Search

• Using SEM and LM, we examined nutlet samples at various stages, revealing stylopodium's structure. • Germination tests evaluated stylopodium's impact on seed germination under differing water conditions. • Study of five cyperoideae species, including those with both persistent and deciduous stylopodium, showed a consistent ontogenetic origin. • A revealed abscission layer in species with deciduous stylopodium, shed light on this unique trait. • Germination tests showed that persistent stylopodium potentially enhances seed germination, even in water challenges. The stylopodium is a reproductive feature found in the nutlet (fruit) of non-closely related Cyperoideae genera, with little known about its origin and function. We analyzed the stylopodium of Bulbostylis hirtella, Eleocharis sellowiana, Rhynchospora albiceps and R. sparsiflora (with a persistent stylopodium), as well as Fimbristylis dichotoma (with a deciduous stylopodium) to investigate their development and anatomical structure, previous related to water supply. The role of this structure on seed germination was tested in E. sellowiana and F. dichotoma under varying water availability conditions. The results demonstrated that the origin of the stylopodium can be traced to the enlargement of the style base, composed of tracheoids with water-related characteristics. An abscission layer was identified in deciduous stylopodium. Eleocharis sellowiana exhibited significantly higher percentages and rates of seed germination in relation to F. dichotoma , even in challenging water conditions. These findings suggest a potential role of the stylopodium in promoting seed germination, particularly under low water supply. The study emphasizes the significance of considering both historical and current ecological contexts when discussing the function of the stylopodium. Moreover, it underscores the need for further research to fully understand the role of the stylopodium across diverse environments within Cyperoideae genera. [ABSTRACT FROM AUTHOR]

IntroductionRice rationing is one of the ways to increase rice production without expanding the cultivation area. Currently, the average ratoon rice production fa unit area is very low, and one of the most important reasons is the decrease in yield due to the lack of control or improfa control of weeds. Weed control in ratoon rice is difficult for various reasons such as lack of water and big weed seedlings after harvesting the main crop of rice. In rice ratooning, unlike the main rice cultivation, in which several methods such as puddling, flooding, manual weeding and herbicides are used to manage weeds, the control of weeds is limited to foliar herbicides. Currently, there is not much information about ratoon rice weed control, therefore, investigating the efficiency of different herbicides in this field can lead to the introduction of high-efficiency herbicides in controlling weeds and thus improving the yield of ratoon rice fa unit area. Materials and Methods This research was carried out during the 2017 and 2018 crop seasons in the research fields of Rice Research Institute of Iran in Gilan and Mazandaran provinces. The studied herbicide treatments were; Doses of 25, 38, 50, and 63 g/ha, a.i of bispyribac sodium SC 10% (Chif), doses of 31, 47, and 63 g/ha, a.i of bispyribac sodium SC 12.5% (Vejin), 40 g/ha, a.i of bispyribac sodium SC 40% (Clean-weed), 25 g/ha, a.i of bispyribac sodium SC 10% (Nomini), 1398 g/ha, a.i of propanil + benzosulfuronmethyl DF 46.6% (Stamdox), 1150 g/ha, a.i of bentazon + MTHPA SL 46% (Bazagran), 45 g/ha, a.i of Triaphamon + Ethoxysulfuron WG 30% (Council) and weedy control. The rice cultivar used in the main cultivation in both locations was Hashemi. The main rice seedlings were transplanted in 20 x 20 cm planting distance. Visual assessment of weeds control and weed biomass measurement were done in two stages. The evaluation of phytotoxicity and growth disorders of herbicides on rice plant and the effectiveness of them in weed control was carried out based on the European standard system. Results and DiscussionThe results showed that bispyribac sodium herbicide, up to 63 g/ha, a.i, did not lead to visible phytotoxicity symptoms in ratoon rice. In Gilan province, Four weeks after herbicide application, the biomass of barnyardgrass (Echinochloa crus galli) in the weedy check was 35 g/m2. The range of barnyardgrass biomass varied from 19 g/m2 for Stamdax to 32 g/m2 for Bazagaran herbicide. Six weeks after spraying, Vejin herbicide (47 and 63 g/ha, a.i), Clean-weed and Nomini had the lowest amount of barnyardgrass biomass with 26, 20, 23 and 26 g/m2, respectively. Which were 71, 78, 75 and 71 facent reduction compared to the weedy check (91 g/m2). The highest efficiency in the sedge (Schoenoplectus maritimus) control was also recorded in the same four treatments. Four weeks after herbicide application, weedy check had the highest weed biomass fa unit area with 53 g, although it did not have a significant difference with Stamdax, Clean-weed, Nomini and Vejin herbicide recommended dose. Bazagaran and Council had the lowest amount of sedge biomass with 30 and 32 g/m2, respectively. Sedge biomass reached 150 g/m2 six weeks after herbicide application in the weedy check. Twice the recommended dose of Vejin herbicide with 21 g/m2 had the highest efficiency (86%) in sedge control compared to the weedy check. Although there was no significant difference in this respect with the Nomini, Cleanweed and 150% of Vejin herbicide recommended dose. The lowest efficiency with 35 and 37% belonged to Chif and Stamdax herbicide treatments, respectively. The highest paddy yield with 1683 kg/ha was observed in Clean-weed herbicide treatment, which was 237% increase compared to the weedy check control (710 kg/ha). In Mazandaran province, two herbicides, Stamdax and Bazagaran, were the most effective in reducing weed biomass with 90% and 87%, respectively. This was while the highest paddy yield was observed in Clean-weed and Nomini herbicide treatments (2180 and 2210 k kg/ha, respectively). Conclusion This study demonstrated that bispyribac-sodium herbicide effectively controlled weeds in rice ratooning without causing any visible signs of phytotoxicity to the rice plants. This positive outcome led to a significant increase in grain yield. Among the different formulations of this herbicide, Nomini (25 g/ha, a.i) and Cleanweed (40 g/ha, a.i) had the highest efficiency in weed control and as a result, increasing the paddy yield. Therefore, bispyribac sodium herbicide can be used as a suitable replacement for current herbicides in rice ratooning. [ABSTRACT FROM AUTHOR]

Certain plants have been identified with the capability to take up metallic and metal oxide nanoparticles (ENPs), thus suggesting their potential role in phytoremediation. The reported study evaluated the response of two aquatic plants, sedge (Carex rostrata) and cattail (Typha latifolia), on their exposure to Ag, ZnO, TiO2, BiVO4/Pd, and Cu2O/Pd nanoparticles over 15 weeks. Plant physiological responses (chlorophyll content, carbonic anhydrase (CA) activity, leaf area, production of new shoots, and root length) varied according to the plant species and ENP type. By week 15, sedge treated with BiVO4/Pd ENP had a high chlorophyll content and increased CA activity and leaf area compared to the control. In contrast, cattail had reduced chlorophyll levels and number of new shoots when exposed to exogenously applied BiVO4/Pd. Highest sedge chlorophyll content at week 15 was measured in the mixed-ENPs, Cu2O, and Ag (53.2, 35.8, and 32.7%, respectively, greater than the control). The ZnO ENPs were beneficial for sedge chlorophyll content, cattail shoot production and root length. The mixed-ENPs treatment imparted positive effects to several sedge properties (CA and new shoots) and cattail (chlorophyll, leaf area, and root length). Additional research is needed to assess the capabilities of different aquatic plant species to tolerate metal-based ENPs for remediation purposes. HIGHLIGHTS Sedge and cattail plants were exposed to five nanoparticle types over 15 weeks.; Plant physiological response varied with plant species and ENP type.; Cu2O nanoparticles resulted in the reduction of several physiologic variables.; ZnO ENPs were beneficial for shoot production and root growth in cattail.; BiVO4 ENPs were often beneficial to sedge but detrimental to cattail.;

Wastewater from agricultural source carries excess nitrogen and phosphorous into wetlands and causes eutrophication in waterbody. Enrichment of nitrogen and phosphorous affects the natural nutrient removal and plant growth in wetlands. We conducted a greenhouse experience to explore the effects of excess N and P on the growth of Carex schmidtii, so as to provide evidence for wetland phytoremediation. The results showed that high concentration of N had negative effects on the plant height and growth rate of C. schmidtii. Excess N and P significantly reduced the leaf morphology and mass per plant or leaf but increased the length and the ratio of withered leaf. Furthermore, the chlorophyll content and lid peroxidation indicated that high concentrations of N and P exerted much injury to the blades of C. schmidtii. These results help in understanding the responses of C. schmidtii to agricultural wastewater and suggest the limited capacity of C. schmidtii tussock for the phytoremediation of agricultural wastewater in wetlands. [ABSTRACT FROM AUTHOR]

Rhynchospora mesoatlantica sp. nov. (Cyperaceae) is described, illustrated, and compared with morphologically similar species. Rhynchospora mesoatlantica is known only from southern Delaware, southeastern Maryland, and southern New Jersey, all within the Mid-Atlantic region of the U.S.A. It inhabits sunny, wet margins of natural, shallow, nutrient-poor, seasonal ponds of the Coastal Plain. Narrow leaf blades; fruits obpyriform in outline; faces of mature fruits possessing a central, pale, well-demarcated disk; and fruit tubercle margins denticulate for most of their lengths indicate R. mesoatlantica is most similar to R. filifolia and R. harperi. Rhynchospora mesoatlantica is unique in its fruit dimensions, scales intermediate in length between R. filifolia and R. harperi, and relatively long fruit stipe. The NatureServe rank of Critically Imperiled and the IUCN rank of Endangered appear warranted for R. mesoatlantica because only six populations are known to be extant, most quite small and isolated; all populations occur within a small geographic area; populations have declined; and serious threats confront the survival of the species. [ABSTRACT FROM AUTHOR]

During the first author's doctoral research, in part developed at the New York Botanical Garden and guided by William Wayt Thomas, several new species of Rhynchospora were discovered when revising NY herbarium specimens. In this study, we describe and name one of these species as Rhynchospora waytii, in honor of this renowned sedge specialist and friend. Rhynchospora waytii is closely related to R. nanuzae but displays distinguishing characteristics such as broader leaves, inconspicuous rhizomes, and larger spikelets and stylopodia. It also exhibits a peculiar disjunct distribution, occurring in Brazil and Argentina, which is explored here with models of geographical range evolution and suitable area of occupancy. Our analysis suggests that suitable habitats have historically existed along the Atlantic coast, extending to the La Plata estuary, near the location where the Argentinian specimens were collected. [ABSTRACT FROM AUTHOR]

Habitat restoration frequently focuses on reaching an idealized steady state, but this is unrealistic for disturbance‐dependent ecosystems where temporal variability is inherent and habitat conditions are expected to fluctuate. Understanding the ways in which the outcomes of restoration change over time in disturbance‐dependent ecosystems can better inform adaptive management plans and increase the likelihood that restoration efforts will be effective. We conducted a decade‐long restoration experiment to test how restoration efforts to increase disturbance levels impact habitat quality and populations of an endangered butterfly over time. We show that changes in plant communities as a response to disturbance vary depending on time since restoration, with target host plants initially increasing and peaking several years postrestoration but then declining. In the absence of further disturbance, butterfly population sizes follow a similar pattern, with population declines concurrent with declines in host plants. Due to this nonlinear response, management actions within disturbance‐dependent ecosystems need to include long‐term monitoring in order to accurately capture changes in habitat response, as well as active, adaptive planning that shifts according to current system stability. Restoration efforts within these dynamic habitats are more likely to succeed when temporal variability is explicitly tracked and multiple cycles of restoration are considered as part of management actions. [ABSTRACT FROM AUTHOR]

There are 96 species of the genus Carex (Cyperaceae) known in the flora of Ukraine, but so far there are no data about its hybrids for the country yet. However, the first one, C. × takhtadjanii [C. diluta × C. distans], was discovered in Starobilsk town (Luhansk region) during a field investigation in 2021. Detailed information about this floristic finding with the description of morphological characters of this hybrid and its habitat is given. Also a map with known locations of C. × takhtadjanii around the world is compiled, as well as the main morphological differences between this hybrid and its parental species are reported. [ABSTRACT FROM AUTHOR]

Eriophyoid mites (Acariformes, Eriophyoidea) are microscopic chelicerates morphologically greatly preadapted to endoparasitism on plants. Members of at least six phylogenetically distant eriophyoid genera from two families homoplastically transitioned to endoparasitism and acquired the ability to penetrate under the plant epidermis and feed on parenchymatous cells, usually causing necrosis. Theoretically, endoparasites are expected to show patterns of codivergence with hosts more than ectoparasites. Novophytoptus Roivainen 1947 is the only eriophyoid genus comprising exclusively endoparasitic species living in subepidermal tissues of herbaceous monocots of three families of the order Poales: Cyperaceae, Juncaceae, and Poaceae. Here, we described two new endoparasitic species, N. limpopoensis n. sp. and N. zuluensis n. sp., from southern African sedges Carex spicatopaniculata Boeckeler ex C.B.Clarke and C. zuluensis C.B.Clarke, respectively, and investigated the Cox1 phylogeny of Novophytoptus. Contrary to expectations, molecular phylogenetics did not recover host-specific mite clades associated with Cyperaceae and Juncaceae, but revealed geographical groups of Novophytoptus species from Africa and Eurasia. Our results provide a substantial basis for future coevolutionary studies on novophytoptines, which will be possible when more species and sequences of Novophytoptus from geographically remote regions and from diverse hosts representing all major clades of Poales become available for analyses. [ABSTRACT FROM AUTHOR]

Weeds negatively influence agricultural production. However, those losses depend on weed specie, its time of emergence, and period of interference on agricultural crops. Synthetic herbicides are commonly used to control these plants species; however, they may cause damage to the environment, human beings and animals health, and this problem justify the need to develop alternative bioherbicides. To evaluate the allelopathic potential of Ricinus communis (Castor bean) and light spectrum variation on the emergence and growth of Cyperus rotundus L., a trial was carried out in a protected environment with 15% of brightness reduction at the Center for Agricultural and Environmental Sciences at the Paraíba State University. Four aqueous extract concentrations of R. communis leaves were tested (0, 5, 10, and 15%) and four light spectrums variations (white, purple, blue, and red lights). Variables such as emergence, length, dry matter accumulation and growth rates of shoots and root of C. rotundus seedlings were assessed. Data were analyzed by normality test, analysis of variance, polynomial regression, and averages test. Soot and root emergence, length, and dry matter accumulation of C. rotundus seedlings were reduced due to the allelopathy caused by R. communis aqueous extract leaves (15% concentration) and under purple or red light spectrum radiation. [ABSTRACT FROM AUTHOR]

Weeds negatively influence agricultural production. However, those losses depend on weed specie, its time of emergence, and period of interference on agricultural crops. Synthetic herbicides are commonly used to control these plants species; however, they may cause damage to the environment, human beings and animals health, and this problem justify the need to develop alternative bioherbicides. To evaluate the allelopathic potential of Ricinus communis (Castor bean) and light spectrum variation on the emergence and growth of Cyperus rotundus L., a trial was carried out in a protected environment with 15% of brightness reduction at the Center for Agricultural and Environmental Sciences at the Paraíba State University. Four aqueous extract concentrations of R. communis leaves were tested (0, 5, 10, and 15%) and four light spectrums variations (white, purple, blue, and red lights). Variables such as emergence, length, dry matter accumulation and growth rates of shoots and root of C. rotundus seedlings were assessed. Data were analyzed by normality test, analysis of variance, polynomial regression, and averages test. Soot and root emergence, length, and dry matter accumulation of C. rotundus seedlings were reduced due to the allelopathy caused by R. communis aqueous extract leaves (15% concentration) and under purple or red light spectrum radiation.

Introduction: Burrowing activities of plateau pikas cause widespread bare patches in alpine meadows on the Qinghai-Tibet Plateau, affecting the plant community composition and forage production. However, it is not clear how these bare patches influence the main forage composition in alpine meadows. Methods: Therefore, we investigated the plant communities in bare patches (BP) and neighboring control plots (CK) in alpine meadows in Maqu county in the Gannan region of China. Results: Our results showed that plant communities in the CK plots differed from those in the BP plots. The sedge cover, number of sedge species and number of grass species were all significantly higher in the CK plots compared to the BP plots. However, grass cover and its dry weight were significantly higher in the BP plots. Grass cover and the grass dry weight in the BP plots were 1.859 times and 1.802 times higher than that in the CK plots across the five sites, respectively. Grasses also had a significantly higher cover and dry weight than sedge in the BP plots, grass cover was 66.5 times higher than the sedge cover, and the grass dry weight was 68.242 times that of the sedge dry weight. Therefore, bare patches resulting from plateau pika burrowing activity significantly increase the grass/sedge ratio in alpine meadows. Discussion: A potential explanation is that grasses have a stronger reproductive potential than sedges in bare soil. This has implications for pasture yields since grasses have a higher biomass per unit area compared to sedges in alpine meadows. [ABSTRACT FROM AUTHOR]

Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is a significant agricultural and environmental weed found in tropical island countries including north Queensland, Australia. It is a prolific seed producer and consequently forms a high-density seedbank, and therefore understanding the longevity and persistence of the seeds can provide critical information required for the management of this species. A laboratory-controlled artificial ageing experiment was conducted where the seeds were exposed to a temperature of 45 °C and 60% relative humidity for 125 days. Seeds were removed at various times (1, 2, 5, 9, 20, 30, 50, 75, 100 and 125 days) and their viability determined through standard germination tests. It took 20 days in the artificial ageing environment for the seeds to decline to 50% viability which indicates that Navua sedge has relatively short-lived persistent seeds. These findings will assist in developing a better understanding of the seedbank dynamics of this invasive species, allowing managers to tactically implement control strategies and prepare budgets for ongoing treatments, and have implications for the duration and success of management programs. [ABSTRACT FROM AUTHOR]

Cyperus aromaticus (Navua sedge) is a problematic perennial weed in pastures and crops including sugarcane, banana, rice, and fruits and vegetables in tropical climates. It reproduces both via rhizomes and seeds. As a regenerative and storage organ, these rhizomes play an important part in the invasion, establishment, and persistence of this weed. To eliminate their regenerative ability, it is important to understand the regrowth potential with respect to rhizome fragment size and burial depth. This study evaluated the emergence of C. aromaticus from rhizomes in a controlled condition. Three different sizes of rhizome fragments were buried at seven depths of up to 20 cm in two soil types. The experimental measurements included (i) the time for tillers to emerge, (ii) the cumulative emergence of tillers, recorded weekly, and (iii) the number of underground emerging tillers. The cumulative shoot emergence and the number of underground tillers produced were found to be positively correlated with the initial length of the rhizome fragments and negatively correlated with the burial depth. The time for the emergence of the tillers was negatively correlated with the burial depth, and soil type had no significant effect on any of the parameters recorded. There was no emergence recorded from rhizomes buried at 15 cm depth and deeper, irrespective of their size. Our results indicate that the combination of the fragmentation of rhizomes into small pieces and a deep burial, below 15 cm, is an important aspect to control the regeneration of C. aromaticus from rhizomes, if tillage is carried out, and can therefore form a part of an integrated weed management strategy for this troublesome weed. [ABSTRACT FROM AUTHOR]

Based on study of herbarium specimens, Cyperus rosattii is described as a new species from Venezuela. Known from a single collection from the Orinoco lowlands, it appears to be most similar to Cyperus swartzii and C. aggregatus. Similarly, Cyperus gonzaleziae is described as a new species from eastern Mexico (coastal region of Veracruz); it appears to be most similar to C. pallidicolor and C. regiomontanus. [ABSTRACT FROM AUTHOR]

Peatlands store an immense pool of soil carbon vulnerable to microbial oxidation due to drought and intentional draining. We used amplicon sequencing and quantitative PCR to (i) examine how fungi are influenced by depth in the peat profile, water table and plant functional group at the onset of a multiyear mesocosm experiment, and (ii) test if fungi are correlated with abiotic variables of peat and pore water. We hypothesized that each factor influenced fungi, but that depth would have the strongest effect early in the experiment. We found that (i) communities were strongly depth stratified; fungi were four times more abundant in the upper (10-20 cm) than the lower (30-40 cm) depth, and dominance shifted from ericoid mycorrhizal fungi to saprotrophs and endophytes with increasing depth; (ii) the influence of plant functional group was depth dependent, with Ericaceae structuring the community in the upper peat only; (iii) water table had minor influences; and (iv) communities strongly covaried with abiotic variables, including indices of peat and pore water carbon quality. Our results highlight the importance of vertical stratification to peatland fungi, and the depth dependency of plant functional group effects, which must be considered when elucidating the role of fungi in peatland carbon dynamics.

Laboratory and field measurements and mathematical models indicate that engineered nanoparticles (ENPs) escape to the environment during manufacture and use. It is expected that the majority of released ENPs eventually enter freshwater environments. Many aquatic (freshwater) plants are known to tolerate high levels of pollution and may serve as useful indicators of ENP fares. Cattail (Typha latitblia) and sedge (Carex rostrata) served as test plants. Healthy plants were placed into plastic vessels containing dilute nutrient solution. Plants were exposed to five ENP types (ZnO, Ti02, BiVO.4, Cu:10, and Ag) (three replications of each) for 15 weeks. At weeks 5,10, and 15, plant tissues were haivested and processed for recovery of ENPs, Shoot tissue was digested using a microwave system, and samples are currently being analyzed for ENPs via ICP-AES. Selected plant variables such as leaf enzyme activity, chlorophyll production, shoot height, root length, toxicity symptoms and leaf area were determined. Every week PH and EC of the nutrient medium were measured using a pH meter and EC meter, respectively. TEM/SEM was used to visualize ENP particle size and degree of aggregation, and also the presence of nanoparticles in plant roots and shoots. The findings of this study can provide useful data regarding the ability of common aquatic plants to remediate nanoparticle-contaminated aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Cyperus verloovei is described as a new species of Cyperus section Incurvi from northern South America (Guyana and Venezuela). It is most similar to C. grandisimplex from which it is distinguished by its narrower spikelets, smaller scales, and oblong-ellipsoid achenes. A key is provided for all species of section Incurvi in the Neotropical region. [ABSTRACT FROM AUTHOR]

Objective: the objective of this work was to test potential herbicides, tested in a single dose of each commercial product as indicated in the package insert. Materials and Methods: the experiment was carried out in two trials, pre- and post-emergent, in a completely randomized block design with eight treatments and three replications in an 8x3 factorial scheme. The test was carried out in a BOD oven at 25º and 12 hours/light photoperiod in sand beds containing sedge rhizomes, visual evaluations were performed 7 and 14 days after herbicide application, in both tests, followed by a tretrazolium test at the end. of visual evaluation in tubers that did not germinate, thirty days after pre-emergent application. Results: the most efficient control was the herbicide of the Organoarsenic group (MSMA) which presented 0.67% of viable rhizomes in the pre-emergent assay and 0.33% of viable rhizomes in the post-emergent assay. Conclusion: the herbicide of the organoarsenic chemical group (MSMA) was the most efficient for the control of nutsedge in both trials. The herbicides ethoxysulforan and glyphosate showed control efficiency in the post-emergence assay.

Purpose: Aerenchymous plants are an important control for methane efflux from peatlands to the atmosphere, providing a bypass from the anoxic peat and avoiding oxidation in the oxic peat. We aimed to quantify the drivers of aerenchymous peatland species methane transport and the importance of this process for ecosystem-scale methane efflux. Methods: We measured seasonal and interspecies variation in methane transport rate per gram of plant dry mass at a boreal fen and bog, which were upscaled to ecosystem-scale plant methane transport. Results: Methane transport rate was better explained by plant species, leaf greenness and area than by environmental variables. Leaves appeared to transport methane even after senescence. Contrary to our expectations, both methane transport rate and the proportion of plant transport were lower in the fen (with greater sedge cover) than in the bog site. At the fen and bog, average methane transport rate was 0.7 and 1.8 mg g−1 d−1, and the proportion of seasonally variable plant transport was 7–41% and 6–90%, respectively. Species-specific differences in methane transport rate were observed at the ecosystem-scale: Scheuchzeria palustris, which accounted for 16% of the aerenchymous leaf area in the fen and displayed the greatest methane transport rate, was responsible for 45% of the ecosystem-scale plant transport. Conclusion: Our study showed that plant species influence the magnitude of ecosystem-scale methane emissions through their properties of methane transport. The identification and quantification of these properties could be the pivotal next step in predicting plant methane transport in peatlands. [ABSTRACT FROM AUTHOR]

Our field surveys and specimen examination of Carex from southern to south-western regions in China resulted in the discovery of five new species and one new variety, which are here named as Carex brevihispida X.F.Jin & Y.F.Lu (in sect. Surculosae), C. puberuliutriculata Y.F.Lu & X.F.Jin (sect. Clandestinae), C. paratatsiensis Y.F.Lu & X.F.Jin (sect. Aulocystis), C. huanjiangensis S.Yun Liang ex Y.F.Lu & X.F.Jin (sect. Decorae), C. liangiana X.F.Jin & Y.F.Lu and C. thibetica Franch. var. angustifolia X.F.Jin & Y.F.Lu (sect. Rhomboidales). [ABSTRACT FROM AUTHOR]

Eriophyoid mites (Acariformes, Eriophyoidea) are microscopic chelicerates morphologically greatly preadapted to endoparasitism on plants. Members of at least six phylogenetically distant eriophyoid genera from two families homoplastically transitioned to endoparasitism and acquired the ability to penetrate under the plant epidermis and feed on parenchymatous cells, usually causing necrosis. Theoretically, endoparasites are expected to show patterns of codivergence with hosts more than ectoparasites. Novophytoptus Roivainen 1947 is the only eriophyoid genus comprising exclusively endoparasitic species living in subepidermal tissues of herbaceous monocots of three families of the order Poales: Cyperaceae, Juncaceae, and Poaceae. Here, we described two new endoparasitic species, N. limpopoensis n. sp. and N. zuluensis n. sp., from southern African sedges Carex spicatopaniculata Boeckeler ex C.B.Clarke and C. zuluensis C.B.Clarke, respectively, and investigated the Cox1 phylogeny of Novophytoptus. Contrary to expectations, molecular phylogenetics did not recover host-specific mite clades associated with Cyperaceae and Juncaceae, but revealed geographical groups of Novophytoptus species from Africa and Eurasia. Our results provide a substantial basis for future coevolutionary studies on novophytoptines, which will be possible when more species and sequences of Novophytoptus from geographically remote regions and from diverse hosts representing all major clades of Poales become available for analyses.

Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is a significant agricultural and environmental weed found in tropical island countries including north Queensland, Australia. It is a prolific seed producer and consequently forms a high-density seedbank, and therefore understanding the longevity and persistence of the seeds can provide critical information required for the management of this species. A laboratory-controlled artificial ageing experiment was conducted where the seeds were exposed to a temperature of 45 °C and 60% relative humidity for 125 days. Seeds were removed at various times (1, 2, 5, 9, 20, 30, 50, 75, 100 and 125 days) and their viability determined through standard germination tests. It took 20 days in the artificial ageing environment for the seeds to decline to 50% viability which indicates that Navua sedge has relatively short-lived persistent seeds. These findings will assist in developing a better understanding of the seedbank dynamics of this invasive species, allowing managers to tactically implement control strategies and prepare budgets for ongoing treatments, and have implications for the duration and success of management programs.

Vast areas of boreal peatlands are impacted by linear disturbances known as seismic lines. Tree removal and ground disturbance alter vegetation communities and are expected to change ecosystem functioning. As boreal landscapes continue to be disturbed by linear disturbances, understanding the magnitude and mechanisms of vegetation and phenology changes is the first step toward predicting carbon cycling changes across broad spatial scales. We investigate seismic line disturbances on peatland plant community composition and phenological patterns using readily available digital photography at a bog and a fen in Alberta, Canada. Our objectives were to: (a) compare the understory peatland vegetation on seismic lines with those in adjacent undisturbed areas using two phenological metrics (green and red chromatic coordinates); (b) evaluate if vegetation greenness is directly related to vegetation community composition, and (c) determine whether plot‐scale greenness predicts plant productivity. We found that areas of peatlands intersected by seismic lines have an earlier seasonal peak (maximum greenness) compared to undisturbed areas, and vegetation communities had a stronger relationship to greenness and gross primary production (GPP) at disturbed areas relative to undisturbed areas. This change in understory vegetation results in greater CO2 uptake in disturbed areas. We demonstrate an easy‐to‐use application of digital photography that successfully quantifies phenological changes in boreal peatland vegetation. This nondestructive method for understanding vegetation phenology eliminated the need for fixed infrastructure and allowed us to expand our sampling capacity and study sites while allowing for repeated measures in the future. Plain Language Summary: Industrial activities for oil and gas mining across boreal North America can result in a vast network of linear disturbances called seismic lines. These are narrow clearings cut across peatlands and forests, resulting in the removal of trees and compaction to the soil, leading to changes in both the vegetation communities and how these ecosystems function. One such impact is how the ground‐layer vegetation communities green up over the course of the growing season and how this affects how productive they are. In this study, we investigated the greenness patterns of vegetation communities at two different peatland types impacted by seismic lines. To do this, we collect photographs using smartphones, alongside vegetation surveys and carbon exchange measurements. We found that these disturbances significantly impact the greenness of these communities, with disturbed areas becoming more productive faster. Using smartphones to collect photographs provided a quick and easy method to collect greenness data without the need for expensive equipment or fixed infrastructure. As boreal peatlands continue to be under threat from increased disturbances, this study provides a first step in understanding how greenness and productivity may change in the future. Key Points: Seismic lines cause a shift in vegetation communities and changes in green leaf phenology and greenness metricsReadily available smartphone photography successfully captured the phenological characteristics of these vegetation typesThe change in vegetation causes greater CO2 uptake in the disturbed areas and greenness metrics were good predictors of these CO2 changes [ABSTRACT FROM AUTHOR]

High-elevation ecosystems are expected to be particularly sensitive to climate warming because cold temperatures constrain biological processes. Deeper understanding of the consequences of climate change will come from studies that consider not only the direct effects of temperature on individual species, but also the indirect effects of altered species interactions. Here we show that 20 years of experimental warming has changed the species composition of graminoid (grass and sedge) assemblages in a subalpine meadow of the Rocky Mountains, USA, by increasing the frequency of sedges and reducing the frequency of grasses. Because sedges typically have weak interactions with mycorrhizal fungi relative to grasses, lowered abundances of arbuscular mycorrhizal (AM) fungi or other root-inhabiting fungi could underlie warming-induced shifts in plant species composition. However, warming increased root colonization by AM fungi for two grass species, possibly because AM fungi can enhance plant water uptake when soils are dried by experimental warming. Warming had no effect on AM fungal colonization of three other graminoids. Increased AM fungal colonization of the dominant shrub Artemisia tridentata provided further grounds for rejecting the hypothesis that reduced AM fungi caused the shift from grasses to sedges. Non-AM fungi (including dark septate endophytes) also showed general increases with warming. Our results demonstrate that lumping grasses and sedges when characterizing plant community responses can mask significant shifts in the responses of primary producers, and their symbiotic fungi, to climate change.

Background: Mental performance improvement has been among the entities with considerable attention by scientists since long time ago. Nowadays, tendency to use of chemicals, and sometimes detrimental agents, has increased. This is while hypothesis has been raised about the use of natural agents such as honey, saffron, and sedge to improve mental performance, based on their antioxidant and alkaloid ingredients. The current study aimed to assess the efficacy of triple combination of honey-saffron-sedge on university students’ mental performance. Methods: This was a pilot-controlled clinical trial study conducted on 60 students of Isfahan University of Medical Sciences, Isfahan, Iran, in years 2017-18. Students were randomly divided into two 30-member groups of intervention (30 mg saffron, 5 g honey, and 500 mg sedge) and control (500 mg starch and 5 g sugar). Students' normal diet was recorded in nutrition checklist by students in three consecutive days prior to study initiation, and then three consecutive days immediately following intervention cessation, and the micronutrients of two groups were compared and matched using Nutritionist software. Participants used mentioned agents twice a day for a period of two months. The Auditory-Visual Learning Test (AVLT) test was conducted and compared before and after two months for students. Findings: There were no significant differences between the two groups regarding age and gender (P > 0.05). Moreover, in terms of micronutrients, the diet of the two groups was matched (P > 0.05). According to VALT test, two groups were different in the subtests of recall following second time of words reading (P = 0.004) for the control group before and after the test, but not intervention group. There was no significant difference between the two groups in any fields of VALT (P > 0.05). Conclusion: Two-month use of triple combination of honey-saffron-sedge in students did not improve mental performance on the basis of VALT's questionnaire compared with the control group. There is little information in this regard, and further studies using new doses, conducting on greater number of majors and varieties of communities, and by use of more various mental assessing tests are recommended.

Indirect influences of phenology on productivity (e.g., phenology-functional traits-productivity) could exist due to close associations between phenology and plant functional traits, which may further result in the divergent responses of vegetation biomass to phenology among plant functional groups (PFGs). Here, we introduced functional traits (i.e., plant height and growth rate) to analyse the influences of phenology on aboveground biomass (AGB) of two symbiotic PFGs based on 19-year in-situ observational data for plant phenology at 7 sites across the Tibetan Plateau alpine grasslands. The vegetative growth phase (VGP) and reproductive growth phase (RGP) were calculated according to the observed green-up date, first flowering date and first fruit-ripening date. The commonality analysis and structural equation modelling were applied to explore the paths and degrees of phenological influence on AGB. The results showed that the phenological influences on herbaceous AGB included both direct (“phenology-AGB”) and indirect paths (“phenology-functional traits-AGB”) and differed between two PFGs. Phenological metrics, especially VGP, were the key factors driving the adjustment (path coefficients |w| = 0.19 – 0.67), although maximum plant height (Hmax) contributed to the most to the AGB (|w| = 0.78). Specifically, the grasses had two indirect phenological influence paths on AGB, while the sedges had multiple direct and indirect influence paths. Comparing the differences in phenology and functional traits between two PFGs, our study implied that grasses may tend to preferentially adjust vegetative (stem) growth via phenology, while sedges may tend to preferentially adjust root and reproductive growth via phenology, which could be relevant to the differences in the synthesis, accumulation, allocation, and decomposition of organic matter in diverse organs and the growth and reproduction strategies, competition and symbiosis of different PFGs.

The Tricostularia Nees ex Lehm. group of genera is reviewed and formally recognised as Cyperaceae tribe Schoeneae subtribe Tricostulariinae R.L.Barrett, K.L.Wilson & J.J.Bruhl. Molecular data from plastid rbcL and trnL–F and nuclear ITS and ETS regions are combined with a novel assessment of morphological characters to support our new classification. Six genera are included: a new genus, Ammothryon R.L.Barrett, K.L.Wilson & J.J.Bruhl, and the named genera Chaetospora R.Br., Morelotia Gaudich., Tetraria P.Beauv., Tricostularia, and Xyroschoenus Larridon. Ammothryon, Chaetospora and Tricostularia are all endemic to southern Australia. Morelotia has one species each in Hawaii, French Polynesia and New Zealand, and three species in southwest Western Australia. Tetraria has a disjunct distribution in Southern Africa, Borneo, New Guinea and New Caledonia. Xyroschoenus is endemic to the Seychelles. Tetrariopsis C.B.Clarke (based on Tetrariopsis octandra (Nees) C.B.Clarke) is included under an expanded concept of Morelotia, which also includes Tetraria australiensis C.B.Clarke and Tetraria microcarpa S.T.Blake from south-west Western Australia. Tricostularia bennettiana R.L.Barrett & K.L.Wilson, Tricostularia davisii R.L.Barrett & K.L.Wilson, Tricostularia lepschii R.L.Barrett & K.L.Wilson, Tricostularia newbeyi R.L.Barrett & K.L.Wilson, and Tricostularia sandifordiana R.L.Barrett & K.L.Wilson are described as new species from south-west Western Australia. The following new combinations are made: Ammothryon grandiflorum (Nees ex Lehm.) R.L.Barrett, K.L.Wilson & J.J.Bruhl, Morelotia australiensis (C.B.Clarke) R.L.Barrett & K.L.Wilson, Morelotia microcarpa (S.T.Blake) R.L.Barrett & K.L.Wilson, Morelotia octandra (Nees) R.L.Barrett & J.J.Bruhl and Tricostularia drummondii (Steud.) R.L.Barrett & K.L.Wilson. Tricostularia drummondii is reinstated from synonymy (formerly Discopodium drummondii Steud.), having previously been confused with T. exsul (C.B.Clarke) K.L.Wilson & R.L.Barrett. Lectotypes are selected for Chaetospora flexuosa var. gracilis Boeckeler, Discopodium drummondii Steud., Elynanthus grandiflorus Nees ex Lehm., Lampocarya affinis Brongn., Lepidosperma exsul C.B.Clarke, Morelotia gahniiformis Gaudich. var. minor A.Rich., Tetraria australiensis C.B.Clarke, Tetraria capillacea var. intercedens Kük., Tricostularia compressa Nees ex Lehm. and Tricostularia neesii Lehm. [ABSTRACT FROM AUTHOR]

After Poaceae and Orchidaceae, Cyperaceae is the third largest family of monocots. It is also called the Sedge-family. Plants of this family are tolerant to different environmental stresses as they can grow in wide range of environmental conditions. Its largest genera include Carex and Cyperus. Cyperus containing the 600 species of sedges. Approximately, 22 genera and 179 species have been reported to be found in Pakistan. Plants of family Cyperaceae are found in a variety of habitat types such as high altitude, steep slopes, extreme aridity, swamps, extreme salinity, moist areas and marshes. Cyperus is the largest genus of Cyperaceae family. The transverse sections of stems of different species of Cyperus collected from different areas of Punjab including desert and semi-desert, were cut. The stem sections and soil samples were investigated to analyze the adaptations in stem anatomy with respect to changes in soil parameters. The results showed diverse modifications in the stem area, vascular bundle thickness, phloem cell area, metaxylem cell area, collenchyma cell area, sclerenchyma thickness, and epidermal cell area in different plants depending on the type of soil of the particular region. The modifications were parallel to increased growth rate of the plant in that region. [ABSTRACT FROM AUTHOR]

Plants adopt different morphological and physiological strategies for their survival while their anatomical characters are mostly unidentified. Angiosperm and herbaceous plants developed insignificant water transporting channels and storage tissues called parenchyma to survive against environmental stresses. Detailed surveys were conducted throughout the Punjab region for the collection of different species of sedges from different soils. The purpose of the study was to investigate the root anatomical adaptation to salinity stress. The densely spread roots help in plant growth in both temporal and tropical regions. Thick epidermis and endodermis make them drought-resistant by restricting water loss during a wide variety of temperature fluctuations. Larger vascular bundles and thicker cortical area in roots are also significant features of these species to store and transport maximum water from the soil. Each population displayed unique modifications of anatomical characteristics, suggesting its adaptability capacity to a specific environmental situation. Water deficient area showed Intensive sclerification in the root vascular zone, large metaxylem vessels, vascular area and stomatal density. [ABSTRACT FROM AUTHOR]

Methane emission feedbacks in wetlands are predicted to influence global climate under climate change and other anthropogenic stressors. Herein, we review the taxonomy and physiological ecology of the microorganisms responsible for methane production in peatlands. Common in peat soils are five of the eight described orders of methanogens spanning three phyla (Euryarchaeota, Halobacterota and Thermoplasmatota). The phylogenetic affiliation of sequences found in peat suggest that members of the thus-far-uncultivated group Candidatus Bathyarchaeota (representing a fourth phylum) may be involved in methane cycling, either anaerobic oxidation of methane and/or methanogenesis, as at least a few organisms within this group contain the essential gene, mcrA , according to metagenomic data. Methanogens in peatlands are notoriously challenging to enrich and isolate; thus, much remains unknown about their physiology and how methanogen communities will respond to environmental changes. Consistent patterns of changes in methanogen communities have been reported across studies in permafrost peatland thaw where the resulting degraded feature is thermokarst. However much remains to be understood regarding methanogen community feedbacks to altered hydrology and warming in other contexts, enhanced atmospheric pollution (N, S and metals) loading and direct anthropogenic disturbances to peatlands like drainage, horticultural peat extraction, forestry and agriculture, as well as post-disturbance reclamation. [ABSTRACT FROM AUTHOR]

The population of Rocky Mountain water shrew Sorex navigator occurring in the White Mountains, Arizona, is isolated, genetically divergent, and of conservation concern. However, little is known about its distribution and habitat use due to difficulty capturing animals during previous surveys. The objectives of this study were to report captures of S. navigator that occurred during a survey for the New Mexico jumping mouse Zapus luteus luteus that expand its known distribution, evaluate habitat of capture sites, report natural history observations, and describe methods for capturing S. navigator. We captured 17 S. navigator at six sites, making this the most successful survey for this population. The records included two new sites and confirmation of the persistence of two historical populations considered extirpated. At the landscape scale, elevation was the best predictor of sites for capture of S. navigator. We captured Rocky Mountain water shrews on small cold-water streams and seeps on saturated soil with high vertical cover of herbaceous plants primarily consisting of sedges Carex. Sherman live traps were ideal for capturing S. navigator, if set appropriately. Given the population's restricted distribution, fragile habitat, and ongoing threats, conservation measures may be warranted. [ABSTRACT FROM AUTHOR]

This study focuses on the current distribution and habitat preferences of the sedge Kyllinga nemoralis. It is a weed on Mo'orea but an invasive to other islands of hte Pacific. Annual precipitation, temperature, water availability, soil moisture, soil type, canopy cover and elevation are shown to influence the distribution of this species. A minor transplant study affirms its preference of full sun locations to those with low light due to canopy cover.

Elderberry rust (Puccinia sambuci Schwein.) Arthur (=P. bolleyana) (Arthur, 1921) disease is frequently found in commercial American elderberry (Sambucus nigra L. subsp. canadensis L.) plantings when an alternate host, Carex sp., is present. To evaluate potential infection periods of P. sambuci on elderberry plants, micrometeorological conditions were monitored. Rust symptoms were observed on elderberry on 5 Apr. 2016, and conditions favorable for possible infection were 9 to 18 °C, ≥3 hours of continuous leaf wetness, and ≥85% relative humidity. Studies were also conducted to ascertain whether P. sambuci with varying pustule numbers affects fruiting, berry puree quality, or vegetative growth. Fruit yield was reduced by 31% when potted 'Bob Gordon' elderberry averaged six rust pustules per plant compared with noninfected plants. In another experiment, field-grown 'Wyldewood' plants averaging 137 rust pustules/cane at harvest had 47% less fruit weight on canes than uninfected canes. Titratable acidity of fruit puree from plants was lower when plants had either 690 rust pustules/plant or 137/ pustules/cane, but soluble solids and pH of puree were unaffected by P. sambuci infection. The effect of rust infection on vegetative growth of elderberry plants also varied with pustule numbers. With a low infection level (six pustules per plant), P. sambuci did not induce premature leaf loss on 'Bob Gordon' plants or adversely affect shoot dry weight at the end of the growing season. When P. sambuci infection on 'Wyldewood' plants was more severe (137 pustules/cane), greater leaf loss occurred on infected canes than on uninfected canes. At very high infection levels (690 pustules/plant), 'Bob Gordon' plant dry weight was reduced. Because of the potential for fruit yield loss on elderberry plants, control of P. sambuci at relatively low infection levels on this plant may be warranted. Strategies that eliminate or suppress the alternate host would likely reduce the P. sambuci inoculum and limit the potential for elderberry plant infection. [ABSTRACT FROM AUTHOR]

Questions: Are graminoids more poorly detected than other life forms of vascular plants in surveys? How well do observer‐, species‐, and site‐specific variables explain variation in detection of Carex species across forests of different structure? Location: Northeastern Alberta, Canada. Methods: Species inventories were assessed within 50 belt transects, each 100 m in length and 2 m in width. Pseudoturnover was estimated for four life forms and all encountered species. Site‐specific factors were then compared with pseudoturnover of all vascular plants and graminoids using generalized linear regression. Carex detection probabilities were compared based on morphological groups. Detection success at a site and delays in detection within a site were assessed using logistic regression with AIC used to rank a‐priori hypotheses and standardized variables used to determine effect sizes of parameters related to plant detectability. Results: Pseudoturnover for graminoids was similar to that for other life forms and best related to ground layer cover. Morphological groups related to differences in detection, with short, small‐inflorescence Carex most poorly detected. Detection failure was best explained by species abundance and morphology, but delays were more tied to a site's vegetation structure and species abundance than to species morphology. Conclusions: Surveys targeting graminoids, including species of Carex, can achieve high detection rates with high survey effort over small areas, but should consider species‐ and site‐specific biases in detection success. Abundance is likely the most influential factor in determining detection success, and this must be accounted for when searching for low‐density species. We recommend that increased effort (time, repeat observations) be applied when searching for morphologically small graminoids. Imperfect detection is inevitable in surveys, and the degree to which this causes bias against certain taxa is unclear. Graminoids were not more overlooked than other life‐forms, but detectability varies within this group. Abundance and species morphology were the most important determinants of detection success among Carex. Our study showed clear bias toward short, small‐inflorescence Carex, even given high survey effort. [ABSTRACT FROM AUTHOR]

Rhynchosporamesoatlantica sp. nov. (Cyperaceae) is described, illustrated, and compared with morphologically similar species. Rhynchosporamesoatlantica is known only from southern Delaware, southeastern Maryland, and southern New Jersey, all within the Mid-Atlantic region of the U.S.A. It inhabits sunny, wet margins of natural, shallow, nutrient-poor, seasonal ponds of the Coastal Plain. Narrow leaf blades; fruits obpyriform in outline; faces of mature fruits possessing a central, pale, well-demarcated disk; and fruit tubercle margins denticulate for most of their lengths indicate R.mesoatlantica is most similar to R.filifolia and R.harperi . Rhynchosporamesoatlantica is unique in its fruit dimensions, scales intermediate in length between R.filifolia and R.harperi , and relatively long fruit stipe. The NatureServe rank of Critically Imperiled and the IUCN rank of Endangered appear warranted for R.mesoatlantica because only six populations are known to be extant, most quite small and isolated; all populations occur within a small geographic area; populations have declined; and serious threats confront the survival of the species., Competing Interests: The authors have declared that no competing interests exist., (Amanda Treher Eberly, Robert F. C. Naczi.)

Stratigraphic accretion of dormant propagules in soil can result in natural archives useful for studying ecological and evolutionary responses to environmental change. Few attempts have been made, however, to use soil‐stored seed banks as natural archives, in part because of concerns over nonrandom attrition and mixed stratification. Here, we examine the persistent seed bank of Schoenoplectus americanus, a foundational brackish marsh sedge, to determine whether it can serve as a resource for reconstructing historical records of demographic and population genetic variation. After assembling profiles of the seed bank from radionuclide‐dated soil cores, we germinated seeds to "resurrect" cohorts spanning the 20th century. Using microsatellite markers, we assessed genetic diversity and differentiation among depth cohorts, drawing comparisons to extant plants at the study site and in nearby and more distant marshes. We found that seed density peaked at intermediate soil depths. We also detected genotypic differences among cohorts as well as between cohorts and extant plants. Genetic diversity did not decline with depth, indicating that the observed pattern of differentiation is not due to attrition. Patterns of differentiation within and among extant marshes also suggest that local populations persist as aggregates of small clones, likely reflecting repeated seedling recruitment and low immigration from admixed regional gene pools. These findings indicate that persistent and stratified soil‐stored seed banks merit further consideration as resources for reconstructing decadal‐ to century‐long records that can lend insight into the tempo and nature of ecological and evolutionary processes that shape populations over time. [ABSTRACT FROM AUTHOR]

Abstract: Question: Peatlands are globally important for carbon storage due to the imbalance between plant biomass production and decomposition. Distribution of both live standing biomass (BM, dry mass g/m2) and biomass production (BMP, dry mass g m−2 growing season−1) are known to be dependent on the water table (WT). However, the relations of BM and BMP to WT variation are poorly known. Here we investigated, how the above‐ and below‐ground BM and BMP of three different plant functional types (PFTs), dwarf shrubs, sedges and Sphagnum mosses, relate to natural WT variation within an ombrotrophic boreal bog. In addition, we estimated ecosystem‐level BMP and compared that with ecosystem net primary production (NPP) derived from eddy covariance (EC) measurements. Location: Siikaneva bog, Ruovesi, Finland. Methods: We quantified above‐ and below‐ground BM and BMP of PFTs along the WT gradient, divided into six plant community types. Plant community scale BM and BMP were up‐scaled to the ecosystem level. NPP was derived from EC measurements using a literature‐based ratio of heterotrophic respiration to total ecosystem respiration. Results: BM varied from 211 to 979 g/m2 among the plant community types, decreasing gradually from dry to wet community types. In contrast, BMP was similar between plant community types (162–216 g/m2), except on nearly vegetation‐free bare peat surfaces where it was low (38 g/m2). Vascular plant BM turnover rate (BMP:BM, per year) varied from 0.14 to 0.30 among the plant community types, being highest in sedge‐dominated hollows. On average 56% of the vascular BM was produced below ground. Mosses, when present, produced on average 31% of the total BM, ranging from 16% to 53% depending on community type. EC‐derived NPP was higher than measured BMP due to underestimation of certain components. Conclusions: We found that the diversity of PFTs decreases the spatial variability in productivity of a boreal bog ecosystem. The observed even distribution of BMP resulted from different WT optima and BMP:BM of dwarf shrubs, sedges and Sphagnum species. These differences in biomass turnover rate and species responses to environmental conditions may provide a resilience mechanism for bog ecosystems in changing conditions. [ABSTRACT FROM AUTHOR]

Carex arizonica M. Licher, G. Rink, and A. A. Reznicek (Cyperaceae) is a new species of riparian sedge in Arizona, USA and apparently Chihuahua, Mexico. Previously, these plants were determined variously as Carex meadii, C. aurea, or C. hassei. Carex meadii, reported from Arizona based on this entity, is now not known within Arizona. With mostly three stigmas, Carex arizonica would seem to be most closely related to C. klamathensis, a serpentine endemic in southwestern Oregon and northwestern California, which belongs to section Paniceae. However, the widespread Carex aurea of section Bicolores, which usually has flowers with two stigmas, may have played a role in the origins of C. arizonica. [ABSTRACT FROM AUTHOR]

The genus name Limnobaris Bedel is applied in a restricted sense to baridine weevils with a covered pygidium and non-prominent, decussate mandibles which occur on sedges in the Palaearctic Region and immediately adjacent parts of tropical Southeast Asia. Calyptopygus Marshall and Pertorcus Voss are syn. n. of Limnobaris. Some species from Africa and the Americas are maintained provisionally in Limnobaris in the widest sense but will need to be transferred to other genera in future studies. A total of eleven species is recognized in Asia, two of which are widespread and occur also in the Western Palaearctic Region. Limnobaris martensi Korotyaev sp. n. is described from Nepal. Pertorcus tibialis basalis Voss is raised to species rank, as L. basalis (stat. prom.). New or reestablished synonyms are L. dolorosa (Goeze) (= L. jucunda Reitter, = L. koltzei Reitter), L. tibialis (Voss) (= Pertorcus tibialis pilifer Voss) and L. t-album (Linnaeus) (= L. bedeli Reitter, = Baridius crocopelmus Gyllenhal, = L. sahlbergi Reitter, = L. scutellaris Reitter, = Baris t-album sculpturata Faust). Calandra uniseriata Dufour is considered a junior synonym of Sitophilus oryzae (L.) (syn. n.). A key for identification and a distribution map are provided.

Wet-seeded rice is a common method of sowing in Vietnam. Weeds, including weedy rice, however, are a major problem in this establishment method. A study was conducted in a farmer’s field to evaluate the effect of pretilachlor dose (0, 300, 600, and 900 g ai ha–1) on the management of weedy rice and other weeds in wet-seeded rice cultivation in the spring-summer, summer-autumn, and winter-spring seasons of 2012-13. The herbicide was applied 1 day after sowing. Weeds belonging to the grass, broadleaf, and sedge groups were effectively controlled by the lowest herbicide dose (300 g ha–1). Overall, weed control did not increase with increases in herbicide dose after 300 g ha–1, suggesting the optimum dose for pretilachlor in wet-seeded systems. The application of pretilachlor at 300 g ha–1 significantly reduced the number of weedy rice panicles (20 – 69%) and weedy rice biomass (15 – 26%). The highest pretilachlor dose (i.e., 900 g ha–1), however, was better than the lower doses in reducing the number of weedy rice panicles (47 – 80%) and weedy rice biomass (41 – 54%). The non-treated plots produced a rice grain yield of 210, 2000, and 1850 kg ha–1 in the spring-summer, summer-autumn, and winter-spring seasons, respectively. Compared with the non-treated plots, the lowest dose of pretilachlor improved grain yield. However, maximum yield was obtained by applying the highest dose of pretilachlor; 2690, 4490, and 5150 kg ha–1 in the spring-summer, summer-autumn, and winter-spring seasons, respectively. The results of our study suggest that a broad spectrum of weed flora can be easily managed by a lower dosage of pretilachlor in wet-seeded rice; however, the herbicide dose needs to be increased to 900 g ha–1 in order to decrease the weedy rice problem.

Vegetation composition and water surface area are changing in many tundra regions due to climate warming, which is twice as strong in the Arctic as compared to the global mean. Such land cover changes feed back to climate and permafrost thaw through altering the surface energy budget. We quantified the influence of vegetation type, canopy characteristics, and patchiness on the tundra shortwave radiation components. We used in situ measurements and vegetation mapping to parametrise a 3D radiative transfer model (DART) for summer conditions at the Kytalyk test site in northeast Siberia. We analysed model results assessing the most important drivers of canopy albedo, transmittance, and absorptance of photosynthetically active radiation (PAR). Tundra albedo was strongly influenced by the fractional cover of water surfaces. Albedo decreased with increasing shrub cover. However, plant area index effects on albedo were not statistically significant. Canopy transmittance and PAR absorptance (f APAR ) were almost entirely controlled by plant area index at the landscape scale. Only about one half of the total plant area index consisted of green leaves, while wood and standing dead leaves contributed equally to the other half. While spatial patterns and patch sizes of vegetation types and open water did not significantly influence the radiation budget at the landscape scale, it contributed to the large variability at the local scale. Such local variability of shortwave radiation may impact evapotranspiration and primary productivity at a range of scales. Therefore, the variation of radiation fluxes within single vegetation types potentially affects larger scale energy, water, and carbon fluxes. [ABSTRACT FROM AUTHOR]

The effects of increased tropospheric ozone (O 3 ) pollution levels on methane (CH 4 ) emissions from peatlands, and their underlying mechanisms, remain unclear. In this study, we exposed peatland mesocosms from a temperate wet heath dominated by the sedge Schoenus nigricans and Sphagnum papillosum to four O 3 treatments in open-top chambers for 2.5 years, to investigate the O 3 impacts on CH 4 emissions and the processes that underpin these responses. Summer CH 4 emissions, were significantly reduced, by 27% over the experiment, due to summer daytime (8 h day − 1 ) O 3 exposure to non-filtered air (NFA) plus 35 ppb O 3 , but were not significantly affected by year-round, 24 h day − 1 , exposure to NFA plus 10 ppb or NFA plus 25 ppb O 3 . There was no evidence that the reduced CH 4 emissions in response to elevated summer O 3 exposure were caused by reduced plant-derived carbon availability below-ground, because we found no significant effect of high summer O 3 exposure on root biomass, pore water dissolved organic carbon concentrations or the contribution of recent photosynthate to CH 4 emissions. Our CH 4 production potential and CH 4 oxidation potential measurements in the different O 3 treatments could also not explain the observed CH 4 emission responses to O 3 . However, pore water ammonium concentrations at 20 cm depth were consistently reduced during the experiment by elevated summer O 3 exposure, and strong positive correlations were observed between CH 4 emission and pore water ammonium concentration at three peat depths over the 2.5-year study. Our results therefore imply that elevated regional O 3 exposures in summer, but not the small increases in northern hemisphere annual mean background O 3 concentrations predicted over this century, may lead to reduced CH 4 emissions from temperate peatlands as a consequence of reductions in soil inorganic nitrogen affecting methanogenic and/or methanotrophic activity. [ABSTRACT FROM AUTHOR]

Premise of research. Determining population structure and the spatial distribution of existing genetic variation is important for prioritizing areas for conservation of endangered species. Specifically, identifying clusters of genetically differentiated populations ensures that the genetic diversity of a species is conserved. Scirpus ancistrochaetus, northeastern bulrush, is a federally endangered wetland sedge, found in eight states in the northeastern United States, for which little information on genetic structure is available. Methodology. We collected leaf samples from 96 separate wetlands spanning seven states and representing over half of all known sites (N p 71 sites). We sequenced eight variable loci, which were used to construct distance-based trees and calculate population-assignment probabilities to investigate population structure, and we tested isolation by distance by correlating genetic similarity with geographic distance among populations. Pivotal results. All plants sampled from the same wetland (i.e., a population) were genetically identical with low heterozygosity, and there was little to no variation among clustered wetlands within a site. Scirpus ancistrochaetus was genetically structured across its range. Notably, all populations from New England were genetically identical to each other but differed from all other populations, and a similar pattern was observed for northern Pennsylvania populations. Three genetic clusters were identified, including a primarily New England cluster, a primarily Pennsylvanian cluster, and a southern Appalachian cluster, and overall, genetic distances were consistent with isolation by distance. Although genetic clusters mostly corresponded with geography, some populations did not show this geographic-genetic association, suggesting long-distance dispersal; for example, one population from West Virginia was assigned to the New England cluster. Overall, the highest genetic diversity was found within Pennsylvania and nearby states. Conclusions. Whether similarity between geographically distant locations is due to animal-mediated gene flow or retention of ancestral alleles needs additional study. Additionally, the development of a large number of new markers may help to reveal diversity in areas such as New England with wetlands that did not have any diversity using our markers. Nevertheless, conservation of different genetic clusters at a regional scale is important for maintaining the genetic diversity of S. ancistrochaetus, particularly in its southern range, where the greater amount of genetic diversity suggests that this region is a reservoir of genetic variation. [ABSTRACT FROM AUTHOR]

Climate change is considered to alter the functioning of boreal peatland ecosystems, but the vulnerability of pristine, rewetted and drained peatlands to climate change in temperate regions is unknown. We measured carbon (C) gas exchange during wet (2009) and dry (2010) growing periods in pristine, drained and rewetted sites in mountain bogs in the Bohemian Forest (Czech Republic). Wetter lawns with sedges and drier habitats dominated by ericaceous shrubs were distinguished and studied at each site. Methane (CH4) emissions, which decreased in the order pristine > rewetted > drained, were generally lower during the 2010 growing period than in 2009 as a consequence of a drought. During the drought in 2010, photosynthesis (PG) in the drier habitats with shrub vegetation increased on pristine and rewetted sites, while total respiration (RECO) remained the same. Communities dominated by sedges maintained similar rates of PG and RECO during both growing periods. Generally, this led to higher C accumulation during the drought on pristine and rewetted bogs. At the drained bog site, the decreased water table (WT) during the drought led to increased PG and RECO, such that the net C accumulation was similar in the two years. Drained peatlands may be more threatened by future climate change than pristine or rewetted peatlands because of their limited buffering capacity for decreased WT. In the case of further decreases in WT, they could lose the peatland vegetation and functions that have partly persisted through decades of drainage.

Fatty acids in the fruits of 13 sedge species (Carex L., Cyperaceae) were analyzed. The oil contents in the fruits of the studied sedges ranged from 3.73 and 46.52%. In the studied fruit oils 14 different fatty acids were identified. The main unsaturated fatty acids were: linoleic, α-linolenic, oleic, oleopalmitic n-7; oleopalmitic n-9, octadecenic, and eicosenoic acids. The following acids were found in the greatest quantities: linoleic, oleic, α-linolenic and palmitic acids. Based on the fatty acid composition, studied taxa can be divided in two groups. The first group (C. flava, C. pseudocyperus, C. riparia, C. leporina) is a very good source of linoleic acid. The second group, including the remaining species, is a good source of α-linolenic acid. The highest oleic acid contents were observed in C. vulpina. The studied material has shown a low concentration of saturated fatty acids, among which palmitic acid was the main one.Results of the analyses allow for the inclusion of the studied species among plants whose fruits are characterized by a high content of unsaturated fatty acids.