The unique challenges of conserving forest giants
The redwood and sequoia trees in California, the baobab trees in Madagascar, and the rose gum Eucalyptus trees in northeastern Australia are only a few of the spectacular large, old trees still growing today. Protecting these trees, some hundreds or thousands of years old, requires thinking long-term about concerns such as their unique habitat needs and the impacts of climate change, researchers write in a Forum published April 22, Earth Day, in Trends in Ecology & Evolution.
|A coastal redwood in northern California [Credit: Rhett Butler]|
"There's a lot to discuss on the issue," says David Lindenmayer, a conservation ecologist at the Australian National University. "Climate change will mean that, in some places, big trees will not reach the same sizes they used to." The effects of climate change, including prolonged droughts, more invasive species, new pathogens, and habitat fragmentation, compound the simple physical challenges that large trees already face in pulling water from their roots to their leaves and withstanding windstorms.
|This figure shows the height, girth, and locations of some of the world's largest tree species |
[Credit: Lindenmayer and Laurance/Trends in Ecology & Evolution 2016]
These large, old trees dominate the surrounding plant communities, affect water and nutrient distribution, and provide food and shelter for wildlife. "They're really the breadbaskets, the supermarkets, of the forest," says Laurance. "This is a very environmentally and ecologically important group of organisms, and they need special care and handling."
|A rainforest tree in tropical Australia festooned with lianas, epiphytic orchids and ferns, |
and mosses. Many big trees provide habitats for a zoo of other plants and animals
[Credit: William Laurance]
"We have to ensure that we're thinking long-term, to match the way these trees have existed for hundreds or even thousands of years," says Laurance. "It's going to be a real challenge to maintain some places in the world that still have something like a wild nature—that still have natural wildlife, seed dispersers, pollinators, large predators, and the magnificent cathedral-like trees that we all really care about."
Source: Cell Press [April 22, 2016]