| 1. |
- Angelstam, Per, 1953-, et al.
(författare)
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Two-dimensional gap analysis : a tool for efficient conservation planning and biodiversity policy implementation
- 2003
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Ingår i: Ambio. - : Royal Swedish Academy of Sciences. - 0044-7447 .- 1654-7209. ; 32:8, s. 527-534
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Tidskriftsartikel (refereegranskat)abstract
- The maintenance of biodiversity by securing representative and well-connected habitat networks in managed landscapes requires a wise combination of protection, management, and restoration of habitats at several scales. We suggest that the integration of natural and social sciences in the form of "Two-dimensional gap analysis" is an efficient tool for the implementation of biodiversity policies. The tool links biologically relevant "horizontal" ecological issues with "vertical" issues related to institutions and other societal issues. Using forest biodiversity as an example, we illustrate how one can combine ecological and institutional aspects of biodiversity conservation, thus facilitating environmentally sustainable regional development. In particular, we use regional gap analysis for identification of focal forest types, habitat modelling for ascertaining the functional connectivity of "green infrastructures", as tools for the horizontal gap analysis. For the vertical dimension we suggest how the social sciences can be used for assessing the success in the implementation of biodiversity policies in real landscapes by identifying institutional obstacles while implementing policies. We argue that this interdisciplinary approach could be applied in a whole range of other environments including other terrestrial biota and aquatic ecosystems where functional habitat connectivity, nonlinear response to habitat loss and a multitude of economic and social interests co-occur in the same landscape.
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| 2. |
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| 3. |
- Carlsson, Lars, et al.
(författare)
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Institutional frameworks for sustainability? : a comparative analysis of the forest sectors of Russia and the Baltic States
- 2004
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Ingår i: Ambio. - : Royal Swedish Academy of Sciences. - 0044-7447 .- 1654-7209. ; 33:6, s. 366-370
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Tidskriftsartikel (refereegranskat)abstract
- After the break-up of the Soviet system, the divergence in forest management among Soviet republics became obvious. While the forest sectors of the Baltic States have been fundamentally changed, Russia has not been able to develop an institutional framework that would fit the prerequisites for social-ecological resilience. It is argued that sustainable development requires institutional frameworks that have the capacity to adapt and learn, and thus to treat policies as experiments that are constantly assessed and readjusted. This, however, requires a participatory approach and in this respect the Baltic States are believed to be on a more promising track. Finally, it is concluded that only to the extent that suitable institutional frameworks will be developed will social-ecological resilience be a significant feature of the natural resources management in the former communist countries.
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| 4. |
- Ekström, Magnus, 1966-
(författare)
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Quantifying spatial patterns of landscapes
- 2003
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 32:8, s. 573-576
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we discuss information theoretical landscape indices based on data from digitized maps in grid format: measures based on Shannon's entropy, e.g. the measures of diversity and contagion; and measures based on conditional entropy, e.g. a new index which can be seen as an alternative to the measure of contagion that does not have the disadvantage of being highly correlated to the measure of diversity. We also introduce a measurement on how much information Is contained in a coarse-scale map about a fine-scale map.
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| 5. |
- Farahbakhshazad, Neda
(författare)
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Nutrient removal in a vertical upflow wetland in Piracicaba, Brazil
- 2000
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 29:2, s. 74-77
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Tidskriftsartikel (refereegranskat)abstract
- Vertical upflow wetland systems have shown high nutrient removal efficiencies. The removal of nutrients (N and P) from wastewater was investigated in a vertical upflow wetland system in Piracicaba, Brazil. The concentration removal was 93% for phosphate, 78% for nitrate and 50% for ammonia. Effective phosphate removal was observed in the top soil layer which has a high surface adsorption area. Nitrate was removed satisfactory at low loading rates due to plant uptake and denitrification. Removal of ammonia was concentration dependent and decreased at high inflow concentrations. Spatial sampling through the bed showed that the treatment efficiency was not uniform. The possibility of the recycling of nutrients as a soil improver or animal feed is an important feature of this type of vertical flow wetland system.
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| 6. |
- Fleischer, Siegfried
(författare)
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CO2 Deficit in Temperate Forest Soils Receiving High Atmospheric N-Deposition
- 2003
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Ingår i: Ambio. - Stockholm : The Royal Swedish Academy of Science. - 0044-7447 .- 1654-7209. ; 32:1, s. 2-5
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Tidskriftsartikel (refereegranskat)abstract
- Evidence is provided for an internal CO2 sink in forest soils, that may have a potential impact on the global CO2-budget. Lowered CO2 fraction in the soil atmosphere, and thus lowered CO2 release to the aboveground atmosphere, is indicated in high N-deposition areas. Also at forest edges, especially of spruce forest, where additional N-deposition has occurred, the soil CO2 is lowered, and the gradient increases into the closed forest. Over the last three decades the capacity of the forest soil to maintain the internal sink process has been limited to a cumulative supply of approximately 1000 and 1500 kg N ha−1. Beyond this limit the internal soil CO2 sink becomes an additional CO2 source, together with nitrogen leaching. This stage of “nitrogen saturation” is still uncommon in closed forests in southern Scandinavia, however, it occurs in exposed forest edges which receive high atmospheric N-deposition. The soil CO2 gradient, which originally increases from the edge towards the closed forest, becomes reversed.
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| 7. |
- Gullström, Martin, 1968, et al.
(författare)
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Seagrass ecosystems in the Western Indian Ocean
- 2002
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 31:7-8, s. 588-596
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Tidskriftsartikel (refereegranskat)abstract
- Seagrasses are marine angiosperms widely distributed in both tropical and temperate coastal waters creating one of the most productive aquatic ecosystems on earth. In the Western Indian Ocean (WIO) region, with its 13 reported seagrass species, these ecosystems cover wide areas of near-shore soft bottoms through the 12 000 km coastline. Seagrass beds are found intertidally as well as subtidally, sometimes down to about 40 m, and do often occur in close connection to coral reefs and mangroves. Due to the high primary production and a complex habitat structure, seagrass beds support a variety of benthic, demersal and pelagic organisms. Many fish and shellfish species, including those of commercial interest, are attracted to seagrass habitats for foraging and shelter, especially during their juvenile life stages. Examples of abundant and widespread fish species associated to seagrass beds in the WIO belong to the families Apogonidae, Blenniidae, Centriscidae, Gerreidae, Gobiidae, Labridae, Lethrinidae Lutjanidae, Monacanthidae, Scaridae, Scorpaenidae, Siganidae, Syngnathidae and Teraponidae. Consequently, seagrass ecosystems in the WIO are valuable resources for fisheries at both local and regional scales. Still, seagrass research in the WIO is scarce compared to other regions and it is mainly focusing on botanic diversity and ecology. This article reviews the research status of seagrass beds in the WIO with particular emphasis on fish and fisheries. Most research on this topic has been conducted along the East African coast, i.e. in Kenya, Tanzania, Mozambique and eastern South Africa, while less research was carried out in Somalia and the Island States of the WIO (Seychelles, Comoros, Reunion (France), Mauritius and Madagascar). Published papers on seagrass fish ecology in the region are few and mainly descriptive. Hence, there is a need of more scientific knowledge in the form of describing patterns and processes through both field and experimental work. Quantitative seagrass fish community studies in the WIO such as the case study presented in this paper are negligible, but necessitated for the perspective of fisheries management. It is also highlighted that the pressure on seagrass beds in the region is increasing due to growing coastal populations and human disturbance from e.g. pollution, eutrophication, sedimentation, fishing activities and collection of invertebrates, and its effect are little understood. Thus, there is a demand for more research that will generate information useful for sustainable management of seagrass ecosystems in the WIO.
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| 8. |
- Gunnarsson, Jonas, et al.
(författare)
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Effects of eutrophication on contaminant cycling in marine benthic systems
- 2000
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 29:4-5, s. 252-259
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Tidskriftsartikel (refereegranskat)abstract
- Effects of inputs of organic matter were studied on bioavailability and cycling of hydrophobic organic contaminants (HOCs) in benthic ecosystems of the Baltic and Kattegat Seas. In laboratory experiments, effects of microalgae additions were studied on the bioaccumulation of HOCs (PCBs and PAHs) by the blue mussel Mytilus edulis, the brittle star Amphiura filiformis, and the polychaete Nereis diversicolor. Contrary to the equilibrium partitioning theory, bioaccumulation was proportional to the concentrations of algae and organic carbon. This was attributed to the high nutritional quality of the algal organic carbon and suggests that feeding rather than equilibrium partitioning governed bioaccumulation in these species. In the field, annual mass fluxes of PCBs in blue mussels and in brittle stars were estimated, as well as contaminant transfer to higher trophic levels. Our results suggest that: I) Eutrophication processes may contribute to increase HOC accumulation in benthic species. ii) Temporal variation in the quantity and quality of organic carbon needs to be considered when assessing contamination of benthic systems. ill) Macrofaunal feeding activities are important for the benthic-pelagic coupling of HOCs. iv) Bioturbation enhances the release of HOCs from sediment to overlying water.
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| 9. |
- Helander, Björn, 1946-, et al.
(författare)
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The Role of DDE, PCB, Coplanar PCB and Eggshell Parameters for Reproduction in the White-tailed Sea Eagle (Haliaeetus albicilla) in Sweden.
- 2002
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 31:5, s. 386-403
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Tidskriftsartikel (refereegranskat)abstract
- The reproduction of white-tailed sea eagles was monitoredin1964–1999 in 3 differently contaminated sub-populations: BalticSea coast (Bp), inland central Sweden (Ip) and Lapland (Lp). 249dead eggs from 205 clutches were obtained for analyses of DDEand PCBs and for eggshell measurements. A desiccation index(Di) value was calculated for each egg as a measure of waterloss through the shell. In the highly contaminated Bp, p,p´-DDEconcentrations in the eggs decreased continuously and 5-foldduring the study period and PCB concentrations decreased 3-fold from the mid 1980s. The PCB pattern changed slightly overtime towards more high-chlorinated congeners but the relativetoxicity of the PCB mixture, expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ), remained constant and TEQcan be assumed to have decreased in a similar way as PCB overtime. Productivity (P), shell thickness (St), shell index (Si) and Diincreased over time in the Bp but no change in Di or productivityoccurred in the Lp, where residue concentrations were 5–8 timeslower. P of the Bp was not correlated to St or Si but was negatively correlated to Di, DDE and PCB. An S-shaped doseresponse relationship was indicated between P and DDE. After1988, when the PCB/DDE ratio was considerably higher thanpreviously, PCB but not DDE concentrations were significantlyhigher in eggs with dead embryos as compared to undevelopedeggs, implying lethal concentrations of PCB, and a LOEL of 320pg g–1 TEQ is suggested for embryo mortality. In a subset of 21eggs, representing productive and unproductive females, analyzed for a selection of coplanar PCB congeners, tris(4-chlorophenyl) methanol and bis(4-chlorophenyl) sulphone, there wasno evidence for a correlation between P and any of these compounds. A reduction in residue concentrations in old females didnot lead to increased P or improved Di-values, indicating aremaining effect from a previous, higher exposure to contaminants. The inability to reproduce included a high rate ofundeveloped eggs, indicating effects at a prezygotic stage. Pshowed the strongest correlation with Di, and Di was moststrongly correlated to DDE. Thus, the remaining effect of previousexposure resulted in a stronger correlation to the symptom (Di)rather than to the suggested causative agent (DDE). LOEL valuesfor depressed P were estimated at 120 µg g–1 DDE and 500 µgg–1 PCB (lipid basis). It is concluded that the major reason fordepressed P during the study period was DDE, but that effectsalso from PCB were largely concealed by the effects from DDE.
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| 10. |
- Humborg, C., et al.
(författare)
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Silicon retention in river basins : Far-reaching effects on biogeochemistry and aquatic food webs in coastal marine environments
- 2000
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 29:1, s. 45-50
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Tidskriftsartikel (refereegranskat)abstract
- Regulation of rivers by damming as well as eutrophication in river basins has substantially reduced dissolved silicon (DSi) loads to the Black Sea and the Baltic Sea. Whereas removal of N and P in lakes and reservoirs can be compensated for by anthropogenic inputs in the drainage basins, no such compensation occurs for DSi. The resulting changes in the nutrient composition (DSi:N:P ratio) of river discharges seem to be responsible for dramatic shifts in phytoplankton species composition in the Black Sea. In the Baltic Sea, DSi concentrations and the DSi:N ratio have been decreasing since the end of the 1960s, and there are indications that the proportion of diatoms in the spring bloom has decreased while flagellates have increased. The effects on coastal biogeochemical cycles and food web structure observed in the Black Sea and the Baltic Sea may be far reaching, because it appears that the reductions in DSi delivery by rivers are probably occurring worldwide with the ever increasing construction of dams for flow regulation.
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