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Under poor light conditions, as normally used during winter production of greenhouse vegetables, the nitrate concentration in the shoot of spinach (Spinacia oleracea L. cv. Vroeg Reuzenblad) showed a diurnal rhythm. This rhythm was mainly caused by a decrease during the day, followed by an increase during the night in the leaf blade nitrate concentration. Nitrate was mainly located in the vacuoles of the leaf blades. A strong correlation was found between net uptake of nitrate by the roots and the nitrate concentration in the leaf blade vacuoles. The nitrate concentration in the leaf blades increased during the initial hours of the night. This increase was caused by a marked increase in the net uptake rate of nitrate by the roots during the first hours of the dark period. During the second part of the night both net uptake rate of nitrate by the roots and the vacuolar nitrate concentration in the leaf blades remained constant. We conclude that nitrate is taken up for osmotic purposes when light conditions are poor because of a lack of organic solutes. During the night, nitrate influx into the vacuole is needed for replacement of organic solutes, which are metabolized during the night, and possibly also for leaf elongation growth. During the day, vacuolar nitrate may be exchanged for newly synthesized organic solutes and be metabolized in the cytoplasm. A strong diurnal rhythm in nitrate reductase (NR; EC 1.6.6.1.) activity was absent, due to the poor light conditions, and in vitro NR activity was not correlated with nitrate flux from the roots. In vivo NR activity also lacked a strong diurnal rhythm, but it was calculated that in situ nitrate reduction was much lower during the night, so that the major nitrate assimilation took place during the day.

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In highly developed regions, ecosystems are often severely fragmented, whereas the conservation of biodiversity is highly rated. Regional and local actor groups are often involved in the regional planning, but when making decisions they make insufficient use of scientific knowledge of the ecological system that is being changed. The ecological basis of regional landscape change would be improved if knowledge-based systems tailored to the cyclic process of planning and negotiation and to the expertise of planners, designers and local interest groups were available. If regional development is to be sustainable, goals for biodiversity must be set in relation to the actual and demanded patterns of ecosystems. We infer a set of prerequisites for the effective use of biodiversity goal-setting methods in multi-stakeholder decision making. Among these prerequisites are the requirements that ecosystem patterns are set central and that methods integrate the demands of a suite of species, are spatially explicit, and allow the aspiration level to be modified during the planning process. The decision making must also be enriched with local ecological knowledge. The current methods for setting biodiversity targets lack crucial characteristicsin particular, flexibility-and often require too high a level of ecological expertise. The ecoprofile method we designed combines an ecosystem base with spatial conditions for species metapopulations. We report experiences with this approach in two case studies, showing that the method was understood by policy makers, planners, and stakeholders, and was useful in negotiation processes. We recommend experimenting with applying this approach in a variety of circumstances, to further improve its ecological basis.

As environmental challenges and their management are increasingly recognised as complex and uncertain, the concept of ecosystem services has emerged from within scientific communities and is gaining influence within policy communities. To better understand how this concept can be turned into practice we examine knowledge needs from the perspective of the different stakeholders directly engaged with the operationalisation of ecosystem systems concept within nine socio-ecologically different case studies from different countries, levels of governance and ecosystems.We identify four different but interrelated areas of knowledge needs, namely; (i) needs related to develop a common understanding, (ii) needs related to the role of formal and informal institutions in shaping action on the ground, (iii) needs related to linking knowledge and action, and (iv) and needs related to accessible and easy to use methods and tools. These findings highlight the need to view knowledge as a process which is orientated towards action. We discuss the potential to develop 1 Corresponding author: Esther Carmen, NERC Centre for Ecology and Hydrology, Bush Estate, Edinburgh EH26 0QB, UK, +44 (0)131 4458443, esther.carmen78@yahoo.co.uk © <2017>. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http:// creativecommons.org/licenses/by-nc-nd/4.0/ { PAGE \* MERGEFORMAT } transdisciplinary research approaches and the development of tools and methods explicit as boundary objects in the ecosystem service science community to develop more collaborative practices with other stakeholders and facilitate the operationalisation of the concept of ecosystem services across contexts.

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