Mutualisms weaken the latitudinal diversity gradient among oceanic islands. (https://pubmed.ncbi.nlm.nih.gov/38418873/)

These scientists studied why there are more different types of plants in some places on Earth compared to others. They looked at plants on islands in the ocean and found that the number of plant species on islands is not as high as on the mainland at the same latitude. They found that the size of the island and how far it is from the mainland affect how many plants can live there. But they also discovered that plants that rely on other organisms, like animals that help them pollinate or fungi that help them grow, are not as common on islands. This means that the islands have fewer plant species because they lack these helpful partners. The scientists found that this pattern is strongest near the Equator, where the mainland has the most plant species. This study shows that these partnerships between plants and other organisms are important for maintaining a high diversity of plants in tropical regions and influence where different plants can be found on Earth.

Delavaux CS., Crowther TW., Bever JD., Weigelt P., Gora EM. Mutualisms weaken the latitudinal diversity gradient among oceanic islands. Nature. 2024 Feb 28. doi: 10.1038/s41586-024-07110-y.