Overview on the 6th international symposium on modern ecology series of 2011 Adaptation strategies of different plant functional types and their composition along a vegetation restoration gradient in a forest-steppe zone in the Yanhe River catchment, Shaanxi, China The responses of annual plant traits to rainfall variation in steppe and desert regions Growth, accumulation and partitioning of biomass, C, N and P of Sophora davidii seedlings in response to N supply in dry valley of upper Minjiang River