Sedimentary Organic Matter Load Influences the Ecological Effects and Potential Risks of Submerged Macrophyte Restoration Through Rhizosphere Metabolites

Aims Rehabilitation of submerged vegetation is one of the commonly used techniques for the ecological restoration of shallow lakes. The changes of pollution structure in sediments caused by plant recovery and the rhizosphere chemical process under different sediment organic matter (SOM) levels are theoretical basis for the rational application of plant rehabilitation technology in lake management.Methods A circulating extraction system was designed for in situ collection of rhizospheric metabolites especially for the submerged plants. We explored how Vallisneria natans (V. natans) mediate the changes in sediment N and P through rhizospheric metabolites under low (4.94%) and high (17.35%) SOM levels. Results By analysing 63 rhizospheric metabolites from V. natans, glucitol was found to be 146.82% lower in the low SOM than in the high SOM treatment. NH4-N and NO2-N increased by 57% and 68.39%, respectively, in the high SOM treatment, while approximately one-seventh Inorg-P was transferred from Fe/Al-P to Ca-P in the low SOM treatment. The metabolites lactic acid, 3-hydroxybutyric acid, and phosphoric acid mediated NH4-N accumulation. Additionally, 3-hydroxy-decanoic acid and adipic acid mediated the transformation of Fe/Al-P to Ca-P.Conclusions The growth of V. natans significantly changed Inorg-N or Inorg-P fractions. The changes were SOM level-dependent and rhizosphere metabolites related. This study emphasised the benefit of V. natans rehabilitation at low SOM level. When restoring submerged macrophytes from high SOM sediment, care should be taken due to the release potential of labile N and P forms.

Tests of Strength Parameters of Hydro-Mixtures Based on Ashes from a Fluidized Bed Boiler in the In-Situ Approach

The paper presents the practical use of a solidifying hydro-mixture based on ashes from fluidized bed boilers under hard coal mine conditions for filling an incline connecting the headgate and tailgate of a longwall running along the strike with roof caving. The reason for filling the incline with a material of preset strength parameters was to minimize the methane hazard in the extracted coal seam. Due to a great demand for fill material, which translates into economic considerations, the option of applying fine-fraction waste material was selected. Preliminary laboratory tests of the physical and mechanical properties of hydro-mixtures based on ash obtained from a fluidized bed boiler of a power plant, allowed us to select a specific hydro-mixture meeting the requirements. After 95 days, the incline filled with the proposed hydro-mixture was subjected to exploitation along with the advance of longwall working. This enabled the in-situ collection of a number of fill material samples from various places along the entire length of the incline. Then their strength was tested and the results compared with the obtained test results of identical material seasoned under laboratory conditions. The obtained results constitute a unique research material since it is practically impossible to verify the laboratory-determined strength parameters of the solidifying fine-fraction hydro-mixtures under in-situ conditions. Thsis results mainly from the lack of technical capabilities and poor access to the places where fine-fraction hydro-mixtures are applied, mostly abandoned cavings or parts of workings separated by dams.

Agro morphological characterization of cashew trees (Anacardium occidental L.), in improvement for the high yield and high quality of raw nuts in Burkina Faso

The cashew sector has taken a great economic interest, due to the strong global demand for raw nuts. However, in Burkina Faso, the productivity of orchards still remains low, a consequence of a lack of breeding program on the species. In order to increase yields and improve the quality of the raw nut, efficient clones must be developed. Surveys were carried out and a primary in situ collection was made from which a core collection of 15 trees was extracted. An agro-morphological description of the selected trees and an analysis of the structuration of the variability within them were carried out. The study revealed appreciable agro-morphological diversity through shape, size and color of apple, type of inflorescence, fruiting period and the health of trees. A structure of diversity based on agronomic criteria led to identify 5 groups of trees, characterized by an average weight of the nut between 6.64 and 8.32 g, a kernel rate between 28.10 and 31.26% and a yield per tree between 34.27 and 104.42 kg. Performing trees will be erected as heads of clones for the production of grafted plants. La filière anacarde a pris un grand intérêt économique, suite à la forte demande mondiale en noix brutes. Cependant, au Burkina Faso, la productivité des vergers demeure encore faible, conséquence d’une absence de sélection variétale du matériel végétal. En vue d’accroître les rendements et d’améliorer la qualité de la noix brute, une recherche de clones performants était indispensable. Des prospections ont été conduites et une collection primaire in situ a été constituée dont une core collection de 15 arbres a été extraite. Une description agro-morphologique des arbres sélectionnés et une analyse de la structuration de la variabilité en son sein ont été conduites. L’étude a révélé une diversité agro morphologique appréciable à travers la forme, le calibre et la couleur de la pomme, le type d’inflorescence, la période de fructification et l’état sanitaire des arbres. Une structuration de la diversité basée sur les critères agronomiques a permis d’identifier 5 groupes d’arbres, caractérisés par un poids moyen de la noix compris entre 6,64 et 8,32 g, un taux d’amande compris entre 28,10 et 31,26% et un rendement par arbre compris entre 34,27 et 104,42 kg. Les arbres les plus performants constitueront des têtes de clones pour la production de plants par greffage.

Baoshan

Baoshan 寶山 (Treasure Mountain) is a Buddhist site in the Taihang 太行 mountain range in Henan 河南 Province; it includes neighboring Lanfengshan 嵐峰山 (Misty Peak Mountain). It is a network of cave-shrines, devotional and memorial inscriptions, reliquary niches with portrait-statues, and references to buildings and restorations. Most notably, the memorial inscriptions on Lanfengshan are the single largest extant in situ collection of records of medieval Chinese Buddhist nuns. It is claimed that Baoshan was first marked as a Buddhist place by the monk Daoping 道憑 (b. 488–d. 559). Daoping’s disciple Lingyu 靈裕 (b. 518–d. 605) won imperial recognition for the site and probably led the design and construction of the main cave-shrine. Both monks belonged to the southern branch of the Dilun 地論 (Stages treatise) lineage that began in the Northern Qi 北齊 (550–577) capital of Ye 鄴. Two rock-cut cave shrines on Baoshan and Lanfengshan constitute the devotional foci of the site, and a restored temple stands in the valley between them, in what is believed to be its original location. The site’s main cave-shrine Dazhusheng 大住聖 (Great Abiding Holy Ones) is located midway up Baoshan and about five hundred meters west and further up the valley from the restored temple. Mortuary niches for monks and laymen fan out on several levels above the cave to the east and west. An earlier, smaller cave attributed to Daoping was renamed Daliusheng 大留聖 (Great Remaining Holy Ones), establishing correspondence with Dazhusheng. It is situated partway up Langfengshan, overlooking the lower part of the valley. Mortuary niches for nuns and laywomen are carved into cliff-faces above, below, and to the east of the cave. In Lingyu’s Xu gaoseng zhuan續高僧傳 (Continued biographies of eminent monks) biography, it is said that the temple in the valley between the peaks was designated Lingquansi 靈泉寺 (Ling’s Spring/Numinous Spring Temple) in 591 by Emperor Wen of the Sui. This was meant to honor Lingyu, who that year conferred precepts on the imperial household. One of Lingyu’s disciples, the eminent monk Huixiu 慧休 (b. 547–d. 646), also had a formative influence at the site.

In Situ Collection and Preservation of Intact Microcystis Colonies to Assess Population Diversity and Microcystin Quotas

Understanding of colony specific properties of cyanobacteria in the natural environment has been challenging because sampling methods disaggregate colonies and there are often delays before they can be isolated and preserved. Microcystis is a ubiquitous cyanobacteria that forms large colonies in situ and often produces microcystins, a potent hepatotoxin. In the present study a new cryo-sampling technique was used to collect intact Microcystis colonies in situ by embedding them in a sheet of ice. Thirty-two of these Microcystis colonies were investigated with image analysis, liquid chromatography-mass spectrometry, quantitative polymerase chain reaction and high-throughput sequencing to assess their volume, microcystin quota and internal transcribed spacer (ITS) genotype diversity. Microcystin quotas were positively correlated to colony volume (R2 = 0.32; p = 0.004). Individual colonies had low Microcystis ITS genotype diversity and one ITS operational taxonomic unit predominated in all samples. This study demonstrates the utility of the cryo-sampling method to enhance the understanding of colony-specific properties of cyanobacteria with higher precision than previously possible.