Age Determination and Growth Characteristics of the : A Comparison of Two Different Habitats in Western Sichuan Plateau, China.

This study proposes a rapid and non-destructive technique for determining the age of individuals in the field by observing the sequence of leaf scars. Based on two- to three-year-old seedlings, planted in a common garden in the western Sichuan Plateau, China, the study found that the rates of basal leaf production were consistent, with leaves growing from March to April and falling off from October to December, leaving behind basal leaf scars. Thus, the age of individuals in situ could be determined by counting the leaf scars. Through this method, we determined the age structure and growth strategy of populations in two typical habitats in the western Sichuan Plateau. In open land habitats, the age structure of populations was relatively younger compared to understory habitats. In open land, tends to allocate more photosynthate terminal organs (leaves and fine roots) to absorbing more resources, as well as to its reproductive organs (flower stems and aggregate fruits), to expand the population. The population in the understory habitat is in its middle-age stage and concentrates more photosynthate in the coarse root part (e.g., the high coarse root mass fraction (FRMF)) to support the plant. Additionally, we found a significant correlation between plant age and various traits in open land habitats. Therefore, we conclude that plant age can be used as a good predictor of plant growth condition in open land. These results allow for predicting ecological processes, based on the ages and traits of plants, providing a theoretical basis to support the large-scale breeding of .