Carbon capture, utilization, and storage (CCUS) in coal seam is critical for achieving carbon neutrality, yet the risk of CO2 leakage remains a major challenge. Denitrification-induced carbonate precipitation (DICP) mediated by indigenous microorganisms offers a promising strategy to limit CO2 migration in coal seam. This study investigated how organics derived from coal biodegradation (OCB) contribute to bio-carbonate formation via DICP. Results indicated that large amount of low-molecular weight OCB were progressively generated. The concentration of chemical oxygen demand (COD) ranged from 1314 mg/L to 1165.5 mg/L with the dominance of acids, especially aliphatic acids, which were mainly generated from oxygen-containing functional groups in coal. Using OCB as the sole carbon source, a mineralization efficiency of 71.3% was achieved, with propionic and 2-methyl-butanoic acids being consumed by 76.71% and 30.71%, respectively. When coal-degrading microorganisms and DICP microflora coexisted, the mineralization efficiency increased to 80.42%. The continuous generation of OCB during DICP stimulated bacterial growth, promoted denitrification process and extracellular polymeric substance (EPS) production, leading to > 80% calcite formed. The precipitated minerals filled the pores in coal, resulting in a reduction of macropore and mesopore volumes by 38.36% and 91.84%, respectively, suggesting OCB could strongly support DICP to reduce the pore development of coal. These findings demonstrated the benefit of organics in coal to prevent CO2 leakage by supporting DICP, providing a cost-effective and environmentally synergistic approach for CCUS within coal seam.
Coal-derived char has shown improving the geotechnical performance of cement-stabilized soils. This study aimed to assess the effects of coal char on the hydraulic and durability characteristics of a soil mixture composed of equal sodium bentonite and sand, stabilized with 20% cement. The addition of coal char enhanced both hydraulic and durability properties of the cement-stabilized soil. The inclusion of coal char in cement-stabilized soil further reduced the saturated hydraulic conductivity (Ksat) up to 38%, suggesting decreased water infiltration and greater soil compaction. The soil freezing characteristic curve (SFCC) showed that adding char to cement-stabilized soil samples retained more unfrozen water after 12 freeze-thaw (FT) cycles, which can reduce frost heave for better freeze-thaw resistance. Soil water characteristic curve (SWCC) results demonstrated that char addition improved moisture retention at low suction levels, which could prolong hydration, reduce shrinkage & cracking, and improve drought resilience in arid environments.
An understanding of how and why animal populations vary in space and time informs effective conservation and management. We used spatial and temporal flow metrics to explore flow-ecology relationships for two fish species, Mountain Sucker Pantosteus platyrhynchus (Cope, 1874) and Mottled Sculpin Cottus bairdii Girard, 1850, across 64 sites and 8 years in Wyoming, U.S.A. We found variation in Mottled Sculpin and Mountain Sucker abundance was driven to a greater extent by spatial flow metrics (e.g., drainage area, median summer flow) with differing direction of response between species. The opposing responses to spatial variation in median summer flow could reflect the ability of Mountain Sucker to persist in non-perennial habitats, likely due to their relatively high mobility and recolonization capacity. Responses to temporal flow metrics (e.g., previous year spring flow, previous year autumn flow) were weaker but consistent across species likely due to similar reproductive strategies and timing. The lack of stronger flow effects on population variability in both species likely corresponds to high variability in local habitat characteristics that are mediating population response. These findings underscore how considering spatial context informs conservation planning and suggest that flow-ecology relationships may be mediated by species-specific traits and local habitat conditions.
Ecological traits such as behaviour, physiology and morphology mediate an organism's interaction with its environment, and understanding their joint contribution to reproductive fitness is essential for predicting biological responses to global change. We addressed how urbanization shapes trait-function relationships across natural, suburban or urban areas to advance the functional and mechanistic understanding of ecological processes in changing environments. We investigated how interactions among ecological (urbanization, season) and phenotypic (body mass, personality) traits influence reproductive fitness in female Eurasian red squirrels (Sciurus vulgaris) across a natural-urban gradient in Italy. Using 204 records of 72 female squirrels across 12 sites, we found that body mass, mediating the effect of the spring season, was the main factor affecting the probability to reproduce in female red squirrels. Further, our results suggest a direct effect of urbanization on squirrels' reproduction: The probability of reproducing was higher in natural habitats than in the urban and suburban sites. Female red squirrels in natural sites also engaged more frequently in explorative behaviours than their conspecifics in urban sites, but this did not translate into either direct or significant indirect effects of personality on reproductive success. Finally, body mass of females tended to be slightly higher in urban and suburban than in natural habitats, but this did not result in a higher reproductive rate. While body mass emerged as the dominant predictor of reproduction, its functional role was context-dependent, shaped by seasonality, environmental resource distribution and potentially by altered energetic dynamics in urban environments. In contrast, personality traits varied with habitat but did not mediate reproduction, highlighting how trait expression does not equate to ecological function unless matched with the appropriate environmental context. This work underscores the importance of integrating multiple levels of biological organization, behaviour, body mass, life history and environmental context to understand how global change alters ecological and evolutionary trajectories. As urbanization continues to transform natural habitats, studies that disentangle direct and indirect pathways from phenotype to fitness will be essential not only for predicting wildlife persistence but also for linking individual-level processes to population and community dynamics.Read the free for this article on the Journal blog.
Understanding the relationships between nutrition and life-history characteristics can provide insight into the factors limiting populations. Moose (Alces alces) at their southern range periphery are subject to nutritional constraints because of marginal climatic and habitat conditions, but how these limitations influence vital rates remains a point of uncertainty. We examined the nutritional and reproductive dynamics of moose at the fringes of their range in southeast Wyoming, USA. We used an individual-based approach to evaluate the nutritional condition (i.e., body fat) of female moose by recapturing the same individuals each autumn and spring to measure body fat, pregnancy, recruitment of offspring, and survival. Like other temperate ungulates, we anticipated that moose would accumulate body fat over summer and use those reserves to support survival and reproduction over winter. Throughout the annual cycle, we expected that body fat, an integrated measure of energetic gains and losses, would influence pregnancy, recruitment, and adult survival. Contrary to expectations, body fat varied by less than 1.5 percentage points between autumn and spring. Despite relatively low seasonal fluctuations, body fat was positively associated with probability of pregnancy and adult survival but did not influence recruitment of young. Moreover, age influenced probability of pregnancy and overwinter survival. We demonstrate clear signs of nutritional limitation and unexpectedly absent relationships between body fat and recruitment that may be unique to moose living at the fringes of their range, highlighting environmental constraints on reproduction at distributional limits. By investigating the connections between nutrition and reproduction in southern moose, we provide insight into how vital rates can be used to monitor demographic performance for at-risk populations.
