Bolboschoenus Planiculmis Research Articles

Combined effect of temporal inundation and aboveground-cutting on the growth performance of two emergent wetland plants, Phragmites australis and Bolboschoenus planiculmis.

Phragmites australis is a common foundation species found in inland and brackish estuarine ecosystems. P. australis stands provide a wide range of habitats for wetland organisms and perform essential functions, such as nutrient cycling, pollutant filtration, wave energy reduction, and soil stabilization. However, excessive growth of P. australis can degrade the quality of wetland habitats, thereby reducing the functions of restored wetlands. In this study, we investigated the effectiveness of vegetation management techniques, such as aboveground cutting and temporal inundation with varying depth and periodicity, in controlling the growth performance of P. australis and adjacent vegetation, Bolboschoenus planiculmis. Differences in growth responses to manipulated inundation stress between P. australis and B. planiculmis were measured. Inundation stress of 10-50 cm caused significantly greater inhibition of growth performance in B. planiculmis compared to P. australis. The combination of aboveground-cutting and inundation treatments resulted in a significant inhibitory effect on the growth performance and survival rate of P. australis. The growth performance of P. australis, including stem volume and biomass, decreased and its mortality rate increased. Our manipulated experiment suggests a combined treatment approach of moderate inundation, such as 5-10 cm for 20-30 days, and aboveground cutting to manage the overgrowth of P. australis in restored brackish wetlands.

Chromosome-Scale Genome Assembly for Clubrush (Bolboschoenus planiculmis) Indicates a Karyotype with High Chromosome Number and Heterogeneous Centromere Distribution.

Bolboschoenus planiculmis (F.Schmidt) T.V.Egorova is a typical wetland plant in the species-rich Cyperaceae family. This species contributes prominently to carbon dynamics and trophic integration in wetland ecosystems. Previous studies have reported that the chromosomes of B. planiculmis are holocentric; i.e. they have kinetic activity along their entire length and carry multiple centromeres. This feature was suggested to lead to a rapid genome evolution through chromosomal fissions and fusions and participate to the diversification and ecological success of the Bolboschoenus genus. However, the specific mechanism remains uncertain, partly due to the scarcity of genetic information on Bolboschoenus. We present here the first chromosome-level genome assembly for B. planiculmis. Through the integration of high-quality long-read and short-read data, together with chromatin conformation using Hi-C technology, the ultimate genome assembly was 238.01 Mb with a contig N50 value of 3.61 Mb. Repetitive elements constituted 37.04% of the genome, and 18,760 protein-coding genes were predicted. The low proportion of long terminal repeat retrotransposons (∼9.62%) was similar to that reported for other Cyperaceae species. The Ks (synonymous substitutions per synonymous site) distribution suggested no recent large-scale genome duplication in this genome. The haploid assembly contained a large number of 54 pseudochromosomes with a small mean size of 4.10 Mb, covering most of the karyotype. The results of centromere detection support that not all the chromosomes in B. planiculmis have multiple centromeres, indicating more efforts are needed to fully reveal the specific style of holocentricity in cyperids and its evolutionary significance.

Weed survey on cotton (Gossypium hirsutum) fields in the Tarim River region of southern Xinjiang

AbstractThis study was conducted to investigate weed infestations of cotton (Gossypium hirsutum) fields in the region of Tarim River. Forty‐nine species among 17 families were identified in these cotton fields, and 24 of them were annuals. The eight dominant weed species in the cotton fields of Tarim River basin included Chenopodium glaucum, Solanum nigrum, Chenopodium album, Chenopodium hybridum, Bolboschoenus planiculmis, Sonchus arvensis, Phragmites australis, and Mulgedium tataricum. The number of weed species in the Aksu River tributary area, Yeerqiang River tributary area, and the upper and lower reaches of the Tarim River reached 29, 36, 35, and 33, respectively. Twenty species were found widely distributed among each basin. The dominant weeds in the cotton fields in the Aksu River basin and upper reaches of the Tarim River were S. nigrum and C. glaucum, those in the cotton fields in the Yarkand River basin included C. album and C. hybridum, and those in the cotton fields in the lower reaches of the Tarim River were C. glaucum and C. album. Notably the 20 common surveyed species of C. glaucum, S. nigrum, C. album, C. hybridum, B. planiculmis, S. arvensis, P. australis, M. tataricum, and others, could pose a serious challenge to regional crop production if not adequately controlled. As such, each cotton field should adopt a suitable weeding scheme with strengthened weed monitoring according to the local conditions, especially the weed distribution area characteristics.

A cyclic dipeptide for salinity stress alleviation and the trophic flexibility of endophyte provide insights into saltmarsh plant-microbe interactions.

In response to climate change, the nature of endophytes and their applications in sustainable agriculture have attracted the attention of academics and agro-industries. This work focused on the endophytic halophiles of the endangered Taiwanese salt marsh plant, Bolboschoenus planiculmis, and evaluated the functions of these isolates through in planta salinity stress alleviation assay using Arabidopsis. The endophytic strain Priestia megaterium BP01R2, which can promote plant growth and salinity tolerance, was further characterized through multi-omics approaches. The transcriptomics results suggested that BP01R2 could function by tuning hormone signal transduction, energy-producing metabolism, multiple stress responses, etc. In addition, the cyclodipeptide cyclo(L-Ala-Gly), which was identified by metabolomics analysis, was confirmed to contribute to the alleviation of salinity stress in stressed plants via exogenous supplementation. In this study, we used multi-omics approaches to investigate the genomics, metabolomics, and tropisms of endophytes, as well as the transcriptomics of plants in response to the endophyte. The results revealed the potential molecular mechanisms underlying the occurrence of biostimulant-based plant-endophyte symbioses with possible application in sustainable agriculture.

Influence of Seasonal Abiotic Factors and Co-Existing Salt Marsh Plants on the Growth and Reproduction of Zostera japonica in Fluctuating Estuarine Environments

In the biodiverse Nakdong River estuary, the predominant seagrass and salt marsh species, Zostera japonica and Bolboschoenus planiculmis, are declining due to human and natural pressures. Our study investigated how environmental factors and co-existing salt marsh vegetation impact the growth and reproduction of Z. japonica. Understanding the reproductive dynamics of Z. japonica in this estuary is crucial, as sexual reproduction ensures the resilience and stability of seagrass populations in challenging environments. This study revealed that approximately 49% of Z. japonica shoots flowered, yet none persisted to the subsequent growth season, indicating a reliance on sexual reproduction for population resilience. The presence of competing B. planiculmis shoots and Ulva pertusa indirectly suppressed the growth and reproduction of Z. japonica by reducing light availability. Additionally, environmental stresses that occurred during summer, such as elevated temperatures, reduced salinity, and sediment transport, likely affected the vegetative and reproductive performance of Z. japonica in this estuary. Consequently, Z. japonica in this estuary has adopted a mixed annual life history strategy in response to these environmental oscillations. Our findings highlight the vulnerability of the Z. japonica population to seasonal environmental shifts and interspecies competition in this estuary, offering essential considerations for its conservation and effective management.

Nitrogen availability affects the responses of marsh grass and sedge plants (Phragmites australis and Bolboschoenus planiculmis) to flooding time

Flooding time and external nitrogen (N) input have been projected to be the main threats to marsh ecosystems in the scenario of more intense flooding events and N deposition. How flooding and N addition experienced at different growth stages interact in determining phenotypic change remains scarce. We established a controlled experiment (3 flooding time treatments x 5 N addition levels) using two herbaceous marsh species (Phragmites australis and Bolboschoenus planiculmis) to assess the responses of six key traits to environmental changes and the indication of plant performance. Early flooding reduced plant height and aboveground biomass of P. australis and below/aboveground biomass ratio of B. planiculmis and increased below/aboveground biomass ratio of P. australis and root biomass of B. planiculmis, whereas late flooding reduced root biomass of P. australis and ramet number and aboveground biomass of B. planiculmis. The combination of flooding and high N (16 and 32 g N m−2) exerted negative effects on ramet number of both plant species. The interaction of early flooding and low-medium N (8 and 16 g N m−2) inhibited clonal/belowground biomass ratio of both plant species. The combination of early flooding and low N (0, 4 and 8 g N m−2) promoted root biomass and below/aboveground biomass ratio of P. australis. Ramet number, plant height, and root biomass explained 80–90 % of aboveground biomass variation of both plant species, and the contribution of ramet number was greater than that of the other two traits. These results highlight that the influence of flooding time and external N input on the performance of marsh plants depends on species identity. Meanwhile, the ramet number-plant height-root biomass (RHR) strategy is supposed to be the adaptation strategy of wetland clonal plants to environmental changes, and clonal reproductive traits should be incorporated into vegetation dynamics models for marsh plants.

Temperature and flooding depth thresholds for early recruitment stages in a bulbous plant Bolboschoenus planiculmis

Early recruitment process dominated by vegetation reproduction for wetland plant is a key life-history stage affecting species distribution. Extreme climatic events, such as extreme temperature and heavy rainfall have been predicted to become more intense and frequent under future climate scenarios. To explore the effect of temperature and flooding depth on tubers sprouting and early growth of Bolboschoenus planiculmis, we conducted two artificial experiments in the incubator and greenhouse, including ten temperature regimes (8, 10, 12, 14, 16, 19, 22, 25, 28 and 31 °C), and ten flooding depth treatments (− 5, 0, 3, 6, 9, 12, 16, 20, 30 and 40 cm). The results showed that the temperature and flooding depth had significant effect on the tuber sprouting and ramet early growth. The estimated base temperature for the sprouting is 6.2 °C, the final sprouting percentage increased parabolically with increasing temperature and reached a maximum of 61.09% at 25.4 °C. The final sprouting percentage increased first and then decreased with increasing flooding depth, and reached a maximum of 96.04% at 3.92 cm. The ramet height increased first and then decreased with increasing flooding depth, and reached a maximum of 61.29 cm at 8.20 cm. Our study will provide a basis for understanding and predicting the influence of climate change on the distribution of B. planiculmis.

Light–acquisition traits link aboveground biomass and environment in inner saline–alkaline herbaceous marshes

A functional response–effect approach could predict how environmental changes affect ecosystem functioning. However, few studies have applied this approach to inner saline–alkaline marsh ecosystems where soil saline–alkaline, flooding/drought and nutrients stresses threat ecological functioning. To disentangle the relationships between environmental conditions and ecosystem functioning, a total of 81 plots were investigated across 22 marsh sites dominated by Phragmites australis and Bolboschoenus planiculmis in Western Songnen Plain wetlands, China. For both plant communities combined, deep flooding supported communities with higher specific leaf area (SLA), plant height and leaf nitrogen (N) content but lower leaf thickness. On the contrary, high soil salt content induced low leaf N and phosphorus (P) content, SLA and plant height. Only light acquisition–related trait, plant height and SLA, was the key traits which determined the relationships between ecosystem functioning (aboveground biomass) and saline–alkaline wetland environment. Yet indirect key traits related nutrient and water acquisition such as leaf thickness, N and P content were also found, and mediated the response of aboveground biomass through the allometric relationships with plant height or SLA. For the individual species community, only plant height was the key trait shared by P. australis and B. planiculmis, indicating the universality of plant height as a key trait for grass and sedge plants to explain how ecosystem functioning responds to abiotic factors. Hence, our findings suggest that saltmarsh plants are more inclined to alter light–acquisition traits to mediate the response of ecosystem functioning to environmental changes and that plant height is a particularly useful trait to predict plant productivity in earth system models under future environmental changes in inner saline–alkaline wetlands.

A Plant Endophytic Bacterium Priestia megaterium StrainBP-R2 Isolated from the Halophyte Bolboschoenus planiculmis Enhances Plant Growth under Salt and Drought Stresses.

Global warming and climate change have contributed to the rise of weather extremes. Severe drought and soil salinization increase because of rising temperatures. Economically important crop production and plant growth and development are hindered when facing various abiotic stresses. Plant endophytic bacteria live inside host plants without causing visible harm and can be isolated from surface-sterilized plant tissues. Using plant endophytic bacteria to stimulate plant growth and increase environmental stress tolerance has become an alternative approach besides using the traditional breeding and genetically modifying approaches to select or create new crop types resistant to different environmental stresses. The plant endophytic bacterium, Priestia megaterium (previously known as Bacillus megaterium) strain BP-R2, was isolated from the surface-sterilized root tissues of the salt marsh halophyte Bolboschoenus planiculmis. The bacteria strain BP-R2 showed high tolerance to different sodium chloride (NaCl) concentrations and produced the auxin plant hormone, indole acetic acid (IAA), under various tested growth conditions. Inoculation of Arabidopsis and pak choi (Brassica rapa L. R. Chinensis Group) plants with the strain BP-R2 greatly enhanced different growth parameters of the host plants under normal and salt and drought stress conditions compared to that of the mock-inoculated plants. Furthermore, the hydrogen peroxide (H2O2) content, electrolyte leakage (EL), and malondialdehyde (MDA) concentration accumulated less in the BP-R2-inoculated plants than in the mock-inoculated control plants under salt and drought stresses. In summary, the plant endophytic bacterium strain BP-R2 increased host plant growth and stress tolerance to salt and drought conditions.

Flooding effects on population and growth characteristics of Bolboschoenus planiculmis in Momoge wetland, northeast China

Due to the interactive influences of climate change and human activities, flooding events are becoming an increasingly more serious abiotic stress in wetland ecosystems. Bolboschoenus planiculmis is a critical target plant species for the restoration of degraded wetland in the Momoge National Nature Reserve (MNNR), Northeast China. To investigate B. planiculmis growth response under different flooding conditions, we conducted comparative field studies of its population traits and ecological characteristics under alternate wetting to flooding (AF) and continuous flooding (CF) conditions. Under AF conditions, the B. planiculmis population significantly increased, its cover differed significantly (except June) compared to CF conditions, and flood stress significantly promoted its height. Flood events caused seasonal changes in morphological characteristics, especially stem and leaf length which increased in the growth period, and leaf width and area that significantly differed in June. B. planiculmis tuber biomass under CF condition was significantly higher than AF condition in May. B. planiculmis biomass was greater in AF, compared to CF conditions in the mid-late growth period, and its below-aboveground biomass ratio initially decreased before increasing, which indicated that the growth strategy was a trade-off between matter production and allocation during flooding. Flooding conditions had a significant effect on population traits and ecological characteristics, and AF conditions more strongly promoted B. planiculmis population development. Appropriate seasonal regulated floodwater management during the growth stage will assist B. planiculmis growth. Our findings provide invaluable supporting information for B. planiculmis MNNR wetlands restoration and management.

The complete chloroplast genome sequence of Bolboschoenus planiculmis (Cyperaceae)

Bolboschoenus planiculmis is a typical wetland sedge with both ecological and agricultural value. We report the first complete chloroplast genome sequence of this species. The total genome size is 186,539 bp, containing a large single-copy region (LSC) of 104,654 bp, a small single copy region (SSC) of 9,659 bp and two inverted repeats (IRs) of 36,113 bp by each. The GC content is 33.59%. The genome encodes 105 unique genes, including 71 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis shows this species has a strong sister relationship with Cyperus. Our work could be helpful in understanding the evolution of Cyperaceae.

Seasonal flooding regime effects on the survival, growth, and reproduction of Bolboschoenus planiculmis under East Asian monsoon

Seasonal flooding regimes are key hydrodynamic features in estuarine ecosystems, and are mainly influenced by climatic conditions. Today, the original seasonal flooding regimes can be altered due to artificial infrastructure or following sea-level rise. Although the altered flooding regimes determine flooding duration and depth, which further influence growth and development of marsh plants, little is known about the effects of seasonal flooding regimes on marsh plants under the East Asian monsoon climate zone. Therefore, we investigated the effects of different seasonal flooding regimes on survival, growth, and reproduction of the marsh plant Bolboschoenus planiculmis. A greenhouse experiment was conducted to compare the responses of B. planiculmis under combinations of four flooding durations (0-month, 2-month, 3.5-month, and 5-month) and flooding depths (0-cm, 20-cm, and 40-cm). Flooding duration affected the survival and growth of B. planiculmis: Extended flooding (5-month) decreased the survival rate and initial shoot density, while shoot length and biomass increased under extended (5-month) and natural (3.5-month) seasonal flooding after shoots reached the water surface. The flooding depth affected sexual reproduction: Medium flooding depth (20-cm) resulted in the highest flowering rate. According to the results, the natural seasonal flooding duration in the East Asian monsoon climate did not negatively influence survival, growth, and reproduction of B. planiculmis. However, if the seasonal flooding duration was extended, B. planiculmis responded negatively to survival and growth during the young stage. The shortened seasonal flooding duration resulted in the repressed shoot length and biomass of B. planiculmis. For the sustainable conservation of B. planiculmis under East Asian monsoon, it is important to maintain the original seasonal flooding regimes and minimize the effects of embankment on the seasonal flooding regimes.

Optimum water depth for restoration of Bolboschoenus planiculmis in wetlands in semi-arid regions

Optimum water depth for restoration of Bolboschoenus planiculmis in wetlands in semi-arid regions

Morphological and Physiological Traits Related to the Response and Adaption of Bolboschoenus planiculmis Seedlings Grown Under Salt-Alkaline Stress Conditions.

Soil saline-alkalization is expanding and becoming a serious threat to the initial establishment of plants in inland salt marshes on the Songnen Plain in Northeast China. Bolboschoenus planiculmis is a key wetland plant in this area, and its root tubers provide food for an endangered migratory Siberian crane (Grus leucogeranus). However, the survival of this plant in many wetlands is threatened by increased soil saline-alkalization. The early establishment of B. planiculmis populations under salt and alkaline stress conditions has not been well understood. The aim of this study was to investigate the response and adaption of the seedling emergence and growth of B. planiculmis to salt-alkaline mixed stress. In this study, B. planiculmis root tubers were planted into saline-sodic soils with five pH levels (7.31–7.49, 8.48–8.59, 9.10–9.28, 10.07–10.19, and 10.66–10.73) and five salinity levels (40, 80, 120, 160, and 200 mmol⋅L–1). The emergence and growth metrics, as well as the underlying morphological and physiological traits in response to salt-alkaline stress were explored for 2-week-old seedlings. The seedling emergence, growth, and leaf and root traits showed distinct responses to the pH and salt gradients. Under the lower saline-alkaline condition (pH ≤ 9.10–9.28 and salinity ≤ 80 mmol⋅L–1), the seedling growth was substantially facilitated or not significantly altered. Salinity affected the seedlings more significantly than alkalinity did. In particular, among the salt ions, the Na+ concentration had predominantly negative effects on all the morphological and physiological traits of the seedlings. Seedling emergence was more tolerant to salinity and, based on its observed close relationships with pH and the alkaline ion CO32–, was highly alkalinity-dependent. Moreover, the leaf area and photosynthetic rate, as well as the root surface area and tip number mainly accounted for the response of the seedling biomass to salt-alkaline stress. This is evidence of the adaption of B. planiculmis to saline-alkaline conditions largely due to the responses of its morphological and physiological traits. This study provides a mechanistic process-based understanding of the early seedling establishment of B. planiculmis populations in response to increased soil saline-alkalization in natural wetlands.

How soil ion stress and type influence the flooding adaptive strategies of Phragmites australis and Bolboschoenus planiculmis in temperate saline–alkaline wetlands?

Soil saline–alkaline stress and flooding extremes have been projected to be the main factors influencing the degradation of marsh plants in wetlands worldwide, which would affect their ecological functions (i.e. food source for migrating birds). Plants cope with flooding either by escaping from below water through shoot elongation or by remaining quiescent until water subsides. However, little is known about the adaptive strategies of Phragmites australis and Bolboschoenus planiculmis to flooding combined with salinity–alkalinity, which are the key environmental filters in Western Songnen Plain, China. Accordingly, this study investigated the adaptive strategies of P. australis and B. planiculmis subjected to the interacting effects of flooding and soil ion stress under field and greenhouse conditions. Results showed that the two species adopted different strategies to survive flooding. P. australis exhibited an escape strategy because of leaf and shoot elongation with increasing flooding depth whereas B. planiculmis became quiescent with no or deceased leaf and shoot elongation and biomass accumulation. High soil ion stress changed the flooding adaptive strategy of P. australis to a quiescence strategy, whereas B. planiculmis remained quiescent with increasing flooding depth at each soil ion content. The strategies of the two species were changed by alkaline ion stress but not by saline ion stress, and they exhibited different adaptive responses. High alkaline ion stress induced P. australis to remain quiescent with increasing flooding depth, whereas low alkaline ion stress promoted B. planicumis to escape from below water, probably due to the buffer effect of low alkaline ion contents outside the roots probably. Hence, P. australis and B. planicumis might adopt the quiescence strategy with increasing degree of soil salinization and alkalization under high greenhouse gas emissions scenarios in Western Songnen Plain, which may lead to severe degradation of the two kinds of marshes in the future.

Impacts of tidal restriction caused by embankments on the plastic growth responses of Bolboschoenus planiculmis in Korea

Tidal restriction caused by embankments can have large impacts on estuarial ecosystems. It changes the tidal regimes, which influence the growth and development of marsh plants. Although large-scale tidal freshwater marshes are negatively or positively affected by the embankments especially around the Yellow Sea in Korea, little is known regarding how the tidal restriction changes the plastic growth responses of marsh plants, which may cause a population decline in the field. Therefore, we evaluated the impacts of tidal restriction on the growth, plasticity in morphology, reproduction, and biomass allocation of the important but vulnerable marsh plant Bolboschoenus planiculmis in Korea. These responses of B. planiculmis in tidal marshes and tide-restricted marshes were compared. The tide-restricted marshes experienced deeper water (9 cm) and greater dominance of other species (51%) than the tidal marshes (respectively 0 cm, 20%). Populations in the tide-restricted marshes revealed a lower density (128 ramets m−2), decreased sexual reproduction ratio (6%), and higher short rhizome density ratio (17%) with a rapid increase in allocation to below ground biomass compared to the tidal marsh populations (respectively 1046 m−2, 35%, and 0.3%). A redundancy analysis indicated that B. planiculmis with a low density in the tide-restricted marshes developed more short rhizomes and allocated more energy to below ground biomass in order to persist in the original habitats where neighbor species dominated. On the other hand, the tidal marsh populations with higher densities invested more energy to sexual reproduction and developed more long rhizomes to expand into new areas. In this paper, tidal restriction caused the dominance of neighbor species such as Phragmites australis in standing water and negative impacts on B. planiculmis. These results indicate that the impacts of tidal restriction caused by artificial structures should be minimized by maintaining natural tides for sustainable management of B. planiculmis.

New floristic records from Central Europe 8 (reports 109-121)

The presented eighth part of the series includes thirteen new chorological records of vascular plants, one from Hungary, six from Poland and six from Slovakia. In Hungary, Ventenata dubia is reported. In Poland, two native taxa Bolboschoenus planiculmis and Najas marina subsp. marina and four alien taxa Buddleja davidii, Lupinus ehrenbergii var. ehrenbergii, Miscanthus sacchariflorus and Sedum sarmentosum are reported. In Slovakia, two native taxa Taraxacum paucilobum with distribution map and Cotoneaster integerrimus are reported as well as four alien taxa Azolla filiculoides, Eichhornia crassipes, Euphorbia prostrata and Pistia stratioites.

In-situ measurement of greenhouse gas emissions from a coastal estuarine wetland using a novel continuous monitoring technology: Comparison of indigenous and exotic plant species

This study investigated in-situ the seasonal and diurnal variation of emissions of greenhouse gases (GHGs) from both indigenous and exotic plant species and different environments in the Kaomei Estuary Wetland in central Taiwan with a self-designed non-dispersive infrared monitoring system. This study computed CO2 equivalent (CO2-e) emissions to identify their contribution to global warming. The net primary production and carbon sequestration were then estimated to determine the carbon budget of the coastal estuarine wetland. It concluded that the Kaomei Estuary Wetland functioned as a GHG source and a carbon sink. A significant diurnal variation of GHG emissions was observed, with generally lower daytime CO2 emissions than those at nighttime, while an opposite trend was observed for CH4 and N2O emissions. High solar radiation in the daytime enhanced the CO2 uptake by plant species via photosynthesis, and also accelerated the microbial activities in waters and soil/mud, both resulting in the decrease in atmospheric CO2 concentration. The highest GHG emissions were observed in summer, followed by fall, spring, and winter. Although the concentrations of GHG emissions from the coastal estuarine wetland were in the order as CO2>CH4>N2O, N2O has the highest impact on global warming. Biomass debris played an important role in carbon sequestration, which is stored in soils and muds and stimulated methanogenic bacteria to emit CH4. Tidal fluctuation and sewage discharge brought nitrogen-containing organics to the coastal estuarine wetland, resulting in high emission of N2O from nitrification and denitrification processes. Two vascular plants, Spartina alterniflora, and Phragmites australis emitted more GHGs than the other two plant species. However, the highest GHG emissions from the Kaomei Estuary Wetland was attributed to Bolboschoenus planiculmis due to its largest coverage area. The annual net primary production (NPP) varied mainly with vegetation coverage and season. The exotic Spartina alterniflora had the highest annual NPP compared to the indigenous plant species because of its high nutrient uptake from the soil/mud by its thriving roots.

The effect of temperature changes and K supply on the reproduction and growth of Bolboschoenus planiculmis

Abstract Aims Climate warming and agricultural non-point source pollution both resulting from anthropogenic activities have been projected to affect plant reproduction and growth in wetlands worldwide. In order to predict and mitigate impacts of these anthropogenic activities, it is important to investigate how marsh plants respond to such environmental changes. Methods In this study, Bolboschoenus planiculmis, a tuberous sedge with a wide distribution range in Eurasia, was selected to examine the effect of air temperature changes (15, 20 and 25 °C over 24 h; 20/10 and 30/15 °C, day/night) and K supply (0, 1, 3, 9 and 18 mmol/L) on its reproductive and growth traits in climate chambers. Important Findings We found that high constant temperatures (20 and 25 °C) were more beneficial for tuberization of B. planiculmis than high alternating temperatures (30/15 °C), whereas aboveground biomass and shoot height were generally largest at high temperatures (30/15 and 25 °C). Both reproductive and growth traits of B. planiculmis showed hump-shaped relationships with K supply, with an optimum K concentration of around 1–3 mmol/L. The combination of high constant temperatures and optimal K concentrations promoted reproductive traits the most, whereas the combination of higher temperatures (30/15 and 25 °C) and K concentrations up to 9 mmol/L increased growth traits only. We therefore conclude that population abundance of B. planiculmis might benefit from global warming and the additional K supply.

Importance of starting points in heterogeneous environments: interactions between two clonal plants with contrasting spatial architectures

AbstractAimsPlants can benefit from heterogeneous environments via disproportionately increasing resource harvesting in resource-rich patches. Their initial growing positions with respect to resource patches may thus have important influences on their performance and relative competitive ability. Such impacts may differ between species with contrasting spatial architectures. However, the potential influence of initial growing positions in heterogeneous environment on plant growth and competition has largely been ignored.MethodsWe grew the phalanx plant Carex neurocarpa and the guerrilla plant Bolboschoenus planiculmis alone or in competition in a heterogeneous environment consisting of high- and low-nutrient soil patches. In treatments without competition, one ramet of each species was grown in either a high- or a low-nutrient patch in the heterogeneous environment. In treatments with competition, a ramet of the target species was grown in either a high- or a low-nutrient patch, and a ramet of the competitor species was grown in the same patch as the target species or an adjacent patch with a different nutrient level.Important FindingsWithout competition C. neurocarpa produced more biomass and ramets when initially grown in a high-nutrient patch than when initially grown in a low-nutrient patch. With competition, these differences disappeared. Consequently, competitive intensity on C. neurocarpa was higher when it initially grew in a high-nutrient patch than when it initially grew in a low-nutrient patch. These impacts were independent of the initial position of its competitor. By contrast, the initial positions of B. planiculmis did not influence its growth or competitive response. Therefore, in heterogeneous environments, initial growing positions of clonal plants may influence their performance in competition-free environments and may also affect their relative competitive ability, and these effects may depend on spatial architecture of the plants.