#tree migration

Excerpt from this story from the Sierra Club:

While the epic migrations of salmon, humpback whales, and wildebeests are world-renowned, animals aren't the only species on the move. Trees, it turns out, can migrate too. Of course, an individual tree can't pick up its roots and travel south for the winter, but trees do move—in their own way. 

Katie Nigro, a postdoctoral fellow with the Oak Ridge Institute for Science and Education (ORISE), explained that trees expand their range in response to environmental changes. If the climate gets warmer, a tree species may no longer be able to grow in the southernmost parts of its range, but, through wind or animal-dispersed seeds, it can expand farther north over time into areas that were previously too cold.

However, that process might be too slow for human-caused climate change. To keep pace, projections suggest, seeds would need to be dispersed at least 10 times faster than their historic migration rates of about 20 to 40 kilometers (12 to 25 miles) per century. Given the quickening rate of environmental changes and the slow rate of tree growth, researchers believe trees will struggle to adapt.

To help, scientists are taking seeds from habitats they expect will no longer be suitable to a species and planting them in climates that may favor their growth in the coming century. For example, an ecosystem in Colorado that is currently ideal for a Douglas fir could become too warm to sustain it in a few decades, but that fir might thrive somewhere farther north. 

Assisted migration is about planning for the future, explained Mike Battaglia, a research forester at the US Department of Agriculture’s Rocky Mountain Research Station, which also runs ORISE. His work in silviculture—the growth and development of forests—involves figuring out which species to plant in reforestation efforts. 

“Trees live a long time and take a long time to get to reproductive age,” said Battaglia. Because they have such long lifespans, trees have less opportunity than faster-growing plants and animals to evolve and naturally select for the current climate. So, considering the climate of the future is important when choosing what to plant today. 

The research station where Battaglia works sits along the base of the Rocky Mountain foothills, a semi-arid climate home to Ponderosa pine and Colorado blue spruce. While not very far away from one another, a Ponderosa near his station will be adapted to different conditions than another tree of the same species growing only 20 miles away up in the mountains. Foresters like Battaglia and Nigro use climate models to foresee the likely future conditions of a location. The models predict factors such as temperature, humidity, and frequency of natural disasters. They then match the location with the seeds of trees—sometimes even within the same species—currently adapted to those climatic conditions in other places. 

Socratea exorrhiza is the reason why my name on tumblr is what it is, that and the wandering mountain fig of myth that was said to have gone extinct a long time ago by the people of Papua New Guinea. I wish their was a lot more information on both trees but whatever. Oh btw these trees don’t actually walk in the traditional sense but instead when a root collapses the tree *which was leaning towards the light will fall slightly and then over a few years will upright/correct it’s self after new roots connect with the grade. Because of these falling and fixing occurrences these appear to be moving when no one is looking. They only move a few inches a year from it’s original position tbh. The myth about the 20m a year walker seems to just be a myth though. Still cool folk lore and cool morphological structures<3 adventitious uprising anchor/prop roots <3

Excerpt from this story from Grist:

The future of forests is a grim one—too grim for some of us to bear. By 2030, 75 percent of redwoods will disappear from some of their coastal California habitats. In some climate scenarios, almost none of the namesake species in Joshua Tree National Park will exist. Sea level change is creating ghost forests all along the Eastern Seaboard — already, less than a third of New Jersey’s Atlantic white cedar habitat remains.

Like humans, forests have always migrated for their survival, with new trees growing in more hospitable directions and older trees dying where they are no longer best suited to live. The problem now is that they simply can’t move fast enough. The average forest migrates at a rate of roughly 1,640 feet each year, but to outrun climate change, it must move approximately 9,800 to 16,000 feet — up to 10 times as fast. And in most habitats, the impact of highways, suburban sprawl, and megafarms prevents forests from expanding much at all. Forests simply cannot escape climate change by themselves.

Back in 1992, forest geneticists F. Thomas Ledig and J.H. Kitzmiller coined the term “assisted species migration” in a seminal study in the journal Forest Ecology and Management. Since then, hundreds of biologists and geneticists like St. Clair have been studying how best to move forests in advance of their looming destruction. To do so requires a complex set of mapping and experiments—understanding, for instance, what climate trees are best suited to grow in, what region will most closely resemble that same climate in, say, 50 years, and what adaptations best ensure that a tree will take root and flourish, build symbiosis with the soil fungi, and not end up a mere matchstick awaiting the next megafire.

Excerpt from this New York Times article:

Most trees can migrate only as fast as their seeds disperse — and if current warming trends hold, the climate this century will change 10 times faster than many tree species can move, according to one estimate. Rhode Island is already seeing more heat and drought, shifting precipitation and the intensification of plagues such as the red pine scale, a nearly invisible insect carried by wind that can kill a tree in just a few years.

The dark synergy of extreme weather and emboldened pests could imperil vast stretches of woodland.

So foresters in Rhode Island and elsewhere have launched ambitious experiments to test how people can help forests adapt, something that might take decades to occur naturally. One controversial idea, known as assisted migration, involves deliberately moving trees northward. But trees can live centuries, and environments are changing so fast in some places that species planted today may be ill-suited to conditions in 50 years, let alone 100. No one knows the best way to make forests more resilient to climatic upheaval.

As this map shows, heat-sensitive species such as maple, beech and birch are expected to shift north within the next century in response to a warming climate. (Photo: U.S. Global Change Research Program)

Excerpt:

In a new study published in the journal Nature Ecology and Evolution, researchers at the University of Tennessee say these soil organisms play a critical role in influencing a naturally occurring phenomenon known as "tree migration." While many of us likely instantly picture trees sprouting legs, pulling up roots and running away, the concept actually involves the movement of tree populations in geographical space over time.

Largely, these migrations are influenced by environmental changes. With climate change heating up regions all around the world, some species of trees are traveling north to escape the heat at average rates of 62 miles a century.

In the United States, the migration is already well underway. A 2010 U.S. Forest Service study found that 70 percent of tree species are already showing tree range migration, with maple, beech and birch potentially gone entirely in the Northeast by 2100.