Andean ‘Sky Islands’ and Alpine Sunflowers at Risk of Disappearing Forever

Páramo with Espeletia, a species of sunflower that grows in the alpine regions of the Andes in South America. (Andrés Cortés, Santiago Madriñán and coauthors)

(CN) — In 1831, an obscure English naturalist named Charles Darwin participated in a five-year voyage that took him to the Galápagos Islands, an isolated archipelago of volcanic islands 500 miles west of Ecuador. What he found there changed science forever, leading to his theory of evolution that redefined humanity’s understanding of natural adaption.

Now, scientists in Colombia are using Darwin’s work on evolution to understand another isolated ecosystem threatened by climate change.

When overwhelmed by heat, humans and animals can escape to the mountains for cooler temperatures. But habitats, even alpine ones, are not so lucky, making them among the most vulnerable ecosystems to the effects of human-caused climate change, researchers conclude in a new study published in Frontiers in Ecology and Evolution.

By focusing on biodiversity hotspots called páramos, researchers Dr. Andrés Cortés of the Colombian Corporation for Agricultural Research and Dr. Santiago Madriñán at the Universidad de los Andes in Colombia discovered how these fragile ecosystems are dealing with rising global temperatures.

Also known as “sky islands,” páramos are alpine tundra habitats that exist in the narrow places above the treeline and below the permanent snowline in the northern Andes of South America and in southern Central America. The species living in these areas “have adapted to extreme variations in temperature, water availability and sunlight exposure” over millions of years.

Despite such hearty adaptions, these habitats and the species within them “will shrink substantially in the next 30 years without conservation efforts,” hurting both plant and animal biodiversity as well as human populations dependent on these ecosystems, researchers found.

“Páramos are one of the fastest evolving biodiversity hotspots on Earth and they are one of the most threatened,” said Cortés and Madriñán, who is an expert on páramos. “Páramos are also the main water supplier of wetland ecosystems and densely populated areas, hence, disregarding the future of the páramos may jeopardize overall food and water safety in the northern Andes.”

Currently, páramos throughout South America support more than 3,000 plant species, including relatives of the sunflower in the genus Espeletia, recognized by its unbranched trunk topped with a rosette of leaves. But predicting the climate responses of a “typically slow-growing, long-lived plant” has proven difficult.

While Darwin relied on observation, researchers used the latest computer modeling to predict what this iconic species would look like in 2050, hoping to find whether these specialized species can adapt quickly enough to survive global warming. By factoring variables such as nature reserves, surrounding forests, population density, agriculture and mining, Cortés and Madriñán “confirmed the limited opportunities for Espeletia species to migrate or adapt.”

Researchers hope their findings highlight the importance of protecting these “sky islands” through more sustainable land-use practices and the development of ecotourism, which can fund local economies while promoting the preservation of critical ecosystems.

“In the most pessimistic scenario, if Espeletia and páramos were lost forever, science would lose an underexplored laboratory to study evolution happening at incredible rates — it would be just as if the Galápagos Islands disappeared,” the team said.

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