The roll of biotic interactions in driving patterns of plant diversity on islands

• Applicant: Dr. Amanda Taylor
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 447332176

Biotic interactions are among the most important forces structuring ecological communities and are fundamental to the maintenance of species diversity. Despite this, at larger spatial scales, biotic interactions are thought to succumb to the greater influence of bioclimatic and biogeographical factors and are rarely considered as drivers of global-scale biodiversity patterns. Here, I aim to challenge this concept by showing that biotic interactions are in fact important drivers of biodiversity beyond local scales. Specifically, using islands as model systems and orchid-pollinator and orchid-mycorrhizal fungi as model interacting species, I aim to determine; i) do biotic interactions predict orchid diversity on islands, and is the effect comparable to abiotic and biogeographical colonization filters (e.g. island isolation, climatic factors)?; ii) are insular orchid-mycorrhizal fungi interactions more generalized (relative to the mainland), and do insular orchids interact with a similar composition of mycorrhizal fungi as on the mainland?; and iii) do biotic interactions interact with environmental factors that may further limit plant colonization on islands? Using a combination of regional checklists for over 27,000 orchid species obtainable from our Global Inventory of Floras and Traits database (GIFT, gift.uni-goettingen.de), field studies and literature-based searches, I will collate an interaction database to address whether biotic interactions limit orchid colonisation of islands. I will test this using both state-of-the-art Mixed Effects modelling techniques and a ‘Network Analyses’ framework. The results of this research will substantially advance our understanding of the mechanisms underpinning the assembly of island floras and will shed light on the general importance of biotic interactions in driving large-scale species distribution patterns.

• DFG Programme: Research Grants