Growth-survival trade-off in shrub saplings from Neotropical mountain grasslands

The growth-survival trade-off plays a central role in the coexistence of species-rich plant communities. While recurrently described in forest tree communities primarily limited by light availability, this trade-off is still poorly documented in grassland and savanna vegetation. In this comparative study we planted in a quartzitic degraded site eight-month-old saplings of eleven shrub species native from constrained mountain grassland (Brazilian rupestrian grassland). We measured the relative growth rate (RGR) during a 30-week time interval, leaf water potential under dry and wet conditions, and related these traits to the species survival. The interspecific comparison between the saplings performance clearly showed the classic growth-survival trade-off. The RGR expressed in stem diameter and aboveground biomass explained respectively 62% and 40% of the variation in saplings' survival one year after planting, and respectively 65% and 44% of the variation in survival 4.5 years after planting. This trade-off was not related to either leaf water potential or final size in aboveground biomass and basal stem diameter. Our results corroborate the view that the growth-survival trade-off is universally applicable, even in non-forest communities such as grasslands and savannas subjected to severe nutritional deficiency, pronounced seasonal drought, and high light incidence. The environmental differences in micro-habitats that compose rupestrian grasslands should distinctly favour species with contrasting strategies of growth and survival, thus contributing to niche partitioning and coexistence in this species-rich ecosystem. (C) 2016 . Published by Elsevier B.V. All rights reserved.