Tag Archives: research

Higher climate temperatures mean more and faster tree deaths

Higher average temperatures acres of pine trees dead due to pine beetles mean much more frequent droughts and trees dying faster in droughts because of the temperatures. That plus pine beetles, according to research from 2009. Forestry is Georgia’s second largest industry in terms of employment and wages and salaries, more than $28 billion a year according to the Georgia Forestry Commission, plus an estimated $36 billion a year in ecosystem services such as water filtration, carbon storage, wildlife habitat, and aesthetics, not to mention hunting and fishing. Climate change matters to Georgia’s forests and to Georgia.

The paper appeared 13 April 2009 in the Proceedings of the National Academy of the Sciences, Temperature sensitivity of drought-induced tree mortality portends increased regional die-off under global-change-type drought, by Henry D. Adams, Maite Guardiola-Claramonte, Greg A. Barron-Gafford, Juan Camilo Villegas, David D. Breshears, Chris B. Zou, Peter A. Troch, and Travis E. Huxman, 106(17) 7063-7066, doi: 10.1073/pnas.0901438106.

Fig. 1. Water relations progression and death dates.

All drought trees in the warmer treatment died before any of the drought trees in the ambient treatment (on average 18.0 vs. 25.1 weeks, P <0.01; Fig. 1A).

They say warmer trees dying faster in drought wasn’t due to a difference in amount of water. Instead, they infer the warmer trees couldn’t breathe.

Combined, our results provide experimental evidence that piñon pines attempted to avoid drought-induced mortality by regulating stomata and foregoing further photosynthesis but subsequently succumbed to drought due to carbon starvation, not sudden hydraulic failure. Importantly, we isolate the effect of temperature from other climate variables and biotic agents Fig. 3. Drought frequency and die-off projections. and show that the effect of warmer temperature in conjunction with drought can be substantial.

Our results imply that future warmer temperatures will not only increase background rates of tree mortality (13, 16), but also result in more frequent widespread vegetation die-off events (3, 35) through an exacerbation of metabolic stress associated with drought. With warmer temperatures, droughts of shorter duration—which occur more frequently—would be sufficient to cause widespread die-off.

How much more frequently? They calculated an estimate for that, too: five times more frequently. Of course, that’s for the specific kinds of forests they were studying, and the exact number may vary, but the general trend is clear: higher temperatures mean more frequent droughts, like drought in south Georgia the year-long drought we just experienced in south Georgia.

pine beetle tube

This projection is conservative because it is based on the historical drought record and therefore does not include changes in drought frequency, which is predicted to increase concurrently with warming (2, 37—39). In addition, populations of tree pests, such as bark beetles, which are often the proximal cause of mortality in this species and others, are also expected to increase with future warming (7, 9, 38).

Bark beetles, such as the ones that bored into this 19 inch slash pine and spread from there to twenty others I had to cut down to prevent further spread of the pine beetles. What happens when pine beetles spread is what you see in the first picture in this post: acres and acres of dead red pine trees. slash pine killed by pine beetles Monoculture slash pine plantations may show this effect most clearly, but look around here, and you’ll see red dead loblolly and longleaf pines, too.

The article is saying that if the beetles don’t get the trees weakened by droughts that will be much more frequent, the trees will die more quickly of suffocation, because the temperature is higher. Higher temperatures is something that should concern every Georgian in our state where forestry is the second largest industry and our forests protect our wildlife and the air that we breathe and the water that we drink.

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Organic farming as productive as pesticiding (proven yet again)

Rodale Institute has been running a side-by-side comparison of organic and chemical agriculture since 1981. They report:
After an initial decline in yields during the first few years of transition, the organic system soon rebounded to match or surpass the conventional system. Over time, FST became a comparison between the long term potential of the two systems.
Year after year, Rodale found:
Organic yields match conventional yields.

As Tom Philpott reported for Mother Jones 17 November 2011, Yet Again, Organic Ag Proves Just as Productive as Chemical Ag,

And now comes evidence from the very heart of Big Ag: rural Iowa, where Iowa State University’s Leopold Center for Sustainable Agriculture runs the Long-Term Agroecological Research Experiment (LTAR), which began in 1998, which has just released its latest results.

At the LTAR fields in Adair County, the (LTAR) runs four fields: one managed with the Midwest-standard two-year corn-soy rotation featuring the full range of agrochemicals; and the other ones organically managed with three different crop-rotation systems. The chart below records the yield averages of all the systems, comparing them to the average yields achieved by actual conventional growers in Adair County:

Norman Borlaug, instigator of the “green revolution” of no-till and pesticides, when asked in 2000 whether organic agriculture could feed the world, said: Continue reading

Organic yields higher than pesticided, all around the world

To feed the world, we need to get rid of Monsanto’s pesticided patented seeds and get on with diversified sustainable organic agriculture.

A friend commented about Organic farming better for bottom line:

Devil’s advocacy: yields from organic agriculture are lower than from artificially fertilised + pesticide’d crops; therefore, the practice tends to increase food prices; therefore, organic food means starvation for people who would otherwise eat. Discuss!
Nope, that’s simply not true. Organic farming yields more, in addition to being more profitable, healthier, and tastier.

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Two Mexican states ban GM corn

Many if not most pesticides are sprayed on crops genetically modified to resist them. Ban GM crops and reduce spraying. Two states in Mexico prove it can be done. Mexico, the country where corn was originally domesticated could lead the way back to healthy agriculture.

Aleira Lara reported in Health Impact News Daily reported 5 March 2011 that Two Mexican states ban GM corn:

The Mexican States of Tlaxcala and Michoacán each passed legislation banning the planting of genetically modified corn to protect natural plants from further contamination of transgenes. Together, both states produce about a third of all of Mexico’s corn. Below this story is a detailed timeline of genetic contamination and legislation in Mexico.
The timeline is a long saga including intimidation of scientists attempting to research the problem. The Mexican federal government caved in to big agro, but two Mexican states are fighting back anyway.

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The case against agrochemicals

Some people didn’t like the source of a recent post about the toxic effects of agrochemicals and GM plants on the environment, plants, animals, and people. There are plenty of other sources, including:

How big agro causes the problem

Evidence of the ill effects

There are ways forward

What you can do

Fixing a perfect storm of bad planning and design

Asked about typical modern shopping corridors, Texas A&M Assistant Professor of Landscape Architecture and Urban Planning Eric Dumbaugh replied:
“from a traffic safety perspective, the modern commercial arterial is a perfect storm of bad planning and design. These roads are designed to support high operating speeds, making it difficult for drivers to stop quickly to avoid a crash, and the presence of commercial and retail uses on these roads means that drivers will routinely need to stop quickly in order to avoid crashing into pedestrians, bicyclists, and especially vehicles turning in and out of driveways.”
The 2006 article, Safe Urban Form: Revisiting the Relationship Between Community Design and Traffic Safety, by Eric Dumbaugh and Robert Rae, notes: Continue reading

Trees make streets safer

Beta New Urban Network reported 1 September 2006 that Research: trees make streets safer, not deadlier:
Proposals for planting rows of trees along the roads — a traditional technique for shaping pleasing public spaces — are often opposed by transportation engineers, who contend that a wide travel corridor, free of obstacles, is needed to protect the lives of errant motorists.

Increasingly, however, the engineers’ beliefs about safety are being subjected to empirical study and are being found incorrect. Eric Dumbaugh, an assistant professor of transportation at Texas A&M, threw down the gauntlet with a long, carefully argued article, ”Safe Streets, Livable Streets,” in the Summer 2005 issue of the Journal of the American Planning Association. A follow-up article by Dumbaugh, in the 2006 edition of Transportation Research Record, will present further evidence that safe urban roadsides are not what the traffic-engineering establishment thinks they are.

Though engineers generally assert that wide clear areas safeguard motorists who run off the roads, Dumbaugh looked at accident records and found that, on the contrary, wide-open corridors encourage motorists to speed, bringing on more crashes. By contrast, tree-lined roadways cause motorists to slow down and drive more carefully, Dumbaugh says.

Dumbaugh examined crash statistics and found that tree-lined streets experience fewer accidents than do “forgiving roadsides” — those that have been kept free of large, inflexible objects. He points to “a growing body of evidence suggesting that the inclusion of trees and other streetscape features in the roadside environment may actually reduce crashes and injuries on urban roadways.”

The study asks a key question: Continue reading