Migration is not a new phenomenon; it is inherent to human nature. According to a report by the UN Secretary General on International Migration and Development (A/60/871), 191 million people worldwide were international migrants in 2005. This is an obvious cause of international concern (and hope) since it led the nations of the world to engage in a high-level dialogue in 2006 ( www.un.org/migration), focusing on economic and human rights issues. What has not yet been taken up in this dialogue is the ecological dimension of migration. Moreover, though the number of international migrants is impressive in itself, it is only part of the migration equation: a far larger share of migrants move within countries. In mountains, this is typically rural–urban migration, seasonal migration, trade, and transhumance. Traditionally, (rural) seasonal migration and transhumance, aiming at the optimal use of scarce natural resources, have been integral parts of mountain people's livelihood strategies. But the picture is changing at a rapid pace: pressure on natural resources is increasing in some mountain regions and decreasing in others; societies in mountain areas are also changing as a result of migration patterns.
As Saodat Olimova and Muzaffar Olimov underline for the Central Asian and Hindu Kush–Himalaya region, remittances can have a positive impact if re-invested in development of the mountain area of origin, and if migrants can maintain a social connection with the community back home. Indeed, migration can be socially disruptive and lead to further impoverishment of mountain populations, as is the case in the State of Oaxaca, Mexico. Josefina Aranda Bezaury shows how the Oaxaca coffee producers' organization in Mexico is trying to reduce out-migration and mitigate its negative social and economic impacts through collective action and improved access to the market for niche products—in this case organic shade coffee, the production of which is also helping to protect mountain forests. Reliance on a balanced mix of modern approaches and traditional natural resource management is also what Chandra Singh Negi defends in his paper on transhumance and medicinal plant production and collection in the Indian Himalaya.
As H. Ricardo Grau and T. Mitchell Aide argue in their outspoken paper, however, out-migration is not a priori negative. Where it leads to disintensification of land use in fragile tropical and Andean mountain ecosystems with low productivity, it can stimulate ecosystem recovery and improve watershed and biodiversity protection. By contrast, rural depopulation in the European Alps has long been considered problematical for both the environment and society; Reto Soliva presents a methodological framework for a participatory sustainability assessment of development scenarios tested in a mountain region in Switzerland.
In the Research section, Lasanta and Laguna Marín-Yaseli examine the influence of European Union policy and subsidies for mountain regions—partly meant to stop out-migration—on the economy and society of remote areas in the Spanish Pyrenees. Yi Shaoling and co-authors are concerned with the impact on northern Yunnan grasslands of changes in transhumance systems and specifically in livestock migration patterns. Cruz and co-authors focus on using visual methods to analyze shepherds' perceptions of grasslands in Peru, motivated by the aim of improving the sustainability of resource management through a better understanding and integration of people's perceptions. This is also an underlying concern in Zackey's paper on peasants' perceptions of deforestation in southwest China. Forests are also the main focus of the last 2 papers: one on deforestation patterns in Ethiopia's Rift Valley region (Gessesse and Kleman) and the last on the highest northern hemisphere treeline, found in Tibet by Miehe and co-authors.
We hope that our readers will find material that stimulates thought and provides insights and enjoyment in this issue of MRD.