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Anthropogenic contamination of surface waters is a critical issue in urbanised catchments, especially in Mediterranean environments with scarce water resources and intermittent rivers. A combined hydro-geochemical and multivariate statistical methodology has been applied to evaluate the surface water quality of Wadi El Hatab catchment (Central Tunisia). More than half of the 28 samples collected in March 2021 exceeded WHO standards for sodium, chloride and sulphate contents. Most polluted sites are directly influenced by domestic and industrial effluents that contaminate the river for kilometers. Principal Component Analysis and Hierarchical Ascendant Classification distinguished four contamination sources: water-rock interaction, domestic wastewater, untreated industrial effluents mainly from paper mills and irrigation return. A Water Quality Index model indicated that 75% of the surface water was unsuitable for drinking purposes; while according to chemical indices such as saturation index, sodium absorption coefficient (SAR), magnesium ratio (MR) and percent sodium (%Na), 25 to 49% of samples were unsuitable for irrigation. Considering that water of Wadi El Hatab is used for vegetable irrigation, serious public health issues may arise. The investigation demonstrated that a single representative sampling campaign could be a useful way to identify contamination sources when interpreted with both statistical and geochemical tools. [ABSTRACT FROM AUTHOR]

Anthropogenic activities are responsible for degrading rivers and decreasing their capacity to offer ecosystem services. This paper reports the findings of a study carried out to assess the impacts of anthropogenic activities in Pinyinyi River water quality using physicochemical parameters. BOD, COD, phosphate, pH, EC, TDS, turbidity, DO and nitrate were analysed. Anthropogenic activities around Lake Natron Ramsar Site also documented. pH, EC, TDS, turbidity and DO measure in-situ using potentiometric method (HANNA HI 9829). Phosphate and nitrate analysed using photometric method (HACH DR/2700). BOD and COD analysed using bottle incubation method for five days (BOD incubator) and dichromate method (COD digester) respectively. Structured questionnaires used to collect data about anthropogenic activities taking place around Lake Natron Ramsar Site. DO, BOD, COD and turbidity were above the permissible limit. Phosphate, pH, EC, TDS and nitrate were within permissible limit. Irrigation, livestock keeping, fishing, bathing, washing, deforestation, water diversion, sand mining, making bricks along the river, tourist guidance, soda ash harvesting and selling soda ash are the anthropogenic activities taking place around Lake Natron Ramsar Site. River water was found to be unsafe for drinking purposes and was found to be safe for irrigation purposes. The study recommends sustainable anthropogenic activities along Pinyinyi River and mitigation measure to restore the lost ecosystem services. [ABSTRACT FROM AUTHOR]

The aim of this concept paper is the description of a new tool to support institutions in the implementation of targeted countermeasures, based on quantitative and multi-scale elements, for the fight and prevention of emergencies, such as the current COVID-19 pandemic. The tool is a cloud-based centralized system; a multi-user platform that relies on artificial intelligence (AI) algorithms for the processing of heterogeneous data, which can produce as an output the level of risk. The model includes a specific neural network which is first trained to learn the correlations between selected inputs, related to the case of interest: environmental variables (chemical–physical, such as meteorological), human activity (such as traffic and crowding), level of pollution (in particular the concentration of particulate matter) and epidemiological variables related to the evolution of the contagion. The tool realized in the first phase of the project will serve later both as a decision support system (DSS) with predictive capacity, when fed by the actual measured data, and as a simulation bench performing the tuning of certain input values, to identify which of them led to a decrease in the degree of risk. In this way, we aimed to design different scenarios to compare different restrictive strategies and the actual expected benefits, to adopt measures sized to the actual needs, adapted to the specific areas of analysis and useful for safeguarding human health; and we compared the economic and social impacts of the choices. Although ours is a concept paper, some preliminary analyses have been shown, and two different case studies are presented, whose results have highlighted a correlation between NO 2 , mobility and COVID-19 data. However, given the complexity of the virus diffusion mechanism, linked to air pollutants but also to many other factors, these preliminary studies confirmed the need, on the one hand, to carry out more in-depth analyses, and on the other, to use AI algorithms to capture the hidden relationships among the huge amounts of data to process. [ABSTRACT FROM AUTHOR]

The regions near the Tropic of Cancer are a latitudinal geographical zone with typical climatic, topographic, and human landscape features. It is necessary to explore the region's net primary productivity (NPP) dynamics as it combines complex topography, various vegetation types, and intense human activities. The study sets the transect near the Tropic of Cancer (TCT) and uses the Carnegie–Ames–Stanford (CASA) model to estimate the NPP from 2000 to 2020. After using the RESTREND method, the paper calculates and compares the relative contributions of climate variability and anthropogenic activities to NPP changes. Finally, the geographical detector (Geodetector) model is applied to evaluate how anthropogenic and natural factors affect spatial distribution patterns and NPP changes. The results indicated that the average annual NPP is 820.39 gC·m−2·yr−1 during the 21 years. In addition, when the NPP varies, it increases over the entire study area, with a slope of 4.81 gC·m−2·yr−1, particularly in the western region. Across the entire research area, 63.39% and 77.44% of the total pixels positively contribute to climate variability and human activities in NPP, with a contribution of 0.90 and 3.91 gC·m−2·yr−1, respectively. Within the western, central, and eastern regions, anthropogenic activities have a stronger impact on NPP than climate variability, particularly pronounced in the eastern region. Furthermore, vegetation cover is the dominant factor in the spatial patterns and NPP trends across the TCT and the three regions. In contrast, climate factors are shown to be less influential in NPP distribution than in the western region. The results also demonstrated that the effect of population density and the GDP on NPP gradually rises. Two-factor interaction is much larger than any individual factor, with the dominant interaction factor being vegetation cover with climatic factors. Lastly, the findings revealed that anthropogenic activities positively promote NPP accumulation across the TCT, thus highlighting the importance of human activity-led ecological restoration and ecological protection measures that contribute to regional carbon sequestration and carbon balance. [ABSTRACT FROM AUTHOR]

The macro-tidal estuary with a mountain stream is a typical estuary on China′s southeast coast, characterized by intense dynamic forces, active sediment movements, and a robust response to human activities. It demands further investigation of its evolution mechanism under both natural conditions and anthropogenic stresses. This paper takes the Jiangxinyu reach of the Oujiang River estuary as a case example to explore the river′s evolution under the influence of human activities, including effects of longitudinal dam construction, sand mining, and shoreline adjustment since the 1970s. Measured data analysis and a two- dimensional flow and sediment mathematical model were used. The results confirm that anthropogenic stresses have altered the natural periodic alternation of the river′s main and side branches. Moreover, the undercutting of the riverbed caused by sand mining from the beginning of this century has increased tidal range by 0. 5 m and tidal prism by 47%, while weakening the discharge asymmetry and sediment transport asymmetry indices by 0. 08—0. 30 and 0. 28—0. 54, respectively. The undercutting of the riverbed has also weakened the ebb and flood asymmetry. These conditions have subsequently helped slow down the shrinkage of the side branch. The evolution mechanism is dominated by both natural and human activities. Overall, the research findings may be a reference for river evolution and protection under the influence of human activities. [ABSTRACT FROM AUTHOR]

The description of sound as a form of energetic pollutant is very complex as is also its impact on aquatic life. Human activities causing continuous and implosive underwater noise, such as marine traffic, maintenance of ships, coastal tourism, marine research, military, offshore energy platforms, generation of ocean energies and construction operations are expected to increase. The paper analyses current approach to minimise the impact of underwater noise and limit its emissions, examines regulatory approach and discusses the possibilities to control this type of pollution in order to ensure the preservation of natural underwater soundscape. The timely implementation and further development of the European Marine Strategy Framework Directive and its provisions related to underwater noise is of exceptional importance for the Adriatic Sea, which is facing increasing pressure from various industries generating underwater noise. [ABSTRACT FROM AUTHOR]

The Eastern Arc Mountains are one of the most important ecosystems that conserve biodiversity in the world. These ecosystems are threatened by the increasing occurrence of wildfires. Nevertheless, there is inadequate information useful for the development of effective strategies to prevent or respond to future fires. This paper analyses the current extent of dry season fires, underlying causes and the effectiveness of the fire management strategy being implemented in and around the Uluguru Nature Forest Reserve (UNFR) between 2016 and 2021. Differenced Normalised Burn Ratio derived from Landsat satellite images was applied to determine the extent of burned areas, and focus group discussions were held to determine the underlying causes of fires and the extent of implementation of fire management strategies. About 2% (472 ha) of reserved UNFR and 5% (2,854 ha) of unreserved forests were burned in 2017. Some of the fires impacted on 60% (370 ha) of the grassy Lukwangule plateau, which is home to a fire‐sensitive endemic species. The underlying causes of fires varied spatially across the mountains but generally, fire escaping from farm preparation and hunting activities were found to be the most prevalent. On average, survey participants perceived that fire management strategy objectives were achieved by only 29% mainly constrained by a shortage of financial and human resources. Our findings suggest that ignitions and fire spread in UNFR could be prevented or controlled through sustainable funding of fire management activities and the effective engagement of local communities in the management of the reserve. [ABSTRACT FROM AUTHOR]

• Groundwater hydrochemistry evolution interpretation from the viewpoint of water flow system. • Anthropogenic activities and natural processes are distinguished in different zones. • Practical implications for regional water resources exploitation strategy. Groundwater resources are increasingly exploited for industrial and agricultural purposes in many arid/semi-arid regions globally. In order to gain a harmonious development among groundwater resources and economic benefits, urgent investigation of the impacts of anthropogenic activities on the groundwater chemistry is required. Understanding hydrochemical mechanism of groundwater in Yinchuan Plain, arid and semi-arid area in Northwestern China, plays a significant role in water resources planning in this ecologically sensitive area. In this paper, a total of 460 phreatic water samples were collected, including 58 water samples containing isotopic data (D and 2H). Results demonstrate that water chemistry type and isotopic data of phreatic water presents a zonation characteristic from west to east and from south to north. In the eastern part of the Helan Mountain (A 1 zone), the type of hydrochemistry is mainly HCO 3 ·SO 4 -Ca·Mg, SO 4 ·HCO 3 -Ca·Mg, which is mainly recharged by the bedrock fissure water of Helan Mountain. However, in the southern Qingtongxia (A 2 zone) are HCO 3 -Na HCO 3 -Ca·Mg, which receives irrigation and spring water recharge. Phreatic aquifer in Multi-layered structure zone (A 3 zone) reflect multiple recharge sources to the aquifer, the water chemistry demonstrates diverse variations. The anion was dominated by the HCO 3 , while the cation is dominated by sodium. The predominant controlling factors of phreatic water hydrochemistry are divided into anthropogenic activities and natural conditions. Natural conditions mainly include the existence form and lithology of the aquifer, sources of groundwater recharge, soil salinity, and evaporation, mineral dissolution, ion exchange and adsorption and mixing effect. Meanwhile, among natural factors, minerals dissolution in groundwater is the main process dominating the hydrochemical evolution of the groundwater. The other is anthropogenic activities which can be classified as groundwater pollution, excessive exploitation or excretion of groundwater, and excessive groundwater recharge. [ABSTRACT FROM AUTHOR]

Influences of the increasing pressure of climate change and anthropogenic activities on wetlands ecosystems and agriculture are significant around the world. This paper assessed the spatiotemporal land use and land cover changes (LULCC), especially for conversion from marshland to other LULC types (e.g., croplands) over the Songnen and Sanjiang Plain (SNP and SJP), northeast China, during the past 35 years (1980-2015). The relative role of human activities and climatic changes in terms of their impacts on wetlands and agriculture dynamics were quantitatively distinguished and evaluated in different periods based on a seven-stage LULC dataset. Our results indicated that human activities, such as population expansion and socioeconomic development, and institutional policies related to wetlands and agriculture were the main driving forces for LULCC of the SJP and SNP during the past decades, while increasing contributions of climatic changes were also found. Furthermore, as few studies have identified which geographic regions are most at risk, how the future climate changes will spatially and temporally impact wetlands and agriculture, i.e., the suitability of wetlands and agriculture distributions under different future climate change scenarios, were predicted and analyzed using a habitat distribution model (Maxent) at the pixel-scale. The present findings can provide valuable references for policy makers on regional sustainability for food security, water resource rational management, agricultural planning and wetland protection as well as restoration of the region. [ABSTRACT FROM AUTHOR]

Abstract: There is growing evidence that the earth’s climate is changing and will likely continue to change in the future. It is still debated whether these changes are due to natural variability of the climate system or a result of increases in the concentration of greenhouse gases in the atmosphere. Black carbon (BC) has become the subject of interest for a variety of reasons. BC aerosol may cause environmental as well as harmful health effects in densely inhabited regions. BC is a strong absorber of radiation in the visible and near-infrared part of the spectrum, where most of the solar energy is distributed. Black carbon is emitted into the atmosphere as a byproduct of all combustion processes, viz., vegetation burning, industrial effluents and motor vehicle exhausts, etc. In this paper, we present results from our measurements on black carbon aerosols, total aerosol mass concentration and aerosol optical depth over an urban environment namely Hyderabad during January to May, 2003. Diurnal variations of BC indicate high BC concentrations during 6:00–9:00 and 19:00–23:00h. Weekday variations of BC concentrations increase gradually from Monday to Wednesday and gradually decrease from Thursday to Sunday. Analysis of traffic density along with meteorological parameters suggests that the primary determinant for BC concentration levels and patterns is traffic density. Seasonal variations of BC suggest that the BC concentrations are high during dry season compared to rainy season due to the scavenging by air. The fraction of BC to total mass concentration has been observed to be 7% during January to May. BC showed positive correlation with total mass concentration and aerosol optical depth at 500nm. Radiative transfer calculations suggests that during January to May, diurnal averaged aerosol forcing at the surface is −33Wm2 and at the top of the atmosphere (TOA) above 100km it is observed to be +9Wm−2. The results have been discussed in detail in the paper. [Copyright &y& Elsevier]

The Kalahari ecosystem is characterized by natural resource conflicts and land-use pressure resulting from intensification of human activities. This paper addresses three issues of concern associated with the Kalahari ecosystem resource management: (i) the major land-use/land cover shifts in the Kalahari ecosystem since 1970 and the resulting pattern in vegetation species composition, cover and density; (ii) the possible explanations for the observed shifts; and (iii) the possible resource conflicts likely to arise.Data collection involved the comparison of two sets of panchromatic photographs along two transects (Hukunsti–Ngwatle and Tshane–Tsabong) to study land-use/cover shifts that have occurred in the Kalahari ecosystem between 1971 and 1986. Secondly, the nature of possible conflicts resulting from population pressure and associated patterns of land-use was investigated by making observations on selected environmental variables along a 300km transect with diverse environments comprising different-sized settlements, vegetation communities and land-uses.Land-use/land cover shifts have occurred within the Kalahari ecosystem as evidenced by the two transects analysed in this paper. The main changes are the retreat of grass cover up to 18kms from settlements and the increase in thorny and non-thorny woody encroachers closer to the settlements. In the Matsheng area, land-use/land cover gradients reflect marked differences in human pressure. For instance, while settlements (kraals/households) and fields around Tshane (smaller and dwindling settlement) have declined to 5% at the 4km distance in 1986, these land-uses account for 22·3% of land cover at 4km around Hukuntsi (bigger and expanding village).Five major vegetation communities were identified using key plant species during the dry season. However, these communities do not have distinct land-use activities associated with them. Cattle densities were higher in communities found far away from settlements and water points where the grass cover was abundant. Cattle graze far from settlements to obtain quality fodder and trek to the water points around village pans or at cattle posts.There are no definite boundaries between vegetation communities and land-use activities, hence a lot of interaction between activities of these zones depends on the dispersion of resources. Shifts in land-use/cover changes can be accounted for by anthropogenic activities (arable agriculture, livestock grazing and human settlements) enhanced by natural factors like seasonal variations and prolonged droughts of the mid-1980s. It is argued in this paper that potential remedial measures include biosphere conservation areas, resource zoning and resource modeling plans to determine land suitability. [Copyright &y& Elsevier]

As an important part of the global ecosystem, wetlands and their dynamics greatly influence regional eco-environment systems. To understand the distributions, change processes and temporal-spatial characteristics of the wetlands of the inland river basin in an arid region (Heihe River Basin, HRB), this paper employed multi-source remote sensing data to facilitate multi-temporal monitoring of the HRB wetland using a wetland information extraction method. First, we performed monitoring of these wetlands for the years 2000, 2007, 2011 and 2014; then, we analyzed the variation characteristics of the spatial-temporal dynamics of the wetlands in the HRB over the last 15 years via the landscape dynamic change model and the transformation matrix. In addition, we studied the possible driving mechanisms of these changes. The research results showed that the total area of the HRB wetlands had decreased by 2959.13 hectares in the last 15 years (Since 2000), and the annual average loss was 1.09%. The dynamics characterizing the HRB wetlands generally presented a trend of slow increase after an initial decrease, which can be classified into three stages. From 2000 to 2007, the total wetland area rapidly decreased; from 2007 to 2011, the area slowly decreased; and from 2011 to 2014, the area gradually increased. The dynamic changing processes characterizing the wetland resources were ascribed to a combination of natural processes and human activities. The main driving mechanisms of wetland dynamic changes include climatic conditions, upper reach water inflows, population, water resources, cultivated area, and policy. The findings of this study can served as reference and support for the conservation and management of wetland resources in the HRB. [ABSTRACT FROM AUTHOR]

Continental freshwater discharge is vital to global human development. Intensive studies have been conducted on changes of river discharge around the world (Dai et al., 2009; Milliman and Farnsworth, 2011). However, little work has been carried out on the daily continental freshwater discharge of the Red River in response to influence of the natural and anthropogenic forcings. This paper presents results of change analysis of daily continental freshwater discharge over the period 1956–2009 in the Red River. The wavelet analysis results showed observable periodicities in the continental freshwater discharge series with 4–6 months, 8–12 months, 1.5–2 years, and 4–7 years (48–80 months), respectively. The results from Mann–Kendall test indicated insignificant trends in annual continental freshwater discharge during the study period, but there is clearly decrease in annual suspended particulate matter of the Red River. It is shown that the continental freshwater discharge from the Red River was dominated by precipitation over the catchments. Moreover, changes in the continental freshwater discharge are closely related to SASM (the South Asia Summer Monsoon) and ENSO (EI Niño Southern Oscillation). Variations in daily discharge are lagged behind SASM 13–29 days. It revealed that El Niño and La Niña events are likely to induce extreme low and extreme high continental freshwater discharge from the Red River into the Tokin Gulf, respectively. Meanwhile, continental freshwater discharge from the Red River into the Tonkin Gulf experienced abrupt changes with present characteristics as ‘no flood in the flood season, no drought in the drought season’ due to water regulation induced by dam. [ABSTRACT FROM AUTHOR]

Mt. Everest (Qomolangma or Sagarmatha), the highest mount on Earth and located in the central Himalayas between China and Nepal, is characterized by highly concentrated glaciers and diverse landscapes, and is considered to be one of the most sensitive area to climate change. In this paper, we comprehensively synthesized the climate and environmental changes in the Mt. Everest region, including changes in air temperature, precipitation, glaciers and glacial lakes, atmospheric environment, river and lake water quality, and vegetation phenology. Historical temperature reconstruction from ice cores and tree rings revealed the distinct features of 20th century warming in the Mt. Everest region. Meteorological observations further proved that the Mt. Everest region has been experiencing significant warming (approximately 0.33 °C/decade) but relatively stable precipitation during 1961−2018 AD. Projected results (during 2006−2099 AD) under different representative concentration pathway scenarios showed a general warming trend in the region, with larger warming occurring in winter than in summer. Meanwhile, the precipitation projections varied spatially with no significant trends over the region. Intensive glacier shrinkage was characterized by decreasing glacier areas, while glacier-fed river runoff increased. Glacial lakes expanded with increasing glacial lake areas and numbers. These findings indicated a clear regional hydrological response to climate warming. Owing to the remote location of Mt. Everest, the present atmospheric environment remained relatively clean; however, long-range transport of atmospheric pollutants from South Asia and West Asia may have substantially influenced the Mt. Everest region, resulting in increasing concentrations of pollutants since the Industrial Revolution. Anthropogenic activities have been shown to influence river and lake water quality in this remote region, especially in the downstream. The end of the vegetation growing season advanced in the northern slope and did not change in southern slope region of the Mt. Everest, and there was no significant change in start date of the growing season in the region. This review will enhance our understanding of climate and environmental changes in the Mt. Everest region under global warming. • Climate and environmental changes were synthesized in the Mt. Everest region. • Glaciers have retreated significantly, posing impacts to river runoff and glacial lakes. • Transboundary transport of atmospheric pollutants influenced the region. • TThere was no significant change in start date of the growing season. [ABSTRACT FROM AUTHOR]

On 20 August 2005, a landslide with a volume of about 400 m occurred at Fu Yung Shan Tsuen, Tsuen Wan in Hong Kong during a severe rainstorm with a return period of about 100 years on a hillside that has been disturbed locally by past human activities. The incident resulted in one fatality and permanent evacuation of residents of four squatter structures in the vicinity. A forensic investigation into the landslide was carried out to review the mechanism and probable causes of the landslide. The key contributory factors in the landslide were diagnosed. The investigation concluded that the landslide was probably caused by the loss of soil suction and transient build-up of groundwater pressure in the near-surface soil materials following prolonged and intense rainfall. The paper presents the methodology adopted for the landslide study, findings of the investigation and the lessons learnt from this fatal landslide. [ABSTRACT FROM AUTHOR]

This paper presents the results of studies of the physical processes observed in the coastal zone of the eastern part of the Gulf of Gdańsk, from the Vistula river mouth (Poland) to Cape Taran (Russia, Kaliningrad Oblast), because it is under severe environmental and anthropogenic pressure. We present investigations of wind climate, wind-driven currents, deep-water waves, nearshore sediment fluxes, engineering activities, and shoreline changes/response at eight study sites selected along the coast of the study area. Four of the sites are located on the Polish side and four on the Russian side of the state border. An assessment of the anthropogenic impact on coastal litho- and morphodynamics (local sediment fluxes and shoreline response) as a function of different local hydrodynamic climates is performed. Key coastal locations in the Gulf (the Vistula river mouth, the Baltijsk Strait with the harbor of Baltijsk, and the mining plants near Jantarnyj), where natural sediment morphological processes have been affected by human activities, are particularly analyzed. Even in the same system (Gulf of Gdańsk), sites located close to each other and subject to similar anthropogenic activities can display quite different evolutionary patterns. In some cases, anthropogenic effects may be secondary to natural background conditions. [ABSTRACT FROM AUTHOR]

Atalaia beach is situated in the NE of the Brazilian state of Pará and is one of the most popular with tourists and local beachgoers. This paper describes the seasonal variation in the météorologie and oceanographic characteristics of the study area, as well as the effects of the lack of a public sanitation system on the quality of the water used by beachgoers. Oceanographic campaigns were carried out between November 2008 and September 2009. The study area is characterized by high rainfall rates (>1900 mm during the rainy season), NE winds with mean speeds of up to 4.36 m/s in the dry season and 3.06 m/s in rainy season, macrotidal conditions (tidal range >4.0 m), moderate tidal current speeds (up to 0.5 m/s), and significant wave heights up to 1.5 m. Water temperature was relatively homogeneous (27.6°C to 29.3°C). Salinity varied from 5.7 (June) to 37.4 psu (November). The water was well oxygenated (up to 9.17 mg/L), turbid (up to 118 nephelometric turbidity units), alkaline (up to 8.68), and eutrophic (maximum of 2.36 μmol/L for nitrite, 24.34 pmol/L for nitrate, 0.6 pmol/L for phosphate, and 329.7 pmol/L for silicate), and it presented high concentrations of chlorophyll a (up to 82 mg/m³). The natural conditions observed in the present study indicate the need for a review of the hydrologie criteria used for the evaluation of beaches by national and international agencies and their adaptation to the reality ofthe Amazon Coast. The lack of a public sanitation system has led to bacteriologic contamination and the loss of water quality. [ABSTRACT FROM AUTHOR]

The fish community of Lake Victoria, East Africa, has continued to exhibit an intriguing degree of resiliency despite stress from anthropogenic activities. Frequent environmental perturbations include wild fluctuations in fishing pressure, limnological conditions, and lake levels. Surprisingly, many of the endemic and other indigenous fishes have survived, and some have even increased in numbers in recent years. While a positive development, this resiliency is a red flag to scientists because we do not understand it, or know whether it can be expected to continue. Furthermore, besides issues of immediate human well-being, there remain grave concerns about long term resource sustainability. This paper explores possible reasons for ecological resilience in the Lake Victoria fish community, with a focus on omnivory and functional redundancy as possible explanations. The analysis used published data based on both traditional gut content analysis (GCA) and stable isotope analysis (SIA). Trophic plasticity is ubiquitous among the surviving fishes of Lake Victoria. This, combined with an overall simplification of the food web, contributed to the lake community's current resilience. [ABSTRACT FROM AUTHOR]

Coastal morphodynamics and environmental changes have been obviously altered by global warming, sea-level fluctuations, and human activities. Palynological analysis is one of the most important tools for providing information on vegetation, climate, and environmental change, which can be relatively sensitive indicators of human activity during the Holocene. However, Holocene coastal morphodynamics and palynological evidence from the Pearl River Delta and coastal areas has not been sufficiently studied. In this paper, we carry out analyses using detailed grain-size and palynological records of pollen, spores, freshwater algae, and marine dinoflagellate cysts from Borehole QZK13 in the Pearl River Estuary (PRE), southern China. The results show information relating coastal morphodynamics, vegetation evolution, climate changes, and anthropogenic activities during the Holocene based on radiocarbon chronology. In general, the PRE experienced marine transgressive processes; sea-level and the coastline tended to migrate landward between 10,700 and 4250 cal yr BP. Meanwhile, abundant arboreal pollen (mainly Castanopsis , Quercus -evergreen, Oleaceae, and Castanea) and small amounts of non-arboreal pollen (mainly Poaceae, Cyperaceae, and Artemisia) were observed in Borehole QZK13, which suggests that subtropical evergreen broadleaved forests were distributed throughout the PRE and adjacent areas, and relatively warm and moist climatic conditions were present during the early-middle Holocene. After that, there were relatively cool and wet climatic conditions, and marine regressive processes occurred in the PRE during the Late Holocene (ca. 4250–960 cal yr BP) indicated by an abrupt increase in aquatic herbs and Dicranopteris. Moreover, we hypothesize that the Neolithic "cultural fault" in the PRE is likely related to frequent storm surges induced by extreme typhoon events that occurred ca. 3000–2700 yr BP. • Grain size, pollen, spores, freshwater algae and dinoflagellate cysts from the Pearl River Estuary were investigated. • Three major phases shown by palynological results were corresponding to the changes in vegetation and climate. • We hypothesized that the Neolithic "cultural fault" is probably related to the storm surges induced by extreme typhoon events. • Natural vegetation cover has suffered large-scale destruction by ancient humans during the Late Holocene. [ABSTRACT FROM AUTHOR]

Abstract: Rock weathering by carbonic acid is thought to play an important role in the global carbon cycle because it can geologically sequestrate atmospheric CO2. Current model of carbon cycle evolution usually assumes that carbonic acid is the major weathering agent and that other acids are not important. Here, we use carbon isotopic evidence and water chemistry of springs and rivers from the Beipanjiang River basin (Guizhou Province, Southwest China) to demonstrate that sulfuric acid is also an important agent of rock weathering. The δ 13C of dissolved inorganic carbon (DIC) in the water samples ranges from −13.1‰ to −2.4‰, and correlates negatively to [HCO3 −]/([Ca2+]+[Mg2+]) ratios and positively to [SO4 2−]/([Ca2+]+[Mg2+]) ratios. These relationships are interpreted as mixing diagrams between two reactions of carbonate weathering, using carbonic acid and sulfuric acid as a proton donor, respectively. Mixing proportions show that around 42% of the divalent cations in the spring water from Guizhou are originated from the interaction between carbonate minerals and sulfuric acid. It is shown that 40% of this sulfuric acid is derived from the atmosphere and has an anthropogenic origin. The remaining 60% are derived from the oxidative weathering of sulfide minerals in sedimentary rocks. Our results show the positive action of sulfuric acid on the chemical weathering of carbonate. Particularly, we show that sulfuric acid generated by coal combustion has increased by almost 20% the weathering rates of carbonate in Southwest China. This is a clear evidence that human activities are changing the weathering rates of rocks and demonstrates a negative feedback on the acidification of the ocean by greenhouse gases. Because of the involvement of sulfuric acid in weathering reactions, 63% of the alkalinity exported by rivers is derived from carbonate, instead of 50% when atmospheric CO2 is the only acid involved in chemical weathering of carbonate. In the Guizhou Province, the weathering of carbonate is thus, at least transiently, a net source of CO2 to the atmosphere. When extrapolated at global scale, sulfuric acid-induced carbonate weathering could counterbalance a significant part of the CO2 consumed by silicate weathering. This paper highlights the competition between silicate weathering by carbonic acid and carbonate weathering by sulfuric acid for the regulation of the atmospheric CO2 level. [Copyright &y& Elsevier]

This paper reports ecological studies with special reference to avifauna at Jal Mahal Lake (urban) and Kalakho Lake (rural), Rajasthan. Both lakes provide habitats for various migratory and resident birds. More than 180 species of birds, some listed in the Red Data Book, belonging to 49 families were recorded. The birds commonly sighted included some endangered, uncommon, vulnerable, threatened and near threatened species. The overall status of avifaunal species recorded was much better at the less polluted Kalakho Lake than at the Jal Mahal Lake. The human activity around the Jal Mahal Lake and agricultural practices in the dried up area seem to be responsible for the decline in the number of bird species. Drastic regulations are warranted to save these wetlands. [ABSTRACT FROM AUTHOR]

• Knowledge of human impact on ecosystem services (ES) is derived from ethnography. • Landscape factors were examined to study human impacts on subsistence and logging ES. • Impact of variables were stronger at landscape-level than at village-level. • Both subsistence and commercial logging ES were distributed in similar locations. • Spatial analysis reinforced evidences of human impact on ES distributions. Indigenous peoples have long shaped the distributions of plants from which they derive ecosystems services (ES) critical to their subsistence lifestyles. Yet, much of our knowledge on how anthropogenic activities influence these ES by extension has been derived from ethnographic studies. In this paper we examined whether signals of the human presence could be detected from the distributions of two types of provisioning ecosystem services (PES) derived from plants – subsistence uses and commercial logging – in the Rupununi, Southern Guyana. The Rupununi landscape is dominated by indigenous peoples who have strong historical reliance on their forests for subsistence purposes; at the same time, many of the forest species hold considerable commercial timber values. Indices that quantified the subsistence and commercial logging PES were regressed against the five variables intended to estimate the human presence within the landscape – distance-to-village, distance-to-road, distance-to-water, elevation, and slope – at the landscape- and village-level. The analysis showed that the impact of the variables on both types of PES were stronger at the former level than at the latter. At the landscape-level, three variables (distance-to-village, distance-to-road, and elevation) significantly influenced the distributions of subsistence services while four variables (distance-to-village, distance-to-road, distance-to-water, and elevation) significantly influenced the distributions of logging services. On the other hand, at the village-level the effects of each variable on the two PES varied from village to village. In general, although the presence of subsistence services appeared to be more favorable than logging services, the distributions of both types of PES were still comparable across the landscape. The analysis supports earlier observations from ethnographic studies that suggested the human presence does influence the distributions of ES associated with plants and has implications for how logging is practiced in the tropics. [ABSTRACT FROM AUTHOR]

We investigated the natural and anthropogenic drivers controlling the spatiotemporal distribution of the meiofauna in the submarine Blanes Canyon, and its adjacent western slope (NW Mediterranean margin of the Iberian Peninsula). We analyzed the relationships between the main sedimentary environmental variables (i.e. grain size, Chl-a, Chl-a: phaeopigments, CPE, organic carbon and total nitrogen) and the density and structure of the meiofaunal assemblages along a bathymetric gradient (from 500 to 2000 m depth) in spring and autumn of 2012 and 2013. Twenty-one and 16 major taxa were identified for respectively the canyon and slope, where the assemblages were always dominated by nematodes. The gradual decreasing meiofaunal densities with increasing depth at the slope showed little variability among stations and corresponded with a uniform pattern of food availability. The canyon was environmentally much more variable and sediments contained greater amounts of food resources (Chl-a and CPE) throughout, leading not only to increased meiofaunal densities compared to the slope, but also different assemblages in terms of composition and structure. This variability in the canyon is only partly explained by seasonal food inputs. The high densities found at 900 m and 1200 m depth coincided with significant increases in food availability compared to shallower and deeper stations in the canyon. Our results suggest that the disruption in expected bathymetric decrease in densities at 900–1200 m water depth coincided with noticeable changes in the environmental variables typical for disturbance and deposition events (e.g., higher sand content and CPE), evoking the hypothesis of an anthropogenic effect at these depths in the canyon. The increased downward particle fluxes at 900–1200 m depth caused by bottom trawling along canyon flanks, as reported in previous studies, support our hypothesis and allude to a substantial anthropogenic factor influencing benthic assemblages at these depths. The possible relationships of the observed patterns and some major natural environmental (e.g., surface productivity or dense shelf water cascading) and anthropogenic (e.g. the lateral advection and downward transport of food-enriched sediments resuspended by the daily canyon-flank trawling activities) drivers are discussed. [ABSTRACT FROM AUTHOR]