Why Do The Strange Cook Pine Trees Lean Toward The Equator? Study Reveals

Scientists have now figured out why the strange Cook pine trees lean toward the equator. One could see these leaning Cook pines (Araucaria columnaris) in places all around the globe. You maybe wondering how this tall leaning conifer could look like the leaning Pisa in Italy.

The findings of the study were printed in Ecology. The study was led by Matt Ritter from California Polytechnic State University and other colleagues. The scientists have started their study when they noticed these pines that appear to be leaning south. They stated that when grown outside of its native range, this tree has a pronounced lean so ubiquitous that is often used as the identifying characteristics of the species, as noted by Science Alert.

RT @newscientist: Cook pines that always lean towards equator https://t.co/AVShk1AVzU pic.twitter.com/TskPTBfL7w. Like our 2 in Hawaii.

— Bert Kimura (@kimubert) June 4, 2017

Cook pine trees, also referred to as Coral Reef Araucaria, is endemic to New Caledonia in the Melanesia region of the southwestern Pacific Ocean. They are also often grown in Australia. These trees were first classified by botanists of Captain James Cook's second voyage to explore the globe as far as south.

Cook pine tree could grow up to 60 meters (200 feet) tall. It has a slender and spire-like crown. The branchlets of this tree are covered with small, point-tipped and overlapping leaves. Meanwhile, the young leaves look like needle while the broader adult leaves look triangular.

So, why are these pine trees leaning toward the equator? The scientists gathered measurements of 256 trees in 18 regions on five continents. They found that on average, the pines tilt by 8.05 degrees and lean toward the south in the Northern Hemisphere and the opposite direction in the Southern Hemisphere. They also discovered that about less than 9 percent of the trees they measured did not adapt this pattern.

The scientists thought that the leaning could be caused by sunlight and magnetic field, too. They stated that the mechanism regarding the leaning of Cook pine trees toward the equator may be related to an adaptive tropic response to the incidence angles of annual sunlight, magnetism, gravity or any combination of these. These conifers are known for their propensity to lean toward a light source; this is a characteristic referred to as phototropism.