Supplementary Dataset for: Long-distance seed dispersal accelerates the spread of the invasive buttonweed (Cotula coronopifolia)

This repository contains the input files and scripts used in: "Long-distance seed dispersal accelerates the spread of the invasive buttonweed (Cotula coronopifolia)". Migratory waterbirds can accelerate the spread of invasive plants beyond their native ranges by dispersing ingested seeds across wetlands along migratory flyways. Yet, empirical evidence that endozoochory by long-distance migrants drives continental spread and shifts invasions from gradual to stratified diffusion remains scarce, limiting our ability to forecast and manage invasions. We combined landscape genomics with eco-evolutionary simulations to test whether endozoochorous long-distance dispersal explains the accelerated expansion of Cotula coronopifolia in Europe. Flyway connectivity did not explain pairwise genetic differentiation, but population graphs revealed cross-country dependencies consistent with rare long-distance dispersal events. Simulations showed that, with only short-distance dispersal, the species occupied <2% of suitable UK habitat following 140 years after its introduction, whereas rare long-distance dispersal produced near-complete occupancy within 30 years. These results show that endozoochorous waterbird dispersal can drive stratified diffusion and identify migratory flyways as risk corridors for invasive plants.