| 1. |
- Pauly, Daniel, et al.
(författare)
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China's distant-water fisheries in the 21st century
- 2014
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Ingår i: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 15:3, s. 474-488
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Tidskriftsartikel (refereegranskat)abstract
- We conservatively estimate the distant-water fleet catch of the People's Republic of China for 2000-2011, using a newly assembled database of reported occurrence of Chinese fishing vessels in various parts of the world and information on the annual catch by vessel type. Given the unreliability of official statistics, uncertainty of results was estimated through a regionally stratified Monte Carlo approach, which documents the presence and number of Chinese vessels in Exclusive Economic Zones and then multiplies these by the expected annual catch per vessel. We find that China, which over-reports its domestic catch, substantially under-reports the catch of its distant-water fleets. This catch, estimated at 4.6 million t year(-1) (95% central distribution, 3.4-6.1 million t year(-1)) from 2000 to 2011 (compared with an average of 368 000 t year(-1) reported by China to FAO), corresponds to an ex-vessel landed value of 8.93 billion year(-1) (95% central distribution, 6.3-12.3 billion). Chinese distant-water fleets extract the largest catch in African waters (3.1 million t year(-1), 95% central distribution, 2.0-4.4 million t), followed by Asia (1.0 million t year(-1), 0.56-1.5 million t), Oceania (198 000 t year(-1), 144 000-262 000 t), Central and South America (182 000 t year-1, 94 000299 000 t) and Antarctica (48 000 t year(-1), 8 000-129 000 t). The uncertainty of these estimates is relatively high, but several sources of inaccuracy could not be fully resolved given the constraints inherent in the underlying data and method, which also prevented us from distinguishing between legal and illegal catch.
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| 2. |
- Needham, Jessica F., et al.
(författare)
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Demographic composition, not demographic diversity, predicts biomass and turnover across temperate and tropical forests
- 2022
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 28, s. 2895-2909
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Tidskriftsartikel (refereegranskat)abstract
- The growth and survival of individual trees determine the physical structure of a forest with important consequences for forest function. However, given the diversity of tree species and forest biomes, quantifying the multitude of demographic strategies within and across forests and the way that they translate into forest structure and function remains a significant challenge. Here, we quantify the demographic rates of 1961 tree species from temperate and tropical forests and evaluate how demographic diversity (DD) and demographic composition (DC) differ across forests, and how these differences in demography relate to species richness, aboveground biomass (AGB), and carbon residence time. We find wide variation in DD and DC across forest plots, patterns that are not explained by species richness or climate variables alone. There is no evidence that DD has an effect on either AGB or carbon residence time. Rather, the DC of forests, specifically the relative abundance of large statured species, predicted both biomass and carbon residence time. Our results demonstrate the distinct DCs of globally distributed forests, reflecting biogeography, recent history, and current plot conditions. Linking the DC of forests to resilience or vulnerability to climate change, will improve the precision and accuracy of predictions of future forest composition, structure, and function.
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