Gardening – Celebrating the light

Despite 10,000 years of depending on plants for their very survival, humans, who had prospered by learning from their environment, didn’t recognise the part light played in plant growth. 

In the 1620s, the physician Jan Baptist van Helmont turned his attention to testing the dogma that plants ate soil and, in the process, discovered the energy-harvesting secrets of plants.

Earth began life in an atmosphere made mostly of nitrogen, carbon dioxide and methane and the evolution of life as we know it owes everything to photosynthesis.   Photosynthesis is the foundation of the carbon cycle, which is largely the movement of carbon through life forms. Because photosynthesis helps control the makeup of our atmosphere, understanding photosynthesis is crucial to understanding how carbon dioxide and other greenhouse gasses affect the global climate.

Photosynthesis, named in 1893, by Charles Barnes, is the process by which plants change the sun’s light energy to the kinds of energy that can be stored for later use.  Chloroplasts found in leaves convert light energy to the chemical energy that is used by all living organisms. 

When plants have enough sunlight, carbon dioxide, water and fertile soil, the photosynthesis cycle produces sugars, starches, and other high-energy carbohydrates, while our life-giving oxygen is released in the process.

The largest driver of environmental destruction is habitat loss, and when we destroy natural habitats we destroy the very system that absorbs carbon and reduces the capacity of the planet to balance emissions and feed everyone.   

An accepted theory explaining the extinction of the dinosaurs suggests that a meteor or volcano ejected so much material into the atmosphere that the amount of sunlight reaching earth was so limited that plants were unable to photosynthesize. This caused the death, not only of the plants that they depended on for energy, but of the dinosaurs as well.

A better understanding of photosynthesis could transform our knowledge of the interaction of the plant kingdom with carbon dioxide.

Mangroves, which thrive in seawater, provide us with one example. The mangrove miracle provides enormous living space for fish, crabs, molluscs, and shrimp. Their canopies support swarms of insect eating and fruit dispersing birds, while their roots recycle nutrients in the mud and trap millions of tons of carbon, all the while contributing to the diversity and vitality to life on our planet.

Photosynthesis is arguably the most important biological process on earth, without which there would be no economy, no ecosystem, no money, and no people.  

Thanks to the miracle of photosynthesis our world is filled with possibilities. This Christmas enjoy nature’s miracle.