One tree likes seabird poop, the next prefers fresh air

Publié le
23 janvier 2014

Off the west coast of Peru, seabirds deposit thick layers of guano that accumulates on the ground because of the lack of rain. Guano has historically played a key role in agriculture worldwide because it is rich in plant nutrients such as nitrogen and phosphorous. Now, researchers from Wageningen University and Southern Illinois University revealed the effects of guano on the native trees of the arid coasts of South America.

Gilles Havik tree census DSC_3155.jpg

Researchers found that non-nitrogen fixing treesbecome more abundant closer to sea replacing the usually more abundant nitrogenfixing trees in these deserts. “We think this is related to the positive effectof marine nutrients on non-nitrogen fixing trees” explains Gilles Havik, aformer master student at Wageningen University and leading author of the Plos Onepaper that appeared on January 22.

“Nutrients are limiting in the desert, sothis input from the sea through the nitrogen-rich guano has a positive effectfor trees that cannot fix nitrogen. What we found very striking is that treesthat do fix nitrogen from the air do not seem to benefit from nutrients comingfrom the sea even though fixing nutrients from the air is expensive for a plant”continues Havik. These findings highlight the important interactions betweenmarine and terrestrial environments, and the need to understand suchinteraction to guide conservation efforts.