Climate Change
Stranglers of the tropics -- and beyond
But kudzu may be no match for the lianas of the tropics, scientists have found. Data from sites in eight studies show that lianas are overgrowing trees in every instance.
If the trend continues, these "stranglers-of-the-tropics" may suffocate equatorial forest ecosystems.
Tropical forests contain more than half of Earth's terrestrial species, and contribute more than a third of global terrestrial carbon and a third of terrestrial net primary productivity, says ecologist Stefan Schnitzer of the University of Wisconsin-Milwaukee.
Schnitzer is co-author with Frans Bongers of Wageningen University in the Netherlands of a paper on lianas in the current issue of the journal Ecology Letters.
"Any alteration of tropical forests has important ramifications for species diversity, productivity--and ultimately the global carbon cycle," says Schnitzer.
Tropical forests are indeed experiencing large-scale structural changes, the most obvious of which may be the increase in lianas, according to Robert Sanford, program director in the National Science Foundation's (NSF) Division ofEnvironmental Biology, which funded the research.
Lianas are found in most tropical lowland forests. The woody vines are "non-self-supporting structural parasites that use the architecture of trees to ascend to the forest canopy," says Schnitzer.
Climate Change Affects Subterranean Ecosystems
A change in the quantity of carbon dioxide in the atmosphere can also effect the biodiversity beneath our feet as plant roots then release different types and quantities of substances. Plants that grow well if more carbon dioxide is present in the atmosphere can, for example, suppress fungi better. This in turn has consequences for the other subterranean flora and fauna. Some soil organisms benefit from more carbon dioxide in the air, whereas others do not. The effects of climate change are not observed in soil outside of the root zone.
The Effects of Climate Change
Get Adobe Flash Player hereWorld failing on every environmental issue: an op-ed for Earth Day
The biodiversity crisis, the climate crisis, the deforestation crisis: we are living in an age when environmental issues have moved from regional problems to global ones. A generation or two before ours and one might speak of saving the beauty of Northern California; conserving a single species—say the white rhino—from extinction; or preserving an ecological region like the Amazon. That was a different age.
Today we speak of preserving world biodiversity, of saving the 'lungs of the planet', of mitigating global climate change. No longer are humans over-reaching in just one region, but we are overreaching the whole planet, stretching ecological systems to a breaking point. While we are aware of the issues that threaten the well-being of life on this planet, including our own, how are we progressing on solutions?
Although not a scientist, I have a relatively unique perspective, having spent the last three years as an environmental journalist, writing on a wide-variety of issues from species-on-the-brink to indigenous rights to climate change politics. As much as I have written, I have read exponentially more. Sometimes a working day as an environmental reporter can feel like watching a slow succumbing, an endless cataloguing toward the end of the world as we know it. I don't mean that the Earth will keel over and die—hardly. But the Earth may be very different in just a hundred years than the place we inherited: species are vanishing and ecosystems are being ravaged; humans are impacting everything from the deepest ocean to the most inaccessible mountain glaciers, from lion populations in East Africa to stringweed in the Galapagos, from the oceans' chemical make-up to the boreal forest's ability to sequester carbon.
Global Warming
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