Hayes, Deborah C.; Kerns, Becky K.; Patel-Weynand, Toral; Finch, Deborah M. . 2021. Introduction. In: Poland, Therese M.; Patel-Weynand, Toral; Finch, Deborah M.; Ford Miniat, Chelcy; Hayes, Deborah C.; Lopez, Vanessa M., eds. Invasive Species in Forests and Rangelands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Heidelberg, Germany: Springer International Publishing: 1-4. https://doi.org/10.1007/978-3-030-45367-1_1.
Invasive species are a historical, long-term, and continually growing threat to the ecology, economy, and infrastructure of the United States. Widely recognized as one of the most serious threats to the health, sustainability, and productivity of native ecosystems, invasive species issues have commonly been viewed as problems specific to Federal, State, and private landowners. However, it is increasingly apparent that the impacts from these species are all encompassing, affecting ecosystem processes in addition to the economics of land management, public and private infrastructure, the energy sector, international trade, cultural practices, and many other sectors in the United States.
By Helen Briggs
Tree planting is a brilliant solution to tackle climate change and protect biodiversity, but the wrong tree in the wrong place can do more harm than good, say experts at the Royal Botanic Gardens, Kew.
The rules include protecting existing forests first and involving locals.
Forests are essential to life on Earth.
They provide a home to three-quarters of the world’s plants and animals, soak up carbon dioxide, and provide food, fuels and medicines.
But they’re fast disappearing; an area about the size of Denmark of pristine tropical forest is lost every year.
“Planting the right trees in the right place must be a top priority for all nations as we face a crucial decade for ensuring the future of our planet,” said Dr Paul Smith, a researcher on the study and secretary general of conservation charity, Botanic Gardens Conservation International, in Kew…
The 10 golden rules are:
Protect existing forests first
Keeping forests in their original state is always preferable; undamaged old forests soak up carbon better and are more resilient to fire, storm and droughts. “Whenever there’s a choice, we stress that halting deforestation and protecting remaining forests must be a priority,” said Prof Alexandre Antonelli, director of science at RGB Kew.
Put local people at the heart of tree-planting projects
Studies show that getting local communities on board is key to the success of tree-planting projects. It is often local people who have most to gain from looking after the forest in the future.
Maximise biodiversity recovery to meet multiple goals
Reforestation should be about several goals, including guarding against climate change, improving conservation and providing economic and cultural benefits.
Select the right area for reforestation
Plant trees in areas that were historically forested but have become degraded, rather than using other natural habitats such as grasslands or wetlands.
Use natural forest regrowth wherever possible
Letting trees grow back naturally can be cheaper and more efficient than planting trees.
Select the right tree species that can maximise biodiversity
Where tree planting is needed, picking the right trees is crucial. Scientists advise a mixture of tree species naturally found in the local area, including some rare species and trees of economic importance, but avoiding trees that might become invasive.
Make sure the trees are resilient to adapt to a changing climate
Use tree seeds that are suitable for the local climate and how that might change in the future.
Plan how to source seeds or trees, working with local people.
Learn by doing
Combine scientific knowledge with local knowledge. Ideally, small-scale trials should take place before planting large numbers of trees.
Make it pay
The sustainability of tree re-planting rests on a source of income for all stakeholders, including the poorest.
A wide diversity of remarkable animals calls longleaf pine flatwoods and sandhills habitats home. Here, discover species special to naturalist Dirk Stevenson. He has spent much of his life in the Coastal Plain of the southeastern United States wading swamps and exploring pine landscapes in his field studies of imperiled and declining amphibians, reptiles and insects.
Here, Dirk authors accounts of the deep-digging gopher tortoise, a denizen of longleaf sandhills and a keystone species; and the gopher frog and the eastern indigo snake, which have developed intimate associations within the burrows of the tortoise. Discover the secretive frosted flatwoods salamander, an amphibian of mesic longleaf pine savannas, and take a closer look at the odd Say’s spiketail dragonfly. The nymphs of this predatory insect live in mucky springs while the adults hunt for wasps and bees in longleaf pine – turkey oak sandhills. And last is the industrious and comical southeastern pocket gopher, whose numerous mounds can be seen from space.
By Madeline K. Sofia, Maia Stern, and Becky HarlanNalini Nadkarni was one of the first people to study the canopy — the part of trees just above the forest floor to the top branches. Her discoveries have helped shape our understanding of forests.
Then in 2018, more than a decade after Nadkarni started TreeTop Barbie, she got an unbelievable phone call. National Geographic had partnered with Mattel to make a series of Barbies focused on exploration and science. And they wanted Nadkarni to be an advisor.
By Beth Gavrilles
The longleaf pine forests of the southeastern U.S. depend on frequent fire to maintain their structure and the diversity of plants and animals they support. New research from the University of Georgia has found that fire may be playing another, unexpected role: releasing excessive nitrogen that appears to have accumulated as a legacy of prior land use.
“It was not what we were expecting,” said senior author Nina Wurzburger, an associate professor in the Odum School of Ecology. “We first were wondering whether there was enough nitrogen fixation to balance nitrogen losses from fire, and now our hypothesis is that fire might be necessary to remove excess nitrogen from these ecosystems. We basically turned the question on its head.”
“We came to the conclusion that fire might be getting rid of excess nitrogen,” said Wurzburger. “Most of the longleaf pine that exists today has been planted, and those areas have legacy effects of agriculture or grazing or fire exclusion. Our research is suggesting that all those things, and nitrogen deposition too, have put too much nitrogen in the ecosystem. So maybe we should think about fire as a management tool to remove nitrogen that accumulated historically, and to help return these ecosystems to their natural nitrogen-poor state.”
Understanding the interacting role of fire and historical disturbances in longleaf ecosystems is important for several reasons, including carbon sequestration and the conservation of biodiversity: longleaf savannas can contain more than 40 species of plants in a square meter, and harbor a number of rare species of plants and animals, including the federally endangered red cockaded woodpecker.
By Amanda Kolson Hurley
In the 1960s, America fell in love with a new tree: the Bradford pear. Cultivated from Asian stock by scientists at the U.S. Department of Agriculture, Bradford pears display clouds of pretty blossoms in the spring and garnet leaves in the fall, and are hardy enough to grow just about anywhere. Thinking they had found the perfect ornamental tree, homeowners and public-works departments planted Bradford pears up and down the nation’s streets for decades, especially in the East, South, and Midwest.
Then the relationship soured. Bradfords are apt to split and break during storms, and they have a short life span, only 15 or 20 years. Although they are technically sterile, the trees cross-pollinate with other cultivars of the Callery pear species (Pyrus calleryana), producing fruit that splats all over sidewalks. And despite their delicate appearance, the blossoms emit a foul odor that’s been compared to rotting fish (among other things).Cities and states are trying to remove Bradford pears‚ but the “weed trees” have already intruded deep into some forests, a biologist warns.
Once admired for its hardiness, the Bradford pear is now considered an invasive species, which grows even in poor conditions, proliferates fast—thanks to birds that dine on its fruit and spread the seeds—and crowds out native species.
Cities are trying to put an end to the tree’s mischief. Pittsburgh’s Urban Forest Master Plan prohibits planting Bradford pears. This March, Fayetteville, Arkansas, started offering a bounty to anyone who cuts one down. (They can get a free native tree to replace it.)
The bad news is it’s not only in developed areas where the trees threaten to choke biodiversity. Theresa Culley, head of the Department of Biological Sciences at the University of Cincinnati, warns that wild Bradfords and other kinds of Callery pears are making inroads into Eastern forests.
by Elyse Catalina, University of Maine
A mouse scampers through the forest, stopping suddenly at the sight of a tree seed on the ground. A potential meal. And a dilemma.
The mouse must decide if it should eat the seed immediately. Or hide it in a safe place for consumption when food is scarce. Or pass it up in hopes of something better.
Many factors determine what the mouse will do next, including how abundant the seeds are and if the rodent is a fan of that variety.
Personality is another element that might play a role in what the mouse decides, according to a University of Maine researcher.
How animals react to an environment that is transforming due to human behavior and climate change is at the core of research being conducted by Alessio Mortelliti, an assistant professor of wildlife habitat ecology at UMaine.
One study Mortelliti and his students are pursuing focuses on how individual personalities of small mammals affect their response to global change.
Like humans, animals have a personality, according to Mortelliti.
“Anyone that has a pet knows they have a personality,” he says. “It’s the same for squirrels, mice and voles.”
Within a species, individuals can be aggressive or shy, more or less social, Mortelliti explains.
“We’re looking at how this individuality—their own way of being—affects the way they respond to changes in their environment made by humans,” he says of wild small mammals.
When a mouse finds a seed, the decision it makes affects more than the mouse. If the seed is eaten immediately, any chance of a plant sprouting from that seed is gone. If the mouse decides to move and store the seed, a plant has a chance to grow.
Mortelliti believes that by modifying the environment, humans may be favoring certain personality types over others and, in turn, altering the course of evolution and the shape of the forest.
By Steven S. Perakis and Julie C. Pett-Ridge
Tree species that form symbioses with nitrogen-fixing bacteria can naturally fertilize forests by converting atmospheric nitrogen gas into plant-available forms. However, other mineral nutrients that plants require for growth are largely locked in bedrock, and are released only slowly into soil. We used strontium isotopes to trace nutrient sources for six common tree species in a temperate rainforest, including one species from a globally widespread genus known for high rates of biological nitrogen fixation. We found that trees capable of fixing atmospheric nitrogen gas were also best able to directly access mineral nutrients from bedrock. This gives nitrogen-fixing trees the unique ability to provide the full suite of essential nutrients required to fuel growth and carbon uptake in forest ecosystems.
By Amber Dance
Forests are resilient, but researchers wonder if climate change will outpace their adaptations.
Trees bowed to 45-degree angles and flying leaves crisscrossed the sky as Hurricane Florence ravaged North Carolina’s coast and inland regions in mid-September 2018. The storm, which peaked as a Category 4 hurricane before making landfall near Wilmington as a Category 1, deluged parts of the state with nearly three feet of rain. It stripped the leaves off black walnuts, crape myrtles, and their entwining wisterias, especially on the north and northeast sides of the trees, which bore the full brunt of the 100-plus-mile-per-hour wind gusts. An estimated 1.25 million acres of timber, valued at nearly $70 million, suffered varying degrees of damage.
Whoppers like Florence are a reality that North Carolina—not to mention the rest of the Eastern seaboard and the Caribbean—may have to get used to in the near future. Historically, a given location might only see such destructive hurricanes every few decades. But with global temperatures on the rise, the risk that a fledgling storm system will grow to “major” status, defined as category 3 and above, is likely to climb. Warming oceans mean more water vapor in the air, and that vapor is what fuels the storms. “One of the signals that we expect from climate change is that the strongest hurricanes will get stronger,” says Gary Lackmann, an atmospheric scientist at North Carolina State University in Raleigh.
What does that mean for trees? The scene in the woods after Florence was one of seeming devastation. In every direction, trees, branches, and brush littered the ground. Yet just a few weeks after the storm, the stripped trees sprouted fresh leaves and flowers. It may have been autumn, but the trees already had leaf and flower buds in waiting for the upcoming spring, explains Jim Slye, assistant regional forester with the state forest service in Goldsboro. Re-leafing after storms helps keep the trees’ circulation going, and flowering allows trees to drop seeds in case they end up succumbing to storm damage. The trees won’t necessarily die, though; tree ring studies make it clear that many survived past storms.
By Dan Zukowski
A large chunk of the country’s forests were harmed in 2015 by wildlife—77 percent due to deer. Bringing back an apex predator could help staunch the bleeding.
From the peak of Mt. Rausu, a clear view of the Shiretoko Peninsula opens from the Okhotsk Sea on the west to the Pacific Ocean on the east. Below, a dense green boreal forest of conifers, maples, and birch hides hundreds of brown bears and 590,000 sika deer. Japanese wolves once roamed this wilderness but their primeval howls fell silent here, and throughout Japan, more than a hundred years ago.
Narumi Nambu is working to bring wolves back to Japan.
“An apex predator is essential for sustainability of an ecosystem, and in Japan it was a wolf,” she writes in an email. Nambu volunteers for the Japan Wolf Association. Her work earned her the “Who Speaks for Wolf” award at the International Wolf Symposium in Minnesota, where she recently spoke.
She explained that, without the presence of natural predators like wolves, two-thirds of Japan’s 30 national parks are showing signs of deer-induced injury.
Shiretoko National Park, a UNESCO World Heritage Site, has a deer problem, as does much of Japan. According to the most recent annual report by the Japan Forestry Agency, 8,000 hectares of the country’s forest were harmed in 2015 by wildlife—77 percent of it due to deer. All told, deer were responsible for $53 million in damage.