7 research outputs found

    Hydroclimatic vulnerability of peat carbon in the central Congo Basin

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    The forested swamps of the central Congo Basin store approximately 30 billion metric tonnes of carbon in peat1,2. Little is known about the vulnerability of these carbon stocks. Here we investigate this vulnerability using peat cores from a large interfluvial basin in the Republic of the Congo and palaeoenvironmental methods. We find that peat accumulation began at least at 17,500 calibrated years before present (cal. yr BP; taken as AD 1950). Our data show that the peat that accumulated between around 7,500 to around 2,000 cal. yr BP is much more decomposed compared with older and younger peat. Hydrogen isotopes of plant waxes indicate a drying trend, starting at approximately 5,000 cal. yr BP and culminating at approximately 2,000 cal. yr BP, coeval with a decline in dominant swamp forest taxa. The data imply that the drying climate probably resulted in a regional drop in the water table, which triggered peat decomposition, including the loss of peat carbon accumulated prior to the onset of the drier conditions. After approximately 2,000 cal. yr BP, our data show that the drying trend ceased, hydrologic conditions stabilized and peat accumulation resumed. This reversible accumulation–loss–accumulation pattern is consistent with other peat cores across the region, indicating that the carbon stocks of the central Congo peatlands may lie close to a climatically driven drought threshold. Further research should quantify the combination of peatland threshold behaviour and droughts driven by anthropogenic carbon emissions that may trigger this positive carbon cycle feedback in the Earth system

    Information sharing and the stability of cooperation in research joint ventures*

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    The model studies information sharing and the stability of cooperation in cost reducing Research Joint Ventures (RJVs). In a three-stage game-theoretic framework, firms decide on participation in a RJV, information sharing along with R&D expenditures, and output. An important feature of the model is that voluntary information sharing between cooperating firms increases information leakage from the RJV to outsiders. It is found that RJVs representing a larger portion of firms in the industry are more likely to share information. It is also found that when sharing information is costless, firms generally don't choose intermediate levels of information sharing: they share all the information or none at all. The size of the RJV is found to depend on three effects: a coordination effect, an information sharing effect, and a competition effect. Depending on the relative magnitudes of these effects, the size of the RJV may increase or decrease with spillovers. In response to an increase in leakages, RJV members reduce their R&D spending. In addition, they either increase the RJV size while maintaining information sharing unchanged (when leakages are low), or they reduce both information sharing and RJV size (when leakages are high).Endogenous R&D Spillovers, Information Sharing, R&D Cooperation, Research Joint Ventures,

    D. Die einzelnen romanischen Sprachen und Literaturen.

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    Röntgenschäden

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