Recent Anthropogenic Plant Extinctions Differ in Biodiversity Hotspots and Coldspots

Area of Science:

• Ecology and Evolutionary Biology
• Conservation Biology
• Environmental Science

Background:

• Human activities in the Anthropocene are altering Earth systems, leading to habitat destruction, species invasions, and accelerated extinctions.
• While extinction rates are high globally, plant extinctions have appeared low, though biodiversity distribution is uneven, potentially causing regional variations.
• Debate exists on whether novel human-altered habitats and speciation can increase regional biodiversity.

Purpose of the Study:

• To analyze trends, causes, and temporal dynamics of plant extinctions using a comprehensive dataset.
• To compare plant extinctions in biodiversity hotspots versus coldspots over more than 300 years.
• To investigate the drivers and taxonomic uniqueness loss associated with plant extinctions.

Main Methods:

• Compiled one of the most extensive datasets on regional and global plant extinctions.
• Analyzed data from regions covering 15.3% of the Earth's surface spanning over 300 years.
• Compared extinction event accrual, rates, taxonomic uniqueness loss, and extinction drivers between biodiversity hotspots and coldspots.

Main Results:

• Biodiversity hotspots experienced higher absolute numbers and faster accrual of extinction events than coldspots.
• Extinction rates significantly exceeded historical background rates, but recent declines were observed.
• Biodiversity coldspots showed greater loss of unique taxonomic groups; agriculture, invasions, and urbanization drove extinctions in hotspots, while hydrological disturbance was key in coldspots.

Conclusions:

• Plant extinctions over the last three centuries have been relatively low.
• A steady recent extinction rate of 1.26 species per year has been observed since 1990.
• Distinct regional patterns exist in plant extinction drivers and taxonomic uniqueness loss.