Search

Tailings are among the most challenging mined substrates for plant re-establishment, in particular because of a lack of soil-like structure and nitrogen. Potential pioneer plants are sometimes found in such disturbed and infertile sites. We present a group of pioneer species from the genus Maireana (Chenopodiaceae) that are promising candidates for the restoration of magnetite tailings. We found that these Maireana species did not rely on biologically fixed N from the atmosphere, but exhibited an exceptionally high leaf N-resorption efficiency (about 95%) during leaf senescence, at the same time effectively scavenging trace amount of N from the substrate, in part through rapid transpiration., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Wetlands have attracted much attention due to releases of organophosphate esters (OPEs) and other emerging contaminants into this particular environment. Here, Suaeda salsa plants and wetland soils collected from Laizhou Bay, North China, were analyzed to investigate the levels, distribution, and soil-plant transfer of OPEs in these ecosystems. The Σ 18 OPEs concentrations ranged from 137 to 386 ng/g dry weight (dw), whereas in rhizosphere the concentrations were between 99.8 and 198 ng/g dw. Suaeda salsa rhizosphere could promote the absorption of OPEs in wetlands, and Suaeda salsa root presents a greater rate of absorption. The Σ 18 OPEs concentrations ranged from 32.9 to 56.8 ng/g dw in roots, 3.93 to 7.51 ng/g dw in stems, and 2.79 to 4.06 ng/g dw in leaves. Log RCFs, log TF r-s and log TF s-l showed no significant correlations with their log K OW , indicating the complexity of uptake and translocation in the natural environment. Predictive model for the OPEs availability to Suaeda salsa was established from the experimental data. The field-based BCFs of all OPEs were dependent on K OW , decreased with increasing K OW . This study provides important insights into the phytoremediation potential of OPEs using Suaeda salsa as an effective strategy and their role in environmental risk assessment of OPEs in wetlands., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Halimione portulacoides plants were exposed to dissolved cerium (Ce) in a hydroponic medium for five days. Ce accumulation in plants followed the metal's increase in the medium although with a very low translocation factor (TF < 0.01) between roots and shoots. Ce median concentrations in roots were 586, 988 and 1103 μg/g (dry wt.), while in shoots the median values reached 1.9, 3.5 and 10.0 μg/g (dry wt.), for plants exposed to 300, 600 and 1200 μg/L of Ce, respectively. No significant differences occurred in the length of roots and shoots among treatment groups, albeit plants exposed to the highest Ce concentration showed a clear loss of turgor pressure on the fifth day. An increase of hydrogen peroxide and malondialdehyde levels were observed in the plant shoots at 1200 μg/L of Ce. The highest concentration also triggered an answer by the shoots' antioxidant enzymes with a decrease in the activity of superoxide dismutase and an increase in peroxidase. However, no significant change in catalase activity was observed, compared to the control group, which may indicate that peroxidase played a more crucial role against the oxidative stress than catalase. Combined results indicate that H. portulacoides was actively responding to a toxic effect imposed by this higher Ce concentration. Nevertheless, changes in normal environmental conditions, may increase the bioavailability of Ce, while in areas where acid mine drainage may occur, the highest Ce concentration tested in this study may be largely exceeded, placing the sustainability of halophytes and estuarine marshes at risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In this work, eight plants of Juncus sp. and ten of Salicornia europaea were used for an uptake assay of pharmaceuticals (flumequine, cirpofloxacin, enrofloxacin, carbamazepine, diclofenac and ibuprofen) by irrigation at three concentration levels: 10 ng mL -1 (low level); 700 ng mL -1 (medium level) and 10 μg mL -1 (high level). Two plants irrigated with pharmaceutical-free water were set up as controls. For each level, two plants were watered every day with 50 mL (Juncus sp.) and every two days with 20 mL (Salicornia europaea) of aqueous solutions containing all the analytes at the described concentrations. Plants irrigated at 10 μg mL -1 were significantly the most affected, whereas the rest of the plants remained, in general, largely displayed no apparent physiological effects throughout the 30 days (Juncus sp.) and 21 days (Salicornia europaea) assays. Leaves and stems were cut every seven days and roots were collected at the end of the assay. The samples were lyophilized, submitted to a microwave assisted extraction using 5 mL of acetonitrile:water mixture (1:1, v/v) and they were analyzed (in triplicate) in a liquid chromatography-quadrupole time of flight mass spectrometry instrument. Most of the analytes were quantified in many of the samples corresponding to the three exposure levels with the highest concentrations obtained at high exposure levels. Ibuprofen was not detected in any sample and enrofloxacin, ciprofloxacin and diclofenac were not detected in the samples from Salicornia europaea., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Coastal wetlands are ecologically and economically important; however, they are currently faced with fragmentation and loss. Plants are a fundamental element of wetlands and previous researches have focused on wetland plant connectivity; however, these researches have been conducted at the landscape but not species level. Here, given that tidal flats are important areas in coastal wetlands, we investigated the connectivity characteristics of typical plant species and environmental factors in different wetland regions influenced by various tidal conditions to reveal vegetation connectivity and its relationship with environmental factors on a small-patch scale. We found that tides negatively affect plant connectivity because both the Tamarix chinensis and Suaeda salsa have the highest connectivity on river banks, which are not influenced by tides. Of two tidal regions, different tides conditions have different influence on two plant species. T. chinensis had higher connectivity in the supratidal zone, whereas S. salsa had higher connectivity in the intertidal zone. Besides, the soil water content and soil salinity were significantly different in the three regions, but the soil total nitrogen and phosphorous were not. Soil water content and soil salinity were two factors that significantly affected plant connectivity. Specifically, soil water content positively affected the connectivity of T. chinensis and S. salsa, whereas soil salinity negatively affected the connectivity of T. chinensis. Taken together, these results indicate that tidal conditions affect plant connectivity on a small-patch scale. River banks and supratidal zone are beneficial for the recovery and growth of T. chinensis, intertidal zone and river banks are more conducive to the recovery and growth of S. salsa. Based on the above research, this study provides insights that could be applied to vegetation restoration in coastal wetlands., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The consumption of halophytes as healthy gourmet food has increased considerably in the past few years. However, knowledge on the nutritional profile of domesticated halophytes is scarce and little is known on which cultivation conditions can produce plants with the best nutritional and functional properties. In this context, Salicornia ramosissima J. Woods was cultivated in six different salt concentrations, ranging from 35 to 465 mM of NaCl. Both the nutritional profile, the antioxidant capacity, and microbial quality of the produced plants were evaluated including minerals and vitamins. Salt has a marked effect on growth, which decreases for salinities higher than 110 mM. Nonetheless, plants cultivated with intermediate levels of salinity (110 and 200 mM) revealed better antioxidant status with higher amounts of phenolic compounds. Overall, results from this paper indicated that soilless culture systems using low-intermediate salinities produces S. ramosissima plants fit for commercialization and human consumption., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Polybrominated diphenyl ethers (PBDEs) are the ubiquitous contaminants in the coastal wetlands, with high persistence and toxicity. Environmental behaviors of PBDEs in sediment-plant system is a hot research area, where much uncertainties still occurred in field environment. In this study, the sediments and Suaeda heteroptera were synchronously collected to investigate the bioaccumulation and translocation of PBDEs in Liaohe coastal wetland. Mean concentrations of PBDEs in sediments, roots, stems and leaves were 8.37, 6.64, 2.42 and 1.40 ng/g d.w., respectively. Tissue-specific accumulation of PBDEs were detected in Suaeda heteroptera, with predominant accumulation in roots. Congener patterns of PBDEs were similar between sediments and roots, demonstrating root uptake as the key pathway of PBDE bioaccumulation. The proportions of lower brominated congeners increased from roots to leaves, implying the congener-specific translocation. Meanwhile, the lower brominated congeners exhibited higher sediment-tissue bioaccumulation (AFs) and translocation factors (TFs) compared to higher brominated congeners in Suaeda heteroptera, further verifying their preferential translocation. AFs and TFs of PBDEs were both not correlated with their log K ow , which was inconsistent with those of laboratory studies, reflecting the complicated behaviors of PBDEs in field environment. This is the first comprehensive report on bioaccumulation and translocation of PBDEs within Suaeda heteroptera in Liaohe coastal wetland., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Estuarine wetland is the transitional interface linking terrestrial with marine ecosystems, and wetland microbes are crucial to the biogeochemical cycles of nutrients. The soil samples were collected in four seasons (spring, S1; summer, S2; autumn, S3; and winter, S4) from Suaeda wetland of Shuangtaizi River estuary, Northeast China, and the variations of bacterial community were evaluated by high-throughput sequencing. Soil properties presented a significant seasonal change, including pH, carbon (C) and total nitrogen (TN), and the microbial diversity, richness and structure also differed with seasons. Canonical correspondence analysis (CCA) and Mantel tests implied that soil pH, C and TN were the key factors structuring the microbial community. Gillisia (belonging to Bacteroidetes) and Woeseia (affiliating with Gammaproteobacteria) were the two primary components in the rhizosphere soils, displaying opposite variations with seasons. Based on PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) prediction, the xenobiotics biodegradation related genes exhibited a seasonal decline, while the majority of biomarker genes involved in nitrogen cycle showed an ascending trend. These findings could advance the understanding of rhizosphere microbiota of Suaeda in estuarine wetland., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier B.V.)

Marine aquaponics is a promising sustainable approach for the production of profitable crops such as halophytes. However, the effect of this culture approach on the lipid composition of halophytes remains unknown. In this work, we contrasted the polar lipidome of Salicornia ramosissima and Halimione portulacoides when produced in marine aquaponics (effluent from a super-intensive flatfish aquaculture production), with that of conspecifics from donor wild populations. Phospholipids and glycolipids were identified and quantified by LC-MS and MS/MS and their profile statistically analysed. Halophytes produced in aquaponics have higher levels of glycolipids with n-3 fatty acids (DGDG 36:3; SQDG 36:3; MGDG 36:6) compared with the donor wild populations. In the case of H. portulacoides, a significant increase of phospholipids bearing n-3 fatty acids (most in PC and PE) was also recorded. These lipids have potential applications in food, feed and pharmaceutical industries, contributing to the valorization of halophytes produced under sustainable aquaculture practices., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

NAC transcription factors play a pivotal role in plant growth, development and response to abiotic stress. However, their biological functions in desert trees are largely unknown. In this work, the NAC transcription factor HaNAC1 from Haloxylon ammodendron, a typical wooden plant normally grown in desert, was isolated, and its possible role in plant growth and resistance to drought stress was investigated. HaNAC1 encodes an ATAF subfamily transcription factor containing one NAC domain with five conserved regions. Quantitative real time PCR analyses revealed that HaNAC1 was ubiquitously expressed in various tissues and organs such as roots, stems, leaves and seeds, with a predominant expression in stems. Further studies demonstrated that expression of HaNAC1 was significantly induced by osmotic stress in Haloxylon ammodendron seedlings, and subcellular localization analysis indicated that GFP-HaNAC1 fusion protein was localized to the nucleus in Arabidopsis leaf protoplast. Ectopic expression of HaNAC1 led to promoted growth and drought tolerance in transgenic Arabidopsis, accompanied with up-regulated expression of stress-inducible marker genes, and increased accumulation of proline, IAA and ABA under both normal and drought stress conditions. In addition, co-immunoprecipitation and Bi-molecular fluorescence complementation assays illustrated that HaNAC1 directly interacted with AtNAC32. All these results suggest that HaNAC1 is involved in both the growth and drought resistance of Haloxylon ammodendron, and could be used as a promising candidate gene for the breeding of crops with augmented tolerance to drought stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Salt is a major abiotic stress that negatively impacts plant growth and development. Research on the mechanisms of plant salt tolerance and the breeding of salt-tolerant plants is becoming an important research field. Transcription factors are master regulators that control the expression of many target genes, helping to regulate the response of plants to adverse conditions. GRAS are plant-specific transcription factors that play various roles in plant development and stress responses. However, the function of a GRAS gene identified in Halostachys caspica, a salt-tolerant plant with important ecological value, has not been determined. In this study, we characterized a novel gene (HcSCL13) encoding a GRAS transcription factor from H. caspica. Quantitative real-time (qRT)-PCR results indicated that HcSCL13 expression was induced by salt, drought and application of stress-related phytohormone abscisic acid (ABA). The HcSCL13 protein was localized in the nucleus with transactivation activity at the N terminus. Heterologous overexpression of HcSCL13 enhanced plant growth and salt tolerance in transgenic Arabidopsis. With HcSCL13 overexpression, plants had enhanced growth, as well as greater chlorophyll content, fresh weight and root elongation compared to the wild type. Transcriptomic analysis revealed that HcSCL13 overexpression affected the response to light/abiotic stimulus/hormone/organic substance, plant hormone signal-related and plant growth and development genes under normal and saline stress conditions. Taken together, these results indicate that HcSCL13 genes can modulate salt stress tolerance in Arabidopsis through the regulation of plant growth and the activation of gene expression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

This study aims to investigate the biological activities of endemic plant Anabasis aretioïdes harvested in eastern Morocco. Various extracts were prepared from aerial part by aqueous and organic extraction using a Soxhlet and cold maceration. Preliminary phytochemical analysis was carried out on the powder and on the different extracts by standard phytochemical tests, and was confirmed by a quantitative analysis based on the determination of total polyphenols and cathechic tannins. Antioxidant activity was evaluated in vitro by five methods: H 2 O 2 , DPPH, ABTS, FRAP, and RP, and the antibacterial activity was carried out by disc diffusion method and the determination of MIC and MBC. Phytochemical screening revealed the presence of cathechic tannins, saponins, and sterols and quantitative analysis showed that Ethyl acetate extract presented the high level of phenolic and cathechic tannins contents (46.79 ± 0.75  µ g GAE/mg E and 46.46 ± 0.67  µ g CE/mg E). A highest hydrogen peroxide activity was observed in aqueous macerated extract (7.84 ± 0.44%) and the macerated methanol extract has the highest rates for the other four antioxidant activity tests: It was able to reduce DPPH with an IC 50 of 52.91 ± 0.24  µ g/ml, the highest ABTS•+ radical scavenging capacity (48.99 ± 1.316  µ g TE/mg E), it showed also the highest antioxidant activity by the FRAP and reducing power test (99.73 ± 3.570  µ g TE/mg E and 72.176 ± 0.540  µ g AAE/mg E). Antibacterial screening showed that the maximum zone of inhibition was noted for ethyl acetate extract against Staphylococcus aureus (13.5 mm). The lowest MIC value was obtained with methanolic and macerated methanolic extracts against Protéus mirabilis strain (MIC = 3.125 mg/ml). Principal component analysis showed that the four methods ABTS, DPPH, FRAP, and RP are highly correlated and a correlation between the antioxidant activity and the total phenolic contents of the extracts indicated that phenolic compounds were the dominant contributors to the antioxidant activity of the plant., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2020 Souad Senhaji et al.)

Although only 2-4% of absorbed light is emitted as chlorophyll (Chl) a fluorescence, its measurement provides valuable information on photosynthesis of the plant, particularly of Photosystem II (PSII) and Photosystem I (PSI). In this paper, we have examined photosynthetic parameters of Suaeda fruticosa L. (family: Amaranthaceae), surviving under extreme xerohalophytic conditions, as influenced by diurnal rhythm or continuous dark condition. We report here CO 2 gas exchange and the kinetics of Chl a fluorescence of S. fruticosa, made every 3 hours (hrs) for 3 days, using a portable infra-red gas analyzer and a Handy PEA fluorimeter. Our measurements on CO 2 gas exchange show the maximum rate of photosynthesis to be at 08:00 hrs under diurnal condition and at 05:00 hrs under continuous dark. From the OJIP phase of Chl a fluorescence transient, we have inferred that the maximum quantum yield of PSII photochemistry must have increased during the night under diurnal rhythm, and between 11:00 and 17:00 hrs under constant dark. Overall, our study has revealed novel insights into how photosynthetic reactions are affected by the photoperiodic cycles in S. fruticosa under high salinity. This study has further revealed a unique strategy operating in this xero-halophyte where the repair mechanism for damaged PSII operates during the dark, which, we suggest, contributes to its ecological adaptation and ability to survive and reproduce under extreme saline, high light, and drought conditions. We expect these investigations to help in identifying key genes and pathways for raising crops for saline and dry areas.

This paper is the first in a projected series of publications treating the Chenopodiaceae in South America. We present here a taxonomic revision of subfamilies Betoideae, Camphorosmoideae, and Salsoloideae in South America, where all representatives of these subfamilies are introduced. Our research is based on the study of herbarium material, type specimens, digital images, original publications, and field observations. The South American Chenopodiaceae flora includes only Beta vulgaris L. from Betoideae, Bassia hyssopifolia (Pall.) Kuntze, Bassia scoparia (L.) A. J. Scott, and Maireana brevifolia (R. Br.) P. G. Wilson from Camphorosmoideae, and Salsola kali L., Salsola tragus L., and Soda inermis Fourr. from Salsoloideae. Lectotypes for Echinopsilon reuterianus Boiss., Kochia alata Bates, K. parodii Aellen, K. parodii var. elongata Aellen, K. parodii var. densa Aellen, K. parodii var. glabrescens Aellen, and Suaeda sieversiana Pall. are designated here, as well as a second-step lectotype for K. brevifolia R. Br. The distribution of all species is updated based on the revision and proper identification of many herbarium specimens and field observations. The distribution of M. brevifolia in Chile is here expanded. New synonyms for Bassia scoparia are proposed. A preliminary key to the genera of Chenopodiaceae in South America is also presented. [ABSTRACT FROM AUTHOR]

Southwest Asia is climatically and topographically a highly diverse region in the xeric belt of the Old World. Its diversity of arid habitats and climatic conditions acted as an important area for the evolution and diversification of up to 20 (of 38 known) independent Eudicot C4 origins. Some of these lineages present unique evolutionary strategies like single-cell functioning C4 and C3–C4 switching mechanisms. The high diversity of C4 taxa in Southwest (SW) Asia is also related to the presence of seven phytogeographic zones including the Irano-Turanian region as a center of diversification of many Caryophyllales lineages and the Somali-Masai region (Southern Oman and Yemen) as a center of diversification for C4 Monocots. Nevertheless, the C4 flora of SW Asia has not received detailed attention. This paper presents a comprehensive review of all known C4 species in the area based on a literature survey, own floristic observations, as well as taxonomic, phylogenetic and herbarium data, and δ13C-isotope ratio analysis. The resulting checklist includes a total number of 923 (861 native, of which 141 endemic, and 62 introduced) C4 species, composed of 350 Eudicots and 509 Monocots, most of which are therophytic and hemicryptophytic xerophytes with pluriregional and Irano-Turanian distribution. Two hundred thirty-nine new δ13C-isotope ratios of C4 and C3 plants, as well as some taxonomic changes are presented. An analysis of the distribution of the three main C4 plant families (Chenopodiaceae, Poaceae, and Cyperaceae) in the region in relation to climatic variables indicates that the increase of C4 species follows more or less a latitudinal gradient similar to global patterns, while separate taxonomic groups seem to depend on specific factors as continentality (Chenopodiaceae), average annual temperature (Cyperaceae), and the presence of summer precipitation (Poaceae). An increase of C4 Eudicots in W-E direction even in similar longitudinal belts is explained by a combination of edaphic and climatic conditions. The provided data should encourage a deeper interest in the evolution of C4 lineages in SW Asia and their adaptation to ecological and climatical conditions and awaken interest in the importance of local C4 crops, the conservation of threatened C4 taxa, and awareness of human impacts on the rapid environmental changes in the region. [ABSTRACT FROM AUTHOR]

The purpose of the study is to justify the use of the universal scenario method of strategic planning and forecasting the development of the agroindustrial complex of the regional rural economy. The scientific novelty of the study lies in the application of a set of theoretical and methodological provisions for scenario planning and forecasting the development of agriculture in the regions, taking into account the assessment of their existing potential and constructing a territorial planning scheme for the priority of participation in the implementation of strategic directions of rural development in agricultural production. The paper presents a territorial model of the priority of participation of the municipal regions of the Republic of Bashkortostan in the implementation of strategic areas in the areas of development of production of grain crops, sugar beet, and oilseeds. The developed scenario method, reflecting the qualitatively heterogeneous directions of the development of enterprises, is formed taking into account the achievement of the strategic goal and potential opportunities of rural areas. This allows determining strategic decisions for the further development of rural areas and integrating them into a uniform industry development strategy. The developed approach is recommended to be used as a guideline in the development of long-term programs for the development of the crop production industry, as well as for adjusting the activities of ongoing programs. [ABSTRACT FROM AUTHOR]

Water uptake into seeds is a fundamental prerequisite of germination and commonly influenced by commercial seed enhancement technologies. The effect of fruit orientation and contrasting pelleting materials on germination and biological performance of sugar beet was assessed. The results indicated there was orientation dependent fruit shrinkage of 37% for the operculum side supplied by moisture compared to 4% for the basal pore side. The expansion rate of 5% compared to the original size, which was also observed for non-shrinking seeds, indicated this was a temporary effect. This behaviour has importance for the application pelleting materials to seeds. Pellets composed of materials exhibiting low levels of swelling act as a water distribution layer which increased germination rates. Careful selection of pelleting material is crucial as it has direct implications on germination speed and subsequent establishment rates. [ABSTRACT FROM AUTHOR]

Populations of Atriplex canescens var. gigantea were found in Lamta, Bouficha-Enfidha (central Tunisia), and Medenine (southern Tunisia). Literature data concerning the presence of this species in Tunisia are contradictory but now our data confirm its occurrence in the country. On the other hand, this variety is reported in the present paper for the first time both in Tunisia and in North Africa in general. Morphological characters and ecological data are presented, as well as notes about patterns of infraspecific variability of A. canescens. Nomenclatural notes on infraspecific names in A. canescens, as well as on the closely related species A. garrettii, are provided. The types of the names A. canescens var. laciniata, A. canescens var. macilenta, A. garrettii, Obione occidentalis var. angustifolia, and Pterochiton occidentale, that in earlier publications were erroneously considered to be holotypes, are in fact lectotypes (for most of taxa) under Art. 9.10 of the ICN. Isolectotypes were found at CAS (A. canescens var. laciniata and A. canescens var. macilenta), GH (A. canescens var. macilenta), and YU (Atriplex nuttallii). [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to extend the body of knowledge of authentic leadership in extreme contexts by developing a framework grounded in the Sartrean existentialist perspective on authenticity and illustrating this framework using the works of Xenophon. Design/methodology/approach – The authors use Sartre’s existential view of authenticity to develop a framework of authentic leadership in extreme contexts. They then use this framework to examine Xenophon’s recount of the retreat of the 10,000 in the classic work, Anabasis. For this analysis, the authors iterate between the ideas of the past and the concepts of the present to understand how this classic has influenced and informed the current body of knowledge about leadership. Findings – Using a Sartrean existentialist lens, “in extremis” authentic leaders exhibit an awareness of context extremity, responsibility in leading and following to share risks in extreme contexts and self-determination that inspires mutual trust and loyalty. Practical implications – A Sartrean existentialist perspective suggests that authentic leaders in extreme contexts reflect authenticity by exhibiting and encouraging freedom of choice. By espousing this perspective, authentic leaders create common goals and interests that appeal to followers' intrinsic motivation which has been found to result in positive individual and organizational outcomes. Originality/value – This paper contributes to the authentic leadership literature by using an existential conceptualization of authenticity to examine leadership in extreme contexts. This conceptualization might be more appropriate than the Aristotelian virtue-based deterministic philosophy that has dominated authentic leadership research. [ABSTRACT FROM AUTHOR]

Food security is relevant due to the uncertain availability of healthy food. Accordingly, it is necessary to know the biological potential of new crops as a food source to meet the basic nutritional needs of a growing population. This study aimed to analyze chemical extractions of the cultivated species Suaeda edulis and its wild relative S. esteroa to determine their biological and nutritional value. For analysis, we collected 25 plants of S. edulis in the chinampas-producing area of Xochimilco, Mexico City, and 25 plants of S. esteroa in Balandra beach, Baja California Sur, Mexico. We quantified total phenols, total flavonoids, and the total antioxidant capacity of free and conjugated fractions by Folin-Ciocalteu, aluminum trichloride, DPPH, and TEAC spectrophotometric methods. S. esteroa reflected a higher content of total phenols, total flavonoids, and total antioxidant capacity (free and conjugated) than the values of S. edulis. We determined 39.94 and 49.64% higher values of total phenol content in S. esteroa than S. edulis , 36 and 40.33% in total flavonoid content, 32.92 and 40.50% in total antioxidant capacity by DPPH, and 34.45 and 48.91% by TEAC for free and conjugated fractions, respectively. We identified 11 phenolic compounds in both halophytes; among them, the free form ferulic acid, gallic acid, and rutin showed high concentrations in S. edulis , whereas quercetin and ferulic acid were more abundant in S. esteroa. The conjugated fraction showed lower concentrations than the free fraction. In conclusion, we found a high biologically active potential of the halophytes studied; this could boost their consumption, which in turn would offer S. edulis and S. esteroa as new sustainable crops to help address food shortages in regions with water scarcity or soil salinity, as well as to counteract chronic degenerative diseases associated with obesity. [ABSTRACT FROM AUTHOR]

Aim Beta diversity (variation of the species composition of assemblages) may reflect two different phenomena, spatial species turnover and nestedness of assemblages, which result from two antithetic processes, namely species replacement and species loss, respectively. The aim of this paper is to provide a unified framework for the assessment of beta diversity, disentangling the contribution of spatial turnover and nestedness to beta-diversity patterns. Innovation I derive an additive partitioning of beta diversity that provides the two separate components of spatial turnover and nestedness underlying the total amount of beta diversity. I propose two families of measures of beta diversity for pairwise and multiple-site situations. Each family comprises one measure accounting for all aspects of beta diversity, which is additively decomposed into two measures accounting for the pure spatial turnover and nestedness components, respectively. Finally, I provide a case study using European longhorn beetles to exemplify the relevance of disentangling spatial turnover and nestedness patterns. Main conclusion Assigning the different beta-diversity patterns to their respective biological phenomena is essential for analysing the causality of the processes underlying biodiversity. Thus, the differentiation of the spatial turnover and nestedness components of beta diversity is crucial for our understanding of central biogeographic, ecological and conservation issues. [ABSTRACT FROM AUTHOR]

The relationships amongst modern pollen assemblages, vegetation, climate and human activity are the basis for reconstructing palaeoenvironmental changes using pollen records. It is important to determine these relationships at regional scales due to the development of vegetation under different climatic conditions and human activities. In this paper, we report on an analysis of modern pollen assemblages of 31 surface lake samples from 31 lakes (one sample per lake) on the southwestern Tibetan Plateau where the knowledge of modern pollen and their relationships with vegetation, climate and human activities is insufficient. The region includes five vegetation zones: sub-alpine shrub steppe, alpine steppe, alpine meadow and steppe ecotone, mountain desert and alpine desert. The lakes span a wide range of mean annual precipitation (50-500 mm) and mean annual temperature (−8 to 6 °C). Modern pollen assemblages from our samples mainly consist of herb taxa ( Artemisia, Cyperaceae, Poaceae, Chenopodiaceae, etc.) and some tree taxa ( Pinus, Fagaceae, Alnus, etc.). The results indicate that modern pollen assemblages are able to reflect the main vegetation distribution. Redundancy analysis for the main pollen types and environmental variables shows that precipitation is the leading factor that influences the pollen distribution in the study area with the first axis capturing 13.7% of the variance in the pollen data set. The Artemisia/Chenopodiaceae ratio is valid for separating the desert component (<2) from the steppe and other vegetation zones (>2) but is unable to distinguish moisture variations. The Artemisia/Cyperaceae ratio is able to identify meadows (<1) and steppes (>1) and can be used as a moisture index on the southwestern Tibetan Plateau. Our results show that an appropriate range is needed for a modern pollen data set in order to perform pollen-based quantitative climate reconstructions in one region. It is essential to perform modern studies before using pollen ratios to reconstruct palaeovegetation and palaeoclimate at a regional scale. [ABSTRACT FROM AUTHOR]

This paper presents the course of the pollen season of selected allergenic taxa (Rumex spp., Plantago spp., Urtica spp. and Chenopodiaceae) in two towns with different degrees of urbanisation (urban, the city Szczecin, and rural, the village Gudowo in Western Pomerania, northwest Poland). The study was conducted in the years 2012–2014 with the volumetric method. The pollen of allergenic herbaceous plants was present in the air from early May until the end of September. From among the taxa studied, the genusRumexis characterised by the longest pollination period, while the genusUrticaby the shortest. The highest percentage contribution of pollen grains to the total pollen count in the air reaching over 90% is from nettle. The pollen seasons determined for the majority of taxa are longer in the city, however the mean pollen grain counts in the air are higher for the rural area. [ABSTRACT FROM AUTHOR]

The data presented in this paper provide direct microbotanical evidence concerning the early use of potato (Solanum tuberosum) within its botanical locus of origin in the high south-central Andes. The data derive from Jiskairumoko, an early village site in the western Titicaca Basin dating to the Late Archaic to Early Formative periods (~3,400 cal y BC to 1,600 cal y BC). Because the site reflects the transition to sedentism and food production, these data may relate to potato domestication and early cultivation. Of 141 starch microremains recovered from 14 groundstone tools from Jiskairumoko, 50 are identified as consistent with cultivated or domesticated potato, based on reference to published materials and a study of wild and cultivated potato starch morphology. Along with macro- and microbotanical evidence for chenopod consumption and grinding tool data reflecting intensive use of this technology throughout site occupation, the microbotanical data reported here suggest the intensive exploitation, if not cultivation, of plant resources at Jiskairumoko. Elucidating the details of the trajectory of potato domestication is necessary for an overall understanding of the development of highland Andean agriculture, as this crop is central to the autochthonous agricultural suite. A paucity of direct botanical evidence, however, has hindered research efforts. The results of the modern and archaeological starch analyses presented here underscore the utility of this method in addressing questions related to the timing, mode, and context of potato origins. [ABSTRACT FROM AUTHOR]

In this paper, the effect and mechanism of Salicornia bigelovii Torr. plant salt (SPS) on blood pressure in Sprague Dawley (SD) rats were investigated. The results showed that the edible salt induced hypertension, but the SPS did not. Organ indices and Hematoxylin-Eosin (HE) staining analysis indicated that SPS had a protective effect on the kidney and liver. In comparison with the edible salt-treated group, nitric oxide (NO) content, angiotensin-II (Ang-II) and endothelin-1 (ET-1) levels in the serum of the SPS-treated group had no obvious changes, but serum creatinine concentration significantly decreased. Moreover, superoxide dismutase (SOD) and Na(+)-K(+)-ATPase activity increased while malondialdehyde (MDA) content decreased in the SPS-treated group. In conclusion, a long-term high salt intake could lead to hypertension. SPS, as a salt substitute, could increase the body's antioxidant ability to protect the kidney and liver from the damage caused by a high salt intake and effectively avoid the occurrence of hypertension.

It is generally accepted that microbial digestion contributes little to digesta particle size reduction in herbivores, and that faecal particle size reflects mainly chewing efficiency, and may vary with diet. Nevertheless, a decrease in mean particle size (MPS) along the gastrointestinal tract (GIT) has been reported, especially in hindgut fermenters. However, to what degree the very fine particle fraction (non-food origin, especially microbes) affects MPS is unclear. Fat sand rats (Psammomys obesus, diurnal herbivores, n = 23, 175 ± sd 24 g) consumed one of four chenopods (natural dietary items in the wild) for 30 days. Digestibility was related negatively to dietary fibre content. We determined digesta MPS in the forestomach, glandular stomach, small intestine, caecum, colon and faeces by wet sieving, including (MPSfines) or excluding (MPSnofines) particles < 0.25 mm. The proportions of fines were higher and of MPSfines were correspondingly lower in GIT sections that harbour microbes (forestomach, hindgut), whereas MPSnofines did not differ between forestomach and glandular stomach. However, MPSnofines decreased along the GIT, indicating MPS reduction due to digestive (enzymatic and microbial) processes. The four different diets led to different MPS, but the magnitude of MPS reduction in the GIT was not correlated with dietary fibre fractions or dry matter digestibility. These results indicate that within a species, MPS cannot be used as a proxy for diet quality or digestibility, and raise the hypothesis that MPS reduction along the GIT may be more pronounced in smaller than in larger mammalian terrestrial herbivores, possibly due to the fine initial particles produced by chewing in small species. [ABSTRACT FROM AUTHOR]

Vegetation composition has been greatly modified by human activity since Neolithic times, providing valuable insights into the evolution of human-landscape relationships. In this paper, we integrated 26 pollen records from the Zhejiang Province of China where a Neolithic culture of rice farming existed at an early date, to examine the dynamics of agricultural development and its impact on vegetation. Firstly, we synthesized the relative abundance of Oryza pollen and charcoal (Cpeak) using generalized additive models, to produce a record of agricultural development and the intensity of human activities. We found that changes in Oryza abundance and Cpeak were positively correlated, and identified three phases as follows: agricultural initiation before 8000 cal yr BP, agricultural development between 8000 and 6000 cal yr BP and the onset of intensive rice farming after 6000 cal yr BP. Pearson correlation between each pollen taxon and Oryza indicates that arboreal taxa exhibit an overall negative correlation with Oryza , but terrestrial herbs and ferns show a positive correlation, indicating that deforestation accompanied agricultural development. Rosaceae, Castanea , Fagus and Typha display positive correlation with Oryza during the earliest stage dominated by hunter-gathering, reflecting the protection and cultivation of food-producing vegetation. During the intensive farming stage, the Liangzhu ancestors reclaimed more farmland and began to pay attention on farmland management including clearing the fields of weeds. This is the main reason for the enhanced negative correlation between Artemisia , Chenopodiaceae, Brassicaceae, Asteraceae and Lamiaceae with Oryza at 6000–5000 cal yr BP. Finally, we confirm the potential of integrated Oryza abundance in pollen records as a human-impact index in the Zhejiang region, and emphasize that temporal dynamics in vegetation and human activities should be critically pre-examined when applying relevant human-impact indices. • Integrated charcoal and Oryza pollen reveal Neolithic human intensity and rice farming history. • Food-providing plants were protected during the hunter-gatherer stage. • During the intensive agriculture phase, weed taxa exhibited a strengthened negative correlation with Oryza correlation. • The application of anthropogenic pollen necessitates a critical evaluation of its temporal dynamics. [ABSTRACT FROM AUTHOR]

In this study, it was aimed to determine the appropriate seed germination temperature, salt tolerance, salinity and drought tolerance of seedlings in Mountain swan (Atriplex nitens). For this purpose, an experiment was established in 2021 in laboratory conditions according to the factorial experiment design in random plots and in greenhouse conditions according to the random plots experiment design with three replications. Firstly, 4 constant (10, 15, 20, 25, 30°C) and 2 variable (20/15, 25/15°C) temperatures were used in the refrigerated incubator. Total germination rates and average germination times of seeds with and without pericarp were determined. Secondly, 6 different salt concentrations (0, 100, 200, 300, 400 and 500 mM NaCl) were studied considering the optimum germination temperatures (25°C and 20/15°C). At the end of the study, germination rates (%), average germination times (days) and sensitivity indices (SI) were determined. In the last two stages, seedlings were subjected to 4 different salinity (0, 100, 200, 300, 400 and 500 mM NaCl) and 5 different drought (control, low, moderate, high and severe) tests under greenhouse conditions. At this stage, plant and root length, stem thickness, leaf area index (LAI), plant and root dry weight, root/plant ratio and tolerance percentage values were measured. As a result of the laboratory study, it was determined that seeds without pericarp had a better germination percentage than seeds with pericarp. The highest total and normal germination rates were obtained from 200 mM NaCl treatment at 20/15°C. Germination rate was determined from 0, 100 and 200 mM salt treatments at 25°C. These results showed that Atriplex nitens seeds could germinate in high salt concentrations and that their seedlings had high tolerance to drought and salinity. [ABSTRACT FROM AUTHOR]

Tillage systems are sequences of operations (tilling, planting, fertilization, pesticide application, harvesting and residue chopping or shredding) which affect the physical and chemical properties of the soil, which in turn affect plant growth. It is essential to develop a right tillage system in crop production, in order to achieve high yields, using machines rationally and effectively. This paper has been released to emphasize the importance of tillage and the importance of choosing the tillage system, in order to achieve qualitative and quantitative superior yields, protecting in the same time the environment. In Almos Alfons Mosel Handels Group, during 2015-2017, sugar beet crop was cultivated in two tillage systems: conventional system and conservative system. The varieties used in this two tillage systems are Magistral and Damian. Efficiency is presented only for these common varieties, to highlight the differences between two variants of tillage systems. In addition to the evolution of soil properties and the efficiency of the tillage system on the biotic factor, we followed the evolution of economic indicators that establish economic efficiency. Economic efficiency is an instrument for evaluating activity, which helps us make the best decisions. The calculation of economic efficiency, at Almos Alfons Mosel Handels Gmbh, represent an important activity because it shows the connection between the resources used and the results achieved. The indicators analysed ware: average production, total expenses, sales revenue, agricultural subsidy, turnover, gross profit, net profit, profit rate. These indicators have been calculated on the basis of the technological data, specific to each tillage system and each year in the study. The turnover, gross profit and net profit have set higher values under no-tillage system, represented by sowing directly in the crop debris of the pre-crop (mustard). Thus, we can conclude that this no-tillage system has a rate of profit that is higher than that obtained under the conventional tillage system. [ABSTRACT FROM AUTHOR]

Ceratocarpus arenarius (Chenopodiaceae) is an under-investigated annual plant that occurs in dry areas stretching from eastern and south-eastern Europe to East Asia. This article presents the botanical characterization and examination of proximate parameters, minerals and cytotoxic activity of C. arenarius that grows wild in Kazakhstan. The results of morphological analysis using a light microscope, based on cross-sections of stems, roots and leaves, provide the necessary data to develop a regulatory document for this herbal substance as a raw material for use in the pharmaceutical, cosmetic and food industries. The investigated proximate characteristics included moisture content (6.8 ± 0.28%), ash (5.9 ± 0.40%), fat (12.5 ± 21.28%) and protein (392.85 ± 25.50). The plant is also rich in minerals (mg/100 g dry weight); Na (20.48 ± 0.29), K (302.73 ± 1.15), Zn (4.45 ± 0.35), Fe (1.18 ± 0.03), Cu (0.11 ± 0.02), Mn (0.76 ± 0.01), Ca (131.23 ± 0.09) and Mg (60.69 ± 0.72). The ethanolic extract of C. arenarius showed no acute toxicity against the brine shrimp nauplii. [ABSTRACT FROM AUTHOR]

Multi-proxy analysis (spore-pollen, dinoflagellate cysts, other non-pollen palynomorphs (NPPs), radiocarbon dating and lithology) was performed on marine sediments from three new cores retrieved during the two cruise expeditions on board the Research Vessel "Akademik" in 2009 and 2011. The Varna transect comprises three cores extending from the outer shelf, continental slope and deep-water zone. The record spans the last 26000 years (all ages obtained in this study are given in calendar years BP (cal. yrs BP)). The pollen record reveals the spreading of steppe vegetation dominated by Artemisia and Chenopodiaceae, suggesting cold and dry environments during the Late Pleniglacial – Oldest Dryas (25903–15612 cal. yrs BP). Stands of Pinus and Quercus reflect warming/humidity increase during the melting pulses (19.2–14.5 cal. ka BP) and the Late Glacial interstadials Bølling and Allerød. The Younger Dryas (13257–11788 cal. yrs BP) coldest and driest environments are clearly demonstrated by the maximum relative abundance of Artemisia and Chenopodiaceae. During the Early Holocene (Preboreal and Boreal chronozones, 11788–8004 cal. yrs BP), Quercus appeared as a pioneer species and, along with other temperate deciduous arboreal taxa, formed open deciduous forests as a response to the increased temperature. The rapid expansion of these taxa indicates that they survived in Glacial refugia in the coastal mountains. During the Atlantic chronozone (8004–5483 cal. yrs BP), optimal climate conditions (high humidity and increased mean annual temperatures) stimulated the establishment of species-rich mixed temperate deciduous forests. During the Subboreal chronozone (5483–2837 cal. yrs BP), Carpinus betulus and Fagus expanded simultaneously and became more important components of mixed oak forests and probably also formed separate communities. During the Subatlantic chronozone (2837 cal. yrs BP to pre-industrial time), climate-driven changes (an increase of humidity and a cooling of the climate) appear to be the main drivers of the specific vegetation succession expressed by increased abundance of Alnus, Fraxinus excelsior and Salix along with lianas, suggesting formation of flooded riparian forests (so called 'Longoz') lining the river valleys along the Black Sea coast. The first indicators of farming and other human activities have been recorded since 7074 cal. yrs BP. The dinoflagellate cyst (dinocyst) assemblages have been analysed to assess the changes in the Black Sea environment over the last 26000 years in terms of fluctuation in paleoproduction and surface water conditions related to changes in climate, freshwater input and Mediterranean water intrusion. Two major dinocyst assemblages were distinguished: one dominated by stenohaline freshwater/brackish-water species and a successive one dominated by euryhaline marine species. The changes in the composition of the assemblages occurred at 7668 cal. yrs BP. The abrupt decrease of stenohaline freshwater/brackish-water species Pyxidinopsis psilata and Spiniferites cruciformis was followed upwards by a gradual increase in euryhaline marine species, such as Lingulodinium machaerophorum, Spiniferites belerius, S. bentorii and acritarch Cymatiosphaera globulosa. The first occurrence of euryhaline marine species took place synchronously with the onset of sapropel deposition. Modern marine conditions were established after 6417 cal yrs BP when an abundance of Mediterranean-related species, such as Operculodinium centrocarpum and Spiniferites mirabilis, along with other heterotrophic species, occurred. After the stable cold and dry environment during the Last Glacial Maximum, the phytoplankton record of core AKAD 11-17 shows that Pediastrum boryanum var. boryanum has a cyclical abundance associated with the deposition of four red-brown clay layers between 19.2 and 14.5 cal. ka BP. This event is associated with the major melting phase of European Ice drained by the Danube and Dnieper Rivers in response to climate warming observed after the end of the Last Glacial Maximum. During the Early Holocene, P. psilata, characterised by a preference to warmer temperatures, demonstrates its ecological optimum for growth concerning SST reaching maximum relative abundance of 94% between 11072 and 8638 cal. yrs BP. This maximum was interrupted by an abrupt significant short-term decrease in the relative abundance of P. psilata centred between 8500 and 8300 cal. yrs BP reflecting cold conditions similar to those of Younger Dryas. This finding, also confirmed by the rapid significant decrease of arboreal pollen, particularly of Quercus in the same studied core, is considered a regional expression of the well-known '8.2 ka cold event' which is commonly linked to a meltwater-related perturbation of the Atlantic Meridional Overturning Circulation (AMOC) and associated collapse of oceanic northward heat transport. Our fossil pollen and dinocyst data confirm that the high amplitude temperature anomaly associated with 'the 8.2 ka cold event' may have also occurred in south-eastern Europe, at lower latitudes of the western Black Sea coastal area, most probably due to atmospheric transition and/or river discharge. [ABSTRACT FROM AUTHOR]

Microgreens combine visual, taste, flavor and bioactive qualities based on genetic selection, making them a gastronomic novelty. In the present study, ten microgreen genotypes were investigated in terms of biometrical traits (fresh yield, dry matter concentration, and main color indices) alongside compositional analyses, involving cations, nitrate, vitamin C, phenols, and glucosinolate profile. The genotypes were selected from Brassicaceae (five), Chenopodiaceae (one), Portulacaceae (one) and Asteraceae (two) families, according to the availability of unexploited local varieties beyond the commercial ones. The microgreens were cultivated hydroponically in a controlled environment. Distinct genotypic variations were observed for each measured biometric and qualitative trait, with substantial differences noted between and within species. Among the ten genotypes, the underutilized purslane stood out for vitamin C (30 mg 100 g-1 f.w.), Mg (39 mg 100 g-1 f.w.), and the remarkably low nitrate content (7 mg 100 g-1 f.w.). White mustard exhibited the highest levels of glucosinolates (171 mg kg-1 f.w.), phenols (190 mg g.a.e. 100 g-1 f.w), and notable concentrations of cations such as potassium, calcium, and magnesium. From a nutritional perspective, 'Mugnolo' (Brassica oleracea var. italica Plenck) proved less suitable as a microgreen due to its highest Na/K ratio (2.28) and generally the low content of other minerals, phenols, vitamin C, and glucosinolates. The findings of this study hold significance for selecting new microgreen species/varieties that align with the preferences and requirements of both consumers and producers. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Slovenica is the property of Biotechnical Faculty of the University of Ljubljana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two formerly broadly distributed woody Atriplex species now occur as fragmented populations across a range of microhabitats in the San Joaquin Valley Desert, southern California. We hypothesized that A. lentiformis and A. polycarpa exhibit inter- and intra-specific differences in their leaf and stem structural and functional traits corresponding with differences in soil salinity and aridity. Water potential, xylem structure and function and leaf traits were compared between three populations of A. lentiformis and four populations of A. polycarpa. The two species significantly differed in their xylem traits, with A. lentiformis displaying lower xylem density, wider mean and maximum vessel diameters and higher hydraulic conductivity (K s). They also differed in their leaf traits, such that A. lentiformis had larger leaves with higher specific leaf area (SLA) than A. polycarpa. Significant intra-specific differences occurred among leaf traits (leaf area, SLA) in A. lentiformis populations. In contrast, populations varied in their stem xylem structural traits (mean vessel wall thickness, mean vessel diameter, maximum vessel length) among A. polycarpa populations. Many of these differences were associated with soil salinity in A. lentiformis , and with minimum seasonal water potential in A. polycarpa. Overall, both saltbush species showed high intra- and inter-specific trait variation. This could be a critical consideration in understanding the evolution of these native species and has important implications for their conservation and restoration. [ABSTRACT FROM AUTHOR]

The paper analyses total of 58 samples representing 32 species of the 14 genera of shrub plant of the carbon isotope composition in Xinjiang representatives of Chenopodiaceae and a detailed discussion on the various factors that can influence them. The value of 38 samples fall between −14.88‰ and −11.55‰ with a mean of −13.34‰, and values of 20 samples between −27.93‰ and −22.877‰ with a mean of −25.38‰. So we obtained a total of 21 of C4 species (59.4%) and 11 of C3 species (40.6%) from 32 species studied Chenopodiaceae of shrubs plant. Then the relationship of plant-carbon-isotope and environmental factors has been analyzed. The results showed that the importance environmental factors for the δC-value of the Shrubs was annual precipitation (0.78) > temperature (0.66) > elevation (0.55). The three principal components has important factors to influence on C/C shrub plant distribution. Environmental conditions play significant roles in the distribution and ecophysiological features of different photosynthetic types and even change the photosynthetic pathways. On the other hand, such as geographic location, Sunshine duration, evaporation capacity are more or less correlation with δC values, however, they would be interfered by annual precipitation. Desert plants to adapt to drought conditions by increasing water use efficiency (WUE) strategy. In short, plant physiology function is sensitive and timely to adapt environmental change. [ABSTRACT FROM AUTHOR]

Cellulose was extracted from the roots, stems and stem tips of Salicornia brachiata Roxb. Each crude cellulose sample obtained was fractionated into alpha- and beta-celluloses. The yields of crude cellulose from the stems and stem tips were greatest and lowest, respectively, while the yields of alpha- and beta-celluloses were in the order, roots > stems > stem tips. The cellulose samples were characterized by Fourier transform infrared spectroscopy (FT-IR), solid state cross polarisation magic angle spinning carbon-13 nuclear magnetic resonance spectroscopy (CP/MAS 13C NMR), X-ray diffraction pattern (XRD), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The data were compared with those of the celluloses (predominantly alpha-cellulose) isolated from Whatman filter paper No. 4 (WFP).

Background and Aims: Information on the initial growth characteristics of annuals found in Chinese deserts is very limited. The aim of this study was to investigate seed germination and interactive effects of irrigation and seed burial depth in sand on seedling emergence and seedling survival in three annuals (Agriophyllum squarrosum, Bassia dasyphylla and Aristida adscensionis) commonly growing on sand dunes in these regions., Methods: Effects of temperature, light and polyethylene glycol-6000 on seed germination were examined by irrigating seeds sown on filter paper in Petri dishes. Seedling emergence was examined for seeds sown on the surface of, or at different depths (5, 10, 20, 30, 40 and 50 mm) in, sand-filled pots, which were irrigated under different regimes. For seeds buried at a depth of 50 mm, seed viability was examined after irrigation of the pots., Key Results: Seeds of three species germinated at most temperatures recorded between spring and autumn in their native habitats. No seed dormancy was found in any species. For all three species, seedling emergence was most favoured when seeds were buried at a depth of 10 mm. When seeds sown on the sand surface were irrigated, seed germination was considerably suppressed due to water deficiency, but many seeds remained viable. For A. squarrosum and B. dasyphylla, many seeds that were deeply buried and irrigated remained ungerminated but viable, while for A. adscensionis deeply buried seeds germinated, but the seedlings did not emerge due to unfavourable seedling growth in deep sand., Conclusions: Precipitation is the most crucial factor in determining the seasonal emergence of seedlings of the three tested species in the field. The vertical distribution of seeds in sand determines the proportion of seeds that germinate after precipitation and acts to maintain seed banks over multiple years.

In recent years the role of betaines in higher plants has been extensively investigated in relation to environmental stress response. This paper reports the establishment of a simple, rapid and reliable method for the determination of betaines using capillary electrophoresis (CE) at low pH. Betaines were first converted to their phenacyl esters and the crude reaction mixture was then applied directly to CE without any pre-treatment. Employing an electrolyte running solution at pH 3 gave a well-resolved electropherogram for the esters of glycine betaine (1), trigonelline, proline betaine, gamma-butyro betaine, and carnitine. The content of 1 and its variation in plant samples collected from high-salinity areas in north China and west Australia are presented.

Pollen analysis is one of the best and possible approaches for the quantitative reconstruction of paleobotany and paleoclimate, and discrimination of human activities. In this paper, we reveal the characteristics of pollen assemblages in different agricultural units and their spatial distribution of major pollen taxa in the Anyang area where the human influences are serious, so as to get more information about climate change and human activities from pollen records. The pollen assemblages of total 122 surface soil samples from different agricultural units (farm lands, vegetable plots, wastelands, cape-lands, woodlands, etc.) indicate that herbaceous pollen dominates the pollen assemblages with an average of 73%, mainly from Poaceae, Artemisia, Chenopodiaceae and Cruciferae; arboreal pollen percentages reach 18%, mainly from Pinus and Ulmus; shrub pollen and fern spores have very low percentages. In general, pollen assemblages are consistent with vegetation composition, though some differences also exist in different agricultural units. In farmlands and vegetable lands, Poaceae pollen has the highest percentages (averaging 27%) compared to other agricultural units with dominant corn or wheat pollen, while in wastelands and woodlands, arboreal and Artemisia pollen percentages have higher values (averaging 20% and 19% respectively). Cruciferae has the highest pollen percentages (70%) in rape-lands. Both pollen assemblages and PCoA can generally identify the vegetable plots, farmlands, woodlands, wastelands, and rape-lands. Pinus and Artemisia pollens mainly appear in the western part of Anyang, which is consistent with the parent plants; Poaceae pollen mainly exist in the eastern part with more farmlands; Chenopodiaceae pollen mainly appear in the urban areas and near major roads where human influences are stronger, Cruciferae pollen can mainly be found in the urban area and in the northwest part of Anyang where more vegetables are planted. [ABSTRACT FROM AUTHOR]

The amino acid composition and the physicochemical and functional properties of quinoa flour proteins (QFP) were evaluated during storage (at 20, 30 and 40 °C). Quinoa flour showed a protein content of 14.2 ± 0.1 g 100 g−1 and high levels of essential amino acids as lysine. SDS–PAGE of the QFP presented ten major band, and native-PAGE of the QFP showed similar banding; there was a little variation due to time-temperature. TCA-protein solubility variation (%) was small and the values of water activity were low, a non-significant endogenous hydrolysis was observed. Differential scanning calorimetry flour analysis allowed determining two endotherms, starch and protein. Important structural changes of protein soluble fractions were not detected by UV and fluorescence spectroscopy due to temperature and time of storage. It was found during storage time loss of protein solubility and water absorption. These changes could be to influence in the manufacture of quinoa flour based products. For avoid changes in these functional properties (solubility and water holding capacity), quinoa flour can be stored at ambient temperature (between 20 and 30 °C) and packed in double kraft paper bags (2 months). [ABSTRACT FROM AUTHOR]

This paper presents the pollen assemblages from 108 surface sediment samples from 4 lakes (the Lake Daihai, Lake Hongjiannao, Lake Hulunnao and Lake Duikounao) in the monsoon fringe area of China. The herb pollen taxa Artemisia, Chenopodiaceae, Poaceae and Compositae are the major components of pollen assemblages of the 4 lakes and Pinus, Betula, Quercus, Ulmus, Populus, Ostryopsis and Elaeagnaceae are frequently presented, which reflect regional and local vegetation well. The mean similarity coefficients for samples from the Lake Daihai, Lake Hongjiannao, Lake Hulunnao and Lake Duikounao are 0.66 ± 0.17, 0.71 ± 0.11, 0.73 ± 0.12 and 0.67 ± 0.12 respectively, so pollen assemblages are relatively consistent in each lake, which shows that focusing and mixing effects have occurred before and after pollen deposition. However, pollen assemblages do differ between sampling sites in each lake. The largest difference is seen in the Lake Daihai, followed by the Lake Duikounao, Lake Hulunnao and Lake Hongjiannao (The mean Euclidean distance is 20.09±11.11, 11.22±3.64, 10.67±4.03 and 8.44± 4.51 respectively). These differences are possibly caused by the differences of focusing and mixing effects, pollen source areas, drainage areas and regional vegetation compositions. The Lake Daihai and Lake Hong jiannao have water deeper than 5 m and strong re-suspension, focusing and mixing effects occur in the lakeshore and shallow water areas, where pollen concentrations are lower than in deeper lake areas. In the Lake Hulunnao and Lake Duikounao, with depths less than 5 m, re-suspension and mixing effects are obvious across the whole lake area, so pollen assemblages and pollen concentrations are more consistent among sampling sites in each lake. Comparison between the lake samples and samples from the inflowing river reveals that wind is primary pollen transportation force in the Lake Hongjiannao, where the consistency of pollen assemblage is conspicuous, while there is greater variation in lakes where pollen input is dominated by waterborne sources. [ABSTRACT FROM AUTHOR]

Models of particular epidemiological systems can rapidly become complicated by biological detail which can obscure their essential features and behaviour. In general, we wish to retain only those components and processes that contribute to the dynamics of the system. In this paper, we apply asymptotic techniques to an SEI-type model with primary and secondary infection in order to reduce it to a much simpler form. This allows the identification of parameter groupings discriminating between regions of contrasting dynamics and leads to simple approximations for the model's transient behaviour. These can be used to follow the evolution of the developing infection process. The techniques examined in this paper will be applicable to a large number of similar models.

Sugar beet pulp is a by-product of sugar production and consists mainly of cellulose, hemicellulose and pectin. Its composition is suitable for biological degradation. A possible alternative for the utilization of this material (besides cattle feeding) can be anaerobic methanogenic degradation. It has an additional advantage--biogas production. Beet pulp was treated by a two-step anaerobic process. The first step consisted of hydrolysis and acidification. The second step was methanogenesis. In this paper, observation of the process of anaerobic degradation and determination of optimal parameters is discussed. A laboratory-scale model for sugar beet pulp anaerobic biodegradation was operated. Results of model performance have shown very good pulp digestion characteristics. In addition, high efficiency removal of organic matter was achieved. Methane yield was over 0.360 m3 kg(-1) dried pulp and excess sludge production was 0.094 g per gram COD added.

The use of meteorological autocorrelation variables and pollen concentrations from previous days, coupled with classification of meteorological data according to multivariate analysis techniques, is shown to improve the predictive power of multiple regression models for daily pollen forecasts. This paper presents an investigation of the meteorological and autocorrelation variables which influence pollen counts in Cartagena, from 1995 to 1999, as a basis for the development of predictive models. The analysis of total pollen concentrations, and especially Chenopodiaceae-Amaranthaceae, was determined. Initially, forecasting models for total pollen counts were developed, using data from 1995 to 1998, and autocorrelation and meteorological variables. Secondly, predictive models were developed for different meteorological situations, which improved the results by decreasing the number of predictive parameters. Finally, data from 1999 were used to validate the predictive models. [ABSTRACT FROM AUTHOR]

The focus of this paper is on the reconstruction of the mid-Holocene climatic changes based on the pollen records contained in a 6.2 m thick section in the southern part of the Tengger Desert, northwestern China. To understand the modern analogues of the mid-Holocene changes, modern pollen spectra across different vegetation zones from the Qilian Mountains to the lowland Tengger Desert were studied first. Four pollen combinations were identified, corresponding to four different modern ecological environments: (1) a Picea-Artemisia combination in a spruce forest and its vicinity; (2) an Artemisia-Chenopodiaceae-Gramineae-Salix combination in a mixture belt of montane grassland and poplar woodland; (3) a Chenopodiaceae-Artemisia-Nitraria combination in a desert steppe belt; and (4) an Elaeagnus-Artemisia-Chenopodiaceae-Nitraria combination in a desert riparian forest. Our study also shows that a relatively low percentage of Picea pollen (30–10%) seems to be associated with water transportation (alluvial deposits) and a very low percentage of Picea pollen (10–5%) appears to be related to long-distance air transportation. With references to the modern relationships between pollen assemblages and associated bioclimates, the pollen sequence covering the period between 8500 and 3000 cal. BP was used to infer the climatic change history. The results show that a warmer and drier climate dominated between 8500 and 7950 cal. BP. Subsequent decreases in Artemisia and warm desert forbs/shrubs taxa and contemporaneous fluctuating increases in montane coniferous and aquatics elements from 7950 to 7400 cal. BP reflect a fluctuating increase in humidity and/or a fluctuating decrease in temperature. The following period from 7400 to 5650 cal. BP was generally warm with the Holocene Climate Optimum occurring between 7400 and 6500 cal. BP. A remarkably cool spell followed between 6500 and 6300 cal. BP that was then succeeded by a warmer and more humid period between 6300 and 5650 cal. BP. The period between 5650 and 4450 cal. BP was characterized by drastic oscillations in climatic conditions with three humid and probably cold spells intervened by three relatively dry and warm spells. The period between 4450 and 3500 cal. BP was cold and humid, followed by a wet spell as indicated by a very high percentage of Typha pollen. [ABSTRACT FROM AUTHOR]

Understanding human impact on the vegetation of the Tibetan Plateau through the Holocene is important for developing strategies for sustainable ecosystem management in the region. In this paper, 53 pairs of surface-soil samples from inside and outside livestock enclosures were obtained from across the Tibetan Plateau to investigate the differences in pollen assemblages between grazed and ungrazed sites. This modern dataset was then applied to palynological records from four lakes in the northeast Tibetan Plateau region to investigate middle to late Holocene grazing history. Results show that modern grazing activities have a limited impact on the vegetation, although grazing activity leads to an increase in the pollen proportion of Cyperaceae, Artemisia , Ranunculaceae, Brassicaceae, Taraxacum -type, Fabaceae, and Saxifrageceae while representatives of Poaceae, Chenopodiaceae, and Aster -type pollen decrease. Application of these grazing indicators to the pollen spectra obtained from the four lake sites, together with other proxies, reveals that grazing activity only commenced during the last few hundred years in the northeast marginal areas of the Tibetan Plateau at c. 3000 m a.s.l, while there is no grazing signal in pollen records from above 4000 m a.s.l. Our study emphasises the importance of using multi-proxy methods in estimating signals of past human activity. • Pollen assemblage should be insensitive to grazing activities on the Tibetan Plateau. • Human impacts on vegetation at ∼3400 m a.s.l are limited to within a few centuries. • No significant pollen signal of grazing is revealed for the high-elevation areas. [ABSTRACT FROM AUTHOR]

The vegetation history of the central Tibetan Plateau over the last two millennia provides an important baseline for exploring future vegetation evolution. In this paper, we analyze high-resolution records of pollen, grain-size, total organic carbon (TOC) and total nitrogen (TN) for a 66.5 cm deep sediment core collected from Beilei Co on the central Tibetan Plateau. Between ca. 210 CE and 1988 CE, pollen spectra together with other proxies show that the Beilei Co region was covered by alpine steppe and experienced a relatively stable environment, with only slight changes in vegetation composition and minor climatic variations. However, since 1988 CE, abundances of Artemisia and Cyperaceae have begun to increase, while those of Chenopodiaceae (current accepted Latin name is Amaranthaceae) and Asteraceae have decreased sharply. Both the pollen assemblages and other proxies show that the study area is currently undergoing a major change and that the period of vegetation stability that has characterized the past two millenia has now ended. We argue that the recent changes in the vegetation may be caused by increasing precipitation and/or thawing permafrost due to global warming. In the future, the alpine steppe around Beilei Co may be replaced by alpine meadow. • High-resolution pollen spectra covering last two millennia completed for the central Tibetan Plateau. • Vegetation of the central Tibetan Plateau is stable for most of the time until the last few decades. • The central Tibetan Plateau is experiencing an unprecedented phase of wetting. [ABSTRACT FROM AUTHOR]