|
Post by marchesarosa on Jun 6, 2011 22:18:04 GMT 1
Forget deforestation: The world's woodland is getting denser and change could help combat climate changeBy DAILY MAIL REPORTER 6th June 2011 ...the density of forests and woodland across much of the world is actually increasing, according to a respected scientific study. The change, which is being dubbed the ‘Great Reversal’, could be crucial in reducing atmospheric carbon, which is linked to climate change. Mountain gorillas in a Rwandan forest. The density of woodland across much of the world is actually increasing, according to a scientific study In countries from Finland to Malaysia, the thickening has taken place so quickly that it has reversed the carbon losses caused by deforestation between 1990 and 2010. In Britain, forest density has increased by 10.8 per cent from 2000 to 2010 and by 6.6 per cent across the whole of Europe. Even South America and Africa, which have suffered deforestation because of logging and farming, have recorded increases in forest density of 0.8 per cent and 1.1 per cent respectively.... The research, [entitled "A National and International Analysis of Changing Forest Density"*] carried out by teams from the University of Helsinki and New York's Rockefeller University, shows that forests are thickening in 45 of 68 countries, which together account for 72 per cent of global forests. Traditionally, environmentalists have focused their concern solely on the dwindling extent of forested areas, but the authors believe evidence of denser forests could be crucial in reducing the world’s carbon footprint. Professor Pekka Kauppi of Helsinki University, a co-author of the study, said: ‘People worry about forest area, and that's quite correct. But if you want to know the carbon budget, it cannot be monitored observing only the changes in area. It is more important to observe this change in forest density.’ Aapo Rautiainen, lead author of the report, also based at Helsinki University, said: ‘The reversal occurred in Europe much earlier, then a little bit later in North America, and it has now spread to certain parts of Asia. So that is a positive sign.’... Every year, more than 10 million hectares of forest are planted worldwide, either on newly felled woodland or reclaimed land. * full research paper here www.plosone.org/article/info:doi/10.1371/journal.pone.0019577Read more: www.dailymail.co.uk/sciencetech/article-1394692/Forget-deforestation-The-worlds-woodland-getting-denser-change-help-combat-climate-change.html#ixzz1OX6uOxgs
|
|
|
Post by marchesarosa on Jun 6, 2011 22:35:59 GMT 1
K D Knoebel says:
If the woodlands are denser, then there is more transpiration, more heat moving upwards carried away by the extra water vapor. We’re familiar with the Urban Heat Island (UHI) effect driving up surface temperatures. Do thicker woodlands lead to an increased Forest Cool Area effect? We already see this in the Amazon rainforest, which generates its own thunderstorms providing cooling during the day. Will these denser woodlands worldwide significantly lower surface air temperatures on land?
What does Louise think?
|
|
|
Post by marchesarosa on Jun 6, 2011 22:45:05 GMT 1
And what has caused the increase in woodland density? The enhanced CO2 fertilization effect, perhaps, of slightly warmer temperature?
This could be one of those stabilizing "thermostatic" feedbacks, I suppose?
What does Louise think?
(You can't say I'm not attentive to her education.)
|
|
|
Post by marchesarosa on Jun 10, 2011 1:52:55 GMT 1
Why does STA think the forests are increasing in *density* if Louise can't come up with an answer?
Is the carbon sink that was reduced through previous deforestation now being augmented again? Why?
Very early in my reading about AGW I wondered about what I now realise is a really crucial question, namely, how much of the apparent recent growth of atmospheric CO2 is down to the reduction in photosynthetic CO2 removal due to deforestation?
A reduction in the removal of CO2 from the atmosphere via photosynthesis is a different source of variation from the increase in fossil fuel burning even though they are expressed by warmists as the same "anthropogenic" effect. This is sloppy. A REDUCTION in photosynthesis via deforestation albeit *anthropogenic* is not equivalent (except in net effect) to EXTRA PRODUCTION of CO2.
So, How much of the extra CO2 produced through burning fossil fuels will be recycled through this recently confirmed *extra* growth of forest?
Are we are seeing the *evolution* of the carbon cycle in action? More CO2 equals more plant growth equals more sequestration of CO2 and not just by tomatoes in commercial greenhouses.
Great! And what is even better, the forests don't CARE about the source of this extra plant food.
Will we hear STA and Louise expressing delight at these observations of enhanced forest growth? I think not.
|
|
|
Post by louise on Jun 19, 2011 8:59:22 GMT 1
Will we hear STA and Louise expressing delight at these observations of enhanced forest growth? I think not. Did you miss the second posting on this thread? I think it reduces the strength of your argument when you constantly claim others' views are different to what they have clearly already shown them to be. Or is it a deliberate policy so that those on the receiving end of this treatment spend so much time correcting your misrepresentation of their opinions that they spend less and less time explaining how you have misrepresented the science?
|
|
|
Post by marchesarosa on Jun 19, 2011 15:35:42 GMT 1
Just talk science instead of whining, louise, there's a good girl.
|
|
|
Post by marchesarosa on Oct 14, 2011 12:01:25 GMT 1
More experimental good news re CO2 fertilization and ozone resistance in boreal forests. From the University of Michigan U-M ecologist: Future forests may soak up more carbon dioxide than previously believed
An aerial view of the 38-acre experimental forest in Wisconsin where U-M researchers and their colleagues continuously exposed birch, aspen and maple trees to elevated levels of carbon dioxide and ozone gas from 1997 through 2008. Credit: David Karnosky, Michigan Technological University ANN ARBOR, Mich.—North American forests appear to have a greater capacity to soak up heat-trapping carbon dioxide gas than researchers had previously anticipated. As a result, they could help slow the pace of human-caused climate warming more than most scientists had thought, a U-M ecologist and his colleagues have concluded. The results of a 12-year study at an experimental forest in northeastern Wisconsin challenge several long-held assumptions about how future forests will respond to the rising levels of atmospheric carbon dioxide blamed for human-caused climate change, said University of Michigan microbial ecologist Donald Zak, lead author of a paper published online this week in Ecology Letters. “Some of the initial assumptions about ecosystem response are not correct and will have to be revised,” said Zak, a professor at the U-M School of Natural Resources and Environment and the Department of Ecology and Evolutionary Biology in the College of Literature, Science, and the Arts. To simulate atmospheric conditions expected in the latter half of this century, Zak and his colleagues continuously pumped extra carbon dioxide into the canopies of trembling aspen, paper birch and sugar maple trees at a 38-acre experimental forest in Rhinelander, Wis., from 1997 to 2008. Some of the trees were also bathed in elevated levels of ground-level ozone, the primary constituent in smog, to simulate the increasingly polluted air of the future. Both parts of the federally funded experiment—the carbon dioxide and the ozone treatments—produced unexpected results. In addition to trapping heat, carbon dioxide is known to have a fertilizing effect on trees and other plants, making them grow faster than they normally would. Climate researchers and ecosystem modelers assume that in coming decades, carbon dioxide’s fertilizing effect will temporarily boost the growth rate of northern temperate forests. Previous studies have concluded that this growth spurt would be short-lived, grinding to a halt when the trees can no longer extract the essential nutrient nitrogen from the soil. But in the Rhinelander study, the trees bathed in elevated carbon dioxide continued to grow at an accelerated rate throughout the 12-year experiment. In the final three years of the study, the CO2-soaked trees grew 26 percent more than those exposed to normal levels of carbon dioxide. It appears that the extra carbon dioxide allowed trees to grow more small roots and “forage” more successfully for nitrogen in the soil, Zak said. At the same time, the rate at which microorganisms released nitrogen back to the soil, as fallen leaves and branches decayed, increased. “The greater growth has been sustained by an acceleration, rather than a slowing down, of soil nitrogen cycling,” Zak said. “Under elevated carbon dioxide, the trees did a better job of getting nitrogen out of the soil, and there was more of it for plants to use.” Zak stressed that growth-enhancing effects of CO2 in forests will eventually “hit the wall” and come to a halt. The trees’ roots will eventually “fully exploit” the soil’s nitrogen resources. No one knows how long it will take to reach that limit, he said. The ozone portion of the 12-year experiment also held surprises. Ground-level ozone is known to damage plant tissues and interfere with photosynthesis. Conventional wisdom has held that in the future, increasing levels of ozone would constrain the degree to which rising levels of carbon dioxide would promote tree growth, canceling out some of a forest’s ability to buffer projected climate warming. In the first few years of the Rhinelander experiment, that’s exactly what was observed. Trees exposed to elevated levels of ozone did not grow as fast as other trees. But by the end of study, ozone had no effect at all on forest productivity. “What happened is that ozone-tolerant species and genotypes in our experiment more or less took up the slack left behind by those who were negatively affected, and that’s called compensatory growth,” Zak said. The same thing happened with growth under elevated carbon dioxide, under which some genotypes and species fared better than others. “The interesting take home point with this is that aspects of biological diversity—like genetic diversity and plant species compositions—are important components of an ecosystem’s response to climate change,” he said. “Biodiversity matters, in this regard.” Discussion here wattsupwiththat.com/2011/10/13/plant-trees-not-carbon-laws/#more-49225
|
|
|
Post by marchesarosa on Oct 14, 2011 12:12:04 GMT 1
Abstract of the above study in Ecology Letters entitled Forest productivity under elevated CO2 and O3: positive feedbacks to soil N cycling sustain decade-long net primary productivity enhancement by CO2 by Donald R. Zak, Kurt S. Pregitzer, Mark E. Kubiske and Andrew J. Burton
Abstract
The accumulation of anthropogenic CO2 in the Earth’s atmosphere, and hence the rate of climate warming, is sensitive to stimulation of plant growth by higher concentrations of atmospheric CO2.
Here, we synthesise data from a field experiment (!) in which three developing northern forest communities have been exposed to factorial combinations of elevated CO2 and O3.
Enhanced net primary productivity (NPP) (c. 26% increase) under elevated CO2 was sustained by greater root exploration of soil for growth-limiting N, as well as more rapid rates of litter decomposition and microbial N release during decay.
Despite initial declines in forest productivity under elevated O3, compensatory growth of O3-tolerant individuals resulted in equivalent NPP under ambient and elevated O3. After a decade, NPP has remained enhanced under elevated CO2 and has recovered under elevated O3 by mechanisms that remain un-calibrated or not considered in coupled climate–biogeochemical models simulating interactions between the global C cycle and climate warming.
-----
Note the first sentence of the abstract
The accumulation of anthropogenic CO2 in the Earth’s atmosphere... is sensitive to stimulation of plant growth
So, the world's ecology is a two way street. This is "negative feedback" in action, demonstrated experimentally.
|
|
|
Post by fascinating on Oct 14, 2011 18:06:53 GMT 1
|
|
|
Post by marchesarosa on Oct 14, 2011 21:01:44 GMT 1
It is also the case, fascinating, that the worldwide trend in the developing nations for large population movements from countryside to city (the same happened in the West in the 19th century) is causing abandoned smallholdings to revert to forest - so that is an additional cause of forest growth and of CO2 recycling in addition to increasing forest density thanks to the fertilizing effect of CO2.
|
|
|
Post by marchesarosa on Mar 26, 2012 17:26:38 GMT 1
March 22, 2012 from Dr Pat Michaels Tropical Forests Rejoice!www.worldclimatereport.com/index.php/2012/03/22/tropical-forests-rejoice/When was the last time you heard good news about our tropical forests? Well, that’s just too long. All we ever seem to hear about the tropical forests is that they are being destroyed, their destruction will exacerbate global warming, and on and on. You will even discover that some scientists think global warming destroyed the first tropical forests that evolved on our planet bringing rise to the dinosaurs! So it’s high time for some good news and World Climate Report is at your service! A recent article in Landscape Ecology caught our eye with the title “Has global environmental change caused monsoon rainforests to expand in the Australian monsoon tropics?” Is someone really suggesting that global environmental change is causing rainforests to expand? We knew we would really like this one! The article was produced by a team of three scientists with various agencies in Australia, and the work was supported financially by Australian Research Council and Kakadu National Park. Bowman et al. note that changes have been occurring in the northern Australian home of the rainforest resulting in an expansion of the forest. The expansion is well-documented and a subject of great interest. In trying to explain the expansion, Bowman et al. report “Average yearly rainfall has shown an increasing trend in northern Australia over the last century. Between 1910 and 1995 total annual rainfall in the Northern Territory rose by 15–18%, with the increasing trend considerably steeper for the second half of the 20th century. There was also an almost 20% increase in the number of rain days between 1910 and 1995”. They suggest “the observed expansion of rainforest boundaries throughout northern Australia may be driven by a wetting trend.” While it is tempting to speculate that the buildup of carbon dioxide (CO2) may have been indirectly beneficial to the rainforest by causing the increase in rainfall, we wonder whether the elevated CO2 may have had more of a direct impact on the rainforest? Bowman et al. help us out here: “tmospheric CO2 concentration has been rapidly increasing for the last two centuries, with the increase dramatically accelerating in the 20th century. Numerous controlled experiments have frequently shown an increase in tree growth rates under elevated CO2 due to the CO2 ‘fertilisation effect’, including species of trees from Australian monsoon rainforest. Elevated atmospheric CO2 has the potential to shift forest-savanna boundaries as it advantages trees and shrubs (C3 photosynthetic pathway) over (predominantly C4) tropical grasses with the consequence of changing the strongly contrasting fuel types between rainforest and savanna (grass vs. leaf litter). Thus, fire regimes may also change because woody plants can suppress grassy fuels, reversing the well known positive feedback between fire and grass cover. Elevated CO2 may also indirectly increase growth by improving plant water status. Thus, rising atmospheric CO2 may be the primary driver of the widespread woody vegetation expansion.”Bowman et al. go on to explain: “There is emerging evidence of profound changes to the structure and function of tropical rainforests, both in northern Australia and elsewhere. The expansion of northern Australian monsoon rainforests parallels reports of expansion of tropical rainforest on the east coast of Australia and increased tree growth and biomass accumulation in tropical rainforests elsewhere in the world”.Can you believe this talk about rainforests expanding throughout the world? They conclude: “We consider it most likely that the expansion of rainforest patches is related to global climate change via increased rainfall and/or the CO2 ‘fertiliser effect’.”Wow! But not all tropical trees grow in rainforests where precipitation is plentiful; there are tropical dry forests where the trees are forced to cope with periods of low rainfall and even extended periods of drought. Such a forest exists in southern Mexico where large amounts of rainfall occur during the summer but only a few inches of rain occur from November to May. One of the common trees there is Mimosa acantholoba which is a deciduous tree that forms distinctive annual growth rings. Most of these trees are indeed in southern Mexico, but it is found in forests extending south into Ecuado www.worldclimatereport.com/wp-images/mimosa_fig1.jpg [/img] Figure 1. Geographical range of Mimosa acantholoba. An article appeared recently in the journal Trees with a title suggesting that these tropical dry forest plants have improved their water use efficiency and their responses to drought – sounded interesting to us. We definitely became interested when we saw “CO2” appearing six times in the abstract, including the first and last sentences. The three authors are from Mexico and Austria; they acknowledge financial support for their work from agencies in both Mexico and Austria. Brienen et al. begin noting that “Understanding the responses of tropical trees to increasing [CO2] and climate change is important as tropical forests play an important role in carbon and hydrological cycles.” They define several key terms including water use efficiency which is the ratio of photosynthesis to transpiration; the ratio is basically the amount of water used per carbon gain by the trees. As fate would have it, a carbon isotope signal is preserved in each annual growth ring, and that signal is strongly related to the water use efficiency of each year. The key finding of the work is that water use efficiency has shown “an increase of nearly 40% over the past four decades”. The explanation for this increase is that rising levels of atmospheric CO2 are allowing for a reduction in the stomatal conductance. At higher levels of CO2, the plants relax a bit, the CO2 is easier to extract from the atmosphere, the pores in the leaves through which transpiration takes place are smaller in diameter, and far less water escapes from the plants. The trees grow at the same rate with far less water! They did observe increasing wet season temperatures and an increase in cloud cover, but neither seemed to explain the increase in water use efficiency. The facts seem inescapable—extra atmospheric CO2 is our gift to the trees growing throughout tropical regions! References Brienen, R.J.W., W. Wanek, and P. Hietz. 2011. Stable carbon isotopes in tree rings indicate improved water use efficiency and drought responses of a tropical dry forest tree species. Trees, 25, 103-113. Bowman, D.M.J.S., B.P. Murphy, and D.S. Banfai. 2010. Has global environmental change caused monsoon rainforests to expand in the Australian monsoon tropics? Landscape Ecology, 25, 1247–1260.
|
|
|
Post by StuartG on Mar 26, 2012 18:10:22 GMT 1
|
|
|
Post by marchesarosa on Mar 26, 2012 18:13:43 GMT 1
The Mauna Loa graph that is trotted out by alarmists is VERY small in scale, stu, and there are, in fact, big annual as well as seasonal changes in the rate of change of CO2 ppm. Look where the scale starts, too, at 310! Re. our green and pleasant land. Even our cities are very green with all those gardens, parks, golf courses, playing fields and grass verges sprouting wildly. Just google your postcode and choose satellite view, then zoom out. Here's Birmingham
|
|
|
Post by marchesarosa on Mar 23, 2013 11:30:16 GMT 1
Unwelcome discovery for the environment industry
|
|
|
Post by nickrr on Mar 24, 2013 10:23:08 GMT 1
Why?
|
|