Leaf-height-seed strategy of paired Meconopsis species and their impact factors along the elevational gradients in the south-eastern margin of Qinghai- Tibet Plateau

Abstract

Abstract Plant functional trait reflects plant growth information and resource utilization strategy. Leaf-height-seed (LHS) scheme is to quantify the strategy of plants by the location of three easily measurable functional traits in three-dimensional space. We applied this scheme to paired Meconopsis species to assess the variation of life-history traits over altitudinal gradients in the south-eastern margin of Qinghai-Tibet Plateau. LHS traits of 3 ~ 6 M. punicea and M. integrifolia populations had been measured. Furthermore, the impact of environmental factors on LHS traits had been addressed by regression models. We found both species displayed a significant decrease with increasing elevation for plant height and only the SLA of M. punicea varied significantly among elevations, while the elevation had no significant effect on seed mass. Moreover, most LHS traits have no significant relationships within species. Along the elevational gradient, the LHS strategies adopted by these two species varied to some extent. At high elevation, M. punicea tended to adopt conservative nutrient utilization strategies and enhance surviability, while M. integrifolia tended to adopt strategies that ensured rapid nutrient utilization and enhanced surviability. The most important environmental factor for their trait variation is the average growing season mean temperature. Variations in LHS traits of a single species suggested that plant strategy determined by the position within this three-factor triangle is not constant along the elevational gradient. Additionally, our study didn’t support some previously established cross-species correlations for interspecific patterns of LHS traits not widespread within species.