Up to 16% of U.S. tree species are ‘threatened with extinction’
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- A new study has created a comprehensive checklist of all tree species native to the contiguous United States.
- With 881 species currently assessed for extinction threats, up to 16 percent of tree species are threatened.
- Botanical gardens can provide a safe haven for tree species, including some that currently live only in the wild.
Some of the most magnificent trees native to the United States, including the mighty California redwood and the famed Northeastern black ash, are at risk of extinction. The same goes for some tree species that are generally unknown.
A published study by Plants People Planet estimates that between 11% and 16% of all American trees are now at risk of extinction. The most common threat comes from “invasive and problematic pests and diseases”. With 881 species in 269 genera (scientific term for a group of living things related to one or more species), the first national tree extinction risk analysis finds we are at risk of losing more tree species than ever before. previously.
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The study authors updated the checklist of all tree species native to the contiguous United States and developed more than 700 new or updated assessments. “Most species native to the continental United States had never been assessed or were obsolete on the two most widely used threat assessment platforms in the United States,” the study reports.
The updated information provides a more robust view of trees across the United States, even though only eight of the tree species listed as threatened made a federally recognized list as endangered or threatened. Then there are 17 other species on the study’s at-risk list that live only in the wild, leaving them subject to complete extinction if wiped out.
“It’s easy to feel this sadness and this unhappiness because … the scale of the crisis is really, really big right now,” said Murphy Westwood, vice president for science and conservation at Morton Arboretum in Illinois. Illinois and lead author of the study, recount the Washington Post. “We are losing species even before they are described.”
The Botanic Gardens Conservation International coalition works to expose “plant blindness” and to study and celebrate the world’s more than 58,000 tree species. Westwood was part of the American contingent that investigated threats to American trees.
While the International Union for Conservation of Nature Red List and NatureServe both categorize tree species, the study says the lack of a coordinated mechanism for sharing data across platforms has resulted in missing and duplicate information. Moreover, most of what was measured was simply outdated information, as it did not take into account the latest dangers related to “invasive pests and diseases, climate change, biological resource use (most often l logging) and natural system modification (increased fire frequency and increased fire suppression),” the study said.
Invasive pests and diseases have increased preservation challenges in the United States. Climate change “will likely exacerbate threats,” the authors write in the study. For example, the emerald ash borer, which first appeared in the United States in the 1990s, has since killed nearly half of native Fraxinus species, devastating everything from ash trees to hawthorns to apple trees. . Laurel wilt, a fungal pathogen transmitted by the Redbay Ambrosia beetle, has wreaked havoc on laurel species in the United States, adding three varieties to the newly assessed list as endangered. Bur oaks in the Midwest die from blight, showing up as lesions and wilting on the leaves of trees and plants when a fungus attacks them. Researchers believe that rising temperatures are encouraging fungal growth to unprecedented levels.
Climate change may be the cause of the death of some species that have resisted fungi and disease as normal parts of their ecosystems for countless years, before finally succumbing to disease en masse. The ecosystem imbalance could be due to larger storms, flooding, or temperature changes.
The most affected tree species include 29 endangered hawthorns and 17 oak species. These are high percentages for two of the most abundant trees in the United States – 84 hawthorns and 85 species of oaks exist in the country. Florida, Texas, and the southeastern states hold the highest concentration of tree species and endemic tree species. “These regions,” the study states, “along with California, also hold the highest concentration of threatened tree species in the contiguous United States – threatened hotspots – and as such are clear priorities for the conversation.”
The study suggests that the hope for trees lies in botanical gardens and arboretums. Such parameters can help conserve species and ensure that they will not be completely lost if they disappear from the wild. For example, oak seeds, commonly known as acorns, cannot be saved by conventional methods of seed banking – storing the seeds for future growth – the study notes. “The cultivation of living trees in botanical collections is a critically important conservation tool,” the garden proponents write in the study, “in the absence of a seed bank as an insurance policy against extinction”.
In the meantime, you might want to take a walk in the woods soon.