Intensive Human Activities Research Articles

Source identification of trace elements in groundwater combining APCS-MLR with geographical detector

Accurately identifying the sources of trace elements in groundwater is difficult, especially in the areas with intensive human activities. This study proposes a framework to identify and quantify the contributions of potential sources of trace elements in groundwater. Health risk assessment is first conducted to identify the trace elements with the highest threats to groundwater quality, and then the geographical detector is used to qualitatively investigate the potential sources and processes dominating the pollution from identified trace elements, and the absolute principal component scores-multivariate linear regression (APCS-MLR) is used to quantify the contributions of different sources to the accumulation of trace elements. The proposed approach was applied to China’s Loess Plateau, a typical water-limited area with rapid urbanization and intensive agricultural activities, after conducting two groundwater sampling campaigns in a flood and a dry season. The trace element concentrations in groundwater exhibited significant spatial and seasonal differences. Health risk assessment revealed that Cr and As through oral ingestion were responsible for non-carcinogenic and carcinogenic risks in different seasons. Land use was the primary factor influencing the spatial heterogeneity of Cr in the flood season, while elevation and distance from city were dominant factors in the dry season. Normalized difference vegetation index (NDVI) and distance from city contributed the most to As change in the flood season, but NDVI was the major contributor in the dry season. The average contributions of potential pollution sources to trace elements in groundwater were in the order of natural source (35%) > geogenic process (17%) > industrial source (13%) in the flood season, but mixed sources (47%) > agricultural activities (18%) in the dry season. Distinguished from the traditional source apportionment methods, the newly proposed approach is not limited to identification of pollutant sources, but also can obtain the exact contributions of different sources. The findings provide useful information for groundwater management in the Loess Plateau.

Ensemble learning framework for landslide susceptibility mapping: Different basic classifier and ensemble strategy

The application of ensemble learning models has been continuously improved in recent landslide susceptibility research, but most studies have no unified ensemble framework. Moreover, few papers have discussed the applicability of the ensemble learning model in landslide susceptibility mapping at the township level. This study aims at defining a robust ensemble framework that can become the benchmark method for future research dealing with the comparison of different ensemble models. For this purpose, the present work focuses on three different basic classifiers: decision tree (DT), support vector machine (SVM), and multi-layer perceptron neural network model (MLPNN) and two homogeneous ensemble models such as random forest (RF) and extreme gradient boosting (XGBoost). The hierarchical construction of deep ensemble relied on two leading ensemble technologies (i.e., homogeneous/heterogeneous model ensemble and bagging, boosting, stacking ensemble strategy) to provide a more accurate and effective spatial probability of landslide occurrence. The selected study area is Dazhou town, located in the Jurassic red-strata area in the Three Gorges Reservoir Area of China, which is a strategic economic area currently characterized by widespread landslide risk. Based on a long-term field investigation, the inventory counting thirty-three slow-moving landslide polygons was drawn. The results show that the ensemble models do not necessarily perform better; for instance, the Bagging based DT-SVM-MLPNN-XGBoost model performed worse than the single XGBoost model. Amongst the eleven tested models, the Stacking based RF-XGBoost model, which is a homogeneous model based on bagging, boosting, and stacking ensemble, showed the highest capability of predicting the landslide-affected areas. Besides, the factor behaviors of DT, SVM, MLPNN, RF and XGBoost models reflected the characteristics of slow-moving landslides in the Three Gorges reservoir area, wherein unfavorable lithological conditions and intense human engineering activities (i.e., reservoir water level fluctuation, residential area construction, and farmland development) are proven to be the key triggers. The presented approach could be used for landslide spatial occurrence prediction in similar regions and other fields.

Body condition and corticosterone stress response, as markers to investigate effects of human activities on Adélie penguins (Pygoscelis adeliae)

IntroductionIn Antarctica, there is growing concern about the potential effect of anthropogenic activities (i.e., tourism, research) on wildlife, especially since human activities are developing at an unprecedented rate. Although guidelines exist to mitigate negative impacts, fundamental data are currently lacking to reliably assess impacts. Physiological tools, such as circulating corticosterone levels, appear promising to assess the potential impact of human disturbance on Antarctic vertebrates.MethodsIn this study, we compared the body condition, and the physiological sensitivity to stress (i.e., basal and stress-induced corticosterone level) of adult and chick Adélie penguins between a disturbed and an undisturbed area (i.e., 2 colonies located in the middle of a research station exposed to intense human activities and 2 colonies located on protected islands with minimal human disturbance).ResultsWe did not find any significant impact of human activities on body condition and corticosterone levels in adults (incubating adults, brooding adults). In chicks, there were significant inter-colony variations in stress-induced corticosterone levels. Specifically, the chicks from the disturbed colonies tended to have higher stress-induced corticosterone levels than the chicks from the protected areas although this difference between areas was not significant. In addition, and independently of human disturbance we also found significant differences in adult body condition, and chick corticosterone level between colonies.DiscussionOverall, our study suggests that this species is not dramatically impacted by human activities, at least when humans and penguins have cohabited for several decades. Our results support therefore the idea that this species is likely to be tolerant to human disturbance and this corroborates with the persistence of Adélie penguin colonies in the middle of the research station. However, our results also suggest that chicks might be more sensitive to human disturbance than adults and might therefore potentially suffer from human disturbance. Our study also suggests that specific individual and environmental variables outweigh the potential minor impact of human disturbance on these variables. Combining corticosterone with complementary stress-related physiological markers, such as heart rate, may strengthen further studies examining whether human disturbance may have subtle detrimental impacts on individuals.

Microbial community assembly responses to polycyclic aromatic hydrocarbon contamination across water and sediment habitats in the Pearl River Estuary

Along with rapid urbanization and intensive human activities, polycyclic aromatic hydrocarbon (PAH) pollution in the Pearl River Estuary (PRE) and its effects on the microbial community have attracted extensive attention. However, the potential and mechanism of microbial degradation of PAHs across water and sediment habitats remain obscure. Herein, the estuarine microbial community structure, function, assembly process and co-occurrence patterns impacted by PAHs were comprehensively analyzed using environmental DNA-based approaches. The contamination and distribution of PAHs were jointly affected by anthropogenic and natural factors. Some of the keystone taxa were identified as PAH-degrading bacteria (i.e., genera Defluviimonas, Mycobacterium, families 67–14, Rhodobacteraceae, Microbacteriaceae and order Gaiellales in water) or biomarkers (i.e., Gaiellales in sediment) that were significantly correlated with PAH levels. The proportion of deterministic process in the high PAH-polluted water (76%) was much higher than that in the low pollution area (7%), confirming the significant effect of PAHs on the microbial community assembly. In sediment, the communities with high phylogenetic diversity demonstrated a great extent of niche differentiation, exhibited a stronger response to environmental variables and were strongly influenced by deterministic processes (40%). Overall, deterministic and stochastic processes are closely related to the distribution and mass transfer of pollutants, and substantially affect the biological aggregation and interspecies interaction within communities in the habitats.

Spatio-temporal dynamics and sensitive distance of nighttime light environment in Pearl River Delta Protected Areas, China.

Protected areas (PAs) are important barriers to ensure the ecological security of territory. Light pollution is a threat to PAs, which is particularly obvious in the urban agglomeration environment. We used multi-source big data (satellite remote sensing light data, land cover types and points of interest) to quantitatively analyze the temporal and spatial dynamics of nighttime light in the PAs of the Pearl River Delta (PRD) urban agglomeration from 2000 to 2018, the correlation between the night light environment within the PAs and human activity intensity outside, as well as the sensitive distance of the PAs to artificial light interference. The results showed that the total value of nighttime light data of PAs in the PRD increased from 71107 nanoW·cm-2·sr-1 to 127682 nanoW·cm-2·sr-1 from 2000 to 2018, the mean value per pixel increased from 15.3 nanoW·cm-2·sr-1 to 23.7 nanoW·cm-2·sr-1, and the lighted ratio increased from 73.3% to 86.4%, indicating that the nighttime light environment of PAs in the region were facing cumulative deterioration risks and serious challenges. The nighttime light intensity of the PAs in the core area of the PRD was much higher than that in the peripheral areas such as Zhaoqing and Huizhou, whereas the expansion degree of the PAs in the peripheral areas was higher than that in the core area. The nighttime light environment inside the PAs was positively correlated with the intensity of human activities around it. The most sensitive distance of the PAs to the artificial light interference around it was 10 km, and the interference degree tended to be stable after 30 km. We proposed that 0-10 km area outside the boundary of the PAs should be the light control core zone and 10-20 km area as the control buffer zone.

Spatiotemporal trends in ecosystem carbon stock evolution and quantitative attribution in a karst watershed in southwest China

Karst ecosystems serve as a vital part of the Earth’s ecosystem and have a substantial influence on the worldwide carbon cycle. Revealing the features and driving factors of the spatiotemporal evolution of Carbon (C) stock in karst watersheds is critical for the in-depth exploration of the regional carbon cycle and carbon sources/sinks, as well as in regional ecological restoration. In this study, the Nanming River Basin, a representative karst basin in southwest China, was used as the subject region. Based upon data on land use change from 2000 to 2020, an Integrated Valuation of Ecosystem Services & Tradeoffs (InVEST) model was applied to calculate the C stock from 2000 to 2020 and identify the driving factors of the regional change of C stock using an optimal parameters-based geographical detector (OPGD) model. The findings indicate that: (1) the cumulative reduction of C stock in the basin from 2000 to 2020 was 3.16 × 105 t; the center of gravity of C stock increase has shifted to the southwest by 2434.16 m, and the center of gravity of the reduction has shifted to the southwest by 7260.53 m. (2) The transition of forest land into construction land had the highest contribution to the decrease of C stock (60.91%); the transition of cultivated land and grassland into forest land was conducive to a rise in the C stock, and these conversions contributed 45.93% and 35.00%, respectively, to the increase of C stock. (3) The normalized difference vegetation index (NDVI), population density, intensity of human activity, slope, and lithology all have annual average q-values greater than 10%, meaning they are the primary factors driving the spatial differentiation of C stock. The contribution of the NDVI ∩ slope direction to the regional heterogeneity of C stock was the largest among the interactive driving factors, with an explanatory power close to 30%. The interactive combinations of drivers all showed nonlinear enhancement or two-factor enhancement effects. To some extent, this study deepens the study of changes in C stock and related driving mechanisms in karst areas, intending to provide a scientific foundation for the recovery of fragile ecosystems and to support a regional low-carbon economy.

Assessing the dynamics of human activity intensity and its natural and socioeconomic determinants in Qinghai–Tibet Plateau

Investigating the spatiotemporal variation of human activity intensity and its determinants is a crucial basis for further revealing the mechanism of human-environment interaction and optimizing the human development mode. In this study, the human activity intensity on the Qinghai–Tibet Plateau (QTP) from 1990 to 2020 was measured based on the quantitative model of land use data and the actual regional background, and the underlying natural and socioeconomic determinants were investigated using spatial econometric methods. The results demonstrate that (1) the human activity intensity in QTP has increased by 11.96%, and there are differences in different spatial scales; the areas with high human activity intensity are distributed in the Hehuang Valley where Xining City and its surrounding areas are located, as well as the One-River and Two-River Area where Lhasa City and surrounding areas are located. (2) Human activity intensity has significant positive spatial spillover, suggesting that local changes will cause changes in the same direction in adjacent areas. (3) The human activity intensity in QTP is affected by various determinants. Concerning socioeconomic factors, the economic level has no significant impact on the human activity intensity in QTP, which differs from the general regional law. Both urbanization and traffic conditions have a significant positive effect, and the impact intensity continues to increase. Concerning natural factors, topographic relief has a significant positive effect; the impacts of temperature and vegetation coverage have changed from insignificant to a significant positive effect; the impacts of precipitation and river network density have not been verified; there is no linear relationship between altitude and human activity intensity in the entire QTP, while it exists in local regions. Finally, this study proposes three policy implications for the realization of a more harmonious human-environment relationship in QTP.

Differential roles of anthropogenic CO2 in mediating seasonal amplitudes of ocean acidification metrics over a coastal coral habitat

Seasonal-scale local forcings sharply reduce the coastal pH and aragonite saturation state (Ωaragonite). However, habitat-specific seasonality and control change signatures under increasing atmospheric CO2 are still poorly characterized. Here, we investigated carbonate system parameter dynamics over a Dongshan coral habitat that is greatly influenced by seasonal current patterns on the western Taiwan Strait coast. Specifically, relatively low pH and Ωaragonite were observed in the trial zone throughout the seasons. Using a first-order Taylor decomposition considering biological carbon metabolism, we suggest that the higher net aerobic respiration related to intense local human activities produced worse ocean acidity in the trial zone. Seasonally, a decreasing Ωaragonite trend was observed from the transition to the northeast monsoon seasons, mainly controlled by dissolved inorganic carbon (DIC) divergence among seasons. The pH/hydrogen ion concentration ([H+]) seasonal cycle was determined by both DIC and temperature components, revealing the lowest/highest value in the southwest monsoon season. Based on ocean acidification scenario modeling forced with a business-as-usual emissions scenario, the Ωaragonite seasonal amplitude attenuation was projected to exceed 30% during the 21st century. However, [H+] seasonal amplitude was amplified over 170%. The attenuation in the Ωaragonite seasonal amplitude mainly resulted from an increase in anthropogenic CO2 seasonal divergence. The increase in [H+] seasonal amplitude mostly followed from an increase in the [H+] sensitivities to DIC and temperature changes.

Evaluation on the adaptability of Yunnan karst ecosystems based on “rock-soil-water-vegetation”

Because of its fragile nature, the karst ecosystem is prone to instability and gradual degradation of the key elements with “rock-soil-water-vegetation” under the continuous interference of human unreasonable activity, resulting in the final formation of the rocky desertification landscape. Based on the research of the structure of karst critical zone, it was proposed to establish the concept of karst ecosystem adaptability with the evaluation system of “rock-soil-water-vegetation”. At the same time, the analysis of the stress and coupling relationship was conducted in combination with the analysis of human activity intensity in Yunnan karst rocky desertification areas. The results showed that: (1) On the county scale, the karst ecosystem adaptability mainly fell into Level 2–3 (0.10 < Ake ≤ 0.30). The contribution degree of indicators followed the order of annual precipitation > proportion of waterbody area, biological abundance index > rock outcrop rate > wetness index, vegetation cover > soil erosion index. (2) The synergistic relationship between karst ecosystem adaptability and human activity intensity was mainly characterized by ecological priority type (S ≥ 1.20), which was mainly found in West, Northwest and Southwest Yunnan. The development priority type (0 < S ≤ 0.80) was mainly centered around Kunming City, extending eastward to Qilin District of Qujing City, southward to Hongta District of Yuxi City, and further to Gejiu-Mengzi-Kaiyuan of Honghe Prefecture and Wenshan City of Wenshan Prefecture. (3) The coupling relationship between the karst ecosystem adaptability and human activity intensity was mainly in the running-in coupling state (0.50 < C ≤ 0.80). The coupling centers were mainly in Kunming City, Yuxi City, Qujing City and Honghe Prefecture (a high-level coupling, 0.80 < C < 1.00). (4) The coordination relationship between the karst ecosystem adaptability and human activity intensity mainly fell into the imbalanced development category, mostly moderately and mildly imbalanced development (0.20 ≤ D < 0.40). The coordinated development center was mainly centered in Kunming City of Central Yunnan (a coordinated development, D ≥ 0.5), which widely extended southward to Hongta-Jiangchuan-Chengjiang -Tonghai in Yuxi City and slightly spread eastward to Qilin District in Qujing City. The research results can provide effective ways and evaluation basis for enhancing the resilience and stability of the karst ecosystem and repairing damaged links, and also provide theoretical support for further studies on sustainable development of karst rocky desertification areas.

Evaluation of the Influence of Habitat Heterogeneity and Human Activities on the Distribution of Microbial Diversity in a High Elevation Drop River

The aim of this work was to investigate the microbial diversity characteristics and driving factors in a high elevation drop river and to analyze the potential risks of river microorganisms to human health. In March 2019, we analyzed the microbial diversity characteristics in surface water and sludge from the Huotong River using high-throughput sequencing. The Huotong River is of great importance to the production and life of the people living along this river. The sampling points were set at the estuary of the river, on a downstream section of the river, on an upstream section of the main river, at one tributary flowing through a town, at one tributary with a barrage, and at the source of one tributary. The results showed significant differences in bacterial diversity in different areas of the river. For example, actinomycetes were less abundant in water samples from the headwaters of tributaries and more abundant upriver. The results revealed that different intensities of human activities had significant different effects on functional flora. Anthropogenic disturbance and human activities reduced the abundance of probiotic bacteria and increased the abundance of pathogenic bacteria in the river. The changes in functional floral diversity may pose potential threats to human health.

Analyzing Spatial-Temporal Change of Vegetation Ecological Quality and Its Influencing Factors in Anhui Province, Eastern China Using Multiscale Geographically Weighted Regression

Vegetation is a crucial component of terrestrial ecology and plays a significant role in carbon sequestration. Monitoring changes in vegetation ecological quality has important guidance value for sustainable development. In this study, we investigated the spatial and temporal variation characteristics of Ecological Quality Index of Terrestrial Vegetation (EQI) in Anhui Province during the growing season from 2000 to 2020 using trend analysis, partial correlation analysis and bivariate spatial autocorrelation analysis. Based on the Multiscale Geographically Weighted Regression (MGWR), the spatial heterogeneity of the effects of average temperature, precipitation, elevation, slope, and human activity factors on EQI was explored. Our results showed an increasing trend in EQI during the growing season in Anhui Province from 2000 to 2020. The significantly increasing areas accounted for 43.49%, while the significantly decreasing areas accounted for 3.60%. EQI had a mostly positive correlation with precipitation and a negative correlation with average temperature (p &lt; 0.1), showing a higher sensitivity to precipitation than to temperature. Additionally, EQI tended to increase initially and then decrease with increasing elevation and slope. Furthermore, our analysis revealed a significant negative spatial correlation between human activity intensity and EQI (p &lt; 0.01). The bivariate global autocorrelation Moran index between EQI and human activity in 2000, 2005, 2010, 2015, and 2018 were −0.418, −0.427, −0.414, −0.487, and −0.470, respectively. We also found that the influencing factors explain 63–83% of the spatial variation of EQI, and the order of influence of factors on EQI is elevation &gt; human activity &gt; slope &gt; average temperature &gt; precipitation. MGWR results indicated that human activities and topographic factors had a stronger impact on EQI at the local scale, while climate factors tended to influence EQI at the global scale.

Pollution Characteristics and Health Exposure Risks of Heavy Metals in River Water Affected by Human Activities

Under the influence of human activities, surface water quality has been significantly affected, which threatens human health and sustainability. In order to clarify the potential risks of heavy metal pollution to human health in river water, two tributaries of the Tumen River with significant differences in human activity interference were selected for investigation. Comparative analysis of the contents of chromium (Cr), cuprum (Cu), arsenic (As), cadmium (Cd), mercury (Hg), and plumbum (Pb) in the surface water of the two tributaries showed that the concentrations of As and Hg in some sampling sites exceeded the pollution standard values, and the Buerhatong River had a higher pollution level. Further analysis of the health risks revealed that the hazard quotient values of Cr, Cu, As, Cd, Hg, and Pb were &lt;1, but the cumulative risk value of the Buerhatong River was higher than 1 for children, indicating adverse effects on human health. The As levels under the fish ingestion scenario had unacceptable carcinogenic risks, while the Cr in the Buerhatong River for adults and Cr and Pb in the Buerhatong River and Hunchun River for children had acceptable carcinogenic risks. Moreover, the As in the incidental water ingestion scenario also had acceptable carcinogenic risks. Therefore, the increase in human activity intensity can promote the increase in the health exposure risk of heavy metals in river water, and fish ingestion was the main exposure pathway, while children had higher exposure risks than adults.

Coastal Wetland Restoration Strategies Based on Ecosystem Service Changes: A Case Study of the South Bank of Hangzhou Bay

A unique variety of wetlands known as coastal wetlands that connect terrestrial and marine ecosystems is crucial to reducing and adapting to climate change as well as the advancement of human culture. However, the coastal wetland ecosystem is currently in danger as a result of the increasing intensity of human activity, and wetland restoration and reconstruction have garnered a lot of interest. The differentiated ecological restoration strategies based on ecosystem service change analysis can provide a reference for the effective management and sustainability of coastal wetland ecosystems. The InVEST model and ArcGIS were used to analyze the spatiotemporal changes in ecosystem services before and after the implementation of coastal wetland restoration policies based on remote sensing image data, meteorological and soil data, etc. The ecological restoration pattern of coastal wetlands was divided, and the corresponding ecological restoration strategies were proposed in this study. The following are the results: (1) there are still many wetlands that have been converted to non-wetlands following the implementation of the wetland restoration policy, and the ecosystem services as a whole exhibit a rising and then falling trend, with a rise from 2005 to 2015, a fall in 2015 due to the creation of Hangzhou Bay New District, and a slight improvement to 2020. Among them, the water yield increased continuously, the carbon storage fluctuated, and the habitat quality did not improve significantly. (2) The hot spots of ecosystem services were concentrated in the south and southeast of the study area, with no obvious cold spots. (3) By comprehensively analyzing the changes and spatial patterns of ecosystem services, the coastal wetlands on the south bank of Hangzhou Bay were divided into an ecological conservation zone, a green development zone, and an ecological restoration zone at the township level, and corresponding optimization strategies were proposed. The results can provide a reference for the fine-grained and differentiated management of regional ecosystem services.

Study on Spatiotemporal Evolution and Driving Forces of Habitat Quality in the Basin along the Yangtze River in Anhui Province Based on InVEST Model

The basin along the Yangtze River in Anhui Province is an important ecological protective screen in the Yangtze River Delta Economic Belt, with a large number of wetlands, lakes, and nature reserves in the basin. The effect of the rapid development of regional urbanization on the ecological environment quality has become an important threat source that restricts ecosystem function and biodiversity protection in the basin. Therefore, this study used InVEST model to analyze the spatial and temporal evolution of habitat quality based on remote sensing image data from 1990, 2000, 2010, and 2020 in the basin along the Yangtze River in Anhui Province and revealed the spatial evolution trend of habitat quality degradation by using hot and cold spot analysis methods. The geographical detector model was used to discuss the main driving factors of habitat quality change. The study results showed that a trend of increase and decrease of construction land and paddy land in the basin from 1990 to 2020 was the opposite, that is, the area of construction land increased, and the area of paddy land decreased. Especially, the area of construction land increased from 390.18 km2 in 1990 to 1616.34 km2 in 2020. The area of increase and decrease of other land types remained around 1% to 2%. During the period from 2000 to 2020, Construction land was mainly transferred in from paddy land, accounting for over 60% of the area transferred in, which indicated the continuous increase of human activity intensity in the study area. From 1990 to 2020, the areas with a significant decline in habitat quality in the basin were mainly concentrated along the Yangtze River and in the northern part of the Chaohu Lake. The area proportion with the lowest grade of habitat quality showed a trend of increasing year by year, that is, the area proportion increased from 4.85% in 1990 to 8.47% in 2020. The hot spots of habitat quality degradation were concentrated in Hefei and its surrounding areas, while the cold spots of the degradation were mainly concentrated in the southern and western mountainous areas. Land use type was the main driving factor affecting habitat quality, and the interaction between land use and per capita GDP was the main driving factor for changes in habitat quality. The study results had important theoretical and practical value for the ecological environment protection and harmonious development of the relationship between humans and nature in the basin along the Yangtze River in Anhui Province.

Under-Appreciated Phylogroup Diversity of Escherichia coli within and between Animals at the Urban-Wildland Interface.

Wild animals have been implicated as reservoirs and even "melting pots" of pathogenic and antimicrobial-resistant bacteria of concern to human health. Though Escherichia coli is common among vertebrate guts and plays a role in the propagation of such genetic information, few studies have explored its diversity beyond humans nor the ecological factors that influence its diversity and distribution in wild animals. We characterized an average of 20 E. coli isolates per scat sample (n = 84) from a community of 14 wild and 3 domestic species. The phylogeny of E. coli comprises 8 phylogroups that are differentially associated with pathogenicity and antibiotic resistance, and we uncovered all of them in one small biological preserve surrounded by intense human activity. Challenging previous assumptions that a single isolate is representative of within-host phylogroup diversity, 57% of individual animals sampled carried multiple phylogroups simultaneously. Host species' phylogroup richness saturated at different levels across species and encapsulated vast within-sample and within-species variation, indicating that distribution patterns are influenced both by isolation source and laboratory sampling depth. Using ecological methods that ensure statistical relevance, we identify trends in phylogroup prevalence associated with host and environmental factors. The vast genetic diversity and broad distribution of E. coli in wildlife populations has implications for biodiversity conservation, agriculture, and public health, as well as for gauging unknown risks at the urban-wildland interface. We propose critical directions for future studies of the "wild side" of E. coli that will expand our understanding of its ecology and evolution beyond the human environment. IMPORTANCE To our knowledge, neither the phylogroup diversity of E. coli within individual wild animals nor that within an interacting multispecies community have previously been assessed. In doing so, we uncovered the globally known phylogroup diversity from an animal community on a preserve imbedded in a human-dominated landscape. We revealed that the phylogroup composition in domestic animals differed greatly from that in their wild counterparts, implying potential human impacts on the domestic animal gut. Significantly, many wild individuals hosted multiple phylogroups simultaneously, indicating the potential for strain-mixing and zoonotic spillback, especially as human encroachment into wildlands increases in the Anthropocene. We reason that due to extensive anthropogenic environmental contamination, wildlife is increasingly exposed to our waste, including E. coli and antibiotics. The gaps in the ecological and evolutionary understanding of E. coli thus necessitate a significant uptick in research to better understand human impacts on wildlife and the risk for zoonotic pathogen emergence.

Climate and vegetation codetermine the increased carbon burial rates in Tibetan Plateau lakes during the Holocene

The Tibetan Plateau (TP), also known as the “Asian Water Tower,” includes thousands of lakes containing sizable lacustrine sediments that have been proven to be important carbon pools of inland ecosystems. To develop an in-depth understanding of the status of TP lake carbon storage and its response to global changes and human activities, we accurately quantified the change trend of long-term organic carbon burial in lakes over the TP, compared levels of differentiation within the TP, and explored related driving factors of the carbon accumulation rates (CARs) by compiling 24 lake sediment cores. The results show that the lake CAR over the TP presented a rising trend during the Holocene, with an average of 6.50 g C m−2 yr−1 and levels ranging from 1.75 to 18.41 g C m−2 yr−1. The eastern TP (ETP), with warmer and wetter climate conditions and more vegetation coverage, had almost twice the CAR as that of the central and western TP (CWTP). We demonstrate that climate and vegetation could be the main drivers of the lake CAR on the TP despite environmental heterogeneity contributing to subregional discrepancies. During the early Holocene, superior summer temperatures and precipitation favored vegetation development, providing abundant material for lake carbon deposition. In the middle Holocene, together with vigorous vegetation, decreasing summer temperatures led to a decline in mineralization, which enhanced carbon storage efficiency and resulted in an increase in the CAR across the ETP. In contrast, for the CWTP, herbaceous-dominated vegetation continued to expand during the early-mid Holocene, which constrained detritus supply, thus maintaining a relatively stable CAR. However, intensive human activities could be responsible for the CAR peak in the late Holocene on the TP, especially since 2000 cal yr BP. In addition to the anthropogenic impacts, variations in CAR among lakes resulting from local factors lead to large uncertainties in future C predictions for the whole region of TP.

Multiple anthropogenic stressors influence the taxonomic and functional homogenization of macroinvertebrate communities on the mainstream of an urban-agricultural river in China

Biodiversity loss is caused by intensive human activities and threatens human well-being. However, less is known about how the combined effects of multiple stressors on the diversity of internal (alpha diversity) and multidimensional (beta diversity) communities. Here, we conducted a long-term experiment to quantify the contribution of environmental stressors (including water quality, land use, climate factors, and hydrological regimes) to macroinvertebrate communities alpha and beta diversity in the mainstream of the Songhua River, the third largest river in China, from 2012 to 2019. Our results demonstrated that the alpha and beta diversity indices showed a decline during the study period, with the dissimilarity in community composition between sites decreasing significantly, especially in the impacted river sections (upper and midstream). Despite overall improvement in water quality after management intervention, multiple human-caused stressors still have led to biotic homogenization of macroinvertebrate communities in terms of both taxonomic and functional diversities in the past decade. Our study revealed the increased human land use explained an important portion of the variation of diversities, further indirectly promoting biotic homogenization by changing the physical and chemical factors of water quality, ultimately altering assemblage ecological processes. Furthermore, the facets of diversity have distinct response mechanisms to stressors, providing complementary information from the perspective of taxonomy and function to better reflect the ecological changes of communities. Environmental filtering determined taxonomic beta diversity, and functional beta diversity was driven by the joint efforts of stressors and spatial processes. Finally, we proposed that traditional water quality monitoring alone cannot fully reveal the status of river ecological environment protection, and more importantly, we should explore the continuous changes in biodiversity over the long term. Meanwhile, our results also highlight timely control of nutrient input and unreasonable expansion of land use can better curb the ecological degradation of rivers and promote the healthy and sustainable development of floodplain ecosystems.

Regional Sustainable Strategy Based on the Coordination of Ecological Security and Economic Development in Yunnan Province, China

Coordination between ecological security and economic development is crucial to sustainable development, with a development strategy that should be adjusted according to the type of region. Yunnan Province, China, is a treasure trove of biodiversity but is economically lagging. Clarifying the relationship between ecological security and economic development can provide a reference for the sustainable development of similar biodiversity hotspots in the world. The landscape index method and index evaluation method were used to calculate the ecological safety index (ESI) and the economic development index (EDI), respectively, and the median value of the indices was used for the comprehensive zoning. The coupled coordination degree model (CCDM) was used to assess the coordination status of ecological safety and economic development in each zone. The results show that (1) Yunnan’s ecological security pattern is high in the west and low in the east, mainly influenced by topography, climate, and human activities; its economic development is resource-dependent and shows a multi-point dispersed pattern due to poor transportation; (2) Yunnan was partitioned into the Coordinated Development Zone (CDZ), the Ecological Risk Zone (ERZ), the Economic Poverty Zone (EPZ), and the Dual Pressure Zone (DPZ). Among them, CDZs (15%) are mostly areas with outstanding advantageous resources, mature characteristic industries, and relatively spatially dispersed. There are two types of ERZs (35%): one is an area where the intensity of human activities exceeds the ecological carrying capacity, mainly located in the eastern plateau; the other is an area with fragile ecological background conditions, located in high mountains and river valleys. EPZs (35%) are mainly lagging in socioeconomics of DPZ (15%) and the fragile ecological environment constrains each to form a negative cycle. (3) Of the regional coordination levels in Yunnan Province, 76% are moderately coordinated, and there is still space for development from the high-quality coordination level. The order of the average coordination degree of each partition is CDZ &gt; ERZ &gt; EPZ &gt; DPZ. The poor basis for coordination and the single approach to coordination have led to ecological safety and economic development often being more difficult to achieve in areas with large mountainous areas similar to Yunnan. (4) Due to the necessity for biodiversity protection, Yunnan Province should choose the sustainable path of ecological priority and green development. Specifically, CDZ should play to industrial advantages and brand effects, and promote industrial integration and innovative industrial development paths. The keys to ERZ are industrial restructuring, industrial ecologization, and ecological environment restoration and protection. EPZ should improve transportation and other infrastructure and revitalize economic development under the premise of ecological priority. Finally, DPZ should emphasize human and load reduction, and moderate development.

Exploring the changes and driving mechanisms in the production-transport-consumption process of ecosystem services flow in the Yellow River Basin under the background of policy changes

Analyzing the spatiotemporal changes of the ecosystem services flow and the impact mechanism is of great significance for achieving human well-being. It is challenged by regional differences in resource utilization pattern and intensity and the complex mechanisms of action between ecosystem services supply and demand. This study used InVEST model and local indicator of spatial association to delineate ecosystem services supply and demand areas. This study used comparative ecological radiation force to characterize the flow of carbon sequestration from supply to demand areas, and its changes were analyzed. The influence of different factors on the carbon sequestration supply, demand and flow was analyzed using correlation analysis. The results showed that there were significant spatial differences in the supply–demand situation of the Yellow River Basin. In this study, 7 supply areas and 29 demand areas were delineated. Many ecological restoration policies implemented from 2000 to 2020 improved the environmental situation and enhanced carbon sequestration flow. Carbon sequestration flow was more sensitive to human activities. The impact of the same intensity of human activity on the supply potential of carbon sequestration was stronger than the supply capacity. This study can provide a reference for regional ecosystem management.

Chironomidae as indicators of water pollution in Pesquería River (México)

Despite their potential as indicators of water quality and their key role in river ecosystems, Chironomidae is still poorly studied in Neotropical rivers. This lack of knowledge is especially relevant for rivers subjected to intense human activities, such as many rivers in Mexico. The aim of this investigation is to contribute to the knowledge of the midges of the Pesquería River (Mexico) along its main courses and relate the composition and abundance to river health. Thirty samples were collected during two different periods (August 2015 and February 2016) using a D-frame and kick sampling. Thirty-five taxa were found in total, with four taxa found in more than 50% of the sites and 19 only found once. Midges accounted for more than 50% of the total macroinvertebrate abundance. Chironomus gr. plumosus, Rheotanytarsus spp. and Cricotopus gr. bicinctus were the most abundant species. Collector-gatherers dominated in August (71% of individuals), whereas collector-filterers dominated in February (43,2%). The major factor explaining the midge distribution and abundance is pollution, while the structure of riparian area does not explain much of the midge richness. This is most likely related to the organic pollution coming from untreated or poorly treated sewage in the city of Monterrey and its surroundings. Three main sectors are distinguished along the river: i) the upper part section with higher biodiversity and presence of intolerant taxa; ii) the middle sewage polluted area with the presence of large red midges very tolerant to pollution (Chironomus, Dicrotendipes); iii) the lower section in the agricultural zone where the community is dominated by red, small midges (Rheotanytarsus). Overall, our study shows that Chironomidae can be useful as better indicators of water quality when genera or species levels are used instead of family or subfamily, as is usually found in most papers on river pollution.