Introduction history influences aboveground biomass allocation in Brazilian peppertree (Schinus terebinthifolius)

Authors: ERICKSON, KELLEY - University Of Miami; Pratt, Paul; Rayamajhi, Min; HORVITZ, CAROL - University Of Miami

Submitted to: Invasive Plant Science and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2017
Publication Date: 9/18/2017
Citation: Erickson, K., Pratt, P.D., Rayamajhi, M.B., Horvitz, C. 2017. Introduction history influences aboveground biomass allocation in Brazilian peppertree (Schinus terebinthifolius). Invasive Plant Science and Management. 10(3):247-253. https://doi.org/10.1017/inp.2017.23.
DOI: https://doi.org/10.1017/inp.2017.23

Interpretive Summary: Brazilian peppertree is an invasive shrub that was introduced into Florida multiple times and has subsequently hybridized, resulting in three different plant types: eastern, western and hybrids. Do these plant types allocate above ground plant parts differently? We harvested 257 stems from each of 6 populations from the three types. The proportion of aboveground biomass allocated to fruit, wood and leaves differed among the three populations. Statistical analyses indicate that hybrid populations allocated more resources to wood (structure) and leaves (photosynthesis), while western populations produced more fruit. The relationship published in this paper, between stem size and individual plant parts, can be used in the future to predict how many leaves or fruits occur on a plant without having to count them.

Technical Abstract: Multiple introductions of an exotic species can facilitate invasion success by allowing for a wider range of expressed trait values in the adventive range. Brazilian peppertree is an invasive shrub that was introduced into Florida multiple times and has subsequently hybridized, resulting in three distinct introduction histories (eastern, western and hybrid). To determine whether allocation of above ground biomass differed by introduction history we destructively sampled 257 stems from each of 6 populations with differing introduction histories. The proportion of aboveground biomass allocated to fruit, wood and leaves differed among the three populations. To determine whether the relationship between stem size and several dependent variables that measure plant performance (total dry weight, wood dry weight, number of fruits, fruit dry weight, leaf dry weight and number of leaves) differed quantitatively by introduction history, we performed analyses of covariance. Slopes of these relationships (dependent variable vs stem size) varied by history of introduction. Hybrid populations had the steepest slopes for one set of dependent variables (total dry weight, wood dry weight, and leaf dry weight), while Western populations had the steepest slopes for a different set of dependent variables (number of fruits, fruit dry weight and number of leaves). The parameterized regression equations for each dependent variable and introduction history will be used to non-destructively estimate different kinds of production by individuals that are part of long term longitudinal studies to understand the demographic consequences of these different biomass allocation strategies for the performance of Brazilian Peppertree individuals across the invaded range in Florida.