International Institute for Applied Systems Analysis

About: International Institute for Applied Systems Analysis is a nonprofit organization based out in Laxenburg, Austria. It is known for research contribution in the topics: Population & Greenhouse gas. The organization has 1369 authors who have published 5075 publications receiving 280467 citations. The organization is also known as: IIASA.

Vertical Structure, Biomass and Topographic Association of Deep-Pelagic Fishes in Relation to a Mid-Ocean Ridge System

Abstract: The assemblage structure and vertical distribution of deep-pelagic fishes relative to a mid-ocean ridge system are described from an acoustic and discrete-depth trawling survey conducted as part of the international Census of Marine Life field project MAR-ECO 〈 http://www.mar-eco.no 〉. The 36-station, zig-zag survey along the northern Mid-Atlantic Ridge (MAR; Iceland to the Azores) covered the full depth range (0 to >3000 m), from the surface to near the bottom, using a combination of gear types to gain a more comprehensive understanding of the pelagic fauna. Abundance per volume of deep-pelagic fishes was highest in the epipelagic zone and within the benthic boundary layer (BBL; 0–200 m above the seafloor). Minimum fish abundance occurred at depths below 2300 m but above the BBL. Biomass per volume of deep-pelagic fishes over the MAR reached a maximum within the BBL, revealing a previously unknown topographic association of a bathypelagic fish assemblage with a mid-ocean ridge system. With the exception of the BBL, biomass per volume reached a water column maximum in the bathypelagic zone between 1500 and 2300 m. This stands in stark contrast to the general “open-ocean” paradigm that biomass decreases exponentially from the surface downwards. As much of the summit of the MAR extends into this depth layer, a likely explanation for this mid-water maximum is ridge association. Multivariate statistical analyses suggest that the dominant component of deep-pelagic fish biomass over the northern MAR was a wide-ranging bathypelagic assemblage that was remarkably consistent along the length of the ridge from Iceland to the Azores. Integrating these results with those of previous studies in oceanic ecosystems, there appears to be adequate evidence to conclude that special hydrodynamic and biotic features of mid-ocean ridge systems cause changes in the ecological structure of deep-pelagic fish assemblages relative to those at the same depths over abyssal plains. Lacking terrigenous input of allochthonous organic carbon, increased demersal fish diversity and biomass over the MAR relative to the abyssal plains may be maintained by increased bathypelagic food resources. The aggregation of bathypelagic fishes with MAR topographic features was primarily a large adult phenomenon. Considering the immense areal extent of mid-ocean ridge systems globally, this strategy may have significant trophic transfer and reproductive benefits for deep-pelagic fish populations.

Biomass production potentials in Central and Eastern Europe under different scenarios

Abstract: A methodology for the assessment of biomass potentials was developed and applied to Central and Eastern European countries (CEEC). Biomass resources considered are agricultural residues, forestry residues, and wood from surplus forest and biomass from energy crops. Only land that is not needed for food and feed production is considered as available for the production of energy crops. Five scenarios were built to depict the influences of different factors on biomass potentials and costs. Scenarios, with a domination of current level of agricultural production or ecological production systems, show the smallest biomass potentials of 2–5.7 EJ for all CEEC. Highest potentials can reach up to 11.7 EJ (85% from energy crops, 12% from residues and 3% from surplus forest wood) when 44 million ha of agricultural land become available for energy crop production. This potential is, however, only realizable under high input production systems and most advanced production technology, best allocation of crop production over all CEEC and by choosing willow as energy crops. The production of lignocellulosic crops, and willow in particular, best combines high biomass production potentials and low biomass production costs. Production costs for willow biomass range from 1.6 to 8.0 €/GJ HHV in the scenario with the highest agricultural productivity and 1.0–4.5 €/GJ HHV in the scenario reflecting the current status of agricultural production. Generally the highest biomass production costs are experienced when ecological agriculture is prevailing and on land with lower quality. In most CEEC, the production potentials are larger than the current energy use in the more favourable scenarios. Bulk of the biomass potential can be produced at costs lower than 2 €/GJ. High potentials combined with the low cost levels gives CEEC major export opportunities.

The global nexus of food–trade–water sustaining environmental flows by 2050

Abstract: In the face of meeting Sustainable Development Goals for the water–food–energy–ecosystems nexus, integrated assessments are a great means to measure the impact of global change on natural resources. In this study, we evaluate the impact of climate change with the representative concentration pathway 8.5 scenario and the impact of socioeconomics with the shared socioeconomic pathway 2 scenario on land use, water consumption and food trade under four water regulation policy scenarios (invest, exploit, environment and environment+). We used the Global Biosphere Management Model and constrained it with water availability, environmental flow requirements, and water use from agriculture, industry and households (simulated using the Lund–Potsdam–Jena managed Land model, Environmental Policy Integrated Climate model and WaterGap model). Here, we show that an increase in land use by 100 Mha would be required to double food production by 2050, to meet projected food demands. International trade would need to nearly triple to meet future crop demands, with an additional 10–20% trade flow from water-abundant regions to water-scarce regions to sustain environmental flow requirements on a global scale. The challenges of meeting food, water and energy needs are interconnected, requiring integrated assessments of land use, socioeconomic policies and climate change. This study assesses the required increases in water, trade and agricultural land needed to double food production by 2050.