Orchid mycorrhizal communities associated with Orchis italica are shaped by ecological factors and geographical gradients

Aim: The influence of mutualists on plant distributions is only beginning to be understood. Orchids depend on orchid mycorrhizal (OrM) fungi to germinate, yet the distribution of OrM and how they vary according to both abiotic and biotic factors is unclear. We investigated the abundance and diversity of OrM communities associated with the Mediterranean orchid Orchis italica and quantified how they vary according to both geographical and ecological factors.
Location: Mediterranean Basin.
Taxon: Orchis italica Poir. (Orchidaceae)
Methods: We used metabarcoding of the ITS2 region to identify OrM fungi associated with adult individuals in 23 populations of O. italica across latitudinal and longitudinal gradients in the Mediterranean region. We used both multivariate analyses and Joint Species Distribution Models (JSDMs) based on geographical, climate, and soil variables to test how both common OrM fungi and their communities vary according to geographical and ecological factors.
Results: Ei..., , , # Orchid mycorrhizal communities associated with Orchis italica are shaped by ecological factors and geographical gradients: Open Source Data

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We have submitted our raw data (**presence_absence_all_OTU.csv**), presence and absence of all operational taxonomic units (OTUs) (**proportion_OTU.csv**), proportion of OTUs for each sampling point in a population, (**multivariate_analysis_data.csv**), population information, bio-climatic data and soil data for each population sampled.

## Descriptions

### **presence\_absence\_all\_OTU.csv**

* *population*: population name of sampling point.
* *population_code*: population abbreviation which corresponds to Map in Fig. 1.
* *region*: region in which population was sampled.
* *OTU1-OTU80*: Orchid mycorrhizal fungal OTUs detected in Orchis italica roots.

### **proportion\_OTU.csv**

* *numb_indv*: Five replications per sampling population; code corresponds to Map in Fig. 1.
* *lat*: Latitude of sampling point.
* *long*: Longitude of samplin...