Impact Of Anthropogenic Change Research Articles

Impact of anthropogenic changes and rainfall variability on river discharge in tropical Central Africa

Abstract The objective of this study is to investigate the effects of rainfall variability and anthropogenic changes on river discharge in the Benoue and the Logone river basins over the last seven decades (1950–2018). To achieve this goal, hydrometeorological data from these basins were analyzed using the Pettitt and Mann–Kendall tests. Our results show that negative rupture was observed in the hydrometeorological time series of these basins at the annual time step in 1970–1971. The deficits associated with this rupture are estimated at −7% for rainfall and −28% for river flows. The wet season shows similar developments. However, from the 1990s onward, there has been a significant increase in the mean annual flows of the Benoue River, which coincides with that of the rainfall during the same decade. This increase over the recent decades could also be expected in response to an increase in impervious surface area in the catchment area, which could compensate for the deficit generated by the post-1990s rainfall deficit through an increase in runoff. Since the filling of the Lagdo Dam in 1983, an increase in all ranges of minimum flow, as well as an increase in the variability of extreme flows, has been detected.

Impacts of global biogenic isoprene emissions on surface ozone during 2000–2019

Biogenic isoprene is an important precursor of tropospheric ozone (O3). Here, a coupled chemistry–vegetation model was used to quantify the contributions of isoprene emissions to surface O3 pollution on the global scale during 2000–2019. The biogenic isoprene emissions showed high values in mid–low latitudes and seasonal peaks in the summer hemispheres. They promote global surface O3 concentrations by 1.75 ppbv annually with regional hotspots of 4.39 ppbv (8.8%) in China and 5.36 ppbv (11.1%) in the U.S. in boreal summer. In the past two decades, isoprene emissions increased by 1.32 TgC yr−1 (0.67% yr−1) in the Northern Hemisphere but decreased by 0.71 TgC yr−1 (0.44% yr−1) in the Southern Hemisphere. Such changes of isoprene made opposite contributions to the surface O3 trend, with 0.26 ppbv yr−1 in eastern China but −0.32 ppbv yr−1 in the southeastern U.S. due to the changes in the background regime of chemical reactions. The impact of anthropogenic changes on the O3 trend is consistent with that of biogenic isoprene, but two to four times stronger in magnitude. This study revealed that the effective control of anthropogenic NOx emissions could mitigate regional O3 pollution even with the increased isoprene emissions under global warming.

Population structure and abundance of the amphidromous prawn Macrobrachium tenellum (Smith, 1871) (Decapoda: Caridea: Palaemonidae) in the lower basin of Ameca River, western Mexico, before anthropogenic modifications

Abstract The population of the freshwater prawn Macrobrachium tenellum (Smith, 1871) in four sites in the lower part of the coastal plain of the Ameca River, Mexico is analyzed before drastic anthropogenic modifications of the riverbed occurred. Of the 7,100 individuals of M. tenellum collected between February 2015 and January 2016, 45.7% of which were females (3,250), 4.3% ovigerous females (309), 39.3% males (2,79), and 10.6% undifferentiated (750). Males were significantly larger and heavier than females. In general, the largest individuals were collected at the most distant sites from the coastline (Colomo and San Juan), whereas the smallest ones were captured near the river mouth. The sex ratio (males:females 1:1.3) deviated from the expected 1:1. The length-weight relationship of females, males, and the population in general indicated a negative allometric growth for all three groups. The results of our research may serve as a reference point for future investigations assessing the impact of anthropogenic changes on M. tenellum populations.

Численное моделирование участка реки в трехмерной постановке задачи для корректировки параметров проектируемых русловых карьеров

Extraction of alluvial sand and gravel materials is a large industry. It has been widely developed in many regions of Russia, which has an increasing impact on the riverbed processes in the form of changes in the morphological structure of riverbeds and floodplains under the influence of changing flow hydraulics. Changes in the hydrological regime and morphology of the riverbed can bring negative effects and progress over time, as well as at a considerable distance from the mining sites, as can be seen from the examples, which indicates the need for their comprehensive study. Leading higher educational institutions and research organizations in the field of hydrology, water transport and fisheries study the problems of the impact of anthropogenic changes in river beds. Summarizing the experience, it is recommended to predict the impact of a potential quarry on the hydrological conditions and morphology of the whole river section by numerical modeling of the channels in 3-D problem formulation. Different technological schemes of open pit mining are considered and modeled, the most acceptable (sparing) option minimizing the negative impact on the environment is selected and justified. In order to control the results obtained by numerical simulation, studies were also carried out using the methods recommended by the regulatory literature. Analysis of the results revealed their great convergence. The final results of the research were compared with the allowable parameters in the regulatory documents, recommendations were made on improving the quarry mining technology for minimizing its negative impact on the channel processes and the resulting transport logistics.

Oxygen and irradiance constraints on visual habitat in a changing ocean: The luminoxyscape

Oxygen and irradiance constraints on visual habitat in a changing ocean: The luminoxyscape

Changes to the gut microbiota of a wild juvenile passerine in a multidimensional urban mosaic

Urbanisation is a major anthropogenic perturbation presenting novel ecological and evolutionary challenges to wild populations. Symbiotic microorganisms residing in the gastrointestinal tracts (gut) of vertebrates have mutual connections with host physiology and respond quickly to environmental alterations. However, the impact of anthropogenic changes and urbanisation on the gut microbiota remains poorly understood, especially in early development. To address this knowledge gap, we characterised the gut microbiota of juvenile great tits (Parus major) reared in artificial nestboxes and in natural cavities in an urban mosaic, employing two distinct frameworks characterising the urban space. Microbial diversity was influenced by cavity type. Alpha diversity was affected by the amount of impervious surface surrounding the breeding location, and positively correlated with tree cover density. Community composition differed between urban and rural sites: these alterations covaried with sound pollution and distance to the city centre. Overall, the microbial communities reflect and are possibly influenced by the heterogeneous environmental modifications that are typical of the urban space. Strikingly, the choice of framework and environmental variables characterising the urban space can influence the outcomes of such ecological studies. Our results open new perspectives to investigate the impact of microbial symbionts on the adaptive capacity of their hosts.

Persistence is key: investigating innovative problem solving by Asian elephants using a novel multi-access box.

Innovative problem solving is considered a hallmark measure of behavioral flexibility as it describes behavior by which an animal manipulates its environment in a novel way to reach a goal. Elephants are a highly social taxa that have demonstrated a remarkable capacity for adapting to changing environments. To understand how individual differences in behavior impact expressions of innovation, we used a novel extractive foraging device comprised of three compartments to evaluate innovation in 14 captive Asian elephants. In the first phase of testing, elephants had an opportunity to learn one solution, while the second phase gave them an opportunity to innovate to open two other compartments with different solutions. We measured the behavioral traits of neophilia, persistence, motivation, and exploratory diversity, and hypothesized that higher levels of each would be associated with more success in the second phase. Eight elephants innovated to solve three compartments, three solved two, and two solved only one. Consistent with studies in other species, we found that higher success was associated with greater persistence, but not with any other behavioral traits when analyzed per test session. Greater persistence and, unexpectedly, lower exploratory diversity, were associated with success when analyzed at the level of each individual door. Further work is needed to understand how innovation varies both within and between species, with particular attention to the potential impact of anthropogenic changes in wild environments.

Quantifying the impacts of anthropogenic changes and climate variability on runoff changes in central plateau of Iran using nine methods

Quantification of affecting factors on river regime changes can be greatly helpful for water resources planning and management in the basin. Both anthropogenic changes and climate variability have affected rivers’ regime and led to considerable social and economic impacts. Observations in most parts of the world indicate that the hydrological cycle has been influenced by human activity besides of climate variability. In this study, 9 different methods which are divided into three general categories have been used to determine the impact of anthropogenic changes and climate variability on runoff changes in two watersheds in the central plateau of Iran, including Ghaleh-Shahrokh and Javanmardi watersheds. The results indicate that climate variability plays a dominant role in runoff decline in the Ghaleh-Shahrokh watershed, accounting for 60.2% of the total decrease, while human activities accounted for 39.8 %. In the Javanmardi watershed, anthropogenic changes played a dominant role in runoff decline, accounting for 77.1% (on average). In comparison, 22.9% (on average) of the decrease was attributable to climate variability. Sensitivity analysis of the annual mean runoff shows that precipitation plays a key role in runoff changes in both study areas. After precipitation, changes in potential evapotranspiration and temperature have the greatest impact on the annual mean runoff in the studied watersheds, respectively. Comparison of the different applied methods indicate that elasticity-based methods are the fastest and intuitive methods to investigate the impacts of anthropogenic changes and climate variability on runoff changes. Despite this, using different methods should be taken into account.

Influence of different structural modulation scenarios on morphology change within tidal inlets (Case study: Bardawil Lagoon, Egypt)

This paper was specially written to complement the first part series published by (Nassar et al., 2019), to investigate the impact of anthropogenic changes around tidal entrances on sedimentary mass stocks in response to the successive pressures of decision-makers due to the sensitivity of the issue. The CMS package was therefore used to model coastal processes at the Bardawil Lagoon Western inlet1 and to forecast sediment-logical stocks each year such that the accumulation of sediments within the inlet can be mitigated by impeding the navigation of this inlet and by allowing water movement between sea and lake. The CMS package is based on a finite-volume approach. A CMS-Flow and CMS-Wave two steering modules have been introduced. In this analysis, unorthodox structural scenarios inside the tidal inlets were evaluated: extension of the jetties, flow-diverted wall (FDW), current deflector wall (CDW), sediment trap (ST), radial channels (RC) and lateral wide channel (LWC). Following the current posture of inlet 1, the use of CDW, ST or RC was considered to be reasonable compensation for the current dredging operation. This is mostly attributed to a lower infilling pace as well as the fewer dredging at year-end. Whereas the benefits generated from maintenance dredging can be perceived to be slightly costly, the long-term benefits of that expenditure can justify it.

Synthesis of Studies Conducted to Reveal the Impact of the Bastroe Canal on the Physico-Chemical Conditions and Biodiversity in Danube Delta Biosphere Reserve (DDBR)

This paper aims to identify the impact of anthropogenic changes caused by the construction of the Bastroe Canal on the hydrology, hydrochemistry and biodiversity of the Danube Delta Biosphere Reserve (DDBR). The paper wants to provide a knowledge tooi that can be a working basis for government and local decision-makers due to the special importance of conserving the biodiversity of this area. The impact of the Bastroe Canal will be revealed through a synthesis of the conclusions of the main studies carried out by institutes in Romania in the period 2004 - 2020.

Dental Calculus as a Tool to Study the Evolution of the Mammalian Oral Microbiome.

Dental calculus, the calcified form of the mammalian oral microbial plaque biofilm, is a rich source of oral microbiome, host, and dietary biomolecules and is well preserved in museum and archaeological specimens. Despite its wide presence in mammals, to date, dental calculus has primarily been used to study primate microbiome evolution. We establish dental calculus as a valuable tool for the study of nonhuman host microbiome evolution, by using shotgun metagenomics to characterize the taxonomic and functional composition of the oral microbiome in species as diverse as gorillas, bears, and reindeer. We detect oral pathogens in individuals with evidence of oral disease, assemble near-complete bacterial genomes from historical specimens, characterize antibiotic resistance genes, reconstruct components of the host diet, and recover host genetic profiles. Our work demonstrates that metagenomic analyses of dental calculus can be performed on a diverse range of mammalian species, which will allow the study of oral microbiome and pathogen evolution from a comparative perspective. As dental calculus is readily preserved through time, it can also facilitate the quantification of the impact of anthropogenic changes on wildlife and the environment.

Relative Distribution, Diversity, and Bloodmeal Sources of Mosquitoes and Known Vectors of Rift Valley Fever Phlebovirus in Three Differing Ecosystems in Bura, Tana River County, Kenya.

Environmental modifications disturb the equilibrium of mosquito populations, altering the risk of mosquito-borne diseases. Mosquito distribution, diversity, and bloodmeal sources were examined to compare Rift Valley fever (RVF) risk among irrigated, riverine, and pastoral ecosystems in Bura, Tana River County, Kenya, between September 2014 and June 2015. Thirty-eight households and 21 irrigation fields were selected for the study. Mosquitoes were trapped with carbon dioxide-impregnated CDC traps, one trap per household and three traps per irrigated field, and morphologically identified using taxonomic keys. Host DNA was extracted from engorged females and cytochrome b genes amplified by PCR to identify sources of bloodmeals. A total of 21,015 mosquitoes were collected; 5742 within households in the 3 ecosystems and 15,273 within irrigated fields. Mosquitoes collected within irrigated fields belonged to 8 genera and 37 species, while those from households within the irrigation scheme belonged to 6 genera and 29 species. Collections from riverine and pastoral households belonged to five and four genera, respectively. The most abundant genera in the irrigated fields were Aedes (21%) and Mansonia (22%), while Anopheles (43%) was the most abundant within households. Most mosquitoes in riverine and pastoral households belonged to Anopheles (76%) and Aedes (65%) genera, respectively. Seasonal variation driven by rainfall was evidenced by spikes in mosquito numbers within irrigated and riverine ecosystems. Host species identification revealed that goats and humans were the main sources of bloodmeal. There was an overall increase in mosquito abundance and diversity as a result of the presence of the irrigated ecosystem in this county, and an increased availability of highly RVF-susceptible hosts as a result of the establishment and concentration of residential areas, promoting potential vector-host contacts. These results highlight the impact of anthropogenic changes on mosquito ecology, potentially heightening the risk of transmission and maintenance of RVF in this region.

Evaluating cropland in the Canadian prairies as an ecological trap for the endangered Burrowing Owl Athene cunicularia

Anthropogenic development may influence the choices animals make and their resulting reproductive success and survival. If such choices are maladaptive, the impact of anthropogenic change can be catastrophic to small or declining populations. Over the past century, Canada's prairie landscapes have been altered dramatically, with over two‐thirds of its native grasslands now having been converted to cropland. The decline of the endangered Burrowing Owl Athene cunicularia population is assumed to have resulted from this landscape change, yet no causal link has been demonstrated. One hypothesis to explain this population decline is that owls get caught in an ecological trap, whereby they prefer to establish nests at the start of each breeding season in landscapes that later confer lower reproductive success. Agricultural landscapes represent a plausible potential ecological trap because the short and sparse vegetation in annual crops (seeded each spring) is predicted to be attractive nesting/foraging habitat for Burrowing Owls when they arrive from northward migration, yet crops become substantially taller and denser over the growing season so prey are predicted to become less accessible by the time broods have hatched. We tested this ecological trap hypothesis in a 3‐year study, involving 379 Burrowing Owl pairs, across the agricultural landscapes of southern Alberta and Saskatchewan. In support of the hypothesis, Burrowing Owls did prefer to settle in breeding home‐ranges that contained a higher proportion of cropland, and their prey‐delivery rates during brood‐rearing were lower at nests with a higher proportion of cropland growing in the surrounding landscape. However, in contradiction to a key prediction, the number of fledglings produced (range = 0–9) was higher, not lower, for pairs with more actively growing cropland in their landscapes. Therefore, the decline of the Burrowing Owl in Canada does not appear to result from cropland forming an ecological trap during the breeding season. We also found a significant positive relationship between the amount of summer fallow within Burrowing Owl home‐ranges and the quantity of vertebrate prey delivered to the nest and the number of juveniles fledged, highlighting the importance of this declining land use in raptor conservation.

Geologically constrained changes to landforms caused by human activities in the 20th century: A case study from Fukuoka Prefecture, Japan

Human activity has been recognized to be an important geomorphic agent, and the resulting changes to landforms and land cover are regarded as a global problem. Although there has been much research into the relationships between geomorphic processes and types of land use such as agriculture, mining, and urbanization, it is important to clarify spatiotemporal human impacts on topography on a regional scale when predicting future changes in land cover.This study examined changes in land use to clarify the distribution and impact of anthropogenic changes to landforms, as well as the influence of geology on the extent of these changes. In a case study from Fukuoka Prefecture, Japan, changes in land use over the last century were analyzed using a geographic information system (GIS). The study area, which covers approximately 4930 km2, has experienced urban development since 1950 and has a current population of over 5 million. Land use data were prepared using paper-based early editions of topographic maps. Subsequently, the distribution of anthropogenic landforms was evaluated by comparing landforms with regional geological data.GIS analysis using our prepared land use data, landform data, and regional geological data has clarified the following characteristics of the study area. (1) Land uses prior to 1950 were constrained by topographic relief. After 1950, land use was characterized by urban sprawl. Urban areas expanded and contained both higher elevations and steeper slopes at their margins. The relationships between land uses and landforms during this urbanization are unclear. (2) The area of urban land increased in the geological regions with Paleogene sedimentary rocks (PSD) and Mesozoic granitic rocks (GR) during the 20th century. The largest coal mining area in Japan was located in the PSD geological regions, and ancient iron working was common in the GR geological regions, particularly during the 7th century. This result indicates that the land use distribution, especially urban areas in sloping terrain, is related to the regional geology. (3) Deforestation related to land use resulted in steeper terrain in forest land in the PSD and GR geological regions. These changes to landforms in forest areas occurred as a result of rapid urban sprawl and have created many new boundaries between forest areas with steeper slopes and urban areas with gentler slopes. This phenomenon may have caused an increase in the frequency of sediment-related disasters.This case study indicates that predictions of anthropogenic changes to landform, which are important for the assessment of global climate change and natural hazards, must clarify the relationships between land uses, landforms, and regional geology.

Mapping the potential mycorrhizal associations of the conterminous United States of America

Abstract Mycorrhizal associations are recognized as key symbioses in a changing world, yet our understanding of their geographic distribution and temporal dynamics remains limited. We combined data on mycorrhizal associations and historical dominant vegetation to map the pre-European Settlement mycorrhizal associations of the conterminous United States of America (USA). As a demonstration of the map's utility, we estimated changes in mycorrhizal associations due to urbanization, agriculture and the establishment of non-native species in two regions. We found that the conterminous USA was dominated by vegetation associated with arbuscular mycorrhizas, but that ∼40% of vegetation types included multiple mycorrhizal associations. Shifting land use to agriculture and the introduction of non-native species has disproportionately affected ectomycorrhizas, as did urbanization. These preliminary results set a baseline for mycorrhizal biogeography of the USA and illustrate how synthesis of available data can help us understand the impact of anthropogenic changes on an important mutualism.

Why Training in Ecological Research Must Incorporate Ethics Education.

AbstractLike other science, technology, engineering, and mathematics fields, ecological research needs ethics. Given the rapid pace of technological developments and social change, it is important for scientists to have the vocabulary and critical‐thinking skills necessary to identify, analyze, and communicate the ethical issues generated by the research and practices within their fields of specialization. The goal of introducing ethics education for ecological researchers would be to promote a discipline in which scientists are willing and able to engage in ethical questions and problem solving, even if they do so inadequately at first. Practicing ecologists ought to be able to identify and critically evaluate the ethical dimensions of their field studies because ecologists are at the forefront of important interfaces between humans and other‐than‐human organisms and natural systems. They are among the first to identify the impact of anthropogenic changes to the environments. Rapidly changing local and global environments mean that ecologists will be on the front line of any efforts to create a sustainable lifestyle for humans on this planet.

Call for papers for a special issue on impact of anthropogenic changes to water on human pathogens

Call for papers for a special issue on impact of anthropogenic changes to water on human pathogens

Untangling interactions: do temperature and habitat fragmentation gradients simultaneously impact biotic relationships?

Gaining insight into the impact of anthropogenic change on ecosystems requires investigation into interdependencies between multiple drivers of ecological change and multiple biotic responses. Global environmental change drivers can act simultaneously to impact the abundance and diversity of biota, but few studies have also measured the impact across trophic levels. We firstly investigated whether climate (using temperature differences across a latitudinal gradient as a surrogate) interacts with habitat fragmentation (measured according to fragment area and distance to habitat edges) to impact a New Zealand tri-trophic food chain (plant, herbivore and natural enemy). Secondly, we examined how these interactions might differentially impact both the density and biotic processes of species at each of the three trophic levels. We found evidence to suggest that these drivers act non-additively across trophic levels. The nature of these interactions however varied: location synergistically interacted with fragmentation measures to exacerbate the detrimental effects on consumer density; and antagonistically interacted to ameliorate the impact on plant density and on the interactions between trophic levels (herbivory and parasitoid attack rate). Our findings indicate that the ecological consequences of multiple global change drivers are strongly interactive and vary according to the trophic level studied and whether density or ecological processes are investigated.

Impact of Anthropogenic Changes on Liquefaction along the Tone River during the 2011 Tohoku Earthquake

AbstractThe March 11, 2011, Mw 9.0 Tohoku earthquake caused widespread liquefaction, lateral spreading, and dynamically induced settlement in the Kanto plains north of Tokyo, Japan. In April 2011, the authors conducted postearthquake engineering field reconnaissance of the mesoseismal region as part of an ASCE-sponsored investigation of the earthquake. The field investigation revealed that numerous levees, roads, and structures built in proximity of the Tone River and its tributaries were damaged severely by the Tohoku earthquake owing to the liquefaction and associated lateral spreading. More importantly, the investigation revealed that much of the liquefaction and lateral spread damage was directly related to anthropogenic (man-made) land use changes rather than natural conditions. These historical changes generally were related to major fluvial transportation improvements made along the Tone River that started in the seventeenth century and have continued into the present era. These findings have impli...

Myoglobin Expression in Chelonia mydas Brain, Heart and Liver Tissues

An understanding of the underpinning physiology and biochemistry of animals is essential to properly understand the impact of anthropogenic changes and natural catastrophes upon the conservation of endangered species. An observation on the tissue location of the key respiratory protein, myoglobin, now opens up new opportunities for understanding how hypoxia tolerance impacts on diving lifestyle in turtles. The respiratory protein, myoglobin has functions other than oxygen binding which are involved in hypoxia tolerance, including metabolism of reactive oxygen species and of the vascular function by metabolism of nitric oxide. Our work aims to determine whether myoglobin expression in the green turtle exists in multiple non muscle tissues and to confirm the hypothesis that reptiles also have a distributed myoglobin expression which is linked to the hypoxia-tolerant trait. This initial work in turtle hatch Chelonia mydas confirms the presence of myoglobin transcriptin brain, heart and liver tissues. Furthermore, it will serve as a tool for completing the sequence and generating an in situ hybridization probe for verifying of cell location in expressing tissues.