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While clonal integration can improve the performance of rhizomatous plants, it remains unclear whether their clonal integration strategy changes under contrasting clipping and saline-alkali homogeneous and heterogeneous environments. Leymus chinensis is a clonal grass native to the Songnen grassland where heavy grazing and patchy saline-alkali stress are serious environmental and ecological problems. We hypothesized that L. chinensis overcomes these stresses through clonal integration, in particular the transfer of nitrogen and carbohydrates.A pot experiment was carried out with 15N isotope soil labeling method to study clonal integration strategy in the connected mother and daughter ramets of L. chinensis. The connected ramet pairs were grown in homogeneous (both connected ramets were treated) and heterogeneous (only daughter ramets were treated) environments with four treatments: control, clipping (60% aboveground biomass removal), saline-alkali (3.45 g of NaCl, NaHCO3, and Na2CO3 per pot), and clipping × saline-alkali.A significant amount (22.5%) of 15N was transferred from mother to daughter ramets under non-stressed conditions. When homogeneously stressing both mother and daughter ramets, N transfer was significantly reduced to 8.5--14.6%, independent of the nature of the stress. When only daughters were stressed (heterogeneous stress), saline-alkali stress led to a division of labor where daughters had enhanced photosynthesis, and mother ramets had increased 15N uptake and growth. Clipping only daughters reduced biomass and 15N uptake of both daughter and mother ramets.Our results demonstrated that clonal integration also occurs in homogeneous favorable environments but is reduced under homogeneous stress. In heterogeneous environments, clonal integration is used to translocate resource after clipping and a division of labor is established to overcome saline-alkali stress. Clonal integration continued even when daughters were severely stressed by the combined treatments. Our findings suggest that these mechanisms are key to the success of L. chinensis in the Songnen grassland.

Due to its higher oxygen content, biodiesel fuel could play a vital role in the achievement of emission control in the heavy-duty transportation sector. Waste cooking oil (WCO) obtained from various sources such as the food industry, restaurants, and sewers could provide sustainable means of producing low-carbon fuel such as biodiesel. In this research, WCO biodiesel and conventional diesel fuels were characterized fundamentally in terms of their spray and gas entrainment qualities under diesel-like engine conditions using laser-induced fluorescence and particle image velocimetry (LIF-PIV). The impact of fuel injection parameters such as injection pressure and nozzle diameter on the fuel's spray and gas entrainment characteristics were investigated. Furthermore, an empirical equation was used to determine the droplet sizes of the sprays at different injection conditions. For both fuels, spray breakup and atomization were enhanced with the droplet size decreasing as injection pressure increased from 100 to 300 MPa and as nozzle size decreased from 0.16 to 0.08 mm. As a result of higher viscosity and surface tension, it was observed that WCO biodiesel produced longer spray penetration and narrower spray angle than diesel fuel. Furthermore, the quantity of gas entrained by WCO biodiesel spray was lower. As a result of an increase in the surface area, the percentage of gas entrained at the side periphery of the spray increased as time proceeded while the percentage of gas entrained via the spray tip decreased. The combined effect of ultra-high injection pressure of 300 MPa with a smaller nozzle hole diameter of 0.08 mm was observed to enhance gas entrainment processes.

Abstract For passenger cars, various powertrains compete in terms of reducing environmentally-harmful emissions, smooth integration into future energy systems and economic performance. Developing a sound long-term projection of the total cost of ownership (TCO), however, remains challenging. Highlights of our present assessment, include a detailed, component-based manufacturing and operating cost analysis, as well as simulation-based component scaling and fuel consumption analysis. We apply this methodology to eight passenger car concepts based on batteries, fuel cells and combustion engines , spanning four passenger car segments and five different market development scenarios through 2050. With respect to the TCO, our analysis reveals that fully-electric powertrains utilizing batteries (BEVs) and fuel cells (FCEVs) offer the lowest-cost solutions. FCEVs exhibit small but robust benefits compared to BEVs. BEVs will undergo the earliest break-even point with internal combustion engine vehicles (ICEVs), already before 2030. Different market development scenarios would not significantly affect the long-term results.

Abstract To generate power from various biomass using microbial fuel cells (MFCs), microorganisms with high potential are essential. Therefore, this study examined the feasibility of using Cellulomonas fimi and Shewanella oneidensis as MFCs fueled by starch, cellulose, chitin, and chitosan. To our knowledge, this is the first report of power generation using C. fimi fueled by these polysaccharides other than cellulose, furthermore the first report of S. oneidensis fueled by chitosan. No differences were observed in the power generation capacities between C. fimi and S. oneidensis when chitin and chitosan were used. However, C. fimi demonstrated effective power generation from starch and cellulose, showing a maximum current density of 17.4 mA m−2 for starch and 38.8 mA m−2 for cellulose. Shewanella oneidensis could not utilize these fuels. Power generation using C. fimi fueled by starch and cellulose produced acetic acid, lactic acid, and formic acid. However, when chitin and chitosan were used, only acetic acid was produced. These results indicate that electron transfer from C. fimi to the anode may be inefficient. To improve power generation efficiency, it may be necessary to enhance electron transfer from the cells to the anode, e.g. by adding a mediator.

Abstract The coexistence of tree species in tropical forests has remained challenging to explain, characterise and predict with simple theoretical models. To address this phenomenon researchers have focused on processes and factors omitted in simple competition models. Meantime, theoretical considerations of simple models have sought out conditions for stable coexistence of many species. Here we show that a simple competition model parameterised using repeated forest tree inventory data can estimate the stable coexistence of numerous tree species and predict their biomass abundance and productivity in equilibrium communities. We apply a simple Lotka–Volterra competition model to describe species aboveground biomass, and employ leaf biomass as a proxy for exploitative competition among species. In such systems a globally stable multispecies equilibrium arises when, for every species, susceptibility of biomass growth to conspecific (same species) leaf biomass exceeds that to heterospecific leaf biomass. We applied this approach to tree species in the Pasoh 50‐ha plot of Malaysian lowland mixed dipterocarp forest. We parameterised species aboveground biomass productivity by tree growth, by recruitment, and losses from tree mortality. Biomass gains minus losses yields the biomass growth of each species population. Using variation in leaf biomass among quadrat subplots, we estimated the susceptibility of productivity by tree growth to conspecific and heterospecific leaf biomass. Our model analyses with plot census data predicted the stable coexistence of 351 of the 487 tree species assessed. Susceptibility to conspecific versus heterospecific leaf biomass was greater across all species (median: 95 times). The implied effect of conspecific competition appears to reflect ontogeny, that is declining relative tree growth with tree size. The equilibrium biomasses for predicted persistent species were broadly similar to observations. Removal of species indicates that ecosystem biomass and productivity at equilibrium increases asymptotically with species richness. Synthesis. Our analyses with a simple model provide a range of non‐trivial insights into tree species coexistence, community structure and ecosystem stability within a species‐rich rainforest. The insights available from such simple models provide references for a reassessment of the insights from more complex models and approaches.

Polybrominated diphenyl ethers (PBDEs) are persistent xenobiotics with harmful effects on humans and wildlife. Their levels in the environment and accumulation in biota must be carefully controlled especially in species harvested from wild populations and commonly used as medicines. Our objective has been to determine PBDE concentrations (BDEs 28, 47, 66, 85, 99, 100, 153, 154, 183 and 209) in Centaurium erythraea collected at sites with various levels of environmental pollution. PBDE congener profiles in C. erythraea were dominated by BDE209, which accounted for 47-89% of the total PBDE burden in the plants. Principal Component and Classification Analysis, which classifies the concentration of PBDEs in C. erythraea, allowed us to distinguish the pattern of these compounds characteristic for the origin of pollution: BDEs 28, 47, 66, 85, 99, 100 for lignite and general chemical industry and the vicinity of an expressway and BDEs 183 and 209 for a thermal power plant and ferrochrome smelting industry. Careful selection of sites with C. erythraea for medicinal purposes is necessary as this herb can accumulate PBDEs while growing at polluted sites.

AbstractSpecies distributions are conventionally modelled using coarse‐grained macroclimate data measured in open areas, potentially leading to biased predictions since most terrestrial species reside in the shade of trees. For forest plant species across Europe, we compared conventional macroclimate‐based species distribution models (SDMs) with models corrected for forest microclimate buffering. We show that microclimate‐based SDMs at high spatial resolution outperformed models using macroclimate and microclimate data at coarser resolution. Additionally, macroclimate‐based models introduced a systematic bias in modelled species response curves, which could result in erroneous range shift predictions. Critically important for conservation science, these models were unable to identify warm and cold refugia at the range edges of species distributions. Our study emphasizes the crucial role of microclimate data when SDMs are used to gain insights into biodiversity conservation in the face of climate change, particularly given the growing policy and management focus on the conservation of refugia worldwide.