Standing fine root mass and production in four Chinese subtropical forests along a succession and species diversity gradient

The influences of succession and species diversity on fine root production are not well known in forests. This study aimed to investigate: (i) whether fine root biomass and production increased with successional stage and increasing tree species diversity; (ii) how forest type affected seasonal variation and regrowth of fine roots. Sequential coring and ingrowth core methods were used to measure fine root production in four Chinese subtropical forests differing in successional stages and species diversity. Fine root biomass increased from 262 g center dot m(-2) to 626 g center dot m(-2) with increasing successional stage and species diversity. A similar trend was also found for fine root production, which increased from 86 to 114 g center dot m(-2) yr (-1) for Cunninghamia lanceolata plantation to 211-240 g center dot m(-2) yr (-1) for Choerospondias axillaries forest when estimated with sequential coring data. Fine root production calculated using the ingrowth core data ranged from 186 g center dot m(-2) yr (-1) for C. lanceolata plantation to 513 g center dot m(-2) yr (-1) for Lithocarpus glaber - Cyclobalanopsis glauca forest. Fine root biomass and production increased along a successional gradient and increasing tree species diversity in subtropical forests. Fine roots in forests with higher species diversity exhibited higher seasonal variation and regrowth rate.