Galapagos plants, invasive or not?


This National Geographic video is called Galapagos Volcanoes.

From ANI news agency:

Invasive plant species predate humans’ arrival on Galapagos Islands

London, July 18 : Fossil remains have proved that certain plants found on the Galapagos Islands, which were thought to be invasive species brought there by humans, have actually grown there for at least a millennium.

According to a report in Nature News, this means that the presence of the invasive species predate humans’ arrival.

Sorting the native plant life from the trespassers is essential to conservation efforts.

Since the Bishop of Panama landed there in 1535, people have, intentionally or accidentally, brought goats, blackberries, fire ants and a host of other species to the archipelago, altering an ecosystem valuable to both evolutionary biologists and nature lovers.

The islands’ 825 introduced species outnumber the 552 plants that are native to the islands. There are also 62 plant species classified as “doubtful natives”, and scientists aren’t sure if they were present before humans got there or not.

“Whenever you’re dealing with island studies, one of the most important factors is where things came from, how they got there and when,” said Conley McMullen, a botanist at James Madison University in Harrisonburg, Virginia, who has worked in the Galapagos.

By examining fossil remains in sediment samples from Santa Cruz island, Emily Coffey, a graduate student at the University of Oxford, UK, has now confirmed that at least four of those questionable natives, including a species of hibiscus, existed on the island 1,000 years ago.

To collect their samples, Coffey and her collaborators trekked to the misty highlands of Santa Cruz. They drilled into the bogs, where sediment has settled for millennia.

Coffey is collaborating with researchers examining fossil pollen, and more species are likely to be reclassified as natives in the future.

A fossil Argeratum [sic; Ageratum] conyzoides seed confirms that the plant was in the Galapagos Islands before humans arrived.

Scientists have often assessed the origins of a particular plant species by studying its distribution: those spread across an island are likely to be native, while those clustered around human habitation are presumed invasive.

“But there’s only one way to be sure, and that’s to look in the paleoecological record,” said Keith Bennett, a paleoecologist at Queen’s University Belfast in Northern Ireland.

See also here.

Graham Watkins: Runaway tourism threatens the future of the Galapagos Islands: here.

Invasive plants: here.

7 thoughts on “Galapagos plants, invasive or not?

  1. Tue Jul 22, 12:15 AM ET

    QUITO, Ecuador – Lonesome George, the long-living Galapagos Islands giant tortoise thought to be the last of his kind, might soon be a father.

    The Galapagos National Park announced Monday that a female tortoise that has accompanied George since 1993 laid three intact eggs that are being cared for in an artificial incubator. The female belongs to the closest existing phenotype to that of George.

    The eggs have appeared “after 36 years of multiple efforts … when we thought it was impossible for the tortoise known as Lonesome George to reproduce,” the park said in a statement.

    Found in 1972 on Pinta island, George is estimated to be in his 70s — middle age for a giant tortoise.

    It will take another 120 days to learn if the eggs are viable.

    Like

  2. Galapagos under botanical alert for medfly invasion

    Tue Aug 19, 9:11 PM ET

    QUITO (AFP) – Ecuador’s Galapagos Islands, a UNESCO World Heritage Site, were under a botanical alert Tuesday after a destructive Mediterranean fruit fly (medfly) was detected on the archipelago, the Agricultural Health Service (SESA) said.

    It said medflies (Ceratitis capitata Wiedemann), one of the most invasive insects that can wreak havoc to a wide range of fruit crops, were found on San Cristobal and Santa Cruz islands.

    SESA said the medfly “poses a high risk to the preservation of native plants … and several crops in the farming sectors of the islands.”

    Measures to contain the infestation include restricting the transportation of plants from the mainland and between the islands and stricter controls at airports and port facilities, SESA said.

    Located 1,000 kilometers (620 miles) west of Ecuador’s coast, the archipelago of 13 main islands and 17 islets is a UNESCO World Heritage Site.

    In 2007, UNESCO declared the archipelago’s environment in danger due to the increase of tourism and the introduction of invasive species.

    Like

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