scholarly journals Functional and trophic variations in macrofaunal assemblage reflect the ecological effects of bottom-based clam farming

2022 ◽  
Vol 135 ◽  
pp. 108510
Author(s):  
Xin Sun ◽  
Yuyang Zhang ◽  
Ramón Filgueira ◽  
Zheng Zhang ◽  
Jianyu Dong ◽  
...  
Keyword(s):  
1969 ◽  
Vol 60 (4, Pt.1) ◽  
pp. 284-293 ◽  
Author(s):  
Donald L. Thistlethwaite

1993 ◽  
Vol 27 (7-8) ◽  
pp. 547-556 ◽  
Author(s):  
M. Gaft

Exhaustion of rich ore deposits is making it necessary to bring low-grade ores into production, resulting in a sharply increased volume of excavated rock. Huge quantities of waste fill vast areas of the Earth's surface, with severe ecological effects. But the ecological damage could be reduced by extracting additional products from the tailings. Laseroluminescent sorting is a new technology by which this may be achieved. The most promising subjects are about 50 minerals including diamonds, native Au and Ag, ores of V, Pb, Zn, Sn, Li, Be, W, Mo, Zr, Sr, halite, apatite, phosphorite, fluorite, calcite, barite, anhydrite.


Author(s):  
Edwin M. Foekema ◽  
Jacqueline E. Tamis ◽  
Ainhoa Blanco ◽  
Babeth Weide ◽  
Cor Sonneveld ◽  
...  

2021 ◽  
Vol 13 (2) ◽  
pp. 311
Author(s):  
Hongyan Yin ◽  
Yuanman Hu ◽  
Miao Liu ◽  
Chunlin Li ◽  
Jiujun Lv

An estuarine wetland is an area of high ecological productivity and biodiversity, and it is also an anthropic activity hotspot area, which is of concern. The wetlands in estuarine areas have suffered declines, which have had remarkable ecological impacts. The land use changes, especially wetland loss, were studied based on Keyhole and Landsat images in the Liao River delta from 1962 to 2016. The dynamics of the ecosystem service values (ESVs), suitable habitat for birds, and soil heavy metal potential ecological risk were chosen to estimate the ecological effects with the benefit transfer method, synthetic overlaying method, and potential ecological risk index (RI) method, respectively. The driving factors of land use change and ecological effects were analyzed with redundancy analysis (RDA). The results showed that the built-up area increased from 95.98 km2 in 1962 to 591.49 km2 in 2016, and this large change was followed by changes in paddy fields (1351.30 to 1522.39 km2) and dry farmland (189.5 to 294.14 km2). The area of wetlands declined from 1823.16 km2 in 1962 to 1153.52 km2 in 2016, and this change was followed by a decrease in the water area (546.2 to 428.96 km2). The land use change was characterized by increasing built-up (516.25%), paddy fields (12.66%) and dry farmland (55.22%) areas and a decline in the wetland (36.73%) and water areas (21.47%) from 1962–2016. Wetlands decreased by 669.64 km2. The ESV values declined from 6.24 billion US$ to 4.46 billion US$ from 1962 to 2016, which means the ESVs were reduced by 19.26% due to wetlands being cultivated and the urbanization process. The area of suitable habitat for birds decreased by 1449.49 km2, or 61.42% of the total area available in 1962. Cd was the primary soil heavy metal pollutant based on its concentration, accumulation, and potential ecological risk contribution. The RDA showed that the driving factors of comprehensive ecological effects include wetland area, Cd and Cr concentration, river and oil well distributions. This study provides a comprehensive approach for estuarine wetland cultivation and scientific support for wetland conservation.


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