Continental export of si to the coastal zone is closely linked to the ocean carbon sink and to the dynamics of phytoplankton blooms in coastal ecosystems. Presently, however, the impact of human cultivation of the landscape on terrestrial si fluxes remains unquantified and is not incorporated in models for terrestrial si mobilization. In this paper, we show that land use is the most important controlling factor of si mobilization in temperate European watersheds, with sustained cultivation ( > 250 years) of formerly forested areas leading to a twofold to threefold decrease in baseflow delivery of si. This is a breakthrough in our understanding of the biogeochemical si cycle: it shows that human cultivation of the landscape should be recognized as an important controlling factor of terrestrial si fluxes.

To date, no attempt has been made to design efficient choice experiments by means of the G-and V-optimality criteria. These criteria are known to make precise response predictions, which is exactly what choice experiments aim to do. In this article, the authors elaborate on the G-and V-optimality criteria for the multinomial logit model and compare their prediction performances with those of the D-and A-optimality criteria. They make use of Bayesian design methods that integrate the optimality criteria over a prior distribution of likely parameter values. They employ a modified Fedorov algorithm to generate the optimal choice designs. They also discuss other aspects of the designs, such as level overlap, utility balance, estimation performance, and computational effectiveness.

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