Recent and rapid assembly of an island species–area relationship threatened by human disturbance

The island species–area relationship (ISAR) describes how larger islands support more species. Studies on oceanic archipelagos have shown that ISARs assembled over millions of years have predictable shapes. However, it remains unclear how rapidly “classic” ISARs develop, and how they are formed on much younger systems. Here, we compile a dataset for the fish communities of 79 postglacial peri-Alpine lakes, and report that an ISAR with a classical shape has formed de novo in less than 15,000 years. Despite their very young age, these lakes exhibit an ISAR mirroring older systems, with a characteristic asymptotic shape. Immigration responds primarily to area and saturates, whereas speciation is primarily driven by lake depth. This young ISAR has been reshaped by anthropogenic activities, with species introductions erasing its upper limit. We demonstrate that ISARs can develop rapidly after habitat formation in semi-isolated systems, offering insights into the assembly of ecological patter..., , # Recent and rapid assembly of an island species–area relationship threatened by human disturbance

Dataset DOI: [10.5061/dryad.q2bvq83xm](10.5061/dryad.q2bvq83xm)

## Description of the data and file structure

These files contain the raw data and R codes used in the manuscript for the:

1. **Analyses**: Multimodel analysis to test for the best mathematical function to describe the lake ISAR.
2. **GLMM**: Mixed model to identify the lake features related to the richness metrics.
3. **Power Function**: Power function fit to extract the parameters *z* (slope) and *c* (intercept).

## Files and variables

### File: Supporting_information_S1.pdf

**Description:** Additional description of the methods used in the manuscript.

### File: Supp_info_S2_lakeFeat_richn.csv

**Description:** Table containing the lake features and richness metrics used in the analyses.

#### Variables

* *Lake* | Name of the lake.
* *Catchment* | River basin or drainage system to which the lake belongs.
* *Long* | ...,