Extinction is a part of life, and animals and plants (which includes trees) disappear all the time. About 98% of all the organisms that have ever existed on our planet are now extinct.
When a species goes extinct, its role in the ecosystem is usually filled by new species, or other existing ones. Earth’s ‘normal’ extinction rate is often thought to be somewhere between 0.1 and 1 species per 10,000 species per 100 years. This is known as the background rate of extinction.
A mass extinction event is when species vanish much faster than they are replaced. This is usually defined as about 75% of the world’s species being lost in a ‘short’ amount of geological time – less than 2.8 million years. We have had five of those events.
Climate change has triggered the beginning of a “sixth mass extinction” of plant and animal species.
Human activity has been harmful in other ways as well, altering landscapes by cutting down trees, creating large swaths of mono-crop farmland, and polluting regions with toxic waste. In doing so, humans are adding to the destruction of natural, interconnected ecosystems causing the extinction of up to one million species. As temperatures continue to increase across the globe, plants that once thrived in their native habitats are either being forced to adapt to new conditions or accelerate the rate of extinction.
The rate by which plants are going extinct is at an all-time high across the globe. Since 1900, nearly 3 species of seed-bearing plants have disappeared per year ― 500 times faster than they would naturally. In so far as plants form the infrastructure of ecosystems and are interdependent with other organisms, when a plant species goes extinct it can harm every other species in the ecosystem. Dramatic changes to the structure of a previously stable ecosystem can result. For example, the average time between fires in the Yellowstone National Park ecosystem is projected to decrease from 100 to 300 years to less than 30 years, potentially causing coniferous (pine, spruce, etc.) forests to be replaced by woodlands and grasslands.
Now, scientists are working to understand what can be done to lessen the impacts of climate change on endangered plant species and save them from extinction.