Abstract Phragmites australis is a dominant species in estuaries. It can reproduce sexually and clonally. Understanding the latitudinal patterns of the traits can help in predicting adaptive strategies across environmental gradients. However, changes in growth and reproductive traits of P. australis, as well as growth-reproduction relationships along latitudinal gradients remain unclear. We sampled P. australis from five estuaries along latitudinal gradients in China and analyzed changes in growth, reproductive, and biomass allocation. The results revealed that with increasing latitude, the ramet height, flowering frequency, inflorescence biomass per flowering ramet, and weight of 100 seeds increased, whereas the ramet density generally decreased. The latitudinal growth and reproduction patterns were primarily influenced by variations in the temperature, precipitation, and light intensity. These results suggest that high-latitude P. australis populations may reduce their flowering and seed production under climate warming.

Effects of parental environments on offspring phenotypes are ecologically and evolutionarily important for plants. As clonal offspring develop close to their parents and their environments are predictable, plant clonality is hypothesized to influence adaptive parental effects. We conducted a meta-analysis of parental effects on offspring performance of clonal and non-clonal plant species. Offspring performance was extracted from experiments that evaluated offspring in both benign and stressful environments, with parents originating from the same benign or stressful environments. Parental effects generally enhanced offspring performance under matching (predictable) parent-offspring environments, but their direction and intensity varied depending on the environmental context and clonality. Parental effects positively affected offspring growth, reproductive and morphological traits of clonal plant species in predictable benign environments, but parental effects were significantly stronger on growth, morphological and physiological traits of non-clonal plant species in predictable stressful environments. For clonal plant species only, parental effects on reproductive traits were more positive in clonally derived than in sexually derived offspring in predictable benign environments, but more positive in sexually derived than in clonally derived offspring in predictable stressful environments. Synthesis. Plant clonality enhances parental effects on offspring performance in predictable benign environments, but does not increase the chance of adaptive parental effects in predictable stressful environments. The findings highlight the importance of considering reproductive modes and environmental contexts in parental effects on offspring phenotypes.

A large-scale mangrove planting initiative is underway in Zhanjiang, China, to enhance coastal wetland carbon sink capacity, with the selection of species and location being critical. The sediment organic carbon (SOC) component distribution can determine the mangrove carbon sequestration capacity, yet its patterns and primary drivers in different vegetation types remain unclear. We collected sediment cores from 3 mangrove communities and determined sediment properties. The SOC in mangrove communities was mainly distributed in the 0- to 60-cm layer. SOC, dissolved organic carbon, light fraction organic carbon (LFOC), and heavy fraction organic carbon (HFOC) concentrations all decreased with sediment depth. The dissolved organic carbon concentration differed by mangrove species. Sediment nutrients and/or microorganisms were the primary driving factors of LFOC and HFOC among the 3 mangroves. At equivalent nutrient levels, LFOC and HFOC concentrations were ranked as follows: Rhizophora stylosa > Bruguiera gymnorhiza > Kandelia obovata. Our results indicated that the SOC concentration was higher in the R. stylosa community than in the B. gymnorhiza and K. obovata communities and was primarily influenced by nutrient concentrations. When assessing the effect of SOC concentration in mangrove communities, it is important to focus on differences in sediment nutrients (B. gymnorhiza, phosphorus; K. obovata, nitrogen and potassium; and R. stylosa, nitrogen) and microbial biomass. This study provides scientific evidence supporting the effective expansion of the planted area and the restoration of the carbon sink function in the Zhanjiang mangrove forest. Specifically, in high-tide regions, prioritizing the restoration of R. stylosa can facilitate the attainment of China’s Carbon Neutrality Target for 2060.

ABSTRACT Phenotypes of estuarine plants are influenced by salt stress experienced in both the current generation and by their parents, a phenomenon potentially regulated by DNA methylation. In clonal plants, DNA methylation information is effectively transmitted across generations, further influencing offspring phenotypes. However, the role of DNA methylation in clonal transgenerational plasticity and its heritable stability remains poorly understood across various genotypes of wild plants. To this end, we employed controlled genotype × environment interaction experiments to investigate phenotypic responses and DNA methylation in parental and offspring generations of Phragmites australis under salt stress conditions. Furthermore, we investigated the stability of DNA methylation inheritance across three generations exposed to continuous salt stress. Our results demonstrated that parental salt stress significantly increased plant height, maximum leaf area, and rhizome nodes of P. australis offspring from certain genotypes subjected to salt stress similar to their parents, compared to offspring of unstressed parents. Parental salt stress induced an increase in CHG hemi‐methylation and a decrease in CG methylation, potentially modulating changes in offspring plant height, maximum leaf area, and rhizome nodes. Moreover, multigenerational salt stress resulted in a persistent reduction in CG methylation and a cumulative elevation of CHG hemi‐methylation in specific genotypes. These findings reveal that offspring phenotypes in P. australis are jointly determined by genetic background and both parental and offspring environments, mediated through epigenetic modifications, which further advances our understanding of evolutionary adaptation strategies in clonal plants.

Plant traits are influenced by evolutionary and environmental factors co-operating across varying spatial and temporal scales. While significant progress has been made in understanding aboveground-belowground trait relationships in terrestrial plants, little is known about how plant above- and belowground traits perform in marsh wetlands at large scales, particularly for traits related to clonal architecture and resource acquisition strategies. We measured above- and belowground traits of 15 occurring, common clonal plant species in nine marsh wetlands in northern China, and obtained data of soil physicochemical properties and climates. We found a crucial role of soil moisture in shaping traits of wetland clonal plants. Across the nine wetlands, all traits except those of leaves showed higher values in the high- than in the low-moisture areas in the low-precipitation areas, but this trend was reversed in the high-precipitation areas. In particular, clonal plants showed longer rhizome internodes and higher rhizome internode biomass in the higher-moisture areas, thereby displaying a guerrilla architecture. Moreover, most wetland clonal plants also exhibited larger specific leaf area, showing an acquisitive strategy of resource uptake. These findings deepen our understanding of the ecological strategies of wetland clonal species, and provide insights for the conservation and restoration of marsh wetland vegetation.

Background Unvegetated tidal flats of mangrove ecosystems in estuarine and non-estuarine areas play a crucial role in the coastal blue carbon sinks and biogeochemical cycle.However,there is still a lack of comprehensive understand-ing of the differences in soil organic carbon(SOC)contents in mangrove tidal flats between estuarine and non-estua-rine areas,as well as their influencing factors. Methods In this study,soil samples were collected from estuarine and non-estuarine mangrove tidal flats in the Leizhou Peninsula.We compared the SOC and soil physicochemical properties between estuarine and non-estuarine mangrove tidal flats.The Random Forest algorithm was employed to identify the main influencing factors affecting SOC.The direct and indirect effects of the main influencing factors on SOC were studied using partial least squares structural equation modeling. Results SOC,total nitrogen(TN),total phosphorus(TP),available potassium(AK),clay,silt,aluminum(Al),lithium(Li),boron(B),molybdenum(Mo),and cadmium(Cd)contents in the estuarine areas were significantly higher than those in the non-estuarine areas of the mangrove tidal flats.The soil particle size(clay,silt,and sand),soil nutrient(TN andTP),and soil metal elements(Al,Mo,and Cd)were the main influencing factors of the SOC contents in the estua-rine and non-estuarine mangrove tidal flat areas.Soil particle size(clay,silt,and sand)indirectly positively influenced SOC contents by positively influencing soil nutrient(TN and TP). Conclusions Our findings indicate that estuarine tidal flats have higher capacity of SOC sequestration compared with non-estuarine tidal flats.The main cause is that soil particle size has the potential to significantly increase SOC content by increasing soil nutrients,while metal elements have a direct influence on SOC content.The findings of the present study highlight an important mechanism that influences SOC contents in estuarine and non-estuarine mangrove tidal flats.

Introduction:Parental environments can influence offspring fitness via clonal (asexual) propagation, and such clonal parental effects may vary among plant species and depend on offspring environments as well. Consequently, clonal parental effects may alter competitive interactions between plant species, and such impacts may vary with offspring environments. Methods:We conducted a two-phase experiment with two clonal floating duckweeds, Spirodela polyrhiza and Lemna minor. In the parental phase, S. polyrhiza and L. minor were grown separately under two distinct nutrient conditions and produced offspring ramets. In the offspring phase, the ramets produced from the parental phase were grown with or without a heterospecific neighbor under the same two nutrient conditions. Results and discussion:In the first phase, parent ramets of both species produced more biomass and offspring ramets under high nutrient availability than under low. In the second phase, nutrient availability experienced by the parents significantly affected the competitive ability of offspring in both species. Specifically, the offspring of L. minor suppressed those of S. polyrhiza more strongly when the parent of L. minor had been grown under high than low nutrient availability, although such clonal parental effects did not vary with nutrient availability experienced by the offspring. In contrast, the offspring of S. polyrhiza suppressed those of L. minor more strongly when the parent of S. polyrhiza had been grown under high rather than at low nutrient availability, but this effect occurred only under high nutrient availability for the offspring and diminished under low nutrient availability. These results suggest that clonal parental effects can influence competitiveness of plants and may vary depending on offspring environments. Our findings highlight the potential role of clonal parental effects in regulating interspecific interactions, which may further influence species composition and productivity of plant communities.

Phenotypic diversity within a plant community can result from species diversity, genetic diversity and environmental variation. While phenotypic diversity mediated by species and genetic diversity can influence population structure and productivity, it is unclear whether phenotypic diversity induced by environmental variation can produce similar impacts. To test the hypothesis that phenotypic diversity mediated by environmental variation of parent plants can influence their offspring population structure and productivity via epigenetic modification, we conducted a two-phase experiment with the clonal plant Hydrocotyle verticillata. In the first phase, parent ramets derived from the same genotype were grown under eight different environmental conditions (2 light levels × 2 water levels × 2 nutrient levels) to produce offspring ramets of different phenotypes and were applied with a DNA demethylation agent (5-azacytidine) or not. In the second phase, we used the offspring ramets to construct populations containing one, three, or six phenotypes and grew them under the non-stressful condition. As expected, the parent ramets grown in the eight environmental conditions produced offspring ramets of different phenotypes, and such phenotypic variation was reduced by 5-azacytidine application. In contrast to our hypothesis, phenotypic diversity mediated by environmental variation of parents did not significantly affect population productivity (biomass) or population structure as measured by size variation of ramets. Also, this impact did not change by 5-azacytidine application. Therefore, our findings do not support the idea that phenotypic diversity mediated by parental effects can influence population structure and productivity via altering DNA methylation. The lack of sufficient niche differentiation among phenotypes and the absence of environmental stress may have limited the positive effects of phenotypic diversity on productivity.

A belowground bud bank is a collection of asexual propagules produced by the underground storage organs of geophytes. Renewal through belowground bud banks is the main reproductive strategy of geophytes. The belowground bud bank density reflects the potential renewal capacity of geophyte communities. However, the effects of different perturbation regimes and habitats on the belowground bud bank density of geophytes are not comprehensively understood. Moreover, whether different types of belowground bud banks respond differently to perturbations is still unclear. For this meta-analysis, relevant papers on the effects of environmental perturbations on the belowground bud bank density of geophytes were systematically collected. The cumulative effect size of different perturbation regimes and habitats on belowground bud banks among different bud types was analyzed. Overall, the effect of environmental perturbations on belowground bud bank density was small, which may result from opposite or fluctuating responses of bud banks to different perturbations. Drought negatively affected bud bank density. Environmental perturbations decreased rhizome bud density but increased tiller bud density. In wetlands, perturbations decreased belowground bud bank density. However, no significant effect was found for other habitat types. In general, belowground bud banks of geophytes are highly resistant and resilient. Changes in belowground bud bank density depend on the type of perturbations, the habitats in which plants are distributed and the type of bud banks.

Aim Estuarine vegetation routinely experiences natural tidal fluctuations and is highly vulnerable to extreme events such as heavy rainfall, leading to changes in plant population structure and adaptability. Genetic and epigenetic modifications are widely considered to be mechanisms of phenotypic variation, triggered in plants responding to extreme changing environments. However, understanding on correlations among genetic, epigenetic, and phenotypic variation of wild plant populations is still limited. LocationChina. Methods In this study, populations of the typical wetland clonal species Phragmites australis were selected from four estuaries along various latitudes in China. Genetic and epigenetic diversity and phenotypic variation of these populations were analysed. Results Phenotypic variation of P. australis populations was the highest at Yellow River Estuary and the lowest at Min River Estuary. Across all estuaries, Genetic and epigenetic diversity was strongly linear-correlated. Genetic diversity had significant correlations with variation in reproductive traits, whereas epigenetic diversity had significant correlations with variation in growth traits. Climatic factors of mean annual temperature and precipitation, as well as soil nitrogen and phosphorus, were negatively correlated with variation in genetic diversity, epigenetic diversity, and variation in reproductive traits of P. australis populations along latitudes. Variation in growth traits was negatively correlated with soil salinity, reflecting the limiting effect of salinity on plant growth. Main Conclusion Our findings found that genetic and epigenetic variations may play different roles in phenotypic variation of P. australis populations along latitudes, the variation becomes greater when the climatic and edaphic conditions deteriorate. The findings shed new light on the adaptation and evolution of wetland plant populations along a large latitudinal scale, and may contribute to the revegetation of estuary wetlands.

Plant-soil feedback(PSF),as an important driving force for plant distribution,community composition,and succession,has received extensive attention in recent years.The spatial-temporal variation are important factors driving PSF;however,there is currently a lack of review on its research progress.We summarized the research progress on the spatial-temporal variation of PSF and proposed research directions that could be pursued in the future.At the temporal scale of PSF,the relationships among plant developmental stages,experimental cycles,and feedback effects were emphasized.At the spatial scale of PSF,we focused on the spatial distribution and transfer of plants,the spatial differentiation of soil microbial communities and physicochemical factors,as well as the influence of above-and below-ground systems on PSF.Based on the research progress,we proposed to focus on the long-term,multi-point dynamic feedback to improve the temporal resolution of the feedback process.The buffering time of microbial communities on domesticated and tested plants needed to be considered,and reasonable domestication and feedback periods should be set to make the results more objective.At the spatial scale,the effects of plant spatial distribution,spatial heterogeneity of soil factors,and above-and below-ground systems on feedback effects should be paid attention.Efforts should be made to achieve similarity in the physical structure of the inoculated soil,in order to obtain more realistic feedback effects.

Interactions between alien plants and local enemies in introduced ranges may determine plant invasion success. However, little is known about whether herbivory-induced responses are transmitted across vegetative generations of plants and whether epigenetic changes are involved during this process. In a greenhouse experiment, we examined the effects of herbivory by the generalist herbivore Spodoptera litura on the growth, physiology, biomass allocation and DNA methylation level of the invasive plant Alternanthera philoxeroides in the first- (G1), second- (G2) and third-generation (G3). We also tested the effects of root fragments with different branching orders (i.e., the primary- or secondary-root fragments of taproots) of G1 on offspring performance. Our results showed that G1 herbivory promoted the growth of the plants in G2 that sprouted from the secondary-root fragments of G1 but had a neutral or negative effect on the growth of the plants in G2 from the primary-root fragments. The growth of plants in G3 was significantly reduced by G3 herbivory but not affected by G1 herbivory. Plants in G1 exhibited a higher level of DNA methylation when they were damaged by herbivores than when they were not, while neither plants in G2 nor G3 showed herbivory-induced changes in DNA methylation. Overall, the herbivory-induced growth response within one vegetative generation may represent the rapid acclimatization of A. philoxeroides to the unpredictable generalist herbivores in the introduced ranges. Herbivory-induced trans-generational effects may be transient for clonal offspring of A. philoxeroides, which can be influenced by the branching order of taproots, but be less characterized by DNA methylation.

Photo 1. Over 13,718 alien plants have already been introduced in China for cultivation, and 987 of them are traded via online plant nurseries on 1688.com. The photograph shows a typical cultivated alien plant native to Central America, Monstera deliciosa Liebm., which has now been sold in at least 67 online nurseries on 1688.com. Photo credit: Ran Dong. Photo 2. Cactaceae and Crassulaceae are two of the most popular families of cultivated alien plants that are available on 1688.com. There are 183 taxa from these two families (the information was accessed 29 July – 15 August 2019). However, only 19.3% of them are naturalized and/or invasive, because most of them have only a short introduction history (34 years on average) and lack climatic suitability (2.4% on average). Photo credit: Ran Dong. Photo 3. Sphagneticola trilobata (L.) Pruski is one of the 46 invasive cultivated plants that are available on 1688.com. Due to its fast growth and reproduction capabilities, as well as its adaptation to the local environment, this species is considered one of the most invasive in China. Even so, it is still being traded and used for urban greening. Photo credit: Zhi-Cong Dai. These photographs illustrate the article “Cultivated alien plants with high invasion potential are more likely to be traded online in China” by Ran Dong, Bi-Cheng Dong, Qiu-Yue Fu, Qiang Yang, Zhi-Cong Dai, Fang-Li Luo, Jun-Qin Gao, Fei-Hai Yu, and Mark van Kleunen published in Ecological Applications. https://doi.org/10.1002/eap.2811.

Environments experienced by parental plants may potentially influence the performance of their offspring. These effects may also vary depending on the current environment experienced by the offspring. However, whether these transgenerational effects, especially those induced by biotic factors such as competition, can persist for multiple generations has not been tested. Here, we examined intraspecific competition-induced transgenerational effects across multiple generations using a floating clonal plant Spirodela polyrhiza, by growing three successive generations each under either low or high density. The second-generation offspring performed better when the first-generation plants were grown under low than under high density, independently of the density experienced by the second generation. The third-generation offspring performed better under low than under high density, and the difference was more pronounced when the second-generation plants were grown under low density. Moreover, the density of the first and second generation interacted to influence the morphology of the third-generation offspring. These results indicate that competition-induced transgenerational effects in S. polyrhiza can vary depending on the competition environment of its offspring and that these effects can persist across multiple generations.

River deltas are hot spots of biogeochemical cycling. Understanding sources and driving factors of dissolved organic matter (DOM) in river deltas is important for evaluating the role of river deltas in regulating global carbon flux. In this study, spectroscopic properties of soil DOM were analyzed in both freshwater and tidal areas of the Yellow River Delta. Five fluorescent components of soil DOM (two humic-like DOM, two protein-like DOM and one possible contaminant) were identified by parallel factor analysis and further confirmed by comparison with an online database. Concentration, spectroscopic properties and sources of soil DOM and its components differed between freshwater and tidal areas. DOM concentration was much higher in freshwater areas than in tidal areas. In freshwater areas, soil DOM was mainly derived from phytoplankton and microorganisms, while it was mainly derived from microorganisms and human activities in tidal areas. These differences in DOM between both areas were strongly driven by environmental factors, especially soil carbon (C), nitrogen (N) and its stoichiometric ratio C/N. These explained 80.7% and 69.6% of variations in DOM and chromophoric DOM (CDOM), respectively. In addition, phytoplankton also contributed to soil DOM, CDOM and fluorescent components C1-C4 as identified by significant positive correlations between them. These results imply that both the concentration and composition of soil DOM are strongly driven by soil properties and phytoplankton density in the Yellow River Delta.

北方沼泽湿地在水源供给、缓解水土流失、遏制草地沙化等方面具有重要作用,明确其植物群落物种组成和多样性特征对提升其生态系统服务功能具有重要意义.目前,在北方地区开展大尺度湿地植被调查的研究仍相对较少.土壤水分是驱动植物群落发展的主导环境因素之一,为了解高低土壤水分背景下湿地植物群落特征差异及关键驱动要素,对我国7个北方典型沼泽湿地的植物群落物种组成及多样性特征进行了调查,分析了植物群落物种组成及多样性特征与环境因子的关系,以及沼泽湿地植物群落内克隆植物的分布特征.研究结果发现不同沼泽湿地的植物群落物种组成和多样性差异显著,但无明显的地带性分布规律,物种分布呈现区域性.群落物种多样性受降水、温度、土壤养分等多种环境因素的共同影响.沼泽湿地高低土壤水分背景下植物群落的物种组成和多样性差异显著,低土壤水分下植物群落物种多样性指数显著高于高土壤水分下植物群落.低土壤水分下物种多样性主要受降水和总氮影响,而高土壤水分下物种多样性主要受温度和总磷的影响.高土壤水分下克隆植物物种数和盖度在沼泽湿地植物中占有较高的比例,表明克隆植物比非克隆植物更适应高土壤水分环境.研究结果表明了7个沼泽湿地植被的区域性分布特征及受降水和温度的主要影响.随着土壤水分的升高,植物群落多样性降低,但克隆植物的重要性升高.因此,未来降水和温度的变化可能将进一步影响湿地植被的组成和多样性特征.

Background and Aims Plant traits are the results of plant evolutionary and environmental drivers operating at different scales. Although the relationship between above- and below-ground traits of terrestrial plants has been advanced, little is known about above- and below-ground traits of wetland plants, their relationship and influencing factors across a large scale. Methods Species coverage, and above- and below-ground plant traits were measured in nine typical marsh wetlands of northern China. Differences in plant traits at both species- and community-level among wetlands and between low and high soil moisture conditions, correlations between above- and below-ground traits of clonal plants, and the influencing environmental factors were analyzed. Results Plant traits at both species- and community-level were significantly higher in Daihai and Qingtongxia wetlands than that in other wetlands, which was influenced by combined effects of precipitation, soil nutrients, and temperature. Plant traits at both levels were generally higher under high than low soil moisture conditions. At the species level, the coordinated relationships were found between above- and below-ground traits of clonal plants under both low and high soil moisture conditions across all wetlands; while a trade-off relationship was found between internode diameter and length of clonal plants. Conclusions Plant traits exhibited the similar pattern among wetlands at both levels, but performed better at high soil moisture conditions in marsh wetlands. Coordinated relationships between above- and below-ground traits will be further clarified whether such coordination can be also seen in other wetland ecosystems.

The modification of dissolved organic matter (DOM) degradation by plant carbon inputs represents a critical biogeochemical process that controls carbon dynamics. However, the priming effects (PEs) different plant tissues induce on the degradation of DOM pools with different stabilities remain unknown. In this study, PEs, induced by different tissue leachates of Phragmites australis, were evaluated via changes in DOM components and properties of both fresh and tidal water (with different stabilities). The results showed that DOM derived from different plant tissue leachates differed in composition and bioavailability. Inputs of tissue leachates induced PEs with different intensities and directions (negative or positive) on DOM degradation of fresh and tidal water. In fresh water, the PEs of leaf and root leachates were significantly higher than those of stem and rhizome leachates. The PE direction changed for DOM degradation between fresh and tidal water. The addition of leaf and root leachates tended to induce positive PEs on DOM degradation of fresh water, while resulting in negative PEs on DOM degradation of tidal water. Negative PEs for tidal water DOM may be due to preferential utilization of microbes, high salinity, and/or the promotion of exogenous DOM production from plant tissues. The results indicate that intensity and direction of PEs induced by plant leachates depend on both leachate type and water stability. The findings highlight the necessity to examine the nature of exogenous and native DOM when interpreting the interactive processes that regulate DOM degradation.

Biological invasions have become a worldwide problem, and measures to efficiently prevent and control invasions are still being developed. Like many other parts of the world, China is undergoing a dramatic increase in plant invasions. Most of the currently 933 established (i.e., naturalized) plant species, of which 214 are categorized as invasive, have been introduced into China for cultivation. It is likely that many of those species are still being traded, particularly online, by plant nurseries. However, studies assessing whether naturalized and invasive species are currently being traded more or less than non-naturalized aliens are rare. We extracted online-trade information for 13,718 cultivated alien plant taxa on 1688.com, the largest website for domestic B2B in China. We analyzed how the presence in online-nursery catalogues, the number of online nurseries that offer the species for sale, and the product type (i.e., seeds, live plants and vegetative organs) differed among non-naturalized, naturalized non-invasive and invasive species. Compared to non-naturalized taxa, naturalized non-invasive and invasive taxa were 3.7 to 5.2 times more likely available for sale. Naturalized non-invasive and invasive taxa were more frequently offered as seeds by online nurseries, whereas non-naturalized taxa were more frequently offered as live plants. Based on these findings, we propose that, to reduce the further spread of invasive and potentially invasive plants, implementation of plant-trade regulations and a monitoring system of the online horticultural supply chain will be essential.

Parental effects can influence offspring fitness, which may further impact interspecific competition. However, few studies have tested the role of clonal parental effects in regulating interspecific interactions and examined the underlying mechanisms. We conducted two consecutive experiments with two clonal plants (Pistia stratiotes and Eichhornia crassipes). In the first experiment, the mother ramet of P. stratiotes and E. crassipes were grown in two nutrient levels and treated with a DNA demethylation reagent (5-azacytidine) or not. In the second experiment, the offspring ramets from each of the four treatments in the first experiment were grown alone (no competition) or with a heterospecific neighbor (with interspecific competition). We found no parental nutrient effect on the competitive ability of E. crassipes, but a significant parental nutrient effect of both E. crassipes and P. stratiotes on the competitive ability of P. stratiotes. Furthermore, the parental nutrient effect of P. stratiotes on the competitive ability of P. stratiotes varied depending on the DNA methylation status of both P. stratiotes and E. crassipes. These clonal parental effects were related to resource provisioning and/or DNA methylation. We conclude that clonal parental nutrient effects can regulate interspecific competition between P. stratiotes and E. crassipes by altering the competitive ability of P. stratiotes. Both resource provisioning and epigenetic mechanisms can be involved in these clonal parental effects. By regulating interspecific competition, clonal parental effects may further influence species coexistence, community structure, and ecosystem functioning.