Effects of fertilization and container-type on nutrient uptake and utilization by four subtropical tree seedlings

Seedling quality is important for subtropical tree species endangered by the degradation of natural habitats in southern China.At present,the cultural regime for raising these seedlings involving fertilizer levels and size of container is not clear.In this study,seedlings of three endangered species,red-seed tree(Ormosia hosiei),Zhejiang phoebe(Phoebe chekian gensis),and Zhejiang camphor(Cinnamomum japonicum) were evaluated along with red-bark oak(Cyclobalanopsis gilva) as a reference,a species which is not endangered.Seedlings were raised in 2.8,3.6,5.1,and 6.3 L containers and fertilizer applied at 1.0,2.0,3.0 and 4.0 kg m-3.Seedling height and leaf biomass increased in response to higher fertilizer levels while larger containers resulted in greater stem and root biomass.Root biomass of endangered species seedlings did not respond to neither treatments.Zhejiang phoebe seedlings responded to nitrogen and phosphorus uptake but red-seed tree seedlings were unaffected by any nutrient levels.Red-bark oak seedlings had high nitrogen-use efficiency.Based on the results,it is recommended using at least 5.1 L containers to culture Zhejiang phoebe and Zhejiang camphor seedlings with fertilizer at 3.0 kg m~(-3).Red-bark oak and red-seed tree seedlings should be cultured with 2.0 kg m~(-3) in smaller containers.