Abstract:

Our objectives are to determine allometric relationships between lamina mass, area, volume and petiole mass in different leaf developing processes of three types leaf of Populus euphratica, namely broad ovate leaf, lanceolate leaf and ovate leaf, to explore leaf level resource utilization strategy of P. euphratica across ontogenetic stages. The lamina mass, area, volume and petiole mass were measured in early stage, intermediate stage, late stage of development of P. euphratica leaf. The standazed major axis estimation method was used to examine the scaling relationship among leaf traits of P. euphratica. The results showed that:(1) there was no significant relationship between lamina mass, area, volume and petiole mass at the early stage of development; (2) there were significant allometric relationships between lamina mass of broad ovate leaf and its petiole mass, petiole mass of ovate leaf and its lamina mass, lamina area and lamina volume at the intermediate stage; (3) there were significant allometric relationships between lamina mass, lamina area, lamina volume and petiole mass of three types of leaf; (4) common slopes of broad ovate leaf and ovate leaf were >1.0 significantly at the intermediate stage of development and <1.0 significantly at the late stage, which meant that lamina growth rate higher than the petiole, resources investment on lamina was higher than petiole at the intermediate stage, but resources investment of petiole increased at the late stage of development; (5) broad ovate leaf and ovate leaf common slopes significantly higher than lanceolate leaf, which meant broad ovate leaf and ovate leaf invested more resources on lamina than lanceolate leaf.

Key words: allometry, leaf traits, Populus euphratica, lamina, petiole, resource utilization strategy