scholarly journals Long-term changes in an estuarine mud crab community: evaluating the impact of non-native species

2014 ◽  
Vol 34 (6) ◽  
pp. 731-738 ◽  
Author(s):  
Wendy E. Eash-Loucks ◽  
Matthew E. Kimball ◽  
Kathryn M. Petrinec
Keyword(s):  
Native Species ◽  
Mud Crab ◽  
Long Term Changes ◽  
The Impact

scholarly journals Analyzing the market position of fish species subject to the impact of long-term changes: a case study of French fisheries in the Bay of Biscay

2008 ◽  
Vol 21 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Pascal Le Floc'h ◽  
Jean-Charles Poulard ◽  
Olivier Thébaud ◽  
Fabian Blanchard ◽  
Julien Bihel ◽  
...  
Keyword(s):  
Fish Species ◽  
Bay Of Biscay ◽  
Market Position ◽  
Long Term Changes ◽  
The Impact

scholarly journals Long-Term Changes of Softwood Floodplain Forests—Did the Disappearance of Wet Vegetation Accelerate the Invasion Process?

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1218
Author(s):  
Katarína Mikulová ◽  
Ivan Jarolímek ◽  
Jozef Šibík ◽  
Tomáš Bacigál ◽  
Mária Šibíková
Keyword(s):  
Species Richness ◽  
Linear Model ◽  
Native Species ◽  
Danube River ◽  
Floodplain Forests ◽  
Indicator Values ◽  
Long Term Changes ◽  
Native Species Richness ◽  
Over Time

Objectives: We followed the long-term changes of softwood floodplain forests strongly altered by water regime changes and examine the behaviour of neophytes in this environment. Here we ask: (1) How did the composition of neophyte and native species change? (2) How did the presence of species that prefer wetter conditions change? (3) What traditionally distinguished type of softwood floodplain forests (a wetter one or a more mesophilous one) do neophytes prefer? (4) What environmental factors affect the native species richness and the occurrence and cover of neophytes? Materials and Methods: Historical and recent phytosociological relevés of the association Salicetum albae of the Slovak part of the inland delta of the Danube River were used (177 plots together). For each plot, the number and cover of neophytes and number of native species were measured, and the Shannon-Wiener diversity index, the stand structure (cover of tree, shrub and herb layer) and the mean of Ellenberg indicator values were calculated and compared among time periods. Temporal trends of the soil moisture characterized by indicator values calculated for each plot were determined using a Linear Model. The synoptic table of traditional vegetation types was done to show preferences of neophytes for particular softwood forest types. The effect of site conditions on native species richness and occurrence of neophytes was determined using the Generalized Linear Model. Results: The relative number and cover of neophyte species increased and the absolute number of native species decreased over time; the vegetation of the area has changed from variable hygrophilous and mesophilous to homogenised mesophilous; most non-native species prefer the mesophilous vegetation of the floodplain forests; the wetter parts of the floodplain more successfully resisted invasions. Conclusions: The vegetation of the researched area has considerably changed over time to become less diverse and less hygrophilous, and has more invasive species. To preserve floodplain forests, natural hydrological and connectivity patterns should be adequately protected.

Long-term changes in fish community and the impact of exotic fish, between the Nakdong River and Upo Wetlands

2011 ◽  
Vol 34 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Hyun-Bin Jo ◽  
Min-Ho Jang ◽  
Kwang-Seuk Jeong ◽  
Yun-O Do ◽  
Gea-Jae Joo ◽  
...  
Keyword(s):  
Fish Community ◽  
Nakdong River ◽  
Exotic Fish ◽  
Long Term Changes ◽  
The Nakdong River ◽  
The Impact

scholarly journals Physics of Space Weather Phenomena: A Review

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 286
Author(s):  
Ashok Kumar Singh ◽  
Asheesh Bhargawa ◽  
Devendraa Siingh ◽  
Ram Pal Singh
Keyword(s):  
Space Weather ◽  
Modern Society ◽  
Major Elements ◽  
Space Environment ◽  
Time Data ◽  
Physical Relation ◽  
Long Term Changes ◽  
The Impact ◽  
Present Understanding

In the last few decades, solar activity has been diminishing, and so space weather studies need to be revisited with more attention. The physical processes involved in dealing with various space weather parameters have presented a challenge to the scientific community, with a threat of having a serious impact on modern society and humankind. In the present paper, we have reviewed various aspects of space weather and its present understanding. The Sun and the Earth are the two major elements of space weather, so the solar and the terrestrial perspectives are discussed in detail. A variety of space weather effects and their societal as well as anthropogenic aspects are discussed. The impact of space weather on the terrestrial climate is discussed briefly. A few tools (models) to explain the dynamical space environment and its effects, incorporating real-time data for forecasting space weather, are also summarized. The physical relation of the Earth’s changing climate with various long-term changes in the space environment have provided clues to the short-term/long-term changes. A summary and some unanswered questions are presented in the final section.

scholarly journals Historical Aerial Surveys Map Long-Term Changes of Forest Cover and Structure in the Central Congo Basin

2020 ◽  
Vol 12 (4) ◽  
pp. 638 ◽  
Author(s):  
Koen Hufkens ◽  
Thalès de Haulleville ◽  
Elizabeth Kearsley ◽  
Kim Jacobsen ◽  
Hans Beeckman ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Forest Cover ◽  
Congo Basin ◽  
Spatial And Temporal Patterns ◽  
Smallholder Farming ◽  
Aboveground Carbon ◽  
Decadal Scale ◽  
Long Term Changes ◽  
The Impact

Given the impact of tropical forest disturbances on atmospheric carbon emissions, biodiversity, and ecosystem productivity, accurate long-term reporting of Land-Use and Land-Cover (LULC) change in the pre-satellite era (<1972) is an imperative. Here, we used a combination of historical (1958) aerial photography and contemporary remote sensing data to map long-term changes in the extent and structure of the tropical forest surrounding Yangambi (DR Congo) in the central Congo Basin. Our study leveraged structure-from-motion and a convolutional neural network-based LULC classifier, using synthetic landscape-based image augmentation to map historical forest cover across a large orthomosaic (~93,431 ha) geo-referenced to ~4.7 ± 4.3 m at submeter resolution. A comparison with contemporary LULC data showed a shift from previously highly regular industrial deforestation of large areas to discrete smallholder farming clearing, increasing landscape fragmentation and providing opportunties for substantial forest regrowth. We estimated aboveground carbon gains through reforestation to range from 811 to 1592 Gg C, partially offsetting historical deforestation (2416 Gg C), in our study area. Efforts to quantify long-term canopy texture changes and their link to aboveground carbon had limited to no success. Our analysis provides methods and insights into key spatial and temporal patterns of deforestation and reforestation at a multi-decadal scale, providing a historical context for past and ongoing forest research in the area.

scholarly journals ATTRICI v1.1 – counterfactual climate for impact attribution

2021 ◽  
Vol 14 (8) ◽  
pp. 5269-5284
Author(s):  
Matthias Mengel ◽  
Simon Treu ◽  
Stefan Lange ◽  
Katja Frieler
Keyword(s):  
Climate Change ◽  
Climate Impact ◽  
Climate Impacts ◽  
General Definition ◽  
Impact Model ◽  
Climate Data ◽  
Climate Trends ◽  
Long Term Changes ◽  
The Impact

Abstract. Attribution in its general definition aims to quantify drivers of change in a system. According to IPCC Working Group II (WGII) a change in a natural, human or managed system is attributed to climate change by quantifying the difference between the observed state of the system and a counterfactual baseline that characterizes the system's behavior in the absence of climate change, where “climate change refers to any long-term trend in climate, irrespective of its cause” (IPCC, 2014). Impact attribution following this definition remains a challenge because the counterfactual baseline, which characterizes the system behavior in the hypothetical absence of climate change, cannot be observed. Process-based and empirical impact models can fill this gap as they allow us to simulate the counterfactual climate impact baseline. In those simulations, the models are forced by observed direct (human) drivers such as land use changes, changes in water or agricultural management but a counterfactual climate without long-term changes. We here present ATTRICI (ATTRIbuting Climate Impacts), an approach to construct the required counterfactual stationary climate data from observational (factual) climate data. Our method identifies the long-term shifts in the considered daily climate variables that are correlated to global mean temperature change assuming a smooth annual cycle of the associated scaling coefficients for each day of the year. The produced counterfactual climate datasets are used as forcing data within the impact attribution setup of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3a). Our method preserves the internal variability of the observed data in the sense that factual and counterfactual data for a given day have the same rank in their respective statistical distributions. The associated impact model simulations allow for quantifying the contribution of climate change to observed long-term changes in impact indicators and for quantifying the contribution of the observed trend in climate to the magnitude of individual impact events. Attribution of climate impacts to anthropogenic forcing would need an additional step separating anthropogenic climate forcing from other sources of climate trends, which is not covered by our method.

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