Kelp habitats are threatened across the globe, and because of their ecological importance, active conservation and restoration solutions are needed. The use of man-made structures as artificial reefs is one way to enhance kelp habitat by providing suitable substrata, but in the past the ecology of artificial structures has been investigated mainly in contrast to natural coastal habitats, not as elements integrated into the seascape. Indeed, it is now emerging that structuring processes, including ecological interactions (e.g., herbivory), can depend on properties of the surrounding seascape. In Eastern Canada, grazing by the green sea urchin can jeopardize the success of artificial reefs for kelp enhancement. Urchin activity is, however, likely to be influenced by the bottom composition, and thus a seascape approach is needed to integrate urchin behavior and habitat heterogeneity. Adopting a spatially explicit framework, we investigated whether the seascape creates areas of differential grazing risk for kelp by affecting urchin habitat use. Specifically, we transplanted kelp onto modules of artificial substrata distributed on a heterogeneous area that we mapped for bottom type and algal cover. After following kelp survival and urchin distribution over time, we modeled kelp survival as function of urchin metrics and coupled it to urchin use of the habitat models to map grazing risk in the area. Kelp survival was a function of the frequency of the urchins presence. Urchins avoided sandy patches, while bottom composition and algal cover modulated the within-patch urchin use of the habitat, creating heterogeneity in grazing risk. Discrete seascape features (boulders) also increased the grazing risk locally. The heterogeneity of coastal seafloor can thus play a major role in determining the ecological outcomes on artificial structures. Incorporating this information when planning artificial reefs could minimize the detrimental grazing risk, thereby increasing the success of artificial reefs for kelp habitat enhancement.

Lakes are sensitive recorders of anthropogenic activities, as human society often develops in their vicinity. Lake sediments thus have been widely used to reconstruct the history of environmental changes in the past, anthropogenic, or otherwise, and radiocarbon dating provides chronological control of the samples. However, specific values of radiocarbon in different carbon reservoirs due to the different pathways of radiocarbon from the upper atmosphere to the lake, called the radiocarbon reservoir age, is always difficult to evaluate because of dynamic processes in and around lakes. There are few systematic studies on radiocarbon reservoir ages for lakes owing to the complex radiocarbon transfer processes for lakes. Here, we investigate lake waters of the Fuji Five Lakes with monthly monitoring of the radiocarbon reservoir effects. Radiocarbon from dissolved inorganic carbon (DIC) for groundwater and river water is also measured, with resulting concentrations (Δ 14 C) at their lowest at Lake Kawaguchi in August 2018 (–122.4 ± 3.2‰), and at their highest at Lake Motosu in January 2019 (–22.4 ± 2.5‰), despite a distance of 25 km. However, winter values in both lakes show similar trends of rising Δ 14 C (about 20‰). Our lake water DIC Δ 14 C results are compared to previously published records obtained from sediments in Lake Motosu and Lake Kawaguchi. These suggest that total organic carbon and compound-specific radiocarbon found in sediments are heavily influenced by summer blooms of aquatic organisms that fix DIC in water. Thus, future studies to conduct similar analyses at the various lakes would be able to provide further insights into the carbon cycle around inland water, namely understanding the nature of radiocarbon reservoir ages.

Climate impact studies often require a reduction of the ensembles of opportunity from the Coupled Model Intercomparison Project when the simulations are used to drive impact models. An impact model’s nature limits the number of feasible realizations based on complexity and computational requirements or capacities. For the purpose of driving a hydrological model and an ocean model in the BaySys research program, two hierarchical, differently sized simulation ensembles were produced to represent climate evolution for the region of the Hudson Bay Drainage Basin. We compare a 19-member ensemble to a 5-member subset to demonstrate comparability of the driving climate used to produce model results. Ten extreme climate indicators and their changes are compared for the full study region and seven sub regions, on an annual and seasonal basis and for two future climate horizons. Results indicate stronger warming in the North and for cold temperatures and an East-West gradient in precipitation with larger absolute increases to the East and South of the Hudson Bay. Generally, the smaller ensemble is sufficient to adequately reproduce the mean and spread in the indicators found for the larger ensemble. The analysis of extreme climate indicators ensures that the tails of the distribution of temperature and precipitation are addressed. We conclude that joint analysis at the interface of the hydrological and ocean model domains are not limited by the application of differently sized climate simulation ensembles as driving input for the two different modeling exercises of the BaySys project environmental studies, yet acknowledging that impact model output may be dependent on other factors.

Aquaculture is the fastest growing food production sector and currently supplies almost 50% of fish for human consumption worldwide. There are significant barriers to the continued growth of industrial aquaculture, including high production costs and harmful environmental impacts associated with the production of aquaculture feed. Most commercial aquaculture feeds are based on fish meal, fish oil, and terrestrial plant ingredients, which contain indigestible forms of phosphorus. Phosphorus loading from aquaculture effluent can lead to eutrophication in aquatic ecosystems. Formulating fish feeds using ingredients that contain highly bioavailable forms of phosphorus in nutritionally appropriate quantities will reduce phosphorus loading. Using both in vivo and in vitro experiments, we examined the digestibility of phosphorus in three experimental tilapia feeds supplemented with two freshwater microalgae ( Spirulina sp., Chlorella sp.) and one marine microalga, Schizochytrium sp., relative to a reference diet containing fish meal and fish oil. We also calculated a phosphorus budget to quantify metabolic phosphorus waste outputs. The marine Schizochytrium -supplemented diet had the highest phosphorus digestibility and the lowest solid phosphorus discharge compared to the reference diet and the other experimental diets. The Schizochytrium ingredient also had the highest phosphorus digestibility among the three microalgae tested in vitro experiments. These results suggest that Schizochytrium sp. is a highly digestible source of phosphorus and findings on metabolic phosphorus waste outputs have implications for the formulation of sustainable diets for tilapia. Further research must examine the economic feasibility and environmental impacts of producing Schizochytrium sp. as an aquafeed ingredient.

With the increased use of natural gas, safety and environmental concerns from underground leaking natural gas pipelines are becoming more widespread. What is not well understood in leakage incidents is how the soil conditions affect gas migration behavior, making it difficult to estimate the gas distribution. To shed light on these concerns, an increased understanding of subsurface methane migration after gas release is required to support efficient leak response and effective use of available technologies. In this study, three field-scale experiments were performed at the Methane Emission Technology Evaluation Center in Colorado State University to investigate the effect of soil textural heterogeneity, soil moisture, and leak rate (0.5 and 0.85 kg/h) on methane migration caused by leaking pipelines. Subsurface methane concentrations, in addition to soil moisture and meteorological data, were collected over time. A previously validated numerical model was modified and used to understand the observed methane distribution behavior. Results of this study illustrate that the influence of soil texture, leak rate, and moisture on subsurface methane distribution is determined by the relative contribution of advection and diffusion and closely related to the distance to the leak source. Advection dominates gas transport within 1–1.5 m of the leak source, driving the migration of high concentration contours. Beyond this distance, diffusion dominates migration of lower concentration contours to the far-field. Although large leak rates initially result in faster and further gas migration, the leak rate has little influence on the diffusion dominated migration farther from the leak source. Soil moisture and texture complicate gas behavior with texture variations and elevated soil moisture conditions playing a dominant role in locally increasing methane concentrations. Scenarios highlight the importance of understanding the effects of soil moisture, texture, and leak rate on gas migration behavior in an attempt to unravel their contribution to the gas concentration within the soil environment.

Projecting invasion treatment outcomes and determining controlling efficiency under various management strategies have important implications in field management. Different from herbicide usage that may cause environmental pollution and nontarget effects on native plants, nonchemical (i.e., mechanical) methods, such as mowing and hand weeding, have shown great targeted effectiveness on invasion. However, an interesting and important question that remains unclear is how to reduce the need for repeated applications of mechanical treatments. One possible approach is to integrate mechanical treatments with biological control agents, which can attack and limit invasion spread after being established in the field. We hypothesize that applying mechanical methods to remove invasive plants while establishing biological control agents, then using the established biological control agents to limit future regrowth of invasive plants, will decrease the use of mechanical treatments. To include vegetation dispersal, we developed a spatial modeling framework, using paired logistic equation models of both a resident native plant and an invasive plant, and a biological control agent, to capture the dynamics of native and invasive plants under different treatment scenarios. Specifically, we examined four factors, the initial application location of biological agents, their controlling efficiency, the treatment frequency (how often nonchemical treatment will be applied), and the areal extent of mechanical treatment. We found that explicitly targeted biological control agents showed significantly stronger controlling impacts on invasive plants than did nontargeted agents, whereas a higher treatment frequency could compensate for the drawback of untargeted treatment. Our results also suggested that adding mechanical treatment can further limit invasion spread with the cooperation of established biological control agents, and applying mechanical treatment in a lower frequency, but treating larger areas per time, is a more efficient approach than vice versa. We emphasize that a high biological control efficiency can continuously decrease the requirement of repeated treatment of nonchemical methods and maintain the invasive population at a low level. The model we developed here can be potentially extended and used by field managers on prioritizing controlling efforts to achieve a higher efficiency.

The pathways taken throughout any model-based process are undoubtedly influenced by the modeling team involved and the decision choices they make. For interconnected socioenvironmental systems (SES), such teams are increasingly interdisciplinary to enable a more expansive and holistic treatment that captures the purpose, the relevant disciplines and sectors, and other contextual settings. In practice, such interdisciplinarity increases the scope of what is considered, thereby increasing choices around model complexity and their effects on uncertainty. Nonetheless, the consideration of scale issues is one critical lens through which to view and question decision choices in the modeling cycle. But separation between team members, both geographically and by discipline, can make the scales involved more arduous to conceptualize, discuss, and treat. In this article, the practices, decisions, and workflow that influence the consideration of scale in SESs modeling are explored through reflexive accounts of two case studies. Through this process and an appreciation of past literature, we draw out several lessons under the following themes: (1) the fostering of collaborative learning and reflection, (2) documenting and justifying the rationale for modeling scale choices, some of which can be equally plausible (a perfect model is not possible), (3) acknowledging that causality is defined subjectively, (4) embracing change and reflection throughout the iterative modeling cycle, and (5) regularly testing the model integration to draw out issues that would otherwise be unnoticeable.

Widespread overuse and misuse of antibiotics has led to unintended consequences, and it is necessary to find effective ways to remove antibiotics. In this study, a visible-light-response photocatalyst zinc ferrite (ZnFe 2 O 4 ) was synthesized via a hydrothermal method. Meanwhile, the X-ray diffraction, Brunauer–Emmett–Teller, scanning electron microscope, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra analysis were applied to characterize the structure, morphology, and physicochemical properties of the ZnFe 2 O 4 . The results indicated that the ZnFe 2 O 4 was circular granular morphology with a particle size of approximately 30–50 nm and the noticeable intergranular agglomeration. The specific surface area, pore volume, and pore diameter of the ZnFe 2 O 4 were determined to be 126.8655 m 2 /g, 0.2046 cm 3 /g, and 64.5190 Å, respectively, representing that the ZnFe 2 O 4 had a large specific surface area. Moreover, the enhancement of degradation efficiency of ofloxacin (OFL) by peroxymonosulfate (PMS) under the visible light (Vis) was systematically evaluated. The results exhibited that the ZnFe 2 O 4 achieved the relatively optimum catalytic activity with 80.9% of OFL degradation efficiency in 30 min at pH 6.0 under the PMS concentration of 100 mg/L and the corresponding pseudo-first-order kinetic constant of OFL degradation was 0.0438 min –1 . In addition, the effects of ZnFe 2 O 4 dosage, PMS concentration, initial OFL concentration, solution pH, and water matrix on the OFL degradation were comprehensively investigated in the Vis/PMS/ZnFe 2 O 4 process. Furthermore, the ZnFe 2 O 4 exhibited excellent stability and reusability for OFL degradation. The Vis/PMS/ZnFe 2 O 4 process would be a reliable alternative for the degradation of OFL-like antibiotics to solve the increasingly serious problem of antibiotic pollution.

Sun Moon Lake is the first dam reservoir constructed in Taiwan with the capability of generating hydroelectricity satisfying the whole Taiwan need during the Japanese colonial period since 1934 CE. Now, the Sun Moon Lake is one of the biggest hydropower stations in Taiwan and has become an important touring area. During World War II (1944–1945 CE), the hydroelectric power plant at Sun Moon Lake was bombed by the U.S. air force, which caused severe damage to the dam structure. More recently, the dam structure was also damaged during the 1999 CE Chi-Chi earthquake whose epicenter is nearby in the Nantou County. A suite of cores were taken from both Sun Lake and Moon Lake, and two selected cores, Sun 2–1 and SM 16 4–3, from Sun Lake were detailed studied with multiple analyses, including X-ray imaging, magnetic susceptibility, visible spectrophotometry, X-ray fluorescence (XRF) scanning, and mineral analysis. We discovered that the increase of Ca content in the sediments not only clearly indicates when the dam was constructed at Sun Moon Lake but also records evidence of structure repairs after both the World War II bombing and the Chi-Chi earthquake. Additionally, the yellow turbidite, X-ray image, and low-Ca signals in Core Sun 2–1 strongly correlate to the typhoon events that caused severe floods in the watershed of Zhuoshui River. The turbidite layers caused by the 1963 Gloria Typhoon are also characterized by conspicuous high peak of Fe/Mn in both cores. This study shows that XRF scanning results are useful for recognition of human activity and for high precipitation event correlation. Moreover, the appearance of charcoal layers shows evidence of forest burning and slash-and-burn activities by humans during the past 4,000 years back to the Middle Neolithic Age.

Heavy metal pollution is a serious concern in the urban area of China. Understanding metal pollution history is crucial for setting up appropriate measures for pollution control. Herein, we report a record of concentrations of 10 heavy metals (Fe, Mn, Cu, Zn, Ni, Cr, Cd, Pb, Co, and Sr) in Pinus massoniana tree rings from Fuzhou City over the past 168 years, which represents the longest tree-ring chronology of heavy metals in China. The studied metals displayed contrasting distribution patterns. Among them, Mn and Sr showed the strongest migration trend with peak concentrations at the pith. Co, Cd, and Pb also showed distinctively high concentrations near the boundary between heartwood and sapwood. Ni, Cu, Cr, and Fe showed an increasing trend possibly due to migration toward bark caused by physiological activities and increasing tourism activities and traffic pollution. The other elements (Cr, Fe, and Zn) with low migration revealed the historical pollution possibly discharged by the Fuzhou Shipping Bureau and other anthropogenic activities. Strong correlations between Cu content and temperature were found, which provides an alternative tree-ring proxy for climate reconstruction. This study provides a long-term perspective of the joint impacts of physiological, environmental, and climatological factors on the concentrations of heavy metals in southeastern China.

Trace element pollution derived from human activities in aquatic systems has raised widespread concerns due to its toxicity, persistence, and bioaccumulation. In this article, we presented a systematic investigation of the anthropogenic overprints on trace elements geochemistry in three streams of the human-impacted (agriculture, urban area, and abandoned mining), located at Lake Aha, Guiyang, Southwest China. Concentrations reported in the study demonstrated that the abandoned mining stream showed the highest trace elements (608.16 μg/L), followed by the urban stream (566.11 μg/L) and agricultural stream (457.51 μg/L). Nonmetric multidimensional scaling (NMDS), used to display sampling dates and trace elements, showed discernible temporal variation in trace element concentrations. Trace element concentrations in months (May, September, and October) with less rainfall were higher than in June, July, and August indicated by NMDS. Principal component analysis (PCA) had shown that As, Ba, Mo, and Zn were mainly impacted by the urbanized streams, and Fe and Sr influenced by the mine. Risk assessment of human beings to trace elements demonstrated that As may pose a detrimental health risk. The research found that trace elements were potential tracers for the presence of human activities and environmental changes.

Mercury, even in low concentrations, is known to cause severe adverse human health effects. In the early 1900s, mercury became a popular fungicide ingredient, leading to multiple poisoning incidents that forced much of the world to act upon phasing out mercury use in agriculture. These incidents spurred the advancement of mercury science and the implementation of international policies and regulations to control mercury pollution worldwide. Despite these developments internationally, Australia continued using methoxyethyl mercury chloride as a fungicide to treat sugarcane against the fungi Ceratocystis paradoxa (pineapple disease). At the request of the manufacturer and following pressure from Australian researchers and the Minamata Convention on Mercury, Australian authorities announced a ban on mercury-containing pesticide in May 2020. Australia’s unique reluctance to act on controlling this hazardous pollutant makes it an interesting case study for policy inaction that runs counter to global policy trends and evidence-based decision making. As such, it can provide insights into the challenges of achieving multilateral agreement on difficult environmental issues such as global warming. In this review, I discuss the scientific development and policy decisions related to mercury fates and exposure of wildlife and humans in Australia to mercury used in pesticide. The historical uses of mercury pesticide and poisoning incidents worldwide are described to contextualize Australia’s delayed action on banning and controlling this chemical product compared to other nations. Regulations on mercury use in Australia, which has not ratified the Minamata Convention on mercury, are compared to those of major sugarcane and pesticide producer nations (Brazil, China, Japan, India, Thailand, and United States) which have ratified the Convention and replaced mercury pesticides with alternative products. I discuss how mercury regulations have the potential to protect the environment, decrease human exposure to mercury, and safeguard the ban on mercury products. Ratifying the Minamata Convention would give Australia equal footing with its international counterparts in global efforts to control global mercury pollution.

The pyrite ores are strategic industrial resources which generally serve as raw material for producing sulfuric acid. However, during the mining and industrial processing activities, associated toxic elements of cadmium (Cd) and lead (Pb) could be released into the surroundings, posing a significant threat to local environment and human health. In this study, the Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme was used to investigate the geochemical fractionation of Cd and Pb in pyrite ores from a mining area located in Yunfu, western Guangdong, China. The results showed that most of Cd and Pb (>90%) were predominantly found in the geochemically mobile fractions, indicating that Cd and Pb were readily bioaccessible thus easily assimilated and accumulated by organisms. FESEM-EDS results showed that the studied pyrite ores were mainly composed of O, S, and Fe, while the XRD characterizations suggested that FeS 2 and SiO 2 were the major minerals. The high-resolution transmission electron microscope and element mapping characterization further confirmed that FeS 2 was the main mineral of pyrite ores which contained relatively enriched toxic heavy metals (e.g., Pb and Cd). The findings highlight that an extremely large amount of geochemically mobile heavy metals can be released into the environmental media during the mining and utilization processes of pyrite ores based on IRMM sequential extraction protocol. Therefore, proper countermeasures against environmental risks of utilizing pyrite ores should be taken to mitigate the impacts on local ecosystem and human health.

Ingestion of fish is considered the main pathway of human exposure to methylmercury (MeHg), particularly for riverside populations, where fish is the main source of protein. The objective of this study was to estimate concentration of MeHg based on total concentration of mercury in muscles of three species of carnivorous fish: Boulengerella cuvieri (bicuda), Serrasalmus rhombeus (piranha), and Hydrolycus armatus (cachorra), collected from Teles Pires River, Brazil. Furthermore, we calculated human health risk related to MeHg contamination caused by fish consumption. Fish were collected in 20 field campaigns from December 2011 to September 2016 at Teles Pires River, in area of influence of Colíder hydroelectric plant. Risk index (RI) related to ingestion of MeHg through fish intake was calculated considering that MeHg corresponds to around 90% of mercury in fish. There were no significant differences in average mercury concentration between all species: S. rhombeus (0.304 mg/kg –1 ), H. armatus (0.229 mg/kg –1 ), and B. cuvieri (0.199 mg/kg –1 ). RI calculated for sensitive groups (lactating women, breastfeeding infants and children) and RI calculated for general population presented average values, suggesting adverse health effects. This first assessment on MeHg and human exposure to people from Teles Pires River area through fish consumption suggests that mercury concentrations might be posing health adverse effects on people of this sensitive group. Further studies involving more fish specimens and considering fish biological factors are needed to fully understand health risks of mercury exposure to humans in this region.

High latitude ecosystems are characterized by cold soils and long winters, with much of their biogeochemistry directly or indirectly controlled by temperature. Climate warming has led to an expansion of shrubby plant communities across tussock tundra, but whether these clear aboveground shifts correspond to changes in the microbial community belowground remains less certain. Using bromodeoxyuridine to label growing cells, we evaluated how total and actively growing bacterial communities varied throughout a year and following 22 years of passive summer warming. We found that changes in total and actively growing bacterial community structures were correlated with edaphic factors and time point sampled, but were unaffected by warming. The aboveground plant community had become more shrub-dominated with warming at this site, and so our results indicate that belowground bacterial communities did not track changes in the aboveground plant community. As such, studies that have used space-for-time methods to predict how increased shrub cover has altered bacterial communities may not be representative of how the microbial community will be affected by in situ changes in the plant community as the Arctic continues to warm.

Global changes such as increased drought and atmospheric nitrogen deposition perturb both the microbial and plant communities that mediate terrestrial ecosystem functioning. However, few studies consider how microbial responses to global changes may be influenced by interactions with plant communities. To begin to address the role of microbial–plant interactions, we tested the hypothesis that the response of microbial communities to global change depends on the plant community. We characterized bacterial and fungal communities from 395 plant litter samples taken from the Loma Ridge Global Change Experiment, a decade-long global change experiment in Southern California that manipulates rainfall and nitrogen levels across two adjacent ecosystems, a grassland and a coastal sage scrubland. The differences in bacterial and fungal composition between ecosystems paralleled distinctions in plant community composition. In addition to the direct main effects, the global change treatments altered microbial composition in an ecosystem-dependent manner, in support of our hypothesis. The interaction between the drought treatment and ecosystem explained nearly 5% of the variation in bacterial community composition, similar to the variation explained by the ecosystem-independent effects of drought. Unexpectedly, we found that the main effect of drought was approximately four times as strong on bacterial composition as that of nitrogen addition, which did not alter fungal or plant composition. Overall, the findings underscore the importance of considering plant–microbe interactions when considering the transferability of the results of global change experiments across ecosystems.

Tidal marshes are important recycling areas for biogenic silica (BSi) and macro- and microelements at the land–sea interface and are key locations for examining the decomposition process of wetland plant litter. In this study, in situ decomposition experiments were conducted with Phragmites australis , Cyperus malaccensis , and Spartina alterniflora in the Min River estuary wetland. Litterbags of 0.2-mm mesh size were used to evaluate the litter decomposition process and residual values of BSi and macro- and microelements, including C, N, Cr, Cu, Cd, Zn, Pb, Al, Mn, and Fe over 520 days. The litter decomposition rate significantly differed among species in the following order: C. malaccensis (0.005 d –1 ) > S. alterniflora (0.004 d –1 ) > P. australis (0.003 d –1 ) with BSi release rates of 98.64%, 96.75%, and 97.23%, respectively. Although there were net releases of BSi, C, and N from the three litter species, continuous decrease in the BSi/(C, N) ratio indicated that BSi was removed from the litter much faster than C and N. The accumulation index results showed that Cu, Pb, Al, and Fe were net-accumulated in the litter, whereas Cd, Mn, Cr, and Zn were predominantly released during litter decay. Pearson’s correlation analysis results showed that the amounts of N, Cu, Cd, Pb, Al, and Fe in the litter restrained BSi release with a significant negative correlation. These findings in the Min River estuary have important implications for geochemical cycles within wetland systems and the transport processes of potential nutrients out of the system.

Agricultural practices such as fertilization considerably influence soil greenhouse gas fluxes. However, the effects of fertilization on greenhouse gases fluxes remain unclear in tea soil when soil nitrogen is low. In the present study, soil CO 2 and CH 4 fluxes under various fertilization treatments in tea soil were investigated during a 50-day period. The experiment consisted of five treatments: no fertilizer (CK), single nitrogen (urea, N), single oilseed rape cake fertilizer (R), nitrogen + cake fertilizer (2:1, NR1), and nitrogen + cake fertilizer (1:2, NR2). The fertilization proportion of NR1 and NR2 was determined by the nitrogen content of nitrogen fertilizer and cake fertilizer. The results revealed that the single application of nitrogen had no significant effect on soil CO 2 flux. However, the addition of cake fertilizer significantly increased CO 2 emissions through enhanced soil microbial biomass carbon (MBC). Additionally, CO 2 emissions were directly proportional to the amount of carbon (C) in the fertilizer. All treatments were minor sinks for CH 4 except for the treatment NR1. Specifically, the cumulative CH 4 fluxes of NR1 and NR2 were significantly higher than rest of the three treatments, which implies that application of urea and oilseed rape cake reduced the capability of CH 4 oxidation in tea soil. Structural equation models indicated that soil CO 2 flux is significantly and positively correlated with soil dissolved organic carbon, MBC and soil pH, while mineral nitrogen content was the main factor affecting CH 4 flux. Overall, the application of oilseed rape cake increased the oxidation of CH 4 and promoted soil C sequestration but inevitably increased the soil CO 2 emissions.

Human skeletal morphology is a dynamic system affected by both physiological and environmental factors, due to the functional adaptation and remodeling responses of bones. To further explore the adaptation of bone to the environment and the consequent subsistence strategies determined by the diverse natural contexts in the Anthropocene, this study presents a comparative study on the tibiae of seven ancient populations located in different regions of East Asia. Through the analysis of the tibial shaft morphology, a comparative analysis between the populations and genders was conducted to evaluate the differences in external morphology and sexual division of labor. The cnemic indices of the tibial shaft were selected to quantify the external shape. Results showed that different populations had different tibial morphology. Among males, those of Jinggouzi had the flattest tibia while those of Changle had the widest tibia. Among the females, females of Hanben had the flattest tibia, whereas tibia from females of Shiqiao, Changle, and Yinxu were among the widest. The sexual dimorphism was relatively larger in Shiqiao and Jinggouzi and smaller in Tuchengzi and Changle. Through a combination of previous archaeological findings, historical records, and ethnography of the aboriginal Taiwanese, it is concluded that the terrain and ecological environments laid basis for varied subsistence strategies. In addition, the mobility and social labor division under a particular subsistence strategy further contributed to the adaptation of the lower limb morphology to its context. The comparative analysis provides further insight on habitual activities, terrestrial mobility patterns, and subsistence strategies of the populations, which lived in different environmental contexts during the Bronze Age and early Iron Age, thus demonstrating the diverse interactions between human populations and natural environment in the Anthropocene.

Thallium (Tl) is a highly toxic trace metal widely distributed in water environments, which may threaten the water quality and aquatic organisms at excessive levels due to increased anthropogenic activities. This study investigated the changes in microbial communities of intestines and organs of zebrafish. The toxic response assessments include intestinal microbiota composition and the histopathology of zebrafish’s gill and liver tissues under exposure of Tl at environmental-relevant levels. The results support that the intestinal microbial community of zebrafish greatly changed under a relatively high Tl concentration (1000 ng/L). A significant increase of pathogenic intestinal bacteria such as Mycobaterium in the intestine of zebrafish exposed at Tl levels over 500 ng/L was found. Additionally, the gill and liver tissues displayed different degrees of damage under Tl exposure, which possibly leads to mating behavior changes and death of zebrafish. The results indicate that low doses of Tl in the aquatic environment induce high toxicity on zebrafish and may pose pathological threats to the gill and liver of zebrafish. In addition, Tl exposure gives rise to increasing abundance of pathogenic intestinal bacteria and changes the community structure of intestinal microorganisms.