Phytoplankton response to climate changes and anthropogenic activities recorded by sedimentary pigments in a shallow eutrophied lake

2019 ◽  
Vol 647 ◽  
pp. 1398-1409 ◽  
Author(s):  
Hanxiao Zhang ◽  
Shouliang Huo ◽  
Kevin M. Yeager ◽  
Zhuoshi He ◽  
Beidou Xi ◽  
...  
Keyword(s):  
Climate Changes ◽  
Anthropogenic Activities ◽  
Sedimentary Pigments

scholarly journals Impacts of climate and humans on the vegetation in northwestern Turkey: palynological insights from Lake Iznik since the Last Glacial

2016 ◽  
Vol 12 (2) ◽  
pp. 575-593 ◽  
Author(s):  
Andrea Miebach ◽  
Phoebe Niestrath ◽  
Patricia Roeser ◽  
Thomas Litt
Keyword(s):  
Bronze Age ◽  
Climate Changes ◽  
Vegetation History ◽  
Anthropogenic Impacts ◽  
Anthropogenic Activities ◽  
Climatic Conditions ◽  
Forest Steppe ◽  
Marmara Region ◽  
Pollen Record ◽  
Northwestern Turkey

Abstract. The Marmara region in northwestern Turkey provides a unique opportunity for studying the vegetation history in response to climate changes and anthropogenic impacts because of its location between different climate and vegetation zones and its long settlement history. Geochemical and mineralogical investigations of the largest lake in the region, Lake Iznik, already registered climate-related changes of the lake level and the lake mixing. However, a palynological investigation encompassing the Late Pleistocene to Middle Holocene was still missing. Here, we present the first pollen record of the last ca. 31 ka cal BP (calibrated kilo years before 1950) inferred from Lake Iznik sediments as an independent proxy for paleoecological reconstructions. Our study reveals that the vegetation in the Iznik area changed generally between (a) steppe during glacials and stadials indicating dry and cold climatic conditions, (b) forest-steppe during interstadials indicating milder and moister climatic conditions, and (c) oak-dominated mesic forest during interglacials indicating warm and moist climatic conditions. Moreover, a pronounced succession of pioneer trees, cold temperate, warm temperate, and Mediterranean trees appeared since the Lateglacial. Rapid climate changes, which are reflected by vegetation changes, can be correlated with Dansgaard-Oeschger (DO) events such as DO-4, DO-3, and DO-1, the Younger Dryas, and probably also the 8.2 event. Since the mid-Holocene, the vegetation was influenced by anthropogenic activities. During early settlement phases, the distinction between climate-induced and human-induced changes of the vegetation is challenging. Still, evidence for human activities consolidates since the Early Bronze Age (ca. 4.8 ka cal BP): cultivated trees, crops, and secondary human indicator taxa appeared, and forests were cleared. Subsequent fluctuations between extensive agricultural uses and regenerations of the natural vegetation become apparent.

scholarly journals The Influence of Temperature Increase on the Toxicity of Mercury Remediated Seawater Using the NanomaterialGraphene Oxide on the Mussel Mytilus galloprovincialis

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1978
Author(s):  
Francesca Coppola ◽  
Amadeu M. V. M. Soares ◽  
Etelvina Figueira ◽  
Eduarda Pereira ◽  
Paula A. A. P. Marques ◽  
...  
Keyword(s):  
Climate Changes ◽  
Mytilus Galloprovincialis ◽  
Anthropogenic Activities ◽  
Published Data ◽  
Aquatic Environments ◽  
Influence Of Temperature ◽  
Marine Systems ◽  
Influence Of Temperature On ◽  
Higher Temperature ◽  
Aquatic Wildlife

Mercury (Hg) has been increasing in waters, sediments, soils and air, as a result of natural events and anthropogenic activities. In aquatic environments, especially marine systems (estuaries and lagoons), Hg is easily bioavailable and accumulated by aquatic wildlife, namely bivalves, due to their lifestyle characteristics (sedentary and filter-feeding behavior). In recent years, different approaches have been developed with the objective of removing metal(loid)s from the water, including the employment of nanomaterials. However, coastal systems and marine organisms are not exclusively challenged by pollutants but also by climate changes such as progressive temperature increment. Therefore, the present study aimed to (i) evaluate the toxicity of remediated seawater, previously contaminated by Hg (50 mg/L) and decontaminated by the use of graphene-based nanomaterials (graphene oxide (GO) functionalized with polyethyleneimine, 10 mg/L), towards the mussel Mytilus galloprovincialis; (ii) assess the influence of temperature on the toxicity of decontaminated seawater. For this, alterations observed in mussels’ metabolic capacity, oxidative and neurotoxic status, as well as histopathological injuries in gills and digestive tubules were measured. This study demonstrated that mussels exposed to Hg contaminated seawater presented higher impacts than organisms under remediated seawater. When comparing the impacts at 21 °C (present study) and 17 °C (previously published data), organisms exposed to remediated seawater at a higher temperature presented higher injuries than organisms at 17 °C. These results indicate that predicted warming conditions may negatively affect effective remediation processes, with the increasing of temperature being responsible for changes in organisms’ sensitivity to pollutants or increasing pollutants toxicity.

scholarly journals Anticipated climate changes reveal shifting in habitat suitability of high-altitude selaginellas in Java, Indonesia

2020 ◽  
Vol 21 (11) ◽  
Author(s):  
AHMAD DWI SETYAWAN ◽  
Jatna Supriatna ◽  
Nisyawati ◽  
Ilyas Nursamsi ◽  
SUTARNO SUTARNO ◽  
...  
Keyword(s):  
High Altitude ◽  
Habitat Suitability ◽  
Climate Changes ◽  
Anthropogenic Activities ◽  
Annual Rainfall ◽  
Suitable Habitat ◽  
Distribution Models ◽  
Climate Conditions ◽  
Presence Data ◽  
Pessimistic Scenario

Abstract. Setyawan AD, Supriatna J, Nisyawati, Nursamsi I, Sutarno, Sugiyarto, Sunarto, Pradan P, Budiharta S, Pitoyo A, Suhardono S, Setyono P, Indrawan M. 2020. Anticipated climate changes reveal shifting in habitat suitability of high-altitude selaginellas in Java, Indonesia. Biodiversitas 21: 5482-5497. High-altitude ecosystems with humid and cool climate are the preferred habitat for some Selaginella species (selaginellas). Such habitats are available in Java, Indonesia, which also has fertile soils with rich mineral contents resulted from volcanic activities. However, the high-altitude ecosystems in Java are threatened by various anthropogenic activities as well as changes in climate conditions, potentially affecting some Selaginella species. This study aimed to investigate the shift in suitable habitat of four species of high-altitude Selaginella spp. (Selaginella involvens, S. opaca, S. ornata, and S. remotifolia) in Java Island under current and future climate conditions predicted by several representative greenhouse gas concentration pathways. Presence data of Selaginella localities were collected from field survey between 2007 and 2014 across the island, as well as occurrence points from the Global Biodiversity Information Facility database. A total of 1,721 occurrence points data along with environmental and climate data were used to develop species distribution models using MaxEnt. Future habitat distributions were projected under four climate scenarios to see the shift in suitable habitat and altitudinal ranges. The results showed that the distribution of the four high-altitude Selaginella species are strongly influenced by altitude, annual average temperature, and annual rainfall. In the present time, 37.32% (48,974 km2) of the area of Java has been predicted to be suitable for high-altitude Selaginella. Under the optimistic climate scenario (RCP 2.6), the highly suitable area will likely to decrease by almost 35% in the year 2080, whereas the medium and low suitable areas will reduce by about 37.2% and 18.3%, respectively. Under the pessimistic scenario (RCP 8.5), about 21.2% of low suitable areas will be lost in 2080, whereas the medium and highly suitable areas are predicted to decrease by around 38.1% and 33.4%, respectively. Under the pessimistic scenario, there will be upward shift by 51.1 m in the year 2030 from the current’s mean altitude and will shift by almost 150 m in the year 2080. The maximum altitude of predicted suitable habitat is also predicted to increase to reach almost 3500 m asl in the year 2080. The results of this study imply that habitat shift of four high-altitude Selaginella species varies depending on the scenario, but in all cases, the losses are greater than gains.

scholarly journals Flood Hazard Modelling in Upper Mandakini Basin of Uttarakhand

2021 ◽  
Vol 16 (3) ◽  
pp. 880-889
Author(s):  
Gagandeep Singh ◽  
Vishwa Bandhu Singh Chandel ◽  
Simrit Kahlon
Keyword(s):  
Climate Changes ◽  
Flood Hazard ◽  
Anthropogenic Activities ◽  
Weather Extremes ◽  
Mountainous Regions ◽  
Flood Susceptibility ◽  
High Kinetic Energy ◽  
Glacial Melting ◽  
Natural Terrain ◽  
High Flood

Floods in Himalayan region raise serious concerns regarding ongoing path of development as recent manifestations of catastrophic events establish link between climate changes and risk to anthropogenic activities in mountainous regions. Scientists predict frequent occurrence of such disasters wherein rapid glacial melting; incidents of glacial lake outburst and weather extremes may trigger floods in the Himalayan mountains. This paper examined flood risk in Upper Mandakini basin through GIS based flood simulationto highlight flood potential and risk associated with such hazard in the study area.It is observed that floods in study area display hazardous interplay of natural terrain gradient, high kinetic energy of streams, and intense rainfall. The upper sections of basin that includes Kali Ganga, Mandani Ganga, Madhyamaheshwar and Mandakini rivers shows high flood susceptibility with greatest risk in the latter. Such hazardousness is likely to be intensified by ongoing anthropogenic activities in the basin.

scholarly journals Environmental Changes in Historical Times Near Apostag on the Danube-Tisza Interfluve, Hungary (A Complex Research Based on Archaeological Excavation and Geomorphological Investigations)

2014 ◽  
Vol 7 (1-2) ◽  
pp. 39-47 ◽  
Author(s):  
Diána Nyári ◽  
István Knipl ◽  
György Sipos ◽  
Tímea Kiss
Keyword(s):  
Climate Changes ◽  
Environmental Changes ◽  
Anthropogenic Activities ◽  
Good Evidence ◽  
Archaeological Research ◽  
Archaeological Excavation ◽  
Aeolian Activity ◽  
Historical Times ◽  
Sand Movement ◽  
The Town

Abstract The sensitive, partly fixed dune areas are good indicators of alteration, since they react rapidly to changing environmental conditions. Due to the climate changes, especially the increased aridity during the Holocene, many blown sand areas became active. Later, humanity had increasing impact of on its environment, thus sand movements occurred due to anthropogenic activities. Aeolian activities were identified not only in the historical times but also a few decades ago, when the moving sand caused significant problems on surfaces becoming bare. The present work will provide good evidence on sand movement in historical times caused by human impact on the environment with the help of OSL dating and archaeological research in the vicinity of the town of Apostag, which is located on the largest blown-sand area of Hungary on the Danube-Tisza Interfluve. The aims of the research were to identify the ethnical groups and their possible activities; to map the geomorphology of the study area; to determine the periods of aeolian activity; to assign the possible types of human activities in connection with climatic changes enabling aeolian activity.

scholarly journals Impact of climate change on volcanic processes: current understanding and future challenges

2021 ◽  
Author(s):  
Thomas Aubry ◽  
Jamie Farquharson ◽  
Colin Rowell ◽  
Sebastian Watt ◽  
Virginie Pinel ◽  
...  
Keyword(s):  
Climate Change ◽  
Radiative Forcing ◽  
Climate Changes ◽  
Numerical Models ◽  
Anthropogenic Activities ◽  
Volcanic Eruptions ◽  
Climate Impacts ◽  
Volcanic Plume ◽  
Atmospheric Conditions ◽  
Climate Conditions

The impacts of volcanic eruptions on climate are increasingly well understood, but the mirror question of how climate changes affect volcanic systems and processes, which we term “climate-volcano impacts”, remains understudied. Accelerating research on this topic is critical in view of rapid climate change driven by anthropogenic activities. Over the last two decades, we have improved our understanding of how mass distribution on the Earth’s surface, in particular changes in ice and water distribution linked to glacial cycles, affects mantle melting, crustal magmatic processing and eruption rates. New hypotheses on the impacts of climate change on eruption processes have also emerged, including how eruption style and volcanic plume rise are affected by changing surface and atmospheric conditions, and how volcanic sulfate aerosol lifecycle, radiative forcing and climate impacts are modulated by background climate conditions. Future improvements in past climate reconstructions and current climate observations, volcanic eruption records and volcano monitoring, and numerical models will contribute to boost research on climate-volcano impacts. Important mechanisms remain to be explored, such as how changes in atmospheric circulation and precipitation will affect the volcanic ash lifecycle. Fostering a holistic and interdisciplinary approach to climate-volcano impacts is critical to gain a full picture of how ongoing climate changes may affect the environmental and societal impacts of volcanic activity.

scholarly journals Impacts of climate and humans on the vegetation in NW Turkey: palynological insights from Lake Iznik since the Last Glacial

2015 ◽  
Vol 11 (6) ◽  
pp. 5157-5201 ◽  
Author(s):  
A. Miebach ◽  
P. Niestrath ◽  
P. Roeser ◽  
T. Litt
Keyword(s):  
Bronze Age ◽  
Climate Changes ◽  
Vegetation History ◽  
Anthropogenic Impacts ◽  
Anthropogenic Activities ◽  
Forest Steppe ◽  
Marmara Region ◽  
Pollen Record ◽  
Nw Turkey ◽  
Northwestern Turkey

Abstract. The Marmara region in northwestern Turkey provides a unique opportunity for studying the vegetation history in response to climate changes and anthropogenic impacts because of its location between different climate and vegetation zones and its long settlement history. Geochemical and mineralogical investigations of the largest lake in the region, Lake Iznik, already registered climate related changes of the lake level and the lake mixing. However, a palynological investigation encompassing the Late Pleistocene to Middle Holocene was still missing. Here, we present the first pollen record of the last ca. 31 ka cal BP (calibrated kilo years before 1950) inferred from Lake Iznik sediments as an independent proxy for paleoecological reconstructions. Our study reveals that the vegetation in the Iznik area changed generally between steppe during glacial/stadial conditions, forest-steppe during interstadial conditions, and oak dominated mesic forest during interglacial conditions. Moreover, a pronounced succession of pioneer trees, cold temperate, warm temperate, and Mediterranean trees appeared since the Lateglacial. Rapid climate changes, which are reflected by vegetation changes, can be correlated with Dansgaard–Oeschger (DO) events such as DO-4, DO-3, and DO-1, the Younger Dryas, and probably also the 8.2 event. Since the mid-Holocene, the vegetation was influenced by anthropogenic activities. During early settlement phases, the distinction between climate-induced and human-induced changes of the vegetation is challenging. Still, evidence for human activities consolidates since the Early Bronze Age (ca. 4.8 ka cal BP): cultivated trees, crops, and secondary human indicator taxa appeared, and forests got cleared. Subsequent fluctuations between extensive agricultural use and regeneration of the natural vegetation become apparent.

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