CARNIVOROUS PLANTS AT RISK OF EXTINCTION

from Groundswell | April 2021

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A quarter of the world’s carnivorous plants at risk of extinction

Royal Botanic Gardens Victoria calls for conservation action after leading international research with Curtin University.

Newly published international research led by Australian institutions (Curtin University, Royal Botanic Gardens Victoria) has found approximately a quarter of carnivorous plant species across the world may be at risk of extinction due to global climate change, illegal poaching, and the clearing of land for agriculture, mining and development.

Royal Botanic Gardens Victoria Manager Biodiversity Services and research co-author Dr Alastair Robinson has stressed the need for immediate, concrete actions to save carnivorous plants species from extinction.

“Conservation initiatives must be established as a priority to prevent these species being lost in the coming years, particularly to safeguard species endemic to highly-cleared regions like Western Australia, Brazil, Southeast Asia and the United States, which are home to many of the most threatened carnivorous plant species,” Dr Robinson said.

Carnivorous plants are predatory plants which obtain some or most of their nutrients through specialised adaptations that allow them to attract, capture and kill their prey - mainly flies and other small insects but occasionally even birds and small mammals. Well-known species of carnivorous plants include the Venus’ fly trap and pitcher plants.

Restoration ecologist Dr Adam Cross, from the School of Molecular and Life Sciences at Curtin University, said the loss of carnivorous plants would not only be devastating due to their captivating qualities, but could potentially have detrimental effects across ecosystems.

“Carnivorous plants are an iconic group of plants, and they are often involved in complex biological relationships with animals – sometimes providing habitats for animals, or even relying upon animals to digest the prey they catch for them,” Dr Cross said.

“Our research has found around 25 per cent of the world’s carnivorous plants are at increasing risk of extinction. Australia is currently sixth in the world for harbouring the most Critically Endangered carnivorous plant species, behind Brazil, Indonesia, Philippines, Cuba and Thailand.”

Carnivorous plants usually occur in extremely fragile habitats, often in areas experiencing direct conflict with human activities.

During the team’s research, each of the approximately 860 known carnivorous plant species was assessed for its exposure to threats such as residential and commercial development; agriculture and aquaculture activities; energy production and mining; transport development, such as land clearing for roads or trains; human exploitation, such as illegal collection; pollution; geological events; climate change; and severe weather.

It was found that, globally, the greatest threats to carnivorous plants are the result of agricultural practices and natural systems modifications, as well as continental scale environmental shifts caused by climate change.

“In Western Australia, which harbours more carnivorous plant species than any other place on Earth, the biggest threat remains the clearing of habitat to meet human needs, resulting hydrological changes, and of course the warming, drying climate trend that affects much of Australia,” Dr Cross said.

Research co-author Dr Andreas Fleischmann, from Botanische Staatssammlung Munich and Ludwig-Maximilians-University Munich, Germany, also noted that illegal poaching of carnivorous plants was a large problem.

“Noting their unique and fascinating features, some species of carnivorous plants are illegally collected from their natural habitats and sold to collectors. Poached plants of some species sell for hundreds of dollars,” Dr Fleischmann said.

“Urgent global action is required to reduce rates of habitat loss and land use change, particularly in already highly-cleared regions that are home to many threatened carnivorous plant species, including habitats in Western Australia, Brazil, Southeast Asia and the United States of America.”

The research was conducted by Curtin University, Royal Botanic Gardens Victoria, Botanische Staatssammlung Munich and Ludwig-Maximilians-University Munich in Germany, and the Federal University of São João del Rei in Brazil.