Recent studies have noticed a strong positive correlation between the concentration of nitrogen in forests and infrared reflectance measured from aircraft and satellites. Some scientists have suggested this demonstrates a previously overlooked role for nitrogen in regulating the earth's climate system.
However, a new paper in Proceedings of the National Academy of Sciences, shows that the apparent relationship between leaves' nitrogen levels and infrared reflection is spurious and it is in fact the structure of forest canopies (the spatial arrangement of the leaves) that determines their ability to reflect infrared light.
The authors, including Professor Philip Lewis and Dr Mathias Disney (UCL Geography), show that the richer in nitrogen individual leaves are the worse at reflecting infrared radiation they become. However, the complex arrangements of trees with radically different arrangements of leaves within a forest can act to mask this effect, making it appear as if higher levels of leaf nitrogen are leading to increased infrared reflection.
Dr Disney said: "It is impossible to understand how forests reflect infrared without taking into account the arrangement of different types of leaf clumps, such as shoots and crowns, which make up the canopy, as well as the internal structure of the leaves.
"This paper proposes a way to account for structure when measuring canopy infrared reflectance. We hope it will improve our ability to measure forest biochemistry from satellites, allowing us to better quantify forests' current state and how they are responding to climate change."
University College London: http://www.ucl.ac.uk
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
A female from the first wild beaver colony in England for hundreds of years has given birth to at least two young.
In a desperate bid to save one of the world's most endangered animals, conservationists are taking the controversial step of defacing the last survivors.
In a landmark ruling, a court in the Hague has ordered the Dutch government to cut greenhouse gas emissions by at least 25 per cent by 2020
Environmental impacts of food waste aren't a great concern, a new survey shows
Scientists are trying to predict what might happen if genetically modified salmon escaped growth facilities. It's a scenario often raised by critics who don't want the FDA to approve sale of the fish.
The decision comes despite a ruling that Tokyo hasn't proven a scientific need for the hunts
"Twice the sunshine, half the cost"
NPR's Melissa Block interviews Environmental Protection Agency administrator Gina McCarthy on the second anniversary of the president's Climate Action Plan.
Driven by new regulations and fracking, more coal power plants are retiring for cheaper, cleaner-burning natural gas. But scientists have yet to work out the fossil fuel's imperfect climate footprint.
Picture a troop of olive baboons, moving over the savannah. There’s around fifty of them, and they cover …