Outbreak range expansions in geometrid moths as drivers of ecosystem state changes in sub-arctic birch forests

2016 ◽  
Author(s):  
Jane Uhd Jepsen
2021 ◽  
Author(s):  
Jacob Diamond ◽  
Florentina Moatar ◽  
Matthew Cohen ◽  
Alain Poirel ◽  
Cécile Martinet ◽  
...  

<p>Aquatic ecosystem recovery from anthropogenic degradation can be hampered by internal feedbacks that stabilize undesirable states. The challenges of managing and predicting alternative states in lakes are well known, but state shifts in rivers and their attendant effects on ecosystem function remain understudied despite strong recent evidence that such shifts can and do occur. Using three decades of measurements of key state variables such as turbidity, nutrient concentrations, Corbicula fluminea clam densities, and chlorophyll a, including hourly dissolved oxygen, we investigated a sudden shift from phytoplankton to macrophyte dominance in the middle Loire River (France), and its associated effects on the rivers metabolic regime. We show, instead, that despite large and synchronous shifts across all state variables, changes in gross primary production and ecosystem respiration were modest (25% and 14% declines, respectively) and that these shifts lagged the ecosystem state changes by a decade or more. The shift to a macrophyte-dominated state reduced the sensitivity of primary production to abiotic drivers, altered element cycling efficiency, flipped the net carbon balance from positive to negative, and, crucially, weakened the temporal coupling between production and respiration. This weakened coupling, detected using Granger causality, increased the temporal autocorrelation of net ecosystem production, yielding a robust early warning indicator of both state- and metabolic-shifts that may provide valuable guidance for river restoration.</p>


Rangelands ◽  
2012 ◽  
Vol 34 (6) ◽  
pp. 23-26 ◽  
Author(s):  
Thomas A. Monaco ◽  
Chris Call ◽  
Merilynn C. Hirsch ◽  
Beth Fowers

2020 ◽  
Vol 30 (7) ◽  
Author(s):  
Tobias Kuhlmann Andersen ◽  
Anders Nielsen ◽  
Erik Jeppesen ◽  
Fenjuan Hu ◽  
Karsten Bolding ◽  
...  

2018 ◽  
Vol 92 ◽  
pp. 72-81 ◽  
Author(s):  
Cui Xu ◽  
Xin’an Yin ◽  
Zhihao Xu ◽  
Hongrui Liu ◽  
Ying Yang ◽  
...  

2021 ◽  
Author(s):  
Jacob S. Diamond ◽  
Florentina Moatar ◽  
Matthew J. Cohen ◽  
Alain Poirel ◽  
Cécile Martinet ◽  
...  

2020 ◽  
Vol 2020 (10) ◽  
pp. 37-41
Author(s):  
Sergey Bulatov

The effectiveness of manufacturing equipment use taking into account its productivity and reliability for faulty parts of transmission units in municipal buses is estimated. The on-line mode is the most effective method of control allowing the tracking of the processes of technical state changes in municipal buses. As a result of monitoring there were obtained selected data on PAZ-3205 municipal bus operated under winter conditions in the city of Ohrenburg. During the trip there was recorded 39.1 l/100km petrol consumption. The residual life of the PAZ-3205 municipal bus was 1800km.


Author(s):  
Kelly E. Shannon-Henderson

This study demonstrates the importance of references to religious material in Tacitus’ Annals by analyzing them using cultural memory theory. Throughout his narrative of Julio-Claudian Rome in the Annals, Tacitus includes numerous references to the gods, fate, fortune, astrology, omens, temples, priests, emperor cult, and other religious material. Tacitus, who was not only a historian but also a member of Rome’s quindecimviral priesthood, shows a marked interest in even the most detailed rituals of Roman religious life. Yet his portrayal of religious material also suggests that the system is under threat with the advent of the principate. Traditional rituals are forgotten as the shape of the Roman state changes. Simultaneously, a new form of cultic commemoration develops as deceased emperors are deified and the living emperor and his family members are treated in increasingly worshipful ways by his subjects. The study traces the deployment of religious material throughout Tacitus’ narrative, to show how Tacitus views the development of this cultic ‘amnesia’ over time, from the reign of the cryptic, autocratic, and oddly mystical Tiberius, through Claudius’ failed attempts at reviving tradition, to the final sacrilegious disasters of the impious Nero.


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