The trade-off between growth and reproduction in an alpine herbaceous plant along an elevation gradient

摘要

The relationship between growth and reproduction is a fundamental aspect of the reproductive strategy for a plant. Using an allometric perspective for both vegetative and reproductive traits allows us to understand and predict the impact of environmental change on a plant species. Here, we investigated the allometric relationships in Gentiana rigescens Franch. ex Hemsl. individuals at non-flowering and flowering stages along an elevation gradient in southwest China. We found that the mean values of the metrics were significantly higher in G. rigescens plants at reproductive stage than those at vegetative stage. However, allometric analysis showed that the plants in vegetative stage had higher root and stem biomass than those in reproductive stage at a given size, while leaf biomass showed fixed allometric trajectory. The height of G. rigescens was higher in flowering individuals than that in non-flowering individuals at small size, while the contrary was obtained at large size. Analysis of covariance showed that the root biomass was not affected by elevation, whereas the stem biomass, leaf biomass, and total biomass increased with increasing elevation. In conclusion, allocating biomass to roots and stems in G. rigescens individuals reduced when flowering occurred, but the resource investment in leaves was not changed. As the total biomass increased with increasing elevation, the effects of elevation on leave and stem biomass of G. rigescens could be partly size-dependent.