Fragmentation is a diversity ratchet

TL;DR

Fragmentation and reconnection cycles in landscapes can increase biodiversity by selectively removing highly connected species, creating a ratchet effect that enhances diversity over time.

Contribution

This paper introduces the concept that landscape fragmentation and reconnection cycles act as a diversity ratchet, promoting higher biodiversity levels.

Findings

Fragmentation reduces interspecies connectivity, increasing diversity.

Reconnection causes extinction of highly connected species.

Sequential fragmentation-coalescence cycles lead to higher diversity levels.

Abstract

A fragmented landscape reduces the impact of interspecies connectivity, leading to higher diversity levels than otherwise possible in a connected landscape. Reconnecting a previously fragmented landscape initiates an extinction event, preferentially weeding out more highly connected species. A sequence of fragmentation-coalescence events will drive the ecosystem to higher levels of diversity in a ratchet-like effect, than if the landscape continuously remained connected.