Dear Readers,

When the UN General Assembly unanimously adopted the Millennium Declaration in September 2000 and set clear Millennium Development Goals (MDGs) to be achieved by 2015, people in mountain areas in most countries were directly addressed at the global level, although this was not explicitly stated in the documents. The aim of the MDGs is to significantly mitigate social disparities affecting the world's poorest people. It is worth noting that poverty and lack of social services are more pronounced in mountain regions than in any other ecoregion of the world. It is estimated that half of the world's poorest people are in mountain areas.

One of the means of the Millennium Project for fulfilling the MDGs is advances in science and technology, and particularly capacity development in countries affected by widespread poverty. This issue of MRD aims to show how meaningful research can directly contribute to mitigating core problems of non-sustainable development in highland–lowland contexts in selected mountain regions of the world, and hence contribute to the MDGs. The articles in the Development and Research sections exemplify innovative approaches or new insights, which can be characterized as building ‘bridges’ between research and development, highlands and lowlands, the social and the natural sciences, as well as between the North, the South and the East.

Bridges between research and development are being built through a specific project approach called Partnership Actions for Mitigating Syndromes (PAMS), described by Frank Haupt and Ulrike Müller-Böker, and in a number of practical examples of PAMS presented in the Development section. Bridges between highlands and lowlands often relate to the conservation and use of water, the most important natural resource for enabling life support systems in many mountain regions and their adjacent semiarid lowlands. Water issues are addressed in the research articles by Hanspeter Liniger and colleagues, Jos Aeschbacher and colleagues, and Hans Hurni and colleagues. Bridges between the natural and social sciences are part of the trans-disciplinary approaches adopted by a number of research projects focusing on sustainable development, as in the articles by Thomas Breu and colleagues, and Urs Wiesmann and colleagues.

Bridges between different mountain areas in the North and the South are exemplified by the research programme from which all the articles in this special issue of MRD are drawn—the Swiss National Centre of Competence in Research (NCCR) North–South, a long-term international partnership programme initiated in 2001 and focusing on syndrome mitigation research in 3 major contexts (highland–lowland, semiarid, and urban–periurban) and 9 major regions of the world (3 in Africa, 3 in Asia, 2 in South America, and 1 in Europe). The Platform Statement in this issue presents aspects of this programme, of which the editors of this special issue are members. Of the 98 PhD candidates currently in the NCCR North–South, nearly 40 are working on topics related to mountain areas and highland–lowland contexts. The NCCR programme, which is active in over 40 countries, thus constitutes a major effort in helping to develop competence and capacity, first, by helping to fulfil the MDGs by 2015, particularly in mountain regions; and second, by helping to promote sustainable development in general. The cover photograph, showing a real—but rather fragile—bridge in Nepal, is thus a symbol of the concept and approach of the programme, which in itself needs to be further strengthened and enhanced as a tool of international development.