scholarly journals Past environmental changes affected lemur population dynamics prior to human impact in Madagascar

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Helena Teixeira ◽  
Vincent Montade ◽  
Jordi Salmona ◽  
Julia Metzger ◽  
Laurent Bremond ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Human Impact ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Population Decline ◽  
Primate Species ◽  
Population Fluctuations ◽  
Tropical Regions ◽  
The Past ◽  
The Impact

AbstractQuaternary climatic changes have been invoked as important drivers of species diversification worldwide. However, the impact of such changes on vegetation and animal population dynamics in tropical regions remains debated. To overcome this uncertainty, we integrated high-resolution paleoenvironmental reconstructions from a sedimentary record covering the past 25,000 years with demographic inferences of a forest-dwelling primate species (Microcebus arnholdi), in northern Madagascar. Result comparisons suggest that climate changes through the African Humid Period (15.2 – 5.5 kyr) strongly affected the demographic dynamics of M. arnholdi. We further inferred a population decline in the last millennium which was likely shaped by the combination of climatic and anthropogenic impacts. Our findings demonstrate that population fluctuations in Malagasy wildlife were substantial prior to a significant human impact. This provides a critical knowledge of climatically driven, environmental and ecological changes in the past, which is essential to better understand the dynamics and resilience of current biodiversity.

Beyond the austerity-driven hypothesis: Political economic theses on penality and the recent prison population decline

2021 ◽  
pp. 147737082110006
Author(s):  
José A. Brandariz
Keyword(s):  
Prison Population ◽  
Population Decline ◽  
Theoretical Frameworks ◽  
The Past ◽  
Economic Forces ◽  
Global North ◽  
Economic Perspectives ◽  
Political Economic ◽  
The Impact ◽  
Spending Cuts

In what might be called the ‘austerity-driven hypothesis’, a consistent strand of literature has sought to explain the prison downsizing witnessed in many jurisdictions of the global north over the past decade by referring to the financial crisis of the late 2000s to early 2010s and its effects in terms of public spending cuts. Since this economic phase is essentially over, whereas the (moderate) decarceration turn is still ongoing, there are good reasons to challenge this hypothesis. This article delves into the non-economic forces that are fostering a prison population decline that, 10 years on, is becoming the new ‘penal normal’. The article thereby aims to spark a dialogue not only with the scholarship exploring the prison downsizing but also with certain theoretical frameworks that have played a key role in examining the punitive turn era. Additionally, the article contributes to the conversation on the need to reframe materialist readings on penality in a ‘non-reductionist’ fashion. By revisiting heterodox theses and scrutinizing the impact of recent penal changes on traditional materialist accounts, the article joins the collective endeavour seeking to update political economic perspectives on punishment and the penal field.

Small peatland with a big story: 600-year paleoecological and historical data from a kettle-hole peatland in Western Russia

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Agnieszka Mroczkowska ◽  
Piotr Kittel ◽  
Katarzyna Marcisz ◽  
Ekaterina Dolbunova ◽  
Emilie Gauthier ◽  
...  
Keyword(s):  
Human Impact ◽  
Human Activities ◽  
Environmental Changes ◽  
Climatic Variability ◽  
Testate Amoebae ◽  
The Past ◽  
Kettle Hole ◽  
Rapid Changes ◽  
History Of ◽  
Physical And Chemical

Peatlands are important records of past environmental changes. Based on a multiproxy analysis, the main factors influencing the evolution of a peatland can be divided into autogenic and allogenic. Among the important allogenic factors, apart from climate change, are deforestation and drainage, which are directly associated with human impact. Numerous consequences arise from these processes, the most important of which are physical and chemical denudation in the catchment and the related hydrological disturbances in the catchment and peatland. The present study determined how human activities and the past climatic variability mutually influenced the development of a small peatland ecosystem. The main goals of the study were: (1) to trace the local changes of the peatland history over the past 600 years, (2) to investigate their relationship with changes in regional hydroclimate patterns, and (3) to estimate the sensitivity of a small peatland to natural and human impact. Our reconstructions were based on a multiproxy analysis, including the analysis of pollen, macrofossils, Chironomidae, Cladocera, and testate amoebae. Our results showed that, depending on the changes in water level, the history of peatland can be divided into three phases as follows: 1/the phase of stable natural conditions, 2/phase of weak changes, and 3/phase of significant changes in the catchment. Additionally, to better understand the importance of the size of catchment and the size of the depositional basin in the evolution of the studied peatland ecosystem, we compared data from two peatlands – large and small – located close to each other. The results of our study indicated that “size matters,” and that larger peatlands are much more resilient and resistant to rapid changes occurring in the direct catchment due to human activities, whereas small peatlands are more sensitive and perfect as archives of environmental changes.

A qualitative approach to evaluating the impact of human interventions on the middle Charente River (West France)

2020 ◽  
Author(s):  
Amélie Duquesne ◽  
Christine Plumejeaud-Perreau ◽  
Jean-Michel Carozza
Keyword(s):  
Human Impact ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
River Management ◽  
Anthropogenic Pressure ◽  
Human Intervention ◽  
Impact Index ◽  
Human Interventions ◽  
The Impact ◽  
The City

<p><span>Although many studies have analyzed the impact of human interventions on European rivers over decades or centuries, researchers have rarely evaluated the geomorphological effects of these anthropogenic pressures on fluvial systems. However, quantifying anthropogenic impacts is fundamental to understanding how rivers are affected by human interventions and to improving the river management and restoration. The aim of this study is to propose a new and original qualitative method to estimate the importance of human impacts on rivers over the last three centuries using the middle Charente River as a test case. The study area is an anastomosing, low-energy and little mobile river of the lowlands of Western France. It extends from the city of Angoulême (Charente) to the city of Saintes (Charente-Maritime), with a length of approximately 100 km. The study segment has been subjected to high anthropogenic pressure since the High Middle Ages, and it was enhanced during the 19th century to facilitate navigation and terrestrial transportation, to ensure the exploitation of the water's driving force (water mills and paper mills), to maintain the local people (fishing dams and agro-pastoral uses) and to allow for flood protection. To understand and estimate the anthropogenic heritage of the Charente River, this study employed a two-stage method: 1) an inventory of the human interventions on the fluvial system through the consultation of geo-historical data (textual archives, historical maps and iconography) dating from the end of the 17th century to the 2010s and 2) an evaluation of the human impact of each human intervention, sub-category and category of intervention based on the calculation of the Cumulative Human Impact Index. The Cumulative Human Impact Index is composed of several qualitative attributes graded by an evaluator. The results allow one 1) to generate a database and typology of the human interventions affecting the middle Charente River over the long term; 2) to map the cumulative impacts of human interventions on the study area; and 3) to analyze the unitary and overall impact of each human intervention, sub-category and category of intervention on the river landscape's heritage. Finally, this study concludes with 1) a discussion of the advantages of using a qualitative methodology for the estimation of anthropogenic impacts and 2) a reflection on the use of the maps of cumulative human impacts for Charente River management and restoration.</span></p>

Inferring sockeye salmon (Oncorhynchus nerka) population dynamics and water quality changes in a stained nursery lake over the past ∼500 years

2004 ◽  
Vol 61 (7) ◽  
pp. 1235-1246 ◽  
Author(s):  
Irene Gregory-Eaves ◽  
Bruce P Finney ◽  
Marianne SV Douglas ◽  
John P Smol
Keyword(s):  
Population Dynamics ◽  
Sockeye Salmon ◽  
Environmental Changes ◽  
Oncorhynchus Nerka ◽  
The Past ◽  
The North ◽  
Salmon Population ◽  
High Concentrations ◽  
The North Pacific ◽  
Multiproxy Approach

Historical and paleolimnological studies have demonstrated that environmental changes in the North Pacific can strongly affect sockeye salmon (Oncorhynchus nerka) abundances. Whether these marine shifts would be influential on sockeye salmon from all lake types, however, has not yet been studied. This study represents the first paleolimnological analysis of past sockeye salmon population dynamics in a stained nursery lake (Packers Lake, Alaska). We adopted a multiproxy approach to determine whether salmon-derived nutrients (inferred from δ15N) would be available for algal uptake (inferred from the diatom species responses) in this stained lake, as high concentrations of humics and iron are known to sequester phosphorus. The strong degree of coherency between δ15N and diatoms, however, suggests that salmon-derived nutrients were bioavailable and enhanced productivity. Overall, our indicators responded to changes in sockeye salmon abundances and volcanic ashfalls over the past ∼500 years. In a section of the core unaffected by tephras (AD ∼1770–1882), our record suggests that the number of sockeye salmon spawners fluctuated widely. Comparison of temporal shifts in inferred sockeye salmon abundances from Packers Lake with other clearwater nursery lakes reveals a broadly consistent pattern, likely influenced by past climatic changes.

scholarly journals Human Atrial Cell Models to Analyse Haemodialysis-Related Effects on Cardiac Electrophysiology: Work in Progress

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Elisa Passini ◽  
Simonetta Genovesi ◽  
Stefano Severi
Keyword(s):  
Cardiac Electrophysiology ◽  
Environmental Changes ◽  
The Past ◽  
Plasma Electrolyte ◽  
Current State ◽  
Atrial Electrophysiology ◽  
The Moment ◽  
The Impact ◽  
Atrial Cell ◽  
Extracellular Environment

During haemodialysis (HD) sessions, patients undergo alterations in the extracellular environment, mostly concerning plasma electrolyte concentrations, pH, and volume, together with a modification of sympathovagal balance. All these changes affect cardiac electrophysiology, possibly leading to an increased arrhythmic risk. Computational modeling may help to investigate the impact of HD-related changes on atrial electrophysiology. However, many different human atrial action potential (AP) models are currently available, all validated only with the standard electrolyte concentrations used in experiments. Therefore, they may respond in different ways to the same environmental changes. After an overview on how the computational approach has been used in the past to investigate the effect of HD therapy on cardiac electrophysiology, the aim of this work has been to assess the current state of the art in human atrial AP models, with respect to the HD context. All the published human atrial AP models have been considered and tested for electrolytes, volume changes, and different acetylcholine concentrations. Most of them proved to be reliable for single modifications, but all of them showed some drawbacks. Therefore, there is room for a new human atrial AP model, hopefully able to physiologically reproduce all the HD-related effects. At the moment, work is still in progress in this specific field.

scholarly journals Mechanisms behind bottom-up effects: eutrophication increases fecundity by shortening the interspawning interval in stickleback

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9521
Author(s):  
Anne Saarinen ◽  
Ulrika Candolin
Keyword(s):  
Population Dynamics ◽  
Gasterosteus Aculeatus ◽  
Environmental Changes ◽  
Algal Growth ◽  
Anthropogenic Eutrophication ◽  
Bottom Up ◽  
Lifetime Fecundity ◽  
Algae Growth ◽  
Population Processes ◽  
The Impact

Anthropogenic eutrophication is altering aquatic environments by promoting primary production. This influences the population dynamics of consumers through bottom-up effects, but the underlying mechanisms and pathways are not always clear. To evaluate and mitigate effects of eutrophication on ecological communities, more research is needed on the underlying factors. Here we show that anthropogenic eutrophication increases population fecundity in the threespine stickleback (Gasterosteus aculeatus) by increasing the number of times females reproduce—lifetime fecundity—rather than instantaneous fecundity. When we exposed females to nutrient-enriched waters with enhanced algal growth, their interspawning interval shortened but the size of their egg clutches, or the size of their eggs, did not change. The shortening of the interspawning interval was probably caused by higher food intake, as algae growth promotes the growth of preferred prey populations. Enhanced female lifetime fecundity could increase offspring production and, hence, influence population dynamics. In support of this, earlier studies show that more offspring are emerging in habitats with denser algae growth. Thus, our results stress the importance of considering lifetime fecundity, in addition to instantaneous fecundity, when investigating the impact of human-induced eutrophication on population processes. At a broader level, our results highlight the importance of following individuals over longer time spans when evaluating the pathways and processes through which environmental changes influence individual fitness and population processes.

scholarly journals Assessment of Oil Spillage Impact on Vegetation in South-Western Niger Delta, Nigeria

2021 ◽  
pp. 31-45
Author(s):  
Umar Wakil Adamu ◽  
Emmanuel Yeboah ◽  
Isaac Sarfo ◽  
Edward Kweku Nunoo ◽  
Clement Kwang ◽  
...  
Keyword(s):  
Niger Delta ◽  
Environmental Changes ◽  
Driving Forces ◽  
Contributory Factor ◽  
Secondary Source ◽  
Geospatial Techniques ◽  
Dense Vegetation ◽  
The Past ◽  
Oil Spillage ◽  
The Impact

The present study assesses the impact of oil spillage in the Southwestern Niger Delta of Nigeria over the past fifty (50) years. It further sought to find out the driving forces and implications of oil spillage on vegetation, livelihoods and other key parameters. The study employed geospatial techniques and a secondary source of data to achieve the objectives set out in this study. The Global Moran I statistical tool was used to determine the spatial autocorrelation based on feature locations and attribute values. We observed built-up areas, bare land, and less dense vegetation had an overall increment of 1975.98 km2, 1370 km2 and 23805 km2, respectively. Dense vegetation had declension of 22058.33 km2 over the past five decades. Findings depict a declining trend in Normalized Difference Vegetation Index, attributed to oil spillage as the key contributory factor. Occasioned by anthropogenic activities, the driving forces were traced to attacks on oil pipelines during conflicts and illegal means of creating leakages to siphon crude oil for sale. To achieve sustainability in oil spill management in the Delta, the study recommends further research to ascertain the cost of losses incurred apply geospatial techniques to monitor and predict environmental changes that inform decisions of key actors.

ASSESSMENT OF THE NEGATIVE CONSEQUENCES OF THE GROWING LOSS OF THE RUSSIAN POPULATION

2021 ◽  
Vol 1 (12) ◽  
pp. 96-102
Author(s):  
Alexandr V. Dzhioev ◽  
Keyword(s):  
Population Dynamics ◽  
Russian Federation ◽  
Birth Rate ◽  
Negative Impact ◽  
Population Decline ◽  
Negative Consequences ◽  
Demographic Situation ◽  
The Past ◽  
Coronavirus Infection ◽  
The Russian Federation

The article highlights the problems of the high natural loss of the population of the Russian Federation observed since the beginning of 2019 due to the increased mortality and the fall in the birth rate of the population. It is shown that the mortality caused by the COVID-19 coronavirus infection only aggravated the previously established trend of population decline in Russia, but was not the cause of it. To substantiate the conclusion about the historical conditionality of the deterioration of the demographic situation of the country, the indicators of population dynamics over the past decades are analyzed, the negative impact of the demographic crisis of Russia on the security of the country is shown, and the assessment of state measures to improve the demographic situation is given.

Decadal high-resolution multi-proxy analysis to reconstruct natural and human-induced environmental changes over the last 1350 cal. yr BP in the Altai Tavan Bogd National Park, western Mongolia

The Holocene ◽  
2020 ◽  
Vol 30 (7) ◽  
pp. 1016-1028 ◽  
Author(s):  
Julia Unkelbach ◽  
Kaoru Kashima ◽  
Gaadan Punsalpaamuu ◽  
Lyudmila Shumilovskikh ◽  
Hermann Behling
Keyword(s):  
High Resolution ◽  
Water Availability ◽  
National Park ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Climatic Conditions ◽  
Forest Steppe ◽  
Permafrost Degradation ◽  
Rainfall Events ◽  
The Impact

The ‘Altai Tavan Bogd’ National Park in the north-western part of the Mongolian Altai, Central Asia, is located in a forest-steppe ecosystem. It occurs under the influence of extreme continental and montane climate and is sensitive to natural and anthropogenic impacts. High-resolution (<20 years per sample) multi-proxy data of pollen, non-pollen palynomorphs (NPPs), macro-charcoal, diatoms, and XRF scanning from radiocarbon-dated lacustrine sediments reveal various environmental changes and the impact of different settlement periods for the late-Holocene. From 1350 to 820 cal. yr BP (AD 600–1130), the distribution of grass steppe indicates a climate similar to present-day conditions. Rapid improvements of climatic conditions (e.g. increased rainfall events) possibly favored a recovery of forest-steppe encouraging nomadic movements into alpine areas. In the period from 820 to 400 cal. yr BP (AD 1130–1550), the decline of forested areas suggests an increasingly drier and possibly colder climate. Some political shifts during the Mongol Empire (744–582 cal. yr BP; AD 1206–1368) favored variations in nomadic grazing habits. After 400 cal. yr BP (AD 1550), moisture and temperature increased slightly, and from ca. 40 cal. yr BP (AD 1910) to present, annual temperature continued to increase more markedly favoring an additional water availability due to permafrost degradation. Diatom data suggest several intervals of increased water availability in all periods which might have caused erosion due to heavier rainfall events or increased snow melt. Immediately after most of these high-water intervals, NPP data reveal periods of increased grazing activities in the area.

scholarly journals Molluscan benthic communities at Brijuni Islands (northern Adriatic Sea) shaped by Holocene sea-level rise and recent human eutrophication and pollution

The Holocene ◽  
2018 ◽  
Vol 28 (11) ◽  
pp. 1801-1817 ◽  
Author(s):  
Sara-Maria Schnedl ◽  
Alexandra Haselmair ◽  
Ivo Gallmetzer ◽  
Anna-Katharina Mautner ◽  
Adam Tomašových ◽  
...  
Keyword(s):  
Sea Level ◽  
Adriatic Sea ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Benthic Communities ◽  
Marine Species ◽  
Benthic Assemblages ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
The Impact

The effects of and the interplay between natural and anthropogenic influences on the composition of benthic communities over long time spans are poorly understood. Based on a 160-cm-long sediment core collected at 44 m water depth in the NE Adriatic Sea (Brijuni Islands, Croatia), we document changes in molluscan communities since the Holocene transgression ~11,000 years ago and assess how they were shaped by environmental changes. We find that (1) a transgressive lag deposit with a mixture of terrestrial and marine species contains abundant seagrass-associated gastropods and epifaunal suspension-feeding bivalves, (2) the maximum-flooding phase captures the establishment of epifaunal bivalve-dominated biostromes in the photic zone, and (3) the highstand phase is characterized by increasing infaunal suspension feeders and declining seagrass-dwellers in bryozoan-molluscan muddy sands. Changes in the community composition between the transgressive and the highstand phase can be explained by rising sea level, reduced light penetration, and increase in turbidity, as documented by the gradual up-core shift from coarse molluscan skeletal gravel with seagrass-associated molluscs to bryozoan sandy muds. In the uppermost 20 cm (median age <200 years), however, epifaunal and grazing species decline and deposit-feeding and chemosymbiotic species increase in abundance. These changes concur with rising concentrations of nitrogen and organic pollutants due to the impact of eutrophication, pollution, and trawling in the 20th century. The late highstand benthic assemblages with abundant bryozoans, high molluscan diversity, and abundance of soft-bottom epi- and infaunal filter feeders and herbivores represent the circalittoral baseline community largely unaffected by anthropogenic impacts.

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