Study Says Acceleration in Tree Growth Does Not Result to Substantial Reduction in Atmospheric CO2

During photosynthesis, plants particularly trees take in carbon dioxide (CO2) occurring in the atmosphere and store the compound. The plant or tree will later use the stored CO2 in producing new plant cells.

In light of the continuously increasing amount of carbon dioxide in the Earth’s atmosphere, it was widely believed that having more trees in the environment can help reduce the occurrence of carbon dioxide contributing to the green gases that have been warming the earth’s surface.

On the other hand, it was noted that the increased warmth of climate temperatures, or the so-called greenhouse effect, has accelerated the growth of trees. This development presented hopes that as more trees become available, the larger the volume of CO2 reductions taking place when trees undergo photosynthesis.

However, a recent study conducted by the University of Cambridge revealed that new trees also tend to wither and die much faster. The carbon previously stored by the fast-growing, yet fast-dying trees simply return to the atmosphere.

Ulf Büntgen, a professor at the Department of Geography at Cambridge University and lead author of the study, explained that it was everyone’s thinking that growing more trees will result to CO2 reduction in the planet’s atmosphere.

“plants and trees grow faster, but that is only half of the story. The other half is that these fast-growing trees are holding carbon for shorter periods of time.”

Methodology Used in Arriving at the “Grow-Fast, Die-Early” Theory

As it was concluded that the greenhouse effect has promoted the acceleration of tree-growth, the research team led by the University of Cambridge geography experts also learned that trees that grew in high elevations, live longer. Pines and other types of conifers existing in the high-northern boreal forests were able to store the CO2 for centuries.

In studying the past climate conditions, Professor Büntgen and other researchers from Spain, Russia, Switzerland and Germany, used information found in tree rings as indicators. Annual tree-ring width, anatomy and density presented information on what the climate was like during the related year.

They took samples out of living trees and dead trees to reconstruct climate behaviors, and of how ecosystems had responded and are responding to variations in temperature.

Living and dead samples were taken from about 1,100 mountain pines found in the Spanish Pyrenees, and 660 Siberian larch from the Russian Altai, both high elevation forests undisturbed for thousands of years. The researchers then used those samples in reconstructing the lifespan, and rates of juvenile growth of trees that grew during industrial and pre-industrial climates.

They came to the conclusion that harsh, cold climate conditions retard tree growth. Such conditions also made trees stronger, allowing them to live much longer. The cold climate findings stood in contrast to the fast-growing trees, which died sooner after their first 25 years.