There were a number of stories over the last two weeks about the unhappy effects of tropical deforestation. Unsurprisingly, a new study in the journal Nature found that cutting down trees to grow crops or to support cattle grazing results in dramatic reductions in rainfall. The website futurity.org—why isn't it called futility.org?— summed up the results in Will loss of Amazon forests reduce rain?
The loss could have potentially devastating consequences for people living in and near the Amazon and Congo forests, researchers say.
A new study published in Nature shows that for the majority of the Earth’s tropical land surface, air passing over extensive forests produces at least twice as much rain as air passing over little vegetation...
“We were surprised to find that this effect occurs strongly across more than half of the tropics. We found that the Amazon and Congo forests maintain rainfall over the periphery of the forest basins—regions where large numbers of people live and rely on rainfall for their livelihoods,” says Dominick Spracklen from the School of Earth and Environment at the University of Leeds.
“Our study implies that deforestation of the Amazon and Congo forests could have catastrophic consequences for the people living thousands of kilometers away in surrounding countries.”
Scientists have debated whether vegetation increases rainfall for hundreds of years. It is well established that plants put moisture back in the air through their leaves by a process known as evapotranspiration, but the quantity and geographical reach of rainfall generated by large forests has—until now—been unclear.
If you want some details, read up on evapotranspiration, the rainforest's Water Pump. Another study found that cutting down trees hastened the demise of the Mayans. Here's an excerpt from Forest razing by ancient Maya worsened droughts, says study.
For six centuries, the ancient Maya flourished, with more than a hundred city-states scattered across what is now southern Mexico and northern Central America. Then, in A.D. 695, the collapse of several cities in present day Guatemala marked the start of the Classic Maya's slow decline. Prolonged drought is thought to have played a role, but a study published this week in the journal Geophysical Research Letters adds a new twist: The Maya may have made the droughts worse by clearing away forests for cities and crops, making a naturally drying climate drier.
"We're not saying deforestation explains the entire drought, but it does explain a substantial portion of the overall drying that is thought to have occurred," said the study's lead author Benjamin Cook, a climate modeler at Columbia University's Lamont-Doherty Earth Observatory and the NASA Goddard Institute for Space Studies.
However, my favorite "cutting down trees" story was Trees Removed to Make Way for Space Shuttle Endeavour
All told, 400 hundred trees will be felled to make room for the shuttle, which has a 78-foot wingspan.
The center has promised to plant twice as many trees along the parade route after the shuttle’s two-day procession in mid-October, but that’s not enough to appease some local residents who say replacing mature trees with saplings is not an even trade. They argue that young trees will decrease property values — which is not unfounded, as tree-heavy areas are often wealthier neighborhoods — as well as not provide ample shade.
Younger, actively growing trees actually produce more oxygen than more mature trees, scientists say. But mature trees absorb much more carbon dioxide than saplings, making them an important participant in the fight against air pollution.
Engineers charged with mapping a route from LAX airport to the California Science Center originally considered airlifting the shuttle to its final destination. They were forced to give up on that idea because the shuttle weighs too much for a helicopter to handle, and dismantling the shuttle was ruled out of the question because it would damage the heat sensors affixed to the body of the craft.
Dismantling the shuttle would damage the heat sensors, but Endeavour is being mothballed in its new permanent home at the California Science Center.
Well, I can't top that! That's definitely our DOTE stupid story of the week, if not the entire year. On that brain-dead note, I will conclude this post.