VOICES FOR THE AMAZON

A mature shihuahuaco (Dipteryx micrantha) tree. Image by Gianella Espinosa/ ARBIO.

 

The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth.

— Charles Darwin

No story is as old and universal as the tree of life. In Nordic mythology, a huge tree connects the nine worlds of the universe. In Iroquois legend, a pregnant woman creates the world by planting a tree on a turtle’s back. In his theory of evolution, Darwin shows that all organisms are interconnected in a single tree of life.

If one species embodies the tree of life in the modern day, it might be the Dipteryx micrantha, known as the shihuahuaco in Peru. Among roughly 390 billion trees growing in the Amazon, shihuahuacos are among the tallest and most ancient. They take about one millennium to grow to full height of up to 60 m or almost 200 feet.

Forest giants like the shihuahuaco are called “emergent trees” because they reach the emergent layer or overstory of the forest. The emergent layer endures heavy winds, rain and sun exposure. Despite these harsh conditions, bold animals like eagles, bats and monkeys all venture to the emergent layer.

An aerial photo showing an emergent layer of the Amazon rainforest. Image by Rochi León/Amazon Aid Foundation.

Identified as a keystone species, the shihuahuaco sustains a staggering amount of life. During the wet season, lilac flowers blossom in its upper canopy. By the dry season, these flower clusters have morphed into heavy fruit pods or legumes (the shihuahuaco is a member of the bean family).

Bats, spider monkeys, agoutis, possums, squirrels and spiny rats all rely on these fruits. After eating them, these critters store the seeds in a special hiding place for future use. Sometimes, the animals forget where they stored the seeds, allowing the seeds to germinate and the parent tree to reproduce. A towering tree like the shihuahuaco may owe its life to the forgetfulness of a tiny squirrel 1,000 years ago!

A mother spider monkey and her baby climbing in the canopy. Image by Dano Grayson/Amazon Aid Foundation.

While shihuahuaco fruits are not industrially commercialized, many indigenous groups prize the seeds and some use the bark as an antimicrobial medicine. Others, like the Boras people, make the shell-like pods into necklaces and other decorative objects.

Among the countless creatures that live in the shihuahuaco is the mythic harpy eagle, the largest and most menacing raptor in the rainforest. The harpy eagle can dive at 50 mph to catch unsuspecting rodents and monkeys with its crushing talons.

The tree is also a favorite home of macaws, who nest in natural hollows in the trunk. These hollows may remain inhabitable for centuries, harboring literally hundreds of macaw chicks over one shihuahuaco’s lifetime.

Three macaws perched on a branch. Image by Sam Abell/Amazon Aid Foundation.

People also use the shihuahuaco to build homes. With its dark, rich wood, shihuahuaco timber is in high demand as flooring. From 2008 to 2018, about 74 shihuahuacos were felled each day, most of which were exported to China.

While little research has been done on the shihuahuaco’s conservation status, experts agree the population is declining and some fear the species has become critically endangered.

Illicit loggers haul away mature shihuahuacos in Madre de Dios, Peru. Image by Gianella Espinosa/ARBIO.

Unregulated logging of keystones species like the shihuahuaco poses big threats for the rainforest. Experts estimate that over half of the Amazon will be converted into a savanna if more than 20-25% of forest cover is lost. To date, about 19% has been cut down, putting the rainforest on the tipping point.

Despite the shihuahuaco’s thinning population, it is more a symbol of hope than destruction. Forestry research shows that shihuahuacos grow well in treefall gaps and deforested areas. That is one reason experts like the Center for Amazonian Scientific Innovation (CINCIA) include the shihuahuaco in their cutting-edge reforestation designs and organizations like ARBIO have made bold efforts to protect the shihuahuaco from illicit logging.

A recently planted shihuahuaco seedling. Image by France Cabanillas/CINCIA.

Slow-growth species like the shihuahuaco also play a crucial role in carbon dioxide absorption. By itself, a mature shihuahuaco sequesters almost one third of an average hectare of rainforest. As a whole, the Amazon rainforest absorbs about 2 billion tons of CO2 per year, about 5% of global annual emissions.

While more shihuahuacos are being cut down than ever before, more are also being planted. Which way the scale tips will decide not only the fate of the shihuahuaco but all organisms that depend on it, including us.