Biomass Allocation, Water Content and Their Interrelations within Leaves of Cinnamomum camphora, an Evergreen Garden Plant

PurposeTo analyze the variation patterns of lamina-petiole biomass allocation and water contents and their covariation characteristics of an evergreen garden plant Cinnamomum camphora in relation to growing season (i.e, developmental stage), canopy orientation in Anqing City.

MethodA total of 840 leaves at both north and south canopies were collected in summer and winter respectively, and then the biomass and water content within leaves were determined.

ResultGrowing season significantly influenced leaf biomass and water content parameters of C. camphora, while canopy orientation just affected water contents (P< 0.05). The lamina biomass allocation ratio of C. camphora in winter was lower than that in summer, while the petiole allocation ratio presented the opposite tendency. The water contents within leaf indicated higher values in summer than that in winter, and higher values in petiole than that in lamina. Lamina and petiole biomass represented an isometric relationship in summer, while in winter they presented an allometric relationship showing petiole allocation ratio was higher than lamina. Biomass allocations of petiole and its water contents of C. camphora showed obvious negative correlations in both two growing seasons (P<0.01), indicating that higher petiole water content lower support investment. Petiole biomass allocations showed U-shaped relationships with leaf biomass, indicating that medium leaf size has minimum support investment.

ConclusionC. camphora presented varied biomass allocation strategy within leaf in different growing seasons, but the relationships between biomass allocation within leaf, water content and leaf size showed relatively stable.