THE RESPONSE OF FUNCTIONAL TRAITS AND ABOVEGROUND BIOMASS OF PHRAGMITES AUSTRALIS TO HABITAT CHANGES IN THE YELLOW RIVER DELTA, CHINA

Plant functional traits and biomass allocation can reflect the adaptive strategies of plants to environmental changes.However, little is known about how plant functional traits and biomass allocation respond to habitat changes in the Yellow River Delta, China.The dominant species, Phragmites australis (Cav.)Trin.ex Steud (common reed), was chosen to investigate the response of functional traits and aboveground biomass allocation to different habitats (grassland and river bank) with different soil water content.The results showed that plant height and number of leaves of P. australis were lower in grassland compared with river bank, while leaf thickness showed the opposite trend.It suggests that a conservative strategy in grassland was adopted by P. australis.The stem biomass and aboveground biomass were higher in river bank compared with grassland.Plant height was positively correlated with number of leaves, individual leaf dry weight and stem diameter, while it was negatively correlated with leaf thickness.Aboveground biomass was positively correlated with plant height, number of leaves, individual leaf dry weight and stem diameter, and the strongest correlation was found between plant height and aboveground biomass (R 2 = 0.75).The adaptation of P. australis to habitat changes through manipulating key functional traits and biomass allocation was observed.