A study of Front Range forests burned by wildfires between 1996 and 2003 shows they are not regenerating as well as expected and large portions may become grasslands or shrub lands in coming years.
The paper, published in the journal Ecosphere by former doctoral student Monica Rother and geography professor Thomas Veblen, examined the sites of six low-elevation ponderosa pine forest fires which collectively burned 162,000 acres along the Colorado Front Range between 1996 and 2003. Eight to 15 years after the fires, the researchers expected – based on historical patterns – to see young trees cropping up across the landscape. Instead, 59 percent of plots surveyed showed no conifer seedlings at all and 83 percent showed a very low density of seedlings. Although it is possible that more seedlings will appear in upcoming years, future warming and associated drought may hinder significant further recovery.
“It is alarming, but we were not surprised by the results given what you see when you hike through these areas,” said Rother, who earned her doctorate from CU Boulder in 2015 and works as a fire ecologist at Tall Timbers Research Station in Tallahassee, Florida.
By Mike Gaworecki
A study published in the journal Science Advances this month found that, between 2000 and 2013, the global area of intact forest landscape declined by 7.2 percent, a reduction of 919,000 square kilometers, or a little over 227 million acres.
Intact forest landscapes (IFLs) are areas of natural land cover that are large and undisturbed enough to retain all their native plant and animal communities — defined at 500 square kilometers. For an IFL to be considered “lost,” its vegetation needs to be degraded to an extent at which it can no longer support its original levels of biodiversity.
Among the study’s other findings, one in particular was quite surprising: Certification of logging concessions, which aims to ensure sustainable forest management practices, had a “negligible” impact on slowing the fragmentation of IFLs in the Congo Basin, home to the world’s second-largest rainforest as well as high levels of biodiversity, including more than 600 tree species and 10,000 animal species.
Ecologist Suzanne Simard shares how she discovered that trees use underground fungi networks to communicate and share resources, uprooting the idea that nature constantly competes for survival.
About Suzanne Simard:
Suzanne Simard is a professor of forest ecology at the University of British Columbia. Her work demonstrated that these complex, symbiotic networks in our forests mimic our own neural and social networks. She has thirty years of experience studying the forests of Canada.
A new paper published Jan. 13 in Science reveals that the relationship between soil fungi and tree seedlings is more complicated than previously known. The paper was co-written by Ylva Lekberg, an assistant professor of soil community ecology at the University of Montana.
Lekberg and her collaborators studied 55 species and 550 populations of North American trees. Scientists have long known that plants and soil biota can regulate one another, but the new findings highlight the complexity of the feedback loop.
“Fungi differ in their ability to protect tree seedlings from pathogens, and this has implications for seedling recruitment and therefore forest community patterns,” Lekberg said.
Most plant roots are colonized by mycorrhizal fungi, but tree species associate with different fungal groups. The researchers showed that ectomycorrhizal fungi that form a thick sheet around root tips are better able to protect trees from pathogens than arbuscular mycorrhizal fungi.
Thus, while ectomycorrhizal tree seedlings actually prefer growing next to parent trees, arbuscular mycorrhizal tree seedlings can only establish outside the control of parents’ enemies. This can have consequences for how temperate forests are structured and their overall diversity.
By Chelsea Harvey
The world’s natural places are disappearing at a galloping clip, says a new study, released Friday in the journal Science Advances. It suggests that more than 7 percent of Earth’s natural, intact forest landscapes have been lost since 2000 — and these ecosystems may be in danger of disappearing entirely from at least 19 countries in the next 60 years.
These landscapes represent some of “the last portions of the Earth that are not significantly affected by human influence,” said Lars Laestadius, a forest expert, consultant on natural resources policy and co-author of the new study. “As we lose these, we lose something that is bigger than ourselves.”
The study defines “intact forest landscapes” as areas greater than 500 square kilometers, or 193 square miles, containing a mosaic of forests and other associated ecosystems, such as plains or wetlands. The key is that these areas must be undisturbed by human activities — they can’t be fragmented by roads or deforestation or other industrial operations. Once that happens, the ecosystems cease to be considered “intact.” And as the new study indicates, this is happening more and more frequently around the world.
By TODD McLEISH/ecoRI News contributor
While climate change gets most of the media attention these days for the dramatic effects it is predicted to have — and, in some cases, is already having — on coastal communities, it has yet to have serious effects on eastern forests.
Eventually, say local experts, climate change will likely cause a shift in the composition of tree species in the region, due in part to southern species moving into the area and the arrival of new pests and pathogens, which may reduce the abundance of currently common species. The predicted drier weather conditions will also likely play a role in altering woodlands.
But Rhode Island’s forests are already facing what some say is an even greater threat than climate change: an overabundance of deer. That’s the warning from foresters, biologists and ecologists from throughout the Northeast, who say that even without climate change, Rhode Island’s forests are in trouble unless the state’s deer herd can be reduced and managed more effectively.
According to forester Marc Tremblay, outreach coordinator for the Rhode Island Forest Conservators Organization, deer have had a dramatic impact on forest understory by feeding on young trees, shrubs and plants.
Rudy Boonstra has been doing field research in Canada’s north for more than 40 years.
Working mostly out of the Arctic Institute’s Kluane Lake Research Station in Yukon, the U of T Scarborough Biology Professor has become intimately familiar with Canada’s vast and unique boreal forest ecosystem.But it was during a trip to Finland in the mid-1990s to help a colleague with field research that he began to think long and hard about why the boreal forest there differed so dramatically from its Canadian cousin. This difference was crystallized by follow-up trips to Norway.”Superficially they look the same. Both are dominated by coniferous trees with similar low density deciduous trees like aspen. But that’s where the similarities end,” he says.The real differences are most obvious on the ground, notes Boonstra. In Canada, the ground is dominated by tall shrubs like willow and birch but in the Northwestern European forests found in Norway, Finland and Sweden the ground is dominated by dwarf shrubs like bilberry.
Major forest die-offs due to drought, heat and beetle infestations or deforestation could have consequences far beyond the local landscape.
Wiping out an entire forest can have significant effects on global climate patterns and alter vegetation on the other side of the world, according to a study led by the University of Washington and published Nov. 16 in PLOS ONE.
“When trees die in one place, it can be good or bad for plants elsewhere, because it causes changes in one place that can ricochet to shift climate in another place,” said lead author Elizabeth Garcia, a UW postdoctoral researcher in atmospheric sciences. “The atmosphere provides the connection.”
Read more at: http://phys.org/news/2016-11-large-forest-die-offs-effects-ricochet.html#jCp
In an interview with Yale Environment 360, Wohlleben, author of The Hidden Life of Trees, discusses how trees are sophisticated organisms that live in families, support their sick neighbors, and have the capacity to make decisions and fight off predators. He has been criticized for anthropomorphizing trees, but Wohlleben, 52, maintains that to succeed in preserving our forests in a rapidly warming world, we must start to look at trees in an entirely different light.
Do severe wildfires make forests in the western United States more susceptible to future bark beetle outbreaks?
The answer, in a study published Monday (Nov. 7, 2016) in the Proceedings of the National Academy of Sciences, is no. By leading to variability in the density and size of trees that grow during recovery, large fires reduce the future vulnerability of forests to bark beetle attacks and broad-scale outbreaks.
“Fire creates a very heterogeneous landscape,” says study co-author Kenneth Raffa, professor of entomology at the University of Wisconsin-Madison. “Beetles can only reproduce in an individual tree once, so they take advantage of this patch of trees and that patch of trees as they become available, but when the number and size of trees vary a lot, it’s hard for a large outbreak to develop.”
Read more at: http://phys.org/news/2016-11-variable-tree-growth-forests-future.html#jCp