A major contributor to extinctions and loss of biodiversity is human activity. When natural habitats are destroyed, animal and plant extinctions follow. Recent research shows that not all of these extinctions happen at once, however, and there is a small time window in which conservation methods may save some of the remaining species. The study was led by William Newmark, a vertebrate zoologist from the University of Utah. The findings were just published in the journal Nature Communications.
Human development tends to lead to habitat loss for many plant and animal species. This loss of biodiversity is considered inevitable but no previous research had examined the rate of this extinction debt. Extinction debt refers to the change in how many species a habitat can support after being fragmented or otherwise disturbed. Understanding how fast this occurs could help conservation efforts.
The research team analyzed 43 previous studies to develop mathematical models representing extinction debt rates. They compared rates among mammals, birds, reptiles, invertebrates, and plants. The team found that the extinction rates followed the same pattern for all five taxonomic groups. Their models showed that extinction rates are initially very high but then slow down as the extinction debt is “paid off”. They also found that the size of the habitat mattered. In smaller habitats, extinction rates were faster. Larger habitats had reduced rates of species loss and were overall impacted less than small, fragmented habitats.
These findings show that while biodiversity loss will rapidly occur following habitat destruction, the rate slows down as extinction debt decreases. This means that quick conservation efforts may be able to save species from extinction. Extinction rates were higher in smaller, fragmented habitats. Increasing the area of these newly disturbed habitats and bridging habitat fragments together could help prevent species loss. The authors hope their findings will improve current conservation methods.
John M. Halley et al. Dynamics of extinction debt across five taxonomic groups. Nature Communications (2016).