Metabolic regime shifts and ecosystem state changes are decoupled in a large river

2021 ◽  
Author(s):  
Jacob S. Diamond ◽  
Florentina Moatar ◽  
Matthew J. Cohen ◽  
Alain Poirel ◽  
Cécile Martinet ◽  
...  
Keyword(s):  
Large River ◽  
Regime Shifts ◽  
State Changes ◽  
Ecosystem State

Metabolic regime shifts and ecosystem state changes are decoupled in a large river

2021 ◽  
Author(s):  
Jacob Diamond ◽  
Florentina Moatar ◽  
Matthew Cohen ◽  
Alain Poirel ◽  
Cécile Martinet ◽  
...  
Keyword(s):  
Primary Production ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Large River ◽  
Nutrient Concentrations ◽  
State Variables ◽  
Ecosystem Recovery ◽  
Element Cycling ◽  
State Changes ◽  
Ecosystem State

<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>

scholarly journals Repairing Ecological Processes to Direct Ecosystem State Changes

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

scholarly journals Predicting ecosystem state changes in shallow lakes using an aquatic ecosystem model: Lake Hinge, Denmark, an example

2020 ◽  
Vol 30 (7) ◽  
Author(s):  
Tobias Kuhlmann Andersen ◽  
Anders Nielsen ◽  
Erik Jeppesen ◽  
Fenjuan Hu ◽  
Karsten Bolding ◽  
...  
Keyword(s):  
Shallow Lakes ◽  
Aquatic Ecosystem ◽  
Ecosystem Model ◽  
State Changes ◽  
Ecosystem State

Simulating the effects of regulation measures on ecosystem state changes in a shallow lake

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

Key Construction Technologies for Large River-Crossing Slurry Shield Tunnel: Case Study

2021 ◽  
Vol 34 (2) ◽  
pp. 04020118
Author(s):  
Song Zhou ◽  
Guan-Lin Ye ◽  
Lei Han ◽  
Wang Jian-Hua
Keyword(s):  
Large River ◽  
Shield Tunnel ◽  
Slurry Shield

DRAINAGE BASIN AS A COMPLEX SOCIO-NATURAL HIERARCHICAL SYSTEM

2020 ◽  
Vol 42 (3) ◽  
pp. 293-303
Author(s):  
VALERIY BONDAREV
Keyword(s):  
Drainage Basin ◽  
Temporal Analysis ◽  
Large River ◽  
Hierarchical Level ◽  
Effective Management ◽  
Drainage Basins ◽  
Time Intervals ◽  
Natural Systems ◽  
Spatial And Temporal Analysis ◽  
Entire Complex

The theoretical and methodological basis of the systems hierarchical spatial and temporal analysis of a drainage basin, which addresses the problems of effective management in socio-natural systems of different ranks, is considered. It is proposed to distinguish 9 orders of forms that are relevant to the analysis of drainage basins, where the first level is represented by individual aggregates and particles, and the last - by basins of large and the largest rivers. As part of the allocation of geological, historical and modern time intervals, the specificity of the implementation of processes in basins of different scales from changing states, through functioning to evolution is demonstrated. The interrelation of conditions and factors that determine the processes occurring within the drainage basins is revealed. It is shown that a specific combination of conditions and factors that determine processes in the drainage basin is associated with the hierarchy of the objects under consideration, i.e. the choice of a spatial-temporal hierarchical level is crucial for the organization of study within drainage basins. At one hierarchical level, some phenomenon can be considered as a factor, and at another - as a condition. For example, tectonic processes can be considered as an active factor in the evolution of large river basins in the geological perspective, but for small drainage basin, this is already a conservative background condition. It is shown that at the historical time the anthropogenic factor often comes to the fore, with the appearance of which in the functioning of the drainage basin, there is a need to take into account the entire complex of socio-environmental problems that can affect the sustainable state of various territories, especially in the field of water and land use. Hierarchical levels of managing subjects are identified, which are primarily responsible for effective management at the appropriate hierarchical level of the organization of the socio-natural system within the catchment area, starting from an individual to humankind as a whole.

MEASURE COMPLEX SUPPORTING SAFETY AND EFFECTUVE OPERATION OF MUNICIPAL BUSES UNDER WINTER CONDITIONS

2020 ◽  
Vol 2020 (10) ◽  
pp. 37-41
Author(s):  
Sergey Bulatov
Keyword(s):  
Residual Life ◽  
Technical State ◽  
Manufacturing Equipment ◽  
Winter Conditions ◽  
On Line ◽  
State Changes ◽  
The City

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.

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