Indirect facilitation between plants in a coastal dune

• Grant number: 16/20973-1
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2017
• End date: April 30, 2020
• Field of knowledge: Biological Sciences - Ecology
• Principal Investigator: Camila de Toledo Castanho
• Grantee: Camila de Toledo Castanho
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil
• City of the host institution: Diadema

Abstract

A growing body of evidence indicates that direct facilitation between plants is a frequent interaction, especially under severe environmental conditions. However, facilitation can also occur through indirect mechanisms involving other organisms of the same trophic level, a much less studied phenomenon. Using as a model a couple of woody species in which direct facilitation driven by shade was previously identified, the objective of this project is to test the existence of indirect facilitation between adults and seedlings mediated by herbaceous species in a coastal sand dune. In particular, we will test: i) if Guapira opposita has a negative direct effect on the performance of herbaceous plants; ii) if herbaceous plants have a negative direct effect on Ternstroemia brasiliensis seedlings and iii) if G. opposita indirectly facilitates T. brasiliensis seedlings by reducing the effects of competition from herbaceous plants on the seedlings. To test these hypotheses we will use an observational approach that involves the identification of patterns of spatial association, as well as field experiments involving the manipulation of the presence of G. opposita, herbaceous species and transplantation and performance tracking of T. brasiliensis seedlings. Moreover, to understand the mechanisms behind the interactions among these species, we will also test if the presence of these plants changes fertility, soil moisture and temperature, light intensity, as well as air humidity and temperature. Overall, the results of this project will be important to understand the importance of facilitation in coastal dunes in a scenario of multiple interactions, a condition poorly investigated to date. (AU)