canopy

Skydiving Salamanders | Earth Wise

June 28, 2022 By EarthWise Leave a Comment

The redwoods of the California coast are the tallest trees in the world. They are typically a couple of hundred feet tall and the tallest rise to a height of as much as 380 feet. Scientists have been studying the unique world of the redwood forest canopy for years. There are multiple animals that actually live up there. In fact, some spend their entire lives at the top of a single tree.

Over the past 20 years, researchers have been climbing redwoods to observe, capture, and mark salamanders that live in the canopy. The most arboreal species, called the wandering salamander, is a four-inch-long creature what moves up and down the branches of a tree where it spends its entire life. The researchers discovered a remarkable ability for the little amphibian.

The salamander readily leaps from perches in the crowns of redwood trees and has the ability to easily maneuver in midair back to a trunk or branch before it plummets to the ground. When the salamanders were startled by climbing researchers, they simply leap from the canopy and find their way to another perch lower in the tree.

The salamanders assume a skydiving posture with their forelimbs splayed out and can steer themselves by pumping their tails up and down. They can flip themselves over if they end up upside down. They have an impressive level of control.

What is most remarkable is that the salamanders, apart from having slightly larger foot pads, look no different from other salamanders that aren’t skydivers. They have no skin flaps or other anatomical adaptations that would give them the ability to glide. The researchers hope to eventually figure out just how these creatures have become expert skydivers.

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Skydiving salamanders live in world’s tallest trees

Photo, posted August 5, 2010, courtesy of Benson Kua via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Koalas Are Endangered | Earth Wise

March 22, 2022 By EarthWise Leave a Comment

The koala is one of the world’s most iconic animal species and is widely considered to be the symbol of Australia. Koalas are not bears; they are marsupials.

Being iconic symbols is not sufficient to prevent koalas from going extinct. In the 1920s, hundreds of thousands of koalas were shot for the fur trade, greatly reducing their population.

More recently, drought, bush fires, disease, and habitat loss have drastically reduced the numbers of koalas. Since 2018, there has been a 30% decline in koala populations across Australia. It is difficult to get an accurate count of the animals because they don’t move around much, and they live high up in tree canopies where they are hard to spot.

Estimates are that the koala population has dropped from between 45,000-82,000 in 2018 to between 32,000-58,000 in 2021. The koala is now extinct in 47 Australian electorates and in many others, there are only handfuls of animals remaining. The population decline was accelerated by devastating wildfires in late 2019 into early 2020. Some estimates are that koalas could be extinct by 2050. Conservation organizations around the world have been demanding greater protection for koalas for years.

Given this dire situation, the Australian government recently declared the koala an endangered species, reclassifying it from being a vulnerable species. The government plans to adopt a recovery plan that will include new laws protecting koalas and their natural woodland environments. The details of the plan remain to revealed.

According to the Australian Koala Foundation, however, the new status of the koala means very little in and of itself. If the clearing of the koala habitat continues, the species has little chance of surviving in the wild.

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‘In rapid decline’: Australia has lost 30% of its koalas in just 3 years, foundation says

Australia Declares Koalas an Endangered Species

Photo, posted September 18, 2019, courtesy of Guido Konrad via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mercury In The Amazon Rainforest | Earth Wise

March 8, 2022 By EarthWise Leave a Comment

Recent research has found that some of the highest levels of mercury pollution ever recorded are in a patch of pristine Amazonian rainforest. The international team of researchers discovered that illegal goldmining in the Peruvian Amazon is the source of the pollution.

Illegal miners separate gold particles from river sediments using mercury. Mercury binds to gold, forming pellets large enough to be caught in a sieve. The pellets are then burned in open fire ovens, releasing the mercury to the atmosphere, leaving the gold behind. The mercury smoke ends up being washed into the soil by rainfall, deposited onto the surface of leaves, or directly absorbed into leaf tissues.

Deforested areas had low levels of mercury, while the areas with the largest, densest old-growth trees captured huge volumes of atmospheric mercury, more than any other ecosystem studied in the entire world. Mercury levels were directly related to leaf area index: the denser the canopy, the more mercury it holds. Birds from this area have up to twelve times more mercury in their systems than birds from less polluted areas. Such high concentrations of mercury could provoke a decline of up to 30% in these birds’ reproductive success.

Small-scale artisanal gold mining is an important livelihood for local communities. Eliminating it outright may not be a viable solution but coming up with ways to continue to provide a sustainable livelihood while protecting communities from poisonous pollution is essential.

In the meantime, the forests are doing an important service by capturing much of the mercury and preventing it from getting into the general atmosphere and endangering more people and animals. Burning or harvesting the mercury-ridden trees would release the mercury back into the atmosphere.

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Modern Day Gold Rush Turns Pristine Rainforests into Heavily Polluted Mercury Sinks

Photo, posted August 24, 2016, courtesy of Anna and Michal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Thoreau And Climate Change

March 27, 2019 By EarthWise Leave a Comment

Henry David Thoreau was a 19th-century American naturalist, philosopher, poet, essayist, and social reformer. He is best known for “Civil Disobedience,” an essay advocating for the rebellion against an unjust government, and for “Walden,” a book about his experiences living simply in nature. Now, Thoreau’s observations from “Walden” are the foundation of a new study exploring the effects of climate change on tree leaf-out and the emergence of spring wildflowers.

This research, which was recently published in the journal Ecology Letters, relies on Thoreau’s scientific observations gathered during the 1850s when he spent 26 months living in isolation at Walden Pond in Concord, Massachusetts. These observations from Thoreau were combined with current research to measure tree and wildflower leaf-out dates for 37 different years between 1852 and 2018. “Leaf out” refers to the time in spring when plants and trees begin producing leaves. An alteration in this timing can have a domino effect throughout an ecosystem.

Over the past century, temperatures in Concord, Massachusetts have warmed five degrees Fahrenheit. As a result, leaf-out dates have changed significantly. According to researchers, wildflowers are leafing out about one week earlier, while trees are leafing out about two weeks earlier than they did 160 years ago.

Ground-dwelling plants like wildflowers have a narrow window to accomplish growth, photosynthesis, and reproduction, before the canopy trees leaf out and block the sunlight. Temperature-driven shifts in the timing of tree leaf-out between Thoreau’s time and now are likely already hindering wildflower abundance and flowering.

As the climate continues to warm, the already small window of time between wildflower emergence and tree leaf-out will likely shorten further.

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Using Thoreau, scientists measure the impact of climate change on wildflowers

Photo, posted August 13, 2008, courtesy of Adam Pieniazek via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Liana Vines And Carbon

May 25, 2017 By EarthWise

Liana vines are long-stemmed, woody vines that are rooted in the soil at ground level and use trees or other means of vertical support to climb up to the canopy to gain access to sunlight. There are numerous varieties from many plant families. And, for reasons that are not entirely clear, their abundance has doubled in recent decades.