Archives par mot-clé : Forest

Phantom Forests: Why Ambitious Tree Planting Projects Are Failing

by Fred Pearce, Oct 6, 2022 in YaleEnvironment360


High-profile initiatives to plant millions of trees are being touted by governments around the world as major contributions to fighting climate change. But scientists say many of these projects are ill-conceived and poorly managed and often fail to grow any forests at all.

It was perhaps the most spectacular failed tree planting project ever. Certainly the fastest. On March 8, 2012, teams of village volunteers in Camarines Sur province on the Filipino island of Luzon sunk over a million mangrove seedlings into coastal mud in just an hour of frenzied activity. The governor declared it a resounding success for his continuing efforts to green the province. At a hasty ceremony on dry land, an official adjudicator from Guinness World Records declared that nobody had ever planted so many trees in such a short time and handed the governor a certificate proclaiming the world record. Plenty of headlines followed.

But look today at the coastline where most of the trees were planted. There is no sign of the mangroves that, after a decade of growth, should be close to maturity. An on-the-ground study published in 2020 by British mangrove restoration researcher Dominic Wodehouse, then of Bangor University in Wales, found that fewer than 2 percent of them had survived. The other 98 percent had died or were washed away.

“I walked, boated, and swam through this entire site. The survivors only managed to cling on because they were sheltered behind a sandbank at the mouth of a river. Everything else disappeared,” one mangrove rehabilitation expert wrote in a letter to the Guinness inspectors this year, which he shared with Yale Environment 360on the condition of anonymity. The outcome was “entirely predictable,” he wrote. The muddy planting sites were washed by storms and waves and were otherwise “ecologically unsuited to mangrove establishment, because they are too waterlogged and there is no oxygen for them to breathe.”

Fossil leaves show high atmospheric carbon spurred ancient ‘global greening’ Charles Rotter / 3 days ago August 20, 2020

by EARTH INSTITUTE AT COLUMBIA UNIVERSITY, August 20, 2020 in WUWT


Scientists studying leaves from a 23-million-year-old forest have for the first time linked high levels of atmospheric carbon dioxide with increased plant growth, and the hot climate off the time. The finding adds to the understanding of how rising CO2 heats the earth, and how the dynamics of plant life could shift within decades, when CO2 levels may closely mirror those of the distant past.

Scientists retrieved the leaves from a unique onetime New Zealand lake bed that holds the remains of plants, algae, spiders, beetle, flies, fungi and other living things from a warm period known as the early Miocene. Scientists have long postulated that CO2 was high then, and some plants could harvest it more efficiently for photosynthesis. This is the first study to show that those things actually happened in tandem. The findings were published this week in the journal Climate of the Past.

“The amazing thing is that these leaves are basically mummified, so we have their original chemical compositions, and can see all their fine features under a microscope,” said lead author Tammo Reichgelt, an adjunct scientist at Columbia University’s Lamont-Doherty Earth Observatory and assistant professor of geosciences at the University of Connecticut. “Evidence has been building that CO2 was high then, but there have been paradoxes.”

 

IMAGE: A 23-MILLION-YEAR-OLD LEAF PRESERVED IN A ONETIME NEW ZEALAND LAKE BED, KEY TO PAST ATMOSPHERIC CONDITIONS. ONE CAN SEE VEINS, GLANDS ALONG THE TEETH, AND HOLES GNAWED BY INSECTS, WITH… view more CREDIT: JENNIFER BANNISTER/UNIVERSITY OF OTAGO