Contemporary and future distribution patterns of fluvial vegetation under different climate change scenarios and implications for integrated water resource management

Abstract

Knowledge of plant community structure and how it can confer resistance to climate change effects is required for the management of fluvial ecosystems. Findings from such studies can be applied in decision making processes to implement measures to maintain, conserve or improve fluvial quality. Floristic and environmental data from 100 sample stations located in three River Basin Districts in northern Portugal were gathered as part of the 2010 Water Framework Directive monitoring program carried out on mainland Portugal. Three habitat types were characterized based on the flow dynamic level: the wetted channel, the bankfull area and the riparian gallery. Hierarchical cluster analysis of environmental data revealed three distinct environmental groups of sites. Floristic data were organized by these environmental groups characterized by altitudinal, temperature and precipitation data variables. The combination of taxonomic diversity and species frequency reflect functional differences for these habitats, here explained by a resistance and resilience approach. More low-frequency species and higher levels of functional diversity occurred at stations with more variable environmental conditions. Predictive modelling of the future distribution of the three environmental groups under two different climate scenarios supported the relevance of low-frequency traits in conferring resistance to climatic change effects.