Large swaths of forest now seen as more vulnerable to future droughts
California’s extended drought may take a long-term toll on the state’s forests, scientists reported last month after studying severe water loss from tree canopies since 2011.
The study, published in the Proceedings of the National Academy of Sciences, says that up to 58 million large trees in California showed signs of being drought stressed, with persistently low rainfall, high temperatures and outbreaks of the destructive bark beetle combining to increase forest mortality risk. Continue reading “California drought has damaged millions of trees”→
An extensive tree-ring study in the Northeast suggests a widespread and steady decline in the health of sugar maples, one of most economically and ecologically important trees in the eastern United States and Canada.
The decline started showing up in the 1970s a decline in the growth rate of of sugar maple trees, but the reasons are still unclear, according to the State University of New York researchers who recently published their findings in the open-access journal “Ecosphere.” Continue reading “Environment: More maple tree woes”→
Latest study suggests giant trees can persist along central coast, at least for a while
Redwood trees in California face an uncertain climate future, but some of the latest research suggests they’ll be able to persist in the coastal mountains south of San Francisco. And suitable climate conditions for the giant trees may expand northward in to Oregon, according to a new study published in Global Change Biology.
Forests may grow faster as atmospheric CO2 increases, but that doesn’t mean they’ll absorb more of the heat-trapping gas. Instead, a shortage of nitrogen means plants won’t be able to fix as much carbon as projected by some climate models.
“Forests take up carbon from the atmosphere, but in order for the plants to fix the carbon, it requires a certain amount of nitrogen,” said researchers Prasanth who took a close look at the chemistry of secondary forests that are regrowing after deforestation, wood harvest and fires.
Slowing deforestation requires integration of forest planning with other sectors like water and agriculture
Management of the world’s forests must be integrated with other land use planning efforts in order to address the root causes of deforestation, and forests should be recognized as “more than trees,” experts concluded at last week’s World Forestry Congress in Durban, South Africa.
With good management, forests have great potential to help end hunger, increasing wealth and improving livelihoods in developing countries, as well as in slowing climate change, the delegates from around the world said in the session-ending Durban Declaration.
Some aspens and cottonwoods have been hit by leaf blight
FRISCO — Colorado’s wet spring and summer dampened the fire danger and kept the state nearly drought-free, but there may be a down side. Some of the state’s aspens and cottonwoods may not be at their most brilliant this autumn, after leaf-spot diseases afflicted some stands in northern Colorado and along the Front Range.
The Colorado State Forest Service says tree experts have been seeing an unusually high degree of leaf blight spreading as far south as Aspen, the Collegiate Peaks and Colorado Springs.
At least two fungal diseases are to blame for the leaves now showing significant spotting or dark splotches. Marssonina leaf spot is caused by the Marssonina fungus and is the most common leaf disease of aspen and cottonwoods in Colorado. The disease can be identified by the presence of dark brown spots or flecks on leaves, which can then fuse into large, black splotches on severely infected leaves. Continue reading “Wet spring and summer may dampen fall colors”→