrocarbons (PAHs) stress have significant adverse effects on the photosynthetic function and SPAD values of plants. Physiological integration is the typical feature of clonal plants, which can mitigate the adverse effects on ramets under heterogeneous stress. However, the sustainability of physiological integration between clones over prolonged stress durations, the dynamics of integration intensity and potential differences under various stress types remain unclear. This study examined the effects of three different heterogeneous stresses—cadmium (Cd), phenanthrene (Phe), and a combination of Cd and Phe (Cd + Phe) on the physiological integration of Zoysia japonica at different time points. The results indicate that physiological integration significantly enhances SPAD value, net photosynthetic rate (P_N), stomatal conductance (Cond), intercellular CO₂ concentration (C_i), transpiration rate (Tr), and water use efficiency (WUE). However, the physiological integration intensity diminishes with prolonged stress exposure. In addition, among different stress types, the initial integration intensity was highest under the highest toxicity conditions, it decreased most rapidly, resulting in the lowest integration intensity during the later stages of stress. To sum up, this study highlights the role of physiological integration in maintaining the photosynthetic function of clonal plants under heterogeneous stress and elucidates the temporal changes in integration intensity under different stress conditions. Full article

Drought stress is the most common threat to plant growth, while physiological integration can significantly enhance the drought tolerance of clonal plants, making it essential to research the behavior of clones under drought conditions and explore the potential applications of clonal plants. This study applied polyethylene-glycol-6000-induced stress to proximal, middle and distal clonal ramets of Kentucky bluegrass (Poa pratensis L.) and used an isotope labeling technique to evaluate the water physiological integration and photosynthetic capacity. When the proximal ramet was subjected to drought stress treatment, the decrease in ²H isotopes in the roots from 4 h to 6 h was significantly smaller than the increase in ²H isotopes in their own leaves. Additionally, the reductions in δ²H values of middle and distal ramets roots were 4.14 and 2.6 times greater, respectively, than the increases in their respective leaf δ²H values. The results indicate that under drought stress, water physiological integration was observed among different clonal ramets. In addition, drought stress inhibits the photosynthetic-related indicators in clonal ramets, with varying degrees of response and trends in photosynthetic characteristics among different clonal ramets. The proximal ramet treatment group, treated with polyethylene glycol 6000, was most affected by drought stress, while the distal ramet treatment group was least affected. The proximal ramet treatment group, treated with polyethylene glycol 6000, showed a decrease in water use efficiency after 6 h of drought treatment, while the other groups exhibited some increase. This indicates differences in water utilization and regulation among the different clonal ramets under drought stress. This study holds significant theoretical importance for exploring the characteristics of physiological integration and the photosynthetic mechanisms of Kentucky bluegrass clones under drought stress. Full article

Epipactis helleborine (L.) Crantz is considered a challenging and phenotypically difficult species to identify due to its wide range of morphological variability. This variability is mainly observed in the perianth parts but also extends to the gynostemium structure, which has so far been considered one of the most useful diagnostic characteristics. As a result, a simple graphic illustrating the structural pattern of gynostemium morphology has appeared in 10 different forms in available European taxonomic keys, which significantly complicates the identification of this species. A total of 122 flowers of E. helleborine were collected from four natural populations in the Lower Silesia region (Poland) between 2017 and 2019 and analysed for gynostemium morphological variation. Geometric morphometric analyses, including Procrustes ANOVA, PCA, and CVA, were used to examine gynostemium shape, with statistical tests assessing variation in size and stigma inclination angle among populations, individual plants (ramets), and years of research. Statistical analysis revealed significant positive correlations between gynostemium width and height, with significant variation in size and angle of stigma inclination, primarily driven by population, while ramet and year of research had a lesser impact. Geometric morphometric analyses indicated significant population-level variation in gynostemium shape, with principal component analysis identifying the ventral view as the most informative for discriminating these differences. The first two principal components explained the major shape variation, and canonical variate analysis confirmed that this view is most important for species identification. Full article

The physiological performance of clonal plants is largely linked with resource translocation among interconnected ramets. Whereas carbon (C) and nitrogen (N) transferences have been evidenced in several herbaceous clonal plants, empirical evidence in woody species is anecdotal. We evaluated physiological integration in two evergreen tree species, differing in the light requirements in a temperate rainforest of Southern Chile: Embothrium coccineum J.R. et. G. Forster (light-demanding) and Eucryphia cordifolia Cav. (shade-tolerant). We measured light availability for vegetative (root suckers) and sexual (seed-origin plants; hereafter, saplings) recruits of the two species. Then, we compared elemental and isotopic leaf traits between recruit types and species growing under similar light availability. A ¹³CO₂ field pulse labeling was performed on a set of Embothrium root suckers to quantify C transfer from moderately shaded suckers (donors) to highly shaded suckers (receivers). For the two species, leaf N concentration, δ¹³C, and δ¹⁵N were higher in suckers compared to saplings. In the labeling experiment, the δ¹³C and ¹²C equivalent excess did not differ between donor and receiver, indicating a weak C transfer between donors and receivers. Although the results from the pulse labeling were not conclusive, they suggest, together with the differences in natural isotope abundance, the existence of physiological integration in root suckers of both species. Our findings indicate that the formation of root suckers is more important for regeneration and persistence than for resource acquisition at an intermediate ecological succession of a temperate rainforest. Full article

Intra-individual variation in floral traits is linked to plant fitness, playing a central role in sexual selection. This variation can arise from architectural constraints, such as flower position on the inflorescence axis, and from environmental factors. In relation to the environmental influences on floral traits, the most common causes of variation are linked to the presence of pollinators, to plant resource acquisition strategies and to the availability of local resource pools. We investigated how clonal integration and resource depletion through defoliation affect floral trait stability in Eichhornia crassipes, testing whether clonal integration buffer floral traits against resource limitations. Using greenhouse experiments, we manipulated clonal structure and resource availability. We assessed the effects of floral position and clonal integration on floral traits through model selection. Our results showed that basal flowers generally had larger traits, more attractive to pollinators, and isolated or defoliated ramets exhibited significant reductions in floral traits, especially at distal flowers. Clonal integration stabilized floral traits across positions by mitigating the effects of resource variability. Clonal integration in E. crassipes enhances resilience to resource depletion, likely contributing to this species invasiveness. These findings highlight the significance of clonal and architectural integration in sustaining reproductive traits under environmental stress. Full article

European semi-dry grasslands are habitats of high conservation value. Therefore, research into the mechanisms of community assembly is important for their effective management. Using data from 76 vegetation plots of calcareous and acidic semi-dry grasslands in continental Slovenia, the author analysed the composition of plant traits, focusing on less studied belowground traits. Community-weighted means were calculated for nine plant functional traits: life form, growth form, clonal growth organ (CGO) type, persistence of connection in CGO, number of clonal offspring shoots, lateral spreading distance, role of CGO, bud bank, CSR strategy. The results showed that both grassland communities were characterized by high local persistence (perennial plants with long-lived connections between ramets). Acidic grasslands had more species with rosettes, rhizomes and stress-tolerators, indicating more stressful conditions, probably due to low pH. Mesic grassland species with numerous stolons and longer lateral spread were also characteristic of acidic grasslands. Calcareous grasslands hosted more competitors, plants with leafy stems and plants with perennial main roots. This study contributes to a deeper understanding of grassland processes and provides a basis for future investigations of belowground plant traits and their function. Full article

Clonal plants can support the growth of their ramets in heterogeneous environments through clonal integration between the ramets. However, the role of clonal integration in modulating ramet photosynthesis under toxic stress, especially combined stress, is unclear. This study examines the impact of clonal integration on Zoysia japonica under three heterogeneous stresses (Pb, pyrene, and Pb+Pyrene) with two stolon connection conditions (connected and disconnected). Our results show that clonal integration significantly enhances P_N, g_s, C_i, E, and CE while reducing WUE. It also improves ΦPSII, F_v′/F_m′, F_v/F_m, F_v/F₀, and q_P while reducing NPQ. Clonal integration lowers MDA levels, increases SOD activity, and mitigates the decline in CAT and POD activity, resulting in increased biomass under stress. Furthermore, we observed that the synergistic effects of the Pb+Pyrene mixture negatively impacted the adaptability of clonal integration. Our study underscores the role of clonal integration in maintaining photosynthesis and supporting the success of clonal plants in toxic environments. Full article

Submerged macrophytes play an important role in maintaining the structure and function of shallow lakes. Under eutrophication, the community of submerged macrophytes shows a shift of growth forms from rosette-like to canopy-forming macrophytes and a further decline due to the increasing shading from epiphyton and phytoplankton. However, at the early phase of eutrophication, the population of submerged macrophytes may increase due to increased nutrient availability, and the responses of submerged macrophytes to eutrophication are expected to be growth-form dependent. To explore the direct effects of nutrient enrichment on the submerged macrophytes of both growth forms, we constructed a mesocosm study with rosette-like macrophytes (Vallisneria denseserrulata and V. spinulosa) and canopy-forming macrophytes (Potamogeton lucens and P. wrightii) under two nutrient levels but maintained low phytoplankton and epiphyton biomass. Nutrient enrichment had a positive effect on the plant size for both macrophyte growth forms under low algal shading. Based on the 21 plant traits determined, the same growth form responded similarly to the increase in nutrient availability with few exceptions. Interestingly, increased nutrient levels induced different allocation strategies between canopy-forming (especially for ‘magnopotamid’) and rosette-like submerged macrophytes. The increased nutrients promoted leaf growth in rosette-like macrophytes and ramet production in canopy-forming macrophytes. These results provide a case study on the direct effects of increased nutrient levels on submerged macrophytes during the early phase of eutrophication in shallow lakes. Full article