| 1. |
- Leadley, Paul, et al.
(författare)
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Interacting Regional-Scale Regime Shifts for Biodiversity and Ecosystem Services
- 2014
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Ingår i: BioScience. - : Oxford University Press (OUP). - 0006-3568 .- 1525-3244. ; 64:8, s. 665-679
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Tidskriftsartikel (refereegranskat)abstract
- Current trajectories of global change may lead to regime shifts at regional scales, driving coupled human-environment systems to highly degraded states in terms of biodiversity, ecosystem services, and human well-being. For business-as-usual socioeconomic development pathways, regime shifts are projected to occur within the next several decades, to be difficult to reverse, and to have regional- to global-scale impacts on human society. We provide an overview of ecosystem, socioeconomic, and biophysical mechanisms mediating regime shifts and illustrate how these interact at regional scales by aggregation, synergy, and spreading processes. We give detailed examples of interactions for terrestrial ecosystems of central South America and for marine and coastal ecosystems of Southeast Asia. This analysis suggests that degradation of biodiversity and, ecosystem services over the twenty-first century could be far greater than was previously predicted. We identify key policy and management opportunities at regional to global scales to avoid these shifts.
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| 2. |
- Lehner, Bernhard, et al.
(författare)
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High-resolution mapping of the world’sreservoirs and dams for sustainableriver-flow management
- 2011
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Ingår i: Frontiers in Ecology and the Environment. - Washington : Ecological Society of America. - 1540-9295 .- 1540-9309. ; 9:9, s. 494-502
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Tidskriftsartikel (refereegranskat)abstract
- Despite the recognized importance of reservoirs and dams, global datasets describing their characteristics and geographical distribution are largely incomplete. To enable advanced assessments of the role and effects of dams within the global river network and to support strategies for mitigating ecohydrological and socioeconomic costs, we introduce here the spatially explicit and hydrologically linked Global Reservoir and Dam database (GRanD). As of early 2011, GRanD contains information regarding 6862 dams and their associated reservoirs, with a total storage capacity of 6197 km3. On the basis of these records, we estimate that about 16.7 million reservoirs larger than 0.01 ha – with a combined storage capacity of approximately 8070 km3 – may exist worldwide, increasing Earth's terrestrial surface water area by more than 305 000 km2. We find that 575 900 river kilometers, or 7.6% of the world's rivers with average flows above 1 cubic meter per second (m3 s−1), are affected by a cumulative upstream reservoir capacity that exceeds 2% of their annual flow; the impact is highest for large rivers with average flows above 1000 m3 s−1, of which 46.7% are affected. Finally, a sensitivity analysis suggests that smaller reservoirs have substantial impacts on the spatial extent of flow alterations despite their minor role in total reservoir capacity.Read More: http://www.esajournals.org/doi/abs/10.1890/100125
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| 3. |
- McDonald, Robert, et al.
(författare)
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Global Urban Growth and the Geography of Water Availability, Quality, and Delivery
- 2011
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 40:5, s. 437-446
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Tidskriftsartikel (refereegranskat)abstract
- Globally, urban growth will add 1.5 billion people to cities by 2030, making the difficult task of urban water provisions even more challenging. In this article, we develop a conceptual framework of urban water provision as composed of three axes: water availability, water quality, and water delivery. For each axis, we calculate quantitative proxy measures for all cities with more than 50,000 residents, and then briefly discuss the strategies cities are using in response if they are deficient on one of the axes. We show that 523 million people are in cities where water availability may be an issue, 890 million people are in cities where water quality may be an issue, and 1.3 billion people are in cities where water delivery may be an issue. Tapping into groundwater is a widespread response, regardless of the management challenge, with many cities unsustainably using this resource. The strategies used by cities deficient on the water delivery axis are different than for cities deficient on the water quantity or water quality axis, as lack of financial resources pushes cities toward a different and potentially less effective set of strategies.
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| 4. |
- Nilsson, Christer, et al.
(författare)
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Fragmentation and flow regulation of the world's large river systems
- 2005
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 308:5720, s. 405-408
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Tidskriftsartikel (refereegranskat)abstract
- A global overview of dam-based impacts on large river systemsshows that over half (172 out of 292) are affected by dams,including the eight most biogeographically diverse. Dam-impactedcatchments experience higher irrigation pressure and about 25times more economic activity per unit of water than do unaffectedcatchments. In view of projected changes in climate and waterresource use, these findings can be used to identify ecologicalrisks associated with further impacts on large river systems.
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| 5. |
- Pereira, Henrique M., et al.
(författare)
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Scenarios for Global Biodiversity in the 21st Century
- 2010
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 330:6010, s. 1496-1501
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Forskningsöversikt (refereegranskat)abstract
- Quantitative scenarios are coming of age as a tool for evaluating the impact of future socioeconomic development pathways on biodiversity and ecosystem services. We analyze global terrestrial, freshwater, and marine biodiversity scenarios using a range of measures including extinctions, changes in species abundance, habitat loss, and distribution shifts, as well as comparing model projections to observations. Scenarios consistently indicate that biodiversity will continue to decline over the 21st century. However, the range of projected changes is much broader than most studies suggest, partly because there are major opportunities to intervene through better policies, but also because of large uncertainties in projections.
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