Five thousand per cent increase in native trees on rat-free Palmyra Atoll
Native trees benefitted from rat removal at Palmyra Atoll, a magnificent national wildlife refuge and natural research laboratory located about 1,000 miles south of Hawaii.
For five native tree species, including Pisonia grandis, fewer than 150 seedlings were counted in the presence of rats on Palmyra Atoll and P. grandis forests are reported to be in decline globally. However, five years after the rats were removed from Palmyra Atoll, this count increased dramatically to more than 7,700.
Prior to removal, invasive rats devoured native seeds and seedlings, as well as seabird eggs and chicks at Palmyra Atoll. Removing the rats allowed seabirds to flourish, and the rebounding native forest now provides the birds with an important nesting and roosting habitat. Palmyra's tropical rainforest also provides important habitat for a native gecko, insects, crabs and other rare species.
When seabirds perch in the trees, they provide nutrients to the soil below through guano droppings. These nutrients are then taken up by native plants to help them grow, and also wash into the ocean where they dramatically benefit surrounding reefs. Restoring the native forest at Palmyra Atoll therefore not only helps the plant life, but aids in keeping the coral reefs and thriving fish populations healthy too. This improves their chances of overcoming changing temperatures and other climate impacts.
For those shivering through winter, we thought you might enjoy this photo of the researchers making their way to work through tropical waters.
The full research paper can be found online at Plos One.
Source: Island Conservation
Photo Credit: Island Conservation