Wednesday, December 8, 2021

To Regrow US Forests - We Need Billions of Seeds & Many More 'Seed Hunters'

Like everyone one else, I just "assumed" when forest fire happens, the forest "regrows" spontaneously in time. It might sans humans but I learned they do need human help to expedite regrowth (otherwise real estate deals would be made by other humans). 

This is hard but noble work. Thank you for these noble souls and their hard work:

Grandorff’s parents taught him as a teenager how to read the forest. They were part of a niche network of cone collectors whose heyday dates back to President Roosevelt’s Civilian Conservation Corps. Trailing behind him enthusiastically now is Matthew Aghai, senior director of biological research and development at the Seattle-based reforestation company DroneSeed, along to learn traditional gathering skills.

Grandorff stops: “See, right down there.” Nestled between two big rocks on the bank of a brook is what he came for: a cache of pine cones worth $15 a bushel. These woody cones are in steep demand. Tucked inside each one are up to 10 pearly-white seeds, each no bigger than a lentil, which one day could grow to over 200 feet tall and absorb at least 48 pounds of carbon dioxide each year.

Across the western United States, the seeds are in high demand. Over the next 20 years, the U.S. aims to plant billions more trees in order to restore millions of acres of scorched forest and help offset planet-warming carbon emissions. In the West alone, some 10 million acres of recently burned land are waiting to be replanted. In the past few decades, however, the number of skilled seed collectors in the U.S. has been dwindling, though it’s not clear by how much, since the work is seasonal; it’s also gruelling, for not much pay. Fewer collectors means fewer seeds, and ultimately, trees.

[---]

Presaging that, an interim report on native seed supply commissioned by the Bureau of Land Management (BLM) and published in October 2020 states, “There is no agency-wide native plant restoration program … [and the] supply chain is generally inadequate to meet these large demands.”

That’s partly because of how trees reproduce.

Seeds, the embryos for future offspring, begin to form after spring pollination. As part of a species’ survival strategy, the abundance of the seeds varies by year. Seeds are energy-intensive for trees to produce, and after several low-seed years there may be a sudden oversupply. It’s impossible for animals to eat and disburse all of them, ensuring some sprout into seedlings. It’s thought that the timing of these bumper crops—known as masts—are synchronized, with the trees communicating through airborne chemical signals or via underground root networks. 

As a result, a good seed crop happens only once every three to seven years, depending on the plant species, given the irregular reproduction schedules. So 2020 was a good Douglas fir year; noble fir was big in 2016. This year across the area known as Cascadia, the tips of Ponderosa pine branches are heavy with cones.

“When there's a mast this big … it's quite unique,” says Aghai. “It would be irresponsible of us not to take advantage of it.”

These seeds are good candidates for restoring the more than 413,000 acres burned in July by the Bootleg fire in southern Oregon—the state’s third largest wildfire since 1900. To reforest that land with 150 trees per acre via seedlings sprouted in a greenhouse—enough, according to Aghai, to allow the trees to rebound quickly without overcrowding the forest—would require 18,000 pounds of Ponderosa pine seeds, he estimates. If the seeds were simply dumped from the sky by aircraft, a conventional method with a low rate of successful germination, it would take an estimated 400,000 pounds to ensure enough seeds would make it to adulthood.

Timing is everything, says Aghai; the longer it takes to reforest post-fire, the more likely that invasive weeds and shrubs take over. But it’s often difficult to find the right seed for a specific landscape—whether it’s the type, quantity, or quality. And it’s even harder when there’s a need to move quickly, such as after a natural disaster.

No comments: