Trumpet trees may provide a looking glass into the past and present of climate change in the tropics.
They send signs of global warming to researchers without spending a lot of money on studies.
These answers can be found in the lofty green rainforest of Costa Rica. Native to Costa Rica and much of Central and South America is the Cecropia Obtusifolia, or the trumpet tree. They’re called trumpet trees for their wide, flaring leaves.
Trumpet trees adorn the landscape of most regions in Costa Rica, Central and South America, and naturalists tell us they show external signs of climate change and precipitation levels in the tropics. While they vary in structure and appearance, these trees are found in the Monteverde Cloud Reserve, and upper and lower San Luis, Costa Rica.
The tree bark has raised rings with varying distances between each ring. They can be centimeters, inches, or even feet apart from each other.
These rings are particularly important because they show growth from each growing season and rainfall. These rings could answer questions scientists have posed about climate change for many years.
“A growing season in the tropics could be much less than a year. But indirectly, the distance between these rings can tell us about rainfall. It’s a proxy for rain,” said Theodora Panayides, a Resident Naturalist at the University of Georgia, Costa Rica Campus.
Since growing seasons vary annually, ecologists can only estimate growth that occurred in a calendar year and how much the climate and rainfall changed from the prior year. This means that researchers can’t use the tree to determine an exact amount of rainfall in a growing season, but only that the tree grew more or less than the season prior.
“Trumpet trees grow really quickly. They only live about 40 years, which is not a lot in the grand scheme of studying climate change. But these trees are really good for reforestation so they can be used to slow climate change in that aspect,” said Reagan Fink, another Resident Naturalists at UGA Costa Rica.
A HOME FOR ANTS
Trumpet trees also provide a cozy home for Azteca, a variety of ants in the Monteverde and San Luis regions of Costa Rica. The ants and tree have had a symbiotic relationship ever since scientists began studying each species.
“The ants live in the hollow limbs of the tree and defend the tree from herbivores, and from scientists with tree trimmers,” said Garrison Loope, a University of Arizona Ph.D. student who studied both species in San Luis, Costa Rica.
As climate has changed over several years, this relationship between the trees and ants has continued to exist. Loope says that even though this relationship has sustained, other plants and animals in the tropics and globally may not be as tolerant to climate change and have resorted to adaptation.
Loope and other scientists say these trees and ants may teach us a lesson in observing sustained relationships in an environment so rapidly changing.