Begrijpen hoe biotische interacties de verspreiding van epifytische orchideeën in tropische bossen beïnvloeden: een geïntegreerde netwerkbenadering
Understanding the factors that limit species distribution is a longstanding question in ecology. In land plants, species distribution is simultaneously limited by multiple factors, including climate, dispersal ability, competition, and species' physiological tolerance. The ecological requirements of obligate inter-specific interactions impose additional, often over-looked, limitations. How complex interactions influence plant species distribution has received little attention despite its relevance for species conservation in the face of global change. EpiNet will address this gap by investigating how two obligate partners, interacting with abiotic factors, influence plant distribution in mega-diverse tropical assemblages. Tropical epiphytic orchids provide an exceptional study model because they depend on two partners to germinate and grow: a host tree and mycorrhizal fungi. To this end, I propose to study tripartite interaction networks of tropical epiphytic orchids with their partners under different ecological conditions. I will examine the effect of host trees and mycorrhizal fungal diversity on orchid species distribution across geographical and local gradients, analyzing how abiotic factors such as temperature, humidity and light availability affect these interactions. I will establish germination experiments to assess whether orchids replace mycorrhizal partners over ontogeny or retain them for a lifetime. Mycorrhizal replacement is an understudied variable that may influence seedling establishment success. The methodology combines extensive data collection in natural communities (from dry to cloud tropical forests in the Colombian Andes), cutting-edge techniques in molecular biology (mycorrhizal DNA meta-barcoding), and advanced statistical analyses (tripartite networks). This innovative and integrated approach will provide an unprecedented, comprehensive understanding of the ecological factors influencing the distribution of tropical epiphytic orchids.