Skip to Content.
Sympa Menu

permaculture - [permaculture] (FWD) Rising Clouds Leave Forests High and Dry - article in NewScientist --- http://www.newscientist.com/news/news.jsp?id=ns99993521

permaculture@lists.ibiblio.org

Subject: permaculture

List archive

Chronological Thread  
  • From: "Lawrence F. London, Jr." <lfl@intrex.net>
  • To: permaculture@lists.ibiblio.org
  • Subject: [permaculture] (FWD) Rising Clouds Leave Forests High and Dry - article in NewScientist --- http://www.newscientist.com/news/news.jsp?id=ns99993521
  • Date: Wed, 16 Apr 2003 23:42:29 -0700



New Scientist.com
http://www.newscientist.com/news/news.jsp?id=ns99993521
Rising Clouds Leave Forests High and Dry

"The base of clouds that form over the north-eastern states of the US have been getting ever higher over the past 30 years. It is a change that could severely disrupt forests in the Appalachian Mountains. Rising cloud ceilings have been spotted before in other parts of the world. In 1999, scientists found that clouds in the Monteverde cloud forests of Costa Rica were not forming as far down the mountains as they once did. </P> This effect was initially attributed to rising sea temperatures in the Caribbean, caused by global warming,
but in 2001 Robert Lawton of the University of Alabama in Huntsville reported that the main driving force behind the change was warmer, drier air moving up from the lowlands, which had been cleared of trees. The rising cloud ceiling has seriously damaged the cloud forest ecology, causing an alarming decline in populations of toads and frogs. Now Andrew Richardson of Yale University in New Haven, Connecticut, and his colleagues have uncovered a similar trend in the temperate Appalachian ecosystem. The study was prompted by an intriguing observation by team member Thomas Siccama in the 1960s, when he regularly travelled through the mountains. "He noticed that in the fall, a lot of the time the clouds were at a level that coincided with the change from deciduous to coniferous forests," says Richardson. Concerned about the effect of a rising cloud ceiling on this forest boundary, the researchers examined data from 24 airports located along the south-west to north-east axis of the Appalachians. Airports routinely measure the cloud ceiling because it is important to pilots. Richardson's team found that in the 18 most northerly airports, the cloud ceiling has climbed an average of six metres per year since 1973. "Over 30 years, that's 180 metres, which is about six tree heights," says Richardson. "It is pretty stunning."



--
L.F.London
lfl@intrex.net
http://market-farming.com
http://www.ibiblio.org/ecolandtech




  • [permaculture] (FWD) Rising Clouds Leave Forests High and Dry - article in NewScientist --- http://www.newscientist.com/news/news.jsp?id=ns99993521, Lawrence F. London, Jr., 04/16/2003

Archive powered by MHonArc 2.6.24.

Top of Page