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With the current reassessment of the phylogeny of Pandanales, revealing the peculiarities of fruit structure of representatives of the order, as well as determination of apomorphies and plesiomorphies of the families included in the order are of importance. With the aim to fill in gaps in the data on fruit structure and to determine principal trends of fruit morphogenesis in Pandanaceae, the present study focused on pericarp anatomy in the genus Freycinetia , fruits of which are traditionally referred to as berries. The present investigation confirmed the lack of a continuous sclerenchymatous zone in the pericarp of Freycinetia species, and the fruit is treated as a superior paracarpous berry of Nuphar type. Fusiform groups of longitudinally elongated sclereids are revealed in the mesocarp of Freycinetia palawanensis (incertae sedis) and F. graminifolia (section Solmsiella). Since this character is treated as specific for the subgenus Gaudichaudiella , the inclusion of these two studied species in this subgenus is proposed. The principal carpological plesiomorphies and apomorphies of the family are outlined, and two scenarios for fruit morphogenesis, from berries to 'drupaceous' fruits and vice versa, are proposed. [ABSTRACT FROM AUTHOR]

To investigate how hydrodynamic cavitation (HC) affects the adsorption of sodium oleate (NaOl) on diaspore and kaolinite surfaces, a comparative study on NaOl adsorption was conducted under different conditions. The flotation and separation of the minerals were also examined with and without HC pretreatment of NaOl. The results show that short-term HC pretreatment of NaOl solutions did not induce a measurable change in the chemical structure of NaOl, but produced micro-nanobubbles (MNBs) and resulted in decreases in the surface tension and viscosity of liquids. When MNBs interacted with minerals, their anchor on solids could affect the contact angles, zeta potentials, and surface NaOl adsorption toward minerals. At low NaOl concentrations, the presence of MNBs reduced the NaOl adsorption capacity and particles' zeta potential while increasing the minerals' contact angle. At higher NaOl concentrations, the presence of MNBs promoted NaOl adsorption, further increased the minerals' contact angle, and further decreases the particles' zeta potential. Additionally, the flotation and separation of minerals can be enhanced at low NaOl concentrations, largely due to the enhanced bubble mineralization through the selective surface-anchoring of MNBs on diaspore. However, the separation efficiency might deteriorate at high NaOl concentrations, though the presence of MNBs amplified the divergences in minerals' surface wettability and zeta potentials. [ABSTRACT FROM AUTHOR]

This study examined the effects of low-temperature heat treatment on the characteristics of the rubies from Mong Hsu, Myanmar. Five ruby samples were heated to 400, 600, 900 and 1200 °C for different durations, respectively. Before and after each heating step, a visual examination was conducted with a gem microscope under different illumination conditions. Various spectral analyses such as UV-Vis, FTIR, Raman and PL were also used to examine the effect of heating on the ruby samples. The low-temperature heat treatment enhanced the ruby samples by causing the dark blue core to partially or completely fade away. It then increased the overall light transmittance and enhanced the fluorescence peak around 694 nm but did not improve the red hue of the samples. Two major changes were found in the experiments. One was the dark blue core of the samples that faded as the heating temperature increased. They were verified by the spectra to be the variation in the intervalence charge transfer between Fe2+ and Ti4+. The variation in the intervalence charge transfer of Mong Hsu ruby was not noticeable before heating to 900 °C but changed dramatically when heated to 1200 °C. The other was the shift of the FTIR peak, which is caused by decomposition of minerals due to heating. An FTIR 630 cm−1 peak proved to be sensitive to the low-temperature heating and might be helpful for detecting low-temperature treatment. [ABSTRACT FROM AUTHOR]

To investigate how hydrodynamic cavitation (HC) affects the adsorption of sodium oleate (NaOl) on diaspore and kaolinite surfaces, a comparative study on NaOl adsorption was conducted under different conditions. The flotation and separation of the minerals were also examined with and without HC pretreatment of NaOl. The results show that short-term HC pretreatment of NaOl solutions did not induce a measurable change in the chemical structure of NaOl, but produced micro-nanobubbles (MNBs) and resulted in decreases in the surface tension and viscosity of liquids. When MNBs interacted with minerals, their anchor on solids could affect the contact angles, zeta potentials, and surface NaOl adsorption toward minerals. At low NaOl concentrations, the presence of MNBs reduced the NaOl adsorption capacity and particles’ zeta potential while increasing the minerals’ contact angle. At higher NaOl concentrations, the presence of MNBs promoted NaOl adsorption, further increased the minerals’ contact angle, and further decreases the particles’ zeta potential. Additionally, the flotation and separation of minerals can be enhanced at low NaOl concentrations, largely due to the enhanced bubble mineralization through the selective surface-anchoring of MNBs on diaspore. However, the separation efficiency might deteriorate at high NaOl concentrations, though the presence of MNBs amplified the divergences in minerals’ surface wettability and zeta potentials.

Many plants exploit the ability of animals to move in order to disperse their pollen and seeds. Despite the growing understanding of the role animals play in the reproductive lives of plants, there are few examples of amphibians contributing to these processes. We report on an Australian tree frog, Litoria fallax, interacting with and likely moving seeds of the broad‐leaved cumbungi, Typha orientalis, over short distances via external transport. Field observations revealed both juvenile and adult L. fallax individuals carrying typha seeds, which were adhered to the skin on the feet, legs, belly and dorsum. Approximately 30% of observed frogs were found to be carrying 1–14 seeds at a time. The small size and specialised fibre tufts of typha seeds, which enable them to be primarily dispersed by wind, also make them susceptible to being unintentionally picked up and transported by L. fallax as they move through aquatic environments. The moist surfaces of frogs, coupled with their presence in freshwater systems that can be dominated by typha, create favourable conditions for seed attachment. These findings highlight a previously unknown interaction between an amphibian and a plant that enables seed dispersal, supporting the need for further exploration into unexpected plant vectors. [ABSTRACT FROM AUTHOR]

This study examined the effects of low-temperature heat treatment on the characteristics of the rubies from Mong Hsu, Myanmar. Five ruby samples were heated to 400, 600, 900 and 1200 °C for different durations, respectively. Before and after each heating step, a visual examination was conducted with a gem microscope under different illumination conditions. Various spectral analyses such as UV-Vis, FTIR, Raman and PL were also used to examine the effect of heating on the ruby samples. The low-temperature heat treatment enhanced the ruby samples by causing the dark blue core to partially or completely fade away. It then increased the overall light transmittance and enhanced the fluorescence peak around 694 nm but did not improve the red hue of the samples. Two major changes were found in the experiments. One was the dark blue core of the samples that faded as the heating temperature increased. They were verified by the spectra to be the variation in the intervalence charge transfer between Fe2+ and Ti4+. The variation in the intervalence charge transfer of Mong Hsu ruby was not noticeable before heating to 900 °C but changed dramatically when heated to 1200 °C. The other was the shift of the FTIR peak, which is caused by decomposition of minerals due to heating. An FTIR 630 cm−1 peak proved to be sensitive to the low-temperature heating and might be helpful for detecting low-temperature treatment.

The first Phanerozoic bauxite appeared in the Early Cambrian in isolated areas of fold belts during their peneplenization. Commercial deposits of high-quality bauxite were formed in the Northern Urals during the Eifelian. In the Frasnian, bauxite accumulation expanded to the Central Timan. The number of known Devonian deposits does not exceed two dozen, and their total reserves are on the order of one billion tons. In the Early Carboniferous, bauxite accumulation shifted to the platforms of the Northern Hemisphere. Bauxite formation continued throughout the Middle Carboniferous on the Chinese and North American platforms, and up to the Early Permian in Korea. The number of deposits increased dramatically (hundreds), and their total reserves increased to four billion tons. Deposits of Mesozoic bauxite gravitate to fold belts and, within them, to the epi-Hercynian and epi-Kimmeridgian platforms of the Northern Hemisphere, the total number of known deposits being more than 1000. Most of them are small, but the bauxite quality is rather high. The total aluminum reserve of Mesozoic bauxites (3.3 billion tons) is less than those of the Paleozoic, while the number of Mesozoic deposits is greater. Bauxite accumulation in the Cenozoic took on a grandiose scale (85% of the world's total reserves of about 100 billion tons). It was caused by the expansion of areas of leveled land with a tropical climate, abundance of precipitation, and organic matter, which led to the formation of many large and super-large bauxite deposits. In general, the evolution of bauxite accumulation during the Phanerozoic occurred in increasing pulses, resulting in an uneven increase in the areas and capacity of bauxite deposits with time. [ABSTRACT FROM AUTHOR]

Gem-quality rubies and sapphires are often commercially heat treated at about 800 °C or higher to enhance their color and clarity, and hence quality. For this study, selected corundum samples containing diaspore and goethite inclusions were heated step-by-step to a maximum of 1000 °C with the aim of monitoring the dehydration and phase transformation of these oxyhydroxides to corundum and hematite during heating. Based on our experiments and in agreement with the literature, the dehydration of diaspore in corundum occurs between 525 and 550 °C, whereas goethite transforms to hematite between 300 and 325 °C. As both diaspore and goethite may be present as inclusions in rubies, sapphires, and other corundum varieties (e.g., pink sapphires, padparadscha), these dehydration reactions and phase transformations can be considered important criteria to separate unheated from heated stones, specifically in cases in which other methods (e.g., microscopy, FTIR) are unsuccessful. [ABSTRACT FROM AUTHOR]

Longmen - Congyi area is one of the bauxite met allogenic belts in Hen an Province. Based on chemical test of the main compositions of Corigyi bauxite deposit, the paper analyzes the change rule of elements in the bauxite deposit. The results show that the major mineral compositions of bauxite ore is di aspo re (45%-95%), followed by kaolinite and illite (4%-25%), with a small amount of siderite, pyrite, calcite and dolomite, and trace minerals such as zircon and apatite. The main chemical compositions of bauxite ore are Al2O3, SiO2, Fe2O3, TiO2 and S, accounting for 83.42% of the total, among which the Al2O3 content is 40.46% -77.59%, averagely 60.68%, SiO2 1.00%-29:54%, averagely 14.07%, with the aluminum-silicon ratio (A/S) of 1.8-65.1, averagely 4.3. Under different burial depth conditions, the larger the relative depth is, the larger the Al2O3 content and A/S ratio are. The chemical index of alteration (CIA) of the area is up to 91.16, indicating that the aluminum-bean ng rock senes in the area has undergone intense chemical weathering. [ABSTRACT FROM AUTHOR]

The effects of pyrite and diaspore with different particle sizes on the rheological properties of pulp with butyl xanthate added as a collector were studied, and the mechanism for rheological pyrite separation from diaspore by flotation was probed. The apparent viscosity of the diaspore pulp with different particle sizes was higher than that of pyrite, especially for -30 µm diaspore. Microfine diaspore was an important component affecting the apparent viscosity and yield stress of the diaspore-pyrite mixed pulp, and the pulp became a non-Newtonian fluid when the mass fraction of fine-grained diaspore in the mixed pulp was high. In this study, sodium hexametaphosphate (SHMP) was used to control the rheology of the mixed pulp and improve the pyrite flotation, and the S (sulfur) recovery rate first increased and then decreased with increasing SHMP concentration. The apparent viscosity of the pulp decreased by 3.01% and the S recovery rate increased by 34.83% when the amount of added SHMP was 0.05 mg/kg. The apparent viscosity with 0.50 mg/kg SHMP was 21.76% lower than that seen with the addition of 0.05 mg/kg SHMP, but the S recovery rate was also reduced by 14.94%. Further research showed that the increased SHMP concentration led to increases in the electronegativities of the particle surface and the repulsive force between particles, which prevented agglomeration of the particles, reduced the apparent viscosity and yield stress of the mixed pulp, promoted collisions between the pyrite particles and the bubbles, and reduced the resistance of the air bubbles to flotation. [ABSTRACT FROM AUTHOR]

Hydrodynamic cavitation (HC) enhanced fine particle aggregation could be largely due to the generation of tiny bubbles and their role in bridging particles. However, the lack of adequate characterizations of aggregates severally limits our further understanding of the associated aggregation behaviors. In this study, the aggregation of fine diaspore particles was comparatively investigated in sodium oleate (NaOl) solutions with and without HC pretreatment through the small-angle laser scattering (SALS) technique in a shear-induced aggregation (SIA) system. Results showed that HC pretreatment caused the formation of bulk nanobubbles (BNBs), which significantly modified the particle interactions and thereby modified the size and mass fractal dimension (Df) of aggregates under different SIA conditions. Although HC pretreatment did not noticeably alter the gradual change trend of aggregate size and structure characteristics under specific variables, BNBs bridging facilitated the aggregation process towards the diffusion-limited cluster aggregation model, resulting in the formation of larger but looser aggregates. This effect was more pronounced under relatively high NaOl concentrations. Apart from BNBs, the aggregation was also affected by cavitation bubbles formed during shear cavitation, which was more significant under high stirring intensity conditions (i.e., 1800 rpm) than the low stirring intensity conditions (i.e., 600 rpm).

In recent years, with the discovery of oil and gas in the Carboniferous bauxite reservoir in the Ordos basin, the formation and distribution of bauxite and bauxite reservoirs have attracted the attention of oil and gas explorers. Based on the slightly equidistant core testing of minerals and the porosity on the formation and calibration on the logging curves, we established a logging identification method for bauxite in the study area and fitted the formula for calculating the diaspore content and porosity using logging data. By applying this formula and a large amount of logging data, thickness and porosity maps of the Taiyuan formation of bauxite in the southeastern part of the basin were produced. Then, according to the thickness of the earliest deposited Taiyuan formation on the unconformity surface, we analyzed the paleogeomorphology of the bauxite deposition. Finally, a sedimentary facies map of the Taiyuan formation was developed based on the content of sandstone, coal seams, and carbonate rocks contained there. The results show that the diaspore content of bauxite is positively correlated with the natural gamma logging (GR) values. According to the diaspore contents and the GR values, the aluminiferous rocks in the Taiyuan formation can be divided into three categories: ① Bauxite for GR values > 450 API and diaspore content >70%; ② Argillaceous bauxite for GR values = 300–450 API and diaspore content = 25%–70%; and ③ Bauxitic mudstone for GR values = 220–300 API and diaspore content = 0%–25%. Bauxite mainly occurred in the middle and deep lagoon environments in the lower part of the Taiyuan formation. The lagoon is distributed along the paleokarst groove in the NW strike, with a width of approximately 30–40 km and a length of approximately 150–200 km, among which the thickness of pure bauxite is 9 m, argillaceous bauxite 26 m and alumina mudstone 6 m. Bauxite with a high porosity mainly existed in pure bauxite. The lagoon bauxite in the lower part of the Taiyuan formation gradually changes upward into a tidal flat swamp and carbonate platform environment. [ABSTRACT FROM AUTHOR]

• Mucilage envelope is the second adhesive system present in the Commicarpus helenae anthocarps. • For the first time the mucilage structure, morphology and basic chemical composition was studied. • Mucilage belongs to the cellulosic type and possess very long cellulosic fibrils. • We discuss the role of two independent adhesive systems for anthocarp attachment and dispersal. Mucilaginous diaspores (seeds, fruits, anthocarps) responsible for the plant dispersion are known for many diverse plant families. The anthocarp of Commicarpus helenae demonstrates a unique double adhesive system represented by the apical gland-like emergences, which are sticky even without hydration, and mucilaginous cells, which form a mucilage envelope around the whole anthocarp after hydration. In this study, we characterised the type of mucilage, its internal structure, and discussed its biological function. We found that the mucilage was a type of cellulose possessing very long spirally coiled cellulosic fibrils embedded in a mass of hydrophilic pectins. The cellulose fibrils build the main scaffold for the rest of polysaccharides. All of the components are arranged into a net-like spatial structure. The mucilage of C. helenae may play diverse roles e.g., in epizoochory/endozoochory, anchoring the diaspore to the soil and enabling germination due to the presence of water attracted by the pectins. The mucilage envelope, which forms rapidly after hydration (from rain or capillary water condensation), facilitating adhesion to the soil and simultaneously providing optimised germination conditions. The presence of the second adhesive systems in C. helenae i.e., mucilaginous cells producing mucilage seems to be an adaptation with different ecological functions. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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.)

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design 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.)

One of the most important and most easily measurable physical characteristics of plant seeds is their weight, which influences and indicates crucial ecological processes. Seed weight affects spatial and temporal dispersibility, and can also influence seed predation and the germination, growth and survival of seedlings. Providing trait data for species missing from international databases is key to promote studies that advance our understanding of the functioning of plant communities and ecosystems, which is an essential issue in the face of the global climate change and biodiversity loss. Compared to species from Western and Northwestern Europe, those with an Eastern or Central European centre of distribution are underrepresented in most international trait databases. Therefore, the creation of specific trait databases is key to help regional studies. In this respect, it is important not only to collect fresh seeds for weight measurements, but also to measure and process data of seeds preserved in collections and make them available to the broader scientific community. In this data paper we provide seed weight data to fill in missing trait data of plant species of Central and Eastern Europe. Our dataset includes weight measurement for 281 taxa of the Central European flora including also some cultivated and exotic species. The seeds were collected between 1971 and 2021 mostly in Central Europe. One part of the measured seeds was collected in the last decade, the other part is from an older seed collection, but all seeds were measured recently. For each species, we collected a minimum of 3 × 100 intact seeds, if possible. The seeds were air-dried at room temperature (approximately 21 °C and 50% relative humidity) for at least two weeks and measured with an accuracy of 0.001 g using an analytical balance. The thousand-seed weights reported here were calculated based on the measured values. Our goal for the future is to incorporate the seed weight data reported here in a regional database (Pannonian Database of Plant Traits – PADAPT) that gathers plant traits and other plant characteristics for the Pannonian flora. The data presented here will facilitate trait-based analyses of the flora and vegetation of Central Europe.

Gem-quality rubies and sapphires are often commercially heat treated at about 800 °C or higher to enhance their color and clarity, and hence quality. For this study, selected corundum samples containing diaspore and goethite inclusions were heated step-by-step to a maximum of 1000 °C with the aim of monitoring the dehydration and phase transformation of these oxyhydroxides to corundum and hematite during heating. Based on our experiments and in agreement with the literature, the dehydration of diaspore in corundum occurs between 525 and 550 °C, whereas goethite transforms to hematite between 300 and 325 °C. As both diaspore and goethite may be present as inclusions in rubies, sapphires, and other corundum varieties (e.g., pink sapphires, padparadscha), these dehydration reactions and phase transformations can be considered important criteria to separate unheated from heated stones, specifically in cases in which other methods (e.g., microscopy, FTIR) are unsuccessful.

Nicht zuletzt durch den Klimawandel und sich verändernde Anbaumethoden im Ackerbau breitet sich die neophytische Unkrautart Datura stramonium in Deutschland weiter aus. Als Spätkeimer profitiert die Art in landwirtschaftlichen Kulturen davon, dass dann Unkrautregulierungsmaßnahmen bereits abgeschlossen sind und sie sich dann dementsprechend gut entwickeln kann. Kenntnisse zur Samenbildung, zum Keimverhalten sowie zur Samenüberdauerung der Art sind für eine integrierte Bekämpfung notwendig. Um den Einfluss des Samenalters auf die Keimung der Samen zu untersuchen, wurde ein Keimtest mit Diasporen 16 verschiedener Jahrgänge aus dem Zeitraum 1973 bis 2019 durchgeführt. Ermittelt wurde die kumulative Keimrate und der KR50-Wert (Zeitpunkt an dem 50 % der Gesamtkeimrate erreicht sind). Parallel dazu wurde bei 10 der 16 geprüften Jahrgänge ein Triphenyltetrazoliumchlorid-Test durchgeführt, um auf diese Weise die Keimfähigkeit der Populationen im Labortest mit der generellen Lebensfähigkeit der Diasporen zu vergleichen. Die Ergebnisse dokumentieren eine lange Überlebensdauer der Samen, was bei der Bekämpfung der Art berücksichtigt werden muss.

In recent years, with the discovery of oil and gas in the Carboniferous bauxite reservoir in the Ordos basin, the formation and distribution of bauxite and bauxite reservoirs have attracted the attention of oil and gas explorers. Based on the slightly equidistant core testing of minerals and the porosity on the formation and calibration on the logging curves, we established a logging identification method for bauxite in the study area and fitted the formula for calculating the diaspore content and porosity using logging data. By applying this formula and a large amount of logging data, thickness and porosity maps of the Taiyuan formation of bauxite in the southeastern part of the basin were produced. Then, according to the thickness of the earliest deposited Taiyuan formation on the unconformity surface, we analyzed the paleogeomorphology of the bauxite deposition. Finally, a sedimentary facies map of the Taiyuan formation was developed based on the content of sandstone, coal seams, and carbonate rocks contained there. The results show that the diaspore content of bauxite is positively correlated with the natural gamma logging (GR) values. According to the diaspore contents and the GR values, the aluminiferous rocks in the Taiyuan formation can be divided into three categories: ① Bauxite for GR values > 450 API and diaspore content >70%; ② Argillaceous bauxite for GR values = 300–450 API and diaspore content = 25%–70%; and ③ Bauxitic mudstone for GR values = 220–300 API and diaspore content = 0%–25%. Bauxite mainly occurred in the middle and deep lagoon environments in the lower part of the Taiyuan formation. The lagoon is distributed along the paleokarst groove in the NW strike, with a width of approximately 30–40 km and a length of approximately 150–200 km, among which the thickness of pure bauxite is 9 m, argillaceous bauxite 26 m and alumina mudstone 6 m. Bauxite with a high porosity mainly existed in pure bauxite. The lagoon bauxite in the lower part of the Taiyuan formation gradually changes upward into a tidal flat swamp and carbonate platform environment.

The flotation of diasporic bauxite is to separate diaspore (valuable mineral) from aluminosilicate minerals (gangue minerals, mainly including kaolinite, illite and pyrophyllite), and the microscopic interaction force between the two types of minerals and air bubbles determines the separation efficiency. In this paper, based on the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the van der Waals, electrostatic and hydrophobic interaction between particles of the four minerals mentioned above and air bubbles in collectorless solution were calculated first, and then diaspore and kaolinite were taken as examples to analyze the influence of various factors such as electrolyte concentration, mineral particle size, air bubble size, collector type (dodecylamine hydrochloride (DAH) and sodium oleate (NaOL)) and concentration, and pulp pH on the interactions between the particles of valuable mineral and gangue minerals and air bubbles. The results showed that the total extended DLVO interactions between the four minerals and air bubbles were repulsive in most cases in collectorless solution. The increase in electrolyte concentration reduced the interaction force or even changed the direction of the force under certain circumstances. The addition of DAH and NaOL can reduce the adhesion energy barrier of kaolinite-bubble and diaspore-bubble respectively. Each type of minerals exhibited a specific interface interaction response with air bubbles in each collector with different pH values. The research results have theoretical guiding significance for the optimization and directional control of diasporic bauxite flotation conditions.

Molecular force plays an important role in the interaction between collector and minerals, which directly reflects the intrinsic reason for the selectivity and collection of the collector to minerals. In this work, the interaction forces between sodium oleate (NaOL) and minerals (kaolinite and diaspore) were directly characterized by atomic force microscopy (AFM) combined with EDLVO theory. The results show that after interacting with NaOL, the zeta potentials of kaolinite and diaspore were more negative, and the hydrophobicity of minerals increased. EDLVO calculation results indicate that electrostatic repulsion dominated the interaction forces between mineral particles, and the van der Waals interaction energy, electrostatic interaction energy, and hydrophobic interaction energy increased after NaOL treatment. AFM measurements show that the NaOL collector increased the attraction force of diaspore-diaspore and kaolinite-kaolinite particles, and the increase in attraction force for diaspore-diaspore particles was larger than in kaolinite particles, which was consistent with the EDLVO results. The adhesion force between the NaOL collector and the diaspore surface was larger than in kaolinite, confirming the fact that NaOL had better collection and selectivity for diaspore than kaolinite. This work improves understanding of the interaction mechanisms between NaOL collector, diaspore, and kaolinite minerals. [ABSTRACT FROM AUTHOR]

Seed dispersal by wind is one of the most important dispersal mechanisms in plants. The key seed trait affecting seed dispersal by wind is the effective terminal velocity (hereafter "terminal velocity", Vt), the maximum falling speed of a seed in still air. Accurate estimates of Vt are crucial for predicting intra‐ and interspecific variation in seed dispersal ability. However, existing methods produce biased estimates of Vt for slow‐ or fast‐falling seeds, fragile seeds, and seeds with complex falling trajectories. We present a new video‐based method that estimates the falling trajectory and Vt of wind‐dispersed seeds. The design involves a mirror that enables a camera to simultaneously record a falling seed from two perspectives. Automated image analysis then determines three‐dimensional seed trajectories at high temporal resolution. To these trajectories, we fit a physical model of free fall with air resistance to estimate Vt. We validated this method by comparing the estimated Vt of spheres of different diameters and materials to theoretical expectations and by comparing the estimated Vt of seeds to measurements in a vertical wind tunnel. Vt estimates closely match theoretical expectations for spheres and vertical wind tunnel measurements for seeds. However, our Vt estimates for fast‐falling seeds are markedly higher than those in an existing trait database. This discrepancy seems to arise because previous estimates inadequately accounted for seed acceleration. The presented method yields accurate, efficient, and affordable estimates of the three‐dimensional falling trajectory and terminal velocity for a wide range of seed types. The method should thus advance the understanding and prediction of wind‐driven seed dispersal. [ABSTRACT FROM AUTHOR]

Purpose: Soil diaspore banks of bryophytes are poorly known in tundra grasslands, yet can be important for the maintenance of local bryophyte assemblages. We examined the effects of fertilization and grazing exclusion on above-ground bryophyte assemblages and soil diaspore banks in a tundra grassland. Methods: We collected soil diaspore samples and recorded the cover of above-ground bryophytes from a full-factorial experiment with NPK fertilization and grazing exclusion treatments (a Nutrient Network site in NW Finland). Soil diaspore samples were germinated on trays in a greenhouse. We analyzed the compositions of diaspore bank assemblages and of above-ground assemblages and assessed their responses to the experimental treatments. Results: The diaspore bank contained c. 50% of taxa found in above-ground assemblages; 26 bryophyte taxa germinated from the diaspore bank, while 40 taxa were found in the above-ground assemblages. These communities had distinct species compositions: the diaspore bank was dominated by Pohlia nutans, while above-ground assemblages were dominated by several species. NPK fertilization and grazing exclusion had negative effects on bryophyte richness and cover in above-ground assemblages, and weaker effects on these responses in the diaspore bank. Conclusion: Soil diaspore banks comprise about half of the bryophyte taxa encountered in above-ground assemblages. Bryophyte diaspore banks are more buffered against nutrient enrichment and grazing exclusion than above-ground assemblages, suggesting that diaspore banks may enhance persistence and recovery of local bryophyte assemblages from environmental changes. [ABSTRACT FROM AUTHOR]

Copyright of Türkiye Jeoloji Bülteni is the property of TMMOB JEOLOJI MUHENDISLERI ODASI 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.)

Abstract Seed dispersal by wind is one of the most important dispersal mechanisms in plants. The key seed trait affecting seed dispersal by wind is the effective terminal velocity (hereafter “terminal velocity”, Vt), the maximum falling speed of a seed in still air. Accurate estimates of Vt are crucial for predicting intra‐ and interspecific variation in seed dispersal ability. However, existing methods produce biased estimates of Vt for slow‐ or fast‐falling seeds, fragile seeds, and seeds with complex falling trajectories. We present a new video‐based method that estimates the falling trajectory and Vt of wind‐dispersed seeds. The design involves a mirror that enables a camera to simultaneously record a falling seed from two perspectives. Automated image analysis then determines three‐dimensional seed trajectories at high temporal resolution. To these trajectories, we fit a physical model of free fall with air resistance to estimate Vt. We validated this method by comparing the estimated Vt of spheres of different diameters and materials to theoretical expectations and by comparing the estimated Vt of seeds to measurements in a vertical wind tunnel. Vt estimates closely match theoretical expectations for spheres and vertical wind tunnel measurements for seeds. However, our Vt estimates for fast‐falling seeds are markedly higher than those in an existing trait database. This discrepancy seems to arise because previous estimates inadequately accounted for seed acceleration. The presented method yields accurate, efficient, and affordable estimates of the three‐dimensional falling trajectory and terminal velocity for a wide range of seed types. The method should thus advance the understanding and prediction of wind‐driven seed dispersal.

In this paper, the effect of a new mixed collector sodium oleate (NaOl)/tert dodecyl mercaptan (TDM) on the separation of diaspore and kaolinite at 283 K was investigated. The molar ratio of NaOl to TDM is 8:2. The properties of the mixed collector and its adsorption mechanism on diaspore and kaolinite were studied by surface tension measurements, Zeta potential determinations and XPS analysis. The flotation results show that the mixed collector NaOl/TDM has a good collection ability for diaspore and a good selectivity for kaolinite at low temperatures. Therefore, the mixed collector NaOl/TDM can effectively separate diaspore and kaolinite under alkaline conditions at 283 K. The results of surface tension measurements show that the molecular density, hydrophobic association ability and collection ability of the mixed collector NaOl/TDM are better than those of the single collector at 283 K. In addition, the formation of a micelle effect of the mixed collector NaOl/TDM has a synergistic effect, which improves the reagent activity at low temperatures with the flotation effect enhanced. The results of the Zeta potential determinations and XPS analysis show that the total adsorption capacity of the mixed collector NaOl/TDM on the surface of the diaspore at low temperatures is higher than that of NaOl, and the adsorption capacity on the surface of kaolinite is similar to that of NaOl. The mixed collector NaOl/TDM may be adsorbed on the surface of diaspore and kaolinite by a hydrogen bond at 283 K. [ABSTRACT FROM AUTHOR]

This article revisits and reevaluates the role that "stasis" can play as a literary technique in diasporic Chinese Canadian writing. To these ends I read Chinese Canadian author Judy Fong Bates's debut novel Midnight at the Dragon Café (2005) as an important and intimate map of the social geography of a small Canadian town that illuminates how diasporic Chinese life is both constructed and constricted by the institution of the Chinese restaurant. I propose that having a narrative of restaurant life that centres around Chinese Canadian waiters and cooks exposes how socioeconomic institutions reproduce dominant social relations by limiting movement and representational possibilities for immigrant populations. In the book, sedentariness is presented alongside the social and political institutions that generate these diasporic subjects, which, I argue, creates a scene of stasis — where diasporic subjects work to achieve an equilibrium between competing cultural regimes. Bates's book is remarkable insofar as it maps the unevenness brought on by diasporic globality but in a very "fastened" way — showing how the characters' global outlooks are shrunk and slowly withered away by the small-town space. This article considers, then, what writing about diasporic stasis achieves in an age that is often characterized by global mobility. [ABSTRACT FROM AUTHOR]

We compared the species composition of seedlings germinated on ten recently abandoned Formica polyctena nests with the plant species on active nests and the plant species composition of the forest floor around the nests. Compared to no plants at all, when the nests were inhabited, seedlings of 12 different vascular plant species germinated on the nests after their abandonment. Four of them were myrmecochorous, of which two occurred only on the nests. After abandonment, ant activity ceases, the water content of the nests increases, and decomposition of the organic nest material is accelerated, resulting in faster nutrient mineralization. Consequently, more nutrients are available for plants. Our results suggest that abandoned nests can serve as "regeneration niches", ensuring genetic diversity, especially in plant populations which rely mainly on vegetative propagation. However, more research on a larger scale is needed to assess the role of wood ants and their abandoned nests in forest vegetation development. [ABSTRACT FROM AUTHOR]

Diaspores (samaras) of the sheoaks, Casuarina and Allocasuarina, have a mesocarp composed of hydrophilic fibres that, in Allocasuarina, rapidly expand on wetting, capturing significant quantities of water. The ecological function of this water capturing has been the subject of speculation but not quantification or experimentation. Therefore, the rate and quantity of water absorbed, and the floatation properties of samaras of accessions of Casuarina and Allocasuarina were assessed. Casuarina absorbed water slowly (~48 h) with median absorption of 90% (by weight) whereas Allocasuarina absorbed water rapidly (

This article examines Erna Brodber’s 1994 novel, Louisiana, as a methodological invitation to the field of Black Studies to query how we do the work of black study. A Jamaican social scientist turned novelist, Brodber finds the tools of social science and notions of Western rationality and reason that undergird it insufficient for the unique challenges of recovering a past characterized by violent rupture and irreparable loss. In turn, she takes up fiction to imagine a new method and field of study to fill in the gaps of black diasporic history. Merging anthropology and sociology with literature, she produces a fictionalized ethnography—the novel Louisiana—that undermines the tenets of Western Enlightenment thought, its various offspring (social scientific method, History, Christianity, and technology), and their attendant claims to truth, facticity, and progress. Mobilizing the epistemes embedded within black diasporic cultural and political practices such as spirit possession, music, storytelling, and grassroots labor organizing, Louisiana constructs a counter-archive of diaspora that is at once sacred, feminist, and communal. Ultimately, the novel sketches the contours of a new interdisciplinary method and field of study—perhaps Brodber’s own version of Black Studies—that foregrounds 1) “sacred praxis” vis-à-vis spirit possession as a legitimate mode of knowledge acquisition, 2) the “global black south” as a nodal point of diasporic relationality, and 3) a dispossessive logic and an ethic of humility and surrender in the research process that serves as an affront to notions of liberal individual personhood and the hierarchization of peoples and knowledges that produced and sustain the Western “order of things.” [ABSTRACT FROM AUTHOR]

In single crystals of orthorhombic α‐AlOOH, known also as mineral diaspore, χ(3)‐nonlinear lasing by stimulated Raman scattering (SRS) and Raman‐induced four‐wave mixing (RFWM) is investigated. Picosecond pumping at 1.064 µm wavelength produces a broadband Stokes and anti‐Stokes frequency comb with up to 25 SRS‐ and RFWM‐generated emission lines. All observed Stokes and anti‐Stokes lasing components in the visible and near‐IR are identified and attributed to a single SRS‐promoting vibration mode with ωSRS ≈ 445 cm−1. The first Stokes steady‐state Raman gain coefficient in the visible spectral range is estimated to a value not less than 0.36 cm GW−1. [ABSTRACT FROM AUTHOR]

Background and Aims: Diversity in pappus shapes and size in Asteraceae suggests an adaptive response to dispersion challenges adjusting diaspore to optimal phenotypic configurations. Here, by analysing the relationship among pappus-cypsela size relationships, flight performance and pappus types in an evolutionary context, we evaluate the role of natural selection acting on the evolution of diaspore configuration at a macro-ecological scale in the daisy family., Methods: To link pappus-cypsela size relationships with flight performance we collected published data on these traits from 82 species. This allowed us to translate morphometric traits in flight performance for 150 species represented in a fully resolved backbone phylogeny of the daisy family. Through ancestral reconstructions and evolutionary model selection we assessed whether flight performance was associated with and constrained by different pappus types. Additionally, we evaluated, through phylogenetic regressions, whether species with different pappus types exhibited evolutionary allometric pappus-cypsela size relationships., Results: The setose pappus type had the highest flight performances and represented the most probable ancestral state in the family. Stepwise changes in pappus types independently led from setose to multiple instances of pappus loss with associated reduction in flight performance. Flight performance evolution was best modelled as constrained by five adaptive regimes represented by specific pappus types which correspond with specific optimal diaspore configurations that are distinct in pappus-cypsela allometric relationships., Conclusions: Evolutionary modelling suggests natural selection as the main factor of diaspore configuration changes which proceeded towards five optima, often overcoming constraints imposed by allometric relationships and favouring evolution in certain directions. With the perspective that natural selection is the main process driving the observed patterns, various biotic and abiotic are suggested as principal drivers of transitions in diaspore configurations along space and time in the daisy family history. Results also allow discussion of evolutionary changes in a historical context., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The thermoelasticity and stability of diaspore (α-AlOOH, Al1.002Fe0.003OOH) were investigated in this study by in situ synchronous X-ray diffraction (XRD) and Raman spectroscopy methods at high pressure and high temperature conditions. The results indicate that diaspore is stable within the pressure and temperature (P-T) region examined in this study. With increasing pressure, the Raman peaks move toward the high wave number direction, the intensity of the Raman peaks increases, and the vibration mode of diaspore changes linearly. Pressure-volume data from in situ high-pressure XRD experiments were fitted by the third-order Birch-Murnaghan equation of state (EoS) with the zero-pressure unit-cell volume V0 = 118.15 (4) Å3, the zero-pressure bulk modulus KV0 = 153 (2) GPa, and its pressure derivative K'V0 = 2.4 (3). When K'V0 was fixed at 4, the obtained KV0 = 143 (1) GPa. The axial compressional behavior of diaspore was also fitted with a linearized third-order Birch-Murnaghan EoS, showing slight compression anisotropy with Ka0 = 137 (5) GPa, Kb0 = 169 (7) GPa and Kc0 = 178 (6) GPa. In addition, the temperature-volume data from in situ high-temperature XRD experiments were fitted by Fei’s thermal equation with the thermal expansion coefficients αV = 2.7 (2) × 10–5 K−1, αa = 1.13 (9) × 10–5 K−1, αb = 0.77 (5) × 10–5 K−1, and αc = 0.85 (9) × 10–5 K−1 for diaspore, which shows that diaspore exhibits slightly anisotropic thermal expansion. Furthermore, in situ synchrotron-based single-crystal XRD under simultaneously high P-T conditions indicates that the P-T stability of diaspore is up to ∼10.9 GPa and 700 K. Combined with previous results, we infer that diaspore can be subducted to ∼390 km under cold subduction conditions based on existing experimental data and is a good candidate for transporting water to the deep Earth.

Molecular force plays an important role in the interaction between collector and minerals, which directly reflects the intrinsic reason for the selectivity and collection of the collector to minerals. In this work, the interaction forces between sodium oleate (NaOL) and minerals (kaolinite and diaspore) were directly characterized by atomic force microscopy (AFM) combined with EDLVO theory. The results show that after interacting with NaOL, the zeta potentials of kaolinite and diaspore were more negative, and the hydrophobicity of minerals increased. EDLVO calculation results indicate that electrostatic repulsion dominated the interaction forces between mineral particles, and the van der Waals interaction energy, electrostatic interaction energy, and hydrophobic interaction energy increased after NaOL treatment. AFM measurements show that the NaOL collector increased the attraction force of diaspore-diaspore and kaolinite-kaolinite particles, and the increase in attraction force for diaspore-diaspore particles was larger than in kaolinite particles, which was consistent with the EDLVO results. The adhesion force between the NaOL collector and the diaspore surface was larger than in kaolinite, confirming the fact that NaOL had better collection and selectivity for diaspore than kaolinite. This work improves understanding of the interaction mechanisms between NaOL collector, diaspore, and kaolinite minerals.

(C) The relationship between the mass of the artificial diaspore of S. tuberosa and the proportion of diaspores successfully dispersed by wasps demonstrates that wasps manipulate lighter diaspores easily. Keywords: diaspore; disperser; seed dispersal; Stemona; vespicochory; wasp EN diaspore disperser seed dispersal Stemona vespicochory wasp 1 5 5 06/09/21 20210601 NES 210601 Vespicochory, defined as seed dispersal by wasps, was first reported by Pellmyr (1985). The large wasps at KBG could easily handle the small diaspores from JFS (spending less time than handling the large diaspores from the local population), and performed even better at seed dispersal, with the dispersal proportion being 96.4% ( I n i = 83) and dispersal distance being 95.0 ± 2.3 m ( I n i = 79). However, the small JFS wasps did not reject the large KBG diaspores, indicating that the small JFS wasps were similarly attracted by the elaiosomes of large KBG diaspores as they were by the small JFS diaspores did. [Extracted from the article]

Electrical conductivities of diaspore (α-AlOOH), δ-AlOOH, and ε-FeOOH were measured by impedance spectroscopy with a frequency range from 10-1 to 106 Hz at pressures from 8 to 20 GPa and temperatures from 500 to 1200 K, well below the dehydration temperatures of these phases at the relevant pressures. For diaspore, the relationship between electrical conductivity and reciprocal temperature can be well fitted by the Arrhenius formula: where σ0 is the pre-exponential factor, ΔE is the activation energy, and Δ Y is activation volume of 56.0 ± 1.2 S/m, 0.55 ± 0.02 eV, and 1.68 ± 0.12 cm3/mol, respectively. The electrical conductivity of diaspore decreases with increasing pressure ranging from 8 to 12 GPa by a half order of magnitude, whereas the conductivity becomes almost constant in a pressure range above 12 GPa. δ-AlOOH and ε-FeOOH show one and two orders of magnitude higher electrical conductivity than diaspore. Electrical conductivities of δ-AlOOH and ε-FeOOH, which have isostructural CaCl2-type hydroxide structure, show the nearly identical activation enthalpies (0.38 ± 0.01, 0.33 ± 0.05 eV), which are relatively lower than that of diaspore. The dominant conduction mechanism of AlOOH phases can be regarded as proton conduction. The conductivity difference between diaspore and δ-AlOOH attributes to result in the different ORG bond lengths of each phase. The reduction of ORG bond length with increasing pressure could enhance the proton migration by reducing the potential barrier, thereby raising the electrical conductivity. Small polaron conduction may contribute to the conductivity of ε-FeOOH to generate higher conductivity than δ-AlOOH. Furthermore, hydrogen bond symmetrization will also play an important role in the conductivity discrepancy of these hydrous minerals with CaCl2-type hydroxide structure. For subducted sedimentary rocks, polymorphs of AlOOH and FeOOH are representative hydrous phases. Al-rich sediments show conductivity reduction with increasing depth until phase transformation occurs because diaspore represents negative pressure dependence of conductivity. After transformation to δ-AlOOH, the conductivity will jump up around 18 GPa. If ε-FeOOH is stable above 5 GPa in an iron-rich lithology, such as banded iron formation (BIF), a high conductivity zone with positive pressure dependence could be observed to the deep lower mantle. [ABSTRACT FROM AUTHOR]

The microscopic force between collector and mineral is the fundamental mechanism for selective adsorption of collector on mineral surface. Propyl gallate (PG) is a highly selective collector for the separation of diaspore and kaolinite, and its selective collection performance is better than that of traditional collector sodium oleate (NaOL). The selective interaction mechanisms of PG with diaspore were analyzed using EDLVO theory and AFM analysis in this study. EDLVO calculation results indicate that the electrostatic interaction energy and hydrophobic interaction energy of diaspore particles treated by PG were higher than that of NaOL. AFM results also show that the interaction force between PG and diaspore is greater than that between NaOL and diaspore, confirming the fact that PG had better collection and selectivity than NaOL for diaspore. This work revealed the selective interaction mechanism of PG collector with diaspore other than kaolinite at a molecular level, which would deepen the understanding of the selective flotation of PG for diaspore from kaolinite. [Display omitted] • The interaction forces between PG and diaspore were evaluated by AFM an EDLVO. • The collector PG largely increased the repulsion between diaspore particles. • The adhesion force between PG and diaspore was stronger than that of NaOL. [ABSTRACT FROM AUTHOR]

Five typical bauxite samples from three ore deposits from the wider area of Grebnik Mt. (Metohija, Serbia) were examined with the optical microscopic, X-ray powder diffraction (XRPD) and chemical methods. The occurrences in bauxites were studied and described and the presence of major minerals was determined: diaspore, boehmite and hematite; minor minerals: quartz, goethite, rutile, kaolinite and hydro-hematite; as well as anatase, brookite, magnetite and chromite, which occur only sporadically. According to the quantity of main Al-bearers, three types of bauxite ore were recognized: diaspore, boehmite and boehmite-diaspore. Unit cell dimensions of major minerals were determined, mostly with values within reference data. However, all of the studied hematites have smaller a0 and V0 values, most probably due to the substitution of Fe3+ by Al3+. All samples are further classified as iron-rich and ferritic bauxites. It was found that there were changes in origin conditions between major Al-hydroxides minerals and hematite, as well as between the diaspore and boehmite. Determined chemical compositions put this raw material into high-quality raw materials for obtaining the electro corundum and alumina. The synthesis of the obtained data indicate that Grebnik’s bauxites have some unique characteristics, more or less different from most of the World’s known bauxite ore deposits.

In this paper, the effect of a new mixed collector sodium oleate (NaOl)/tert dodecyl mercaptan (TDM) on the separation of diaspore and kaolinite at 283 K was investigated. The molar ratio of NaOl to TDM is 8:2. The properties of the mixed collector and its adsorption mechanism on diaspore and kaolinite were studied by surface tension measurements, Zeta potential determinations and XPS analysis. The flotation results show that the mixed collector NaOl/TDM has a good collection ability for diaspore and a good selectivity for kaolinite at low temperatures. Therefore, the mixed collector NaOl/TDM can effectively separate diaspore and kaolinite under alkaline conditions at 283 K. The results of surface tension measurements show that the molecular density, hydrophobic association ability and collection ability of the mixed collector NaOl/TDM are better than those of the single collector at 283 K. In addition, the formation of a micelle effect of the mixed collector NaOl/TDM has a synergistic effect, which improves the reagent activity at low temperatures with the flotation effect enhanced. The results of the Zeta potential determinations and XPS analysis show that the total adsorption capacity of the mixed collector NaOl/TDM on the surface of the diaspore at low temperatures is higher than that of NaOl, and the adsorption capacity on the surface of kaolinite is similar to that of NaOl. The mixed collector NaOl/TDM may be adsorbed on the surface of diaspore and kaolinite by a hydrogen bond at 283 K.

We compared the species composition of seedlings germinated on ten recently abandoned Formica polyctena nests with the plant species on active nests and the plant species composition of the forest floor around the nests. Compared to no plants at all, when the nests were inhabited, seedlings of 12 different vascular plant species germinated on the nests after their abandonment. Four of them were myrmecochorous, of which two occurred only on the nests. After abandonment, ant activity ceases, the water content of the nests increases, and decomposition of the organic nest material is accelerated, resulting in faster nutrient mineralization. Consequently, more nutrients are available for plants. Our results suggest that abandoned nests can serve as “regeneration niches”, ensuring genetic diversity, especially in plant populations which rely mainly on vegetative propagation. However, more research on a larger scale is needed to assess the role of wood ants and their abandoned nests in forest vegetation development.

The importance of many mutualistic interactions is poorly understood because information on their frequency and distribution at wide spatial scales is lacking. One such interaction is that between ants and plants bearing diaspores equipped with elaiosomes, which function as a reward for ants in exchange for dispersion. Our aim was to estimate the number of taxa having elaiosome-bearing diaspores in the Ibero-Balearic territory and its relationship to several factors. We estimated that at least 572 species and subspecies, almost one-third endemic, are present, which corresponds to ca. 5.1% of European angiosperms and 9% of Iberian ones. Because this number of elaiosome-bearing taxa is much higher than those given so far for the Northern Hemisphere, the Ibero-Balearic territory should be considered an important center of myrmecochory, with myrmecochorous species richness significantly positively correlated with ruggedness, latitude, and longitude. In contrast to other myrmecochorous territories (Australia and Cape Province), where numerous trees and shrubs develop on acid substrates, most myrmecochores in the Ibero-Balearic area are perennial herbs occupying basic substrates. Such perennial herbs are more frequent in the Eurosiberian floristic region, whereas annuals abound in the Mediterranean region. The enumerated taxa mainly inhabit forests, scrubs, and anthropized sites. Among them, 56.5% carry the elaiosome on seeds (especially strophiole and caruncle types). In 36.7%, the elaiosome is borne on indehiscent fruits, such as achenes in Asteraceae, where they are found either at the base of the style or the basal hilum, and at the base of nutlets (Boraginaceae and Lamiaceae). [ABSTRACT FROM AUTHOR]

Seed dispersal is a vital part of a plant’s life cycle that enables progeny to reach new sites suitable for burial and establishment. Awns are characteristic of many grass species and enable diaspores to self-disperse. Little is known, however, about the role of different awn morphologies in dispersal or burial. The objective of this study was to investigate the influence of awn morphology on diaspore surface dispersal and burial among representative Australian Poaceae. Surface dispersal, burial and microsite selectivity of diaspores were compared across 30 grass species and ten awn morphological types using laboratory and natural simulation experiments. The presence of an awn significantly facilitated surface dispersal and burial of diaspores, with awn length and hygroscopic activity being positively related to both surface dispersal and burial depth. Geniculate (once-bent) and bigeniculate (twice-bent) awns were the most efficient at surface dispersal. Burial efficiency, however, was influenced by microsite conditions; a surface obstruction increased burial for almost all awn types, while falcate (curved)-awned species were effective at burying without such objects. This study indicates that awn morphologies likely play different functional roles in the success of Australian grass progeny.