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| -Short Attention Span Theater- |
| 'Myth' that forests improve water flows - study |
| 2005-07-29 |
| Many countries are wasting millions of dollars planting trees because of myths that forests always help improve water flows and offset erosion, a British-led study said on Friday. Many trees, especially fast-growing species like pines and eucalyptus favored by the paper industry, suck more water from the ground than other crops, it said. The water transpires from the leaves and so the trees dry out the land. "Trees on the whole are not a good thing in dry areas if you want to manage water resources," said John Palmer, manager of the tropical Forestry Research Programme run by the British Department for International Development. "When it comes to wet areas, trees may be beneficial or no worse than pasture and crops," he told Reuters of the study of plantings in India, Costa Rica, South Africa and Tanzania in a four-year project led by British and Dutch researchers. Forests have many other benefits -- ranging from habitats for birds, insects or animals to human sources of building materials and firewood. But the report said it was a myth that forests acted as sponges that soak up rain, releasing it throughout the year and ensuring more regular flows in rivers. Instead, trees' deep roots often aggravate water shortages in dry seasons. It also said it was wrong to believe forests attracted more clouds and rainfall or that tree roots helped slow erosion more those of short plants. It said the myths had been anchored in cultural history since at least the 17th century. "We don't want to be seen as against forests or trees," said Ian Calder, a lead researcher who is director of the Center for Land Use and Water Resources Research at England's University of Newcastle. "But there is a need to be careful when you plant forests in the belief you are promoting water resources," he said. "We need policies based more on scientific evidence. Hundreds of millions of dollars are being spent, if not billions." The report said Panama was seeking hundreds of millions of dollars from the World Bank to back a project to plant trees on the apparently mistaken belief that it would attract more rainfall to help feed the Panama Canal. Other countries from China to Mexico also had costly afforestation schemes at least partly based on misconceptions about water. ooops. is the funding stream going to cough dry up?? gosh, and not long after China bought the canal. pity, that .... In the Indian states of Himachal Pradesh and Madhya Pradesh, the study said conversion of agricultural land to forests had damaged water supplies, cutting flows by 16-26 percent. Availability of fresh water is a constant problem. The World Commission on Water has estimated that demand for water will increase by about 50 percent in the next 30 years and that around four billion people, or about half of the world's population in 2025, will have problems with supplies. The study said trees often showed the "clothes line" effect. Just as wet clothes dry quicker if hung out rather than left lying on the ground, the enormous combined surface of trees' leaves combined with their deep roots meant they transpired more water into the air than other crops, it said. |
| Posted by:too true |
| #16 Then why is it always wetter, and cooler, under the trees, and in the forested soil, than in clearcut areas or grasslands of the Pacific Northwest? If not A, then not B, and since A's and B's are C's, then all C's suck. Hence, if we want water, we have to kill all the trees. Great stuff. |
| Posted by: Asedwich 2005-07-29 23:46 |
| #15 Screw the trees. Chop them down and bring down the price of lumber for my woodworking hobby. 200 bf of mahogany. Is that too much to ask? ;) |
| Posted by: Laurence of the Rats 2005-07-29 23:02 |
| #14 "Many trees, especially fast-growing species like pines and eucalyptus favored by the paper industry, suck more water from the ground than other crops, it said. The water transpires from the leaves and so the trees dry out the land." "Water transpires from the leaves" - no, into the atmosphere you say? The point is that forest do offset erosion - root systems hold topsoil in place. While they use water, isn't water also a byproduct of their metabolism? Granted you don't want to use leafy trees because of the support issue. Pine Trees should be fine though. I am not a tree surgeon, but this is poor analysis for a high school student. |
| Posted by: flash91 2005-07-29 19:11 |
| #13 The TTRREEEESSSSS!!!!!! Must have more TTRREEEESSSSS!!!!!! I can feel my oxygen slipping away [cough] [cough] |
| Posted by: Almost Anonymous2520 2005-07-29 16:15 |
| #12 I could have told them this for free. Not cutting the brush in our water catchment areas over 20 years has cut runoff into Perth's dams by almost half and as a consequence I have to endure deceipful advertisements blaming 'our drying climate', which is total crap. |
| Posted by: phil_b 2005-07-29 15:59 |
| #11 SPoD, You think they're bad now, wait till there's a fire. |
| Posted by: Mrs. Davis 2005-07-29 15:58 |
| #10 what Moose said.... and no little tiny robots neede. I have 18 80 yr old plus oaks.... I figure one's gonna get me. |
| Posted by: Shipman 2005-07-29 15:36 |
| #9 While I appreciate the fire hazards associated with eucalyptus trees, for pure suckage, nothing compares with a female ginko tree. In college, we called them "dogshit trees", because their "fruit", which invariably dropped on the sidewalk and got tracked into the buildings, smelled like dogshit. |
| Posted by: Robert Crawford 2005-07-29 15:26 |
| #8 You hate them? Not as much as I do. This new house has a 40 foot tall one in the front yard next to the driveway. It will be removed soon. They are filthy and do noting but drop leaves bark and branches. Eucalyptus trees suck. |
| Posted by: Sock Puppet 0’ Doom 2005-07-29 15:19 |
| #7 The problem are "tree monocultures". A health forest with a variety of trees that always grew thereis a wonderful thing. Eucalypts suck (sorry except in Australia) |
| Posted by: True German Ally 2005-07-29 15:03 |
| #6 I like trees too. I actually own about 12 acres of mixed fir, pine, madrona and oak I like them so much. |
| Posted by: Sock Puppet 0’ Doom 2005-07-29 14:10 |
| #5 Mmmmmmmmmm...trees! Is okay to eat now, yes? |
| Posted by: Kim Jong Starving 2005-07-29 14:07 |
| #4 I recommend ripping out all the trees and replacing the topsoil with a 50% vermiculite mixture. |
| Posted by: ed 2005-07-29 13:57 |
| #3 This is a situation of an obscene number of variables being ignored to justify blanket statements on either side of the argument. First of all, trees are adapted to a particular environment. If they cannot exist in that environment without damaging it, they won't naturally live there. Second thing, these boffins aren't talking about situations of ecological equilibrium. They want *more* fresh water out of the same ecosystem. It has to come at the expense of something, so what will that something be? Third, do you want more surface water or more ground water? The ways you go about getting them are very different. Fourth, the biggest producers of fresh water beyond what naturally occur are first through mining, agricultural, and industrial conservation and second through artificial production, like desalinization and induced rainfall (not cloud seeding, but enhancing coastal ocean evaporation to send moisture inland). |
| Posted by: Anonymoose 2005-07-29 13:51 |
| #2 BUT I LIKE TREES. We just need lots of huge desalination plants to feed them. Why? Because I LIKE TREES. The first place to cover with trees should be Saudi Arabia. Why? Because Saudis like deserts and I like trees. |
| Posted by: 3dc 2005-07-29 13:17 |
| #1 Sounds like another case of junk eco science. Things sound logical so they must be true. Research? We don't need no steenkin' research! |
| Posted by: Xbalanke 2005-07-29 12:57 |