The middle Toarcian cold snap: Trigger of mass extinction and carbonate factory demise

2014 ◽  
Vol 117 ◽  
pp. 64-78 ◽  
Author(s):  
F.N. Krencker ◽  
S. Bodin ◽  
R. Hoffmann ◽  
G. Suan ◽  
E. Mattioli ◽  
...  
2020 ◽  
Author(s):  
Yu Pei ◽  
Jan-Peter Duda ◽  
Joachim Reitner

AbstractThe Permian-Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian-Triassic Critical Interval (P-TrCI) in the Xiakou area (South China). Six microfacies (MF) were classified. The succession begins with a eukaryote-controlled carbonate factory (MF-1) that passes upward into an organomineralization-dominated carbonate factory (MF-2–3). Organic-rich marls atop these units reflect carbonate factory collapse (MF-4). Organomineralization-driven carbonate formation restarts prior to the Permian-Triassic boundary (MF-5) and subsequently develops into a mixed carbonate factory where organomineralization and biomineralization are almost equally important (MF-6). MF-1 reflects oxygenated shallow water environments. In contrast, MF-2–6 were all deposited in somewhat deeper environments, some of which episodically exhibited elevated salinities, oxygen depletion, and, possibly, euxinic conditions. Our results demonstrate that distinct changes in carbonate production styles, biodiversity, and environmental conditions are not synchronous at Xiakou. Furthermore, the Xiakou record is strikingly different to that of other localities, even from the same area (e.g., the Global Stratotype Section and Point section at Meishan). Together, these findings highlight the enormous complexity of the P-TrCI and calls simplified views of the Permian-Triassic mass extinction into question.


PalZ ◽  
2020 ◽  
Author(s):  
Yu Pei ◽  
Jan-Peter Duda ◽  
Joachim Reitner

Abstract The Permian–Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian–Triassic Critical Interval (P–TrCI) in the Xiakou area (South China). Six microfacies (MF) were classified. The succession begins with a eukaryote-controlled carbonate factory (MF-1) that passes upward into an organomineralization-dominated carbonate factory (MF-2–3). Organic-rich marls atop these units reflect carbonate factory collapse (MF-4). Organomineralization-driven carbonate formation restarts prior to the Permian–Triassic boundary (MF-5) and subsequently develops into a mixed carbonate factory where organomineralization and biomineralization are almost equally important (MF-6). MF-1 reflects oxygenated shallow water environments. In contrast, MF-2–6 were all deposited in somewhat deeper environments, some of which episodically exhibited elevated salinities, oxygen depletion, and, possibly, euxinic conditions. Our results demonstrate that distinct changes in carbonate production styles, biodiversity, and environmental conditions are not synchronous at Xiakou. Furthermore, the Xiakou record is strikingly different to that of other localities, even from the same area (e.g., the Global Stratotype Section and Point section at Meishan). Together, these findings highlight the enormous complexity of the P–TrCI and calls simplified views of the Permian–Triassic mass extinction into question.


Nature ◽  
2011 ◽  
Author(s):  
Gayathri Vaidyanathan
Keyword(s):  

2020 ◽  
Vol 639 ◽  
pp. 169-183
Author(s):  
P Matich ◽  
BA Strickland ◽  
MR Heithaus

Chronic environmental change threatens biodiversity, but acute disturbance events present more rapid and immediate threats. In 2010, a cold snap across south Florida had wide-ranging impacts, including negative effects on recreational fisheries, agriculture, and ecological communities. Here, we use acoustic telemetry and historical longline monitoring to assess the long-term implications of this event on juvenile bull sharks Carcharhinus leucas in the Florida Everglades. Despite the loss of virtually all individuals (ca. 90%) within the Shark River Estuary during the cold snap, the catch per unit effort (CPUE) of age 0 sharks on longlines recovered through recruitment within 6-8 mo of the event. Acoustic telemetry revealed that habitat use patterns of age 0-2 sharks reached an equilibrium in 4-6 yr. In contrast, the CPUE and habitat use of age 3 sharks required 5-7 yr to resemble pre-cold snap patterns. Environmental conditions and predation risk returned to previous levels within 1 yr of the cold snap, but abundances of some prey species remained depressed for several years. Reduced prey availability may have altered the profitability of some microhabitats after the cold snap, leading to more rapid ontogenetic shifts to marine waters among sharks for several years. Accelerated ontogenetic shifts coupled with inter-individual behavioral variability of bull sharks likely led to a slower recovery rate than predicted based on overall shark CPUE. While intrinsic variation driven by stochasticity in dynamic ecosystems may increase the resistance of species to chronic and acute disturbance, it may also increase recovery time in filling the diversity of niches occupied prior to disturbance if resistive capacity is exceeded.


2019 ◽  
Author(s):  
Lea Barbett ◽  
Edward Stupple ◽  
Michael Sweet ◽  
Miles Richardson

The planet is facing an anthropogenic mass extinction of wildlife, which will have a grave impact on the environment and humans. Widespread human action is needed to minimize the negative impact of humans on biodiversity and support the restoration of wildlife. In order to find effective ways to promote pro-nature conservation behaviours to the general population, there is a need to provide a list of behaviours which will have worthwhile ecological impact and are worth encouraging. In a novel collaboration between psychologists and ecologists, 70 experts from practical and academic conservation backgrounds were asked to review and rate 48 conservation related behaviours. According to their judgement, this short paper presents a ranked list of pro-nature conservation behaviours for the public in the UK and similar landscapes. This includes behaviours people can engage in in their homes, their gardens, on their land, and in their roles as citizens.


2009 ◽  
Vol 160 (5) ◽  
pp. 124-128
Author(s):  
Claudio Defila

Although the year 2008 in Switzerland belongs to the ten to twelve warmest years since the beginning of measurements, the effects on the development of the vegetation were not very striking. An extreme excess of heat was never registered except in the winter months and in May. The mild winter simply had an effect on the flowering of the hazel, occurring early to very early. Besides this, most of the phenological spring phases were observed at the normal point of time. However, at some observation stations, a small number of phenological phases showed a completely unusual date of occurrence. These were observed very late or even extremely late (new records). Because of the fact that this phenomenon was not only observed at one single phenological phase, showing no spatial pattern and no height dependence, no explanation was found for this extraordinary behavior of these plants. This clearly reflects, despite intensive research on phenology during the last years, that many natural processes are until now not or not yet understood by man. According to the changing weather, the development of the vegetation showed neither a consistent nor an outstanding pattern in the summer. However, the early leaf-fall of the beech was quite striking, caused by the cold snap at the beginning of October. The year 2008 can be considered as a normal phenological year, except the early flowering of the hazel, the inexplicable records (late observations) and the early leaf-fall of the beech.


Author(s):  
Andrei Grachev ◽  
H. A. Kollmann ◽  
O. A. Korchagin ◽  
D. M. Pechersky ◽  
V. A. Tsel'movich
Keyword(s):  

2016 ◽  
Author(s):  
Alexander M. Dunhill ◽  
◽  
William J. Foster ◽  
James Sciberras ◽  
Richard J. Twitchett
Keyword(s):  

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