January 15, 2013
Rare Haleakalā Silverswords May Suffer Severe Consequences From Global Warming
United States Geological Survey
While the iconic HaleakalÄ silversword plant made a strong recovery from early 20th-century threats, it has now entered a period of substantial climate-related decline. New research published this week warns that global warming may have severe consequences for the silversword in its native habitat.
"The silversword example foreshadows trouble for diversity in other biological hotspots," said Dr. Paul Krushelnycky, a biologist with the University of HawaiÊ»i at MÄnoa, College of Tropical Agriculture and Human Resources, and principal investigator for the project, "and it also illustrates how even well-protected and relatively abundant species may succumb to climate-induced stresses."
"The silversword is an amazing story of selective biological adaptation of this distant cousin of the daisy to the high winds and sometimes freezing temperatures on the high slopes and thin soils of HaleakalÄ volcano," said USGS Director Marcia McNutt. "Despite the successful efforts of the National Park Service to protect this very special plant from local disturbance from humans and introduced species, we now fear that these actions alone may be insufficient to secure this plant's future. No part of our planet is immune from the impacts of climate change."
The HaleakalÄ silversword (Argyroxyphium sandwicense macrocephalum) grows only on a single volcano summit in HawaiÊ»i, yet it is viewed by 1 million visitors annually at HaleakalÄ National Park. Although the decline and extinction of other rare species with small ranges (and the accompanying loss of biodiversity) can easily go unobserved and unappreciated, the silversword's high profile makes it a good example with which to educate the public about global climate change.
Krushelnycky co-authored the paper along with Lloyd Loope, scientist emeritus with the U.S. Geological Survey, and others at the University of Hawai'i at MÄnoa, and University of Arizona. They explain that although climate change is predicted to place mountaintop and other narrowly endemic species such as the silversword at severe risk of extinction, the ecological processes involved in such extinctions are still poorly understood, and they are hoping to increase this understanding.
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