Study Shows 5000% Increase in Native Trees on Rat-free Palmyra Atoll

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New research published in PLOS ONE this week demonstrates dramatic positive benefits for native trees following rat removal at Palmyra Atoll, a magnificent National Wildlife Refuge and natural research laboratory located about 1000 miles south of Hawaii.

New research published in PLOS ONE this week demonstrates dramatic positive benefits for native trees following rat removal at Palmyra Atoll, a magnificent National Wildlife Refuge and natural research laboratory located about 1000 miles south of Hawaii.

In one of only a few studies of its kind, scientists measured the effects of rat removal on the tropical Pisonia grandis forest at Palmyra Atoll, which provides critical seabird nesting habitat. Before removal, no seedlings of native Pisonia grandis trees were found in research plots. Immediately following removal of invasive rats, seedlings proliferated and plots had an average of 8 seedlings per square meter. For five native tree species, including Pisonia grandis, fewer than 150 seedlings were counted in the presence of rats, and more than 7700 seedlings were counted five years after rats were removed.

Read more at Island Conservation

Photo: An aerial view of Palmyra Atoll. Credit: Island Conservation