Fall has fallen.
Or maybe the thermometer is broken.
But there are brown oak leaves everywhere.
Snowmaggeddon was a good day to stay off the roads, so I took a kayak on our pond. Saw buzzards, heard some ducks and probably a beaver. Lots of plants looking very strange.
Movie: Ice floe (21M), Starting out
Movie: Wind and ice (16M), Beaver houses
Movie: Icy beaver dam (20M), Between dams
I did eventually break the ice for the dogs, but then they said the water was too cold. Lots of odd stuff during Snowmageddon.Continue reading
Come on down this morning to PineVale Elementary and learn about growing things in our south Georgia subtropical climate! It’s rainy this morning and afternoon, and breezy all day; a great day for growing, and South Georgia Growing Local will be inside a new venue with cooking facilities!
Web: page with schedule.
If you’re still not convinced, watch Gretchen explain it on the radio with Continue reading
Higher average temperatures 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.
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 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 the year-long drought we just experienced in south Georgia.
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. 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.