Carnegie Institute scientists used airborne 3-D mapping to determine that elephants were the main cause for tree loss in South Africa’s Kruger National Park, according to a Carnegie Institute press release.
The scientists found that there are six times more trees knocked down in areas accessible to elephants compared to areas inaccessible to elephants. Elephants knock trees over as they romp through the savannah browsing for food.
Researchers used Light Detection and Ranging (LiDAR) mounted to the Carnegie Airborne Observatory fixed-wing aircraft to monitor tree loss. The device uses sweeping laser pulses to make 3-D images of the savannah canopy.
Once a baseline is set, the laser imaging detects differences in tree height so that scientists can establish changes in the savannah. They monitored 58,000 trees in total and found that nine percent of them decreased in height over two years.
Many of the felled or shortened trees lived where elephants are known to browse for food. The press release states that the elephants prefer to knock over trees in a height range of 16 to 30 feet tall. Tree loss in some areas went as high as 20 percent.
Image: Elephant from Kruger Park, South Africa. (Credit: Rob Hooft, via Wikimedia Commons)