UF researchers have discovered that small mammals are vital to sustaining seed dispersal and the survival of tropical ecosystems.
The researchers are the first to quantify the long-term effects overhunting has on the entire life cycle of tropical tree Miliusa horsfieldii in Thailand. They found that the risk of this species’ extinction will increase by more than 10 times over the course of a century because of overhunting.
The UF-led study, published in the Proceedings of the Royal Society B earlier this month, was completed in collaboration with the Conservation Ecology Program in Thailand, the Royal Thai Forest Department and Wageningen University in the Netherlands.
After eating the trees’ fruits, animals disperse the seeds in different locations, which helps to avoid tree crowding, a general phenomenon that could affect other trees.
Without animal seed dispersers, an entire tree population could collapse, said Jeremy Lichstein, a UF assistant biology professor and one of the study’s authors.
Even if the plants live within 10 to 20 meters of each other, the research shows that trees of all stages are less likely to grow and survive.
Lichstein said one reason for the low survival rates is that some insects carry diseases to attack certain plant species, and if the same trees are close together, pathogens can easily spread.
“It’s like getting sick,” he said. “If you live by yourself, you’re less likely to get communicable diseases. The same thing happens to trees.”
If a seed falls right below its parent tree, it is crowded not only by the original tree, but also by all the other fallen seedlings, said Trevor Caughlin, a UF postdoctoral student and National Science Foundation Fellow.
Crowding can prevent the seeds from germinating as well.
With overhunting causing animals to become extinct in tropical forests worldwide, the researchers studied how Miliusa Horsfieldii was affected.
Caughlin said he hopes the Gainesville community will become aware of the conservation issue to stop the demand and trade of wildlife that causes these potentially catastrophic effects.
“There should be more action to regulate and curb overhunting,” he said.
Manny Rutinel, a UF microbiology and cell science and economics junior, said Gainesville can raise awareness of the issue by contacting local policy makers.
“We’re learning every day how sensitive these ecosystems are to human interactions and we are truly overexploiting areas in ways never before,” Rutinel, 19, said.
[A version of this story ran on page 9 on 11/24/2014]
