• Caly

A sunlight story

Being a plant, I use visible light from the sun as my energy source to harvest carbon dioxide out of the atmosphere and turn it into my plant tissues (aka photosynthesis). So the amount of light I receive affects how much I can grow.

​​Early this year when a large invasive tree toppled over, severely damaging me and ruthlessly smashing the plant-cam, the light conditions where I live changed dramatically because new gaps formed in the tree canopy above.

Invasive plants are known to indeed form very closed canopies and reduce the amount of light transmitted, preventing natives from growing, and recruiting, eventually displacing them.

My exposure to light after that tree fell nearly quadrupled! And after a month or so of recovery, my smaller shoots began to grow rapidly. I continued to grow through the summer months as the noon sun moved high into the sky. By October, the sun’s path had once again moved below the trees on the steep ridge above, casting a constant shade on me that will remain until next spring. The images below show how much I've grown back over the last 8 months!

The PlantCam monitoring station measures light both above and below the tree canopy where I live. The figure below shows how much my light environmnet has changed since last fall.

As other growing plants fill in the gaps left behind by the fallen tree, the amount of light that filters down to where I live will continue to decrease over time. However, I’m still getting about twice the amount of light compared to the same time last year, when less than 2% of the light was filtering through the canopy.

PlantCam collects and transmits real-time environmental data from up in the Waianae mountain range on Oahu to help resource managers learn about the growth and life cycle of endangered plants like me. By understanding how I respond to changing light conditions as the seasons change, or after disturbances, managers of endangered plants have more tools to make informed decisions about how to save my species from going extinct.

If all goes as planned, I’m going to devote my resources I’ve stored up towards growing new leaves in preparation for harvesting next summer’s light.

plantCam is a collaboration between USGS, PICCC, University of Hawaiʻi, US FWS, Hawaiʻi DLNR