Trees vs. Algae

In a recent article published by the ECOLOGY Global Network, “The Most Important Organism?” environmental scientist Dr. Jack Hall posits his theory that photosynthetic marine algae (marine plants) is “hands down the most important organism on this planet”. He backs up his claim by stating that because more than 71 percent of the Earth is covered in ocean, marine forests produce 70-80 percent of our oxygen supply, and therefore are more productive than terrestrial forests.

Although I do agree with Dr. Hall that marine plants produce more oxygen than terrestrial plants, I think his marine plant biased argument is incomplete because he does not take into account the contrasting roles that marine plants and land plants play in the Global Carbon Cycle. In terms of carbon fixation, the terrestrial biosphere is two times more efficient in fixing carbon from the atmosphere during photosynthesis than photosynthetic marine algae. On top of that, land plants have a much longer life-span (about 40 years) compared to marine plants, which allows them to fix carbon for a much longer time period. This obviously boosts the importance of terrestrial forests because in light of today’s sky rocketing anthropogenic carbon emissions, we need as many carbon-fixing plants as we can get.

Hall’s article does not fairly compare the importance of marine plants to terrestrial plants. It would be incorrect to suggest that one is more significant than the other, as both marine and terrestrial biospheres are essential in keeping our planet’s climate at equilibrium.