Bats Aid Tropical Reforestation

German scientists engage bats to kick-start natural reforestation in the tropics by installing artificial bat roosts in deforested areas.

Scientists from the Leibniz Institute for Zoo and Wildlife Research and University of Erlangen –Nuremberg have employed bats to kick-start natural reforestation in the tropics. The team installed artificial bat roosts in deforested areas. The team’s work is presented in a new study published online in the science journal Conservation Biology this week. The press release says that Detlev Kelm from the Leibniz Institute for Zoo and Wildlife Research in Berlin (IZW) and Kerstin Wiesner and Otto von Helversen from the University of Erlangen –Nuremberg report that the deployment of artificial bat roosts significantly increases seed dispersal of a wide range of tropical forest plants into their surroundings, providing a simple and cheap method to speed up natural forest regeneration. Tropical forests have global ecological importance as they function as a key contributor to the global carbon balance and are host to a major part of the world’s biodiversity. Worldwide net losses of tropical forest cover, between 2000 and 2005, averaged 0.18 per cent annually and regionally even exceeded 1.5 per cent annually in some Latin American countries. Agriculture often replaces forests and as a result soils can become rapidly infertile and land is abandoned. Areas that have been deforested are not often able to provide food and shelter for the areas rarely offer much food or protection for seed dispersers such as birds or small mammals that disperse the seeds which are needed to keep the forest growing. This means that natural forest regeneration is hampered by a lack of these natural seed inputs. The alternative is replanting a tropical forest, however, this method is too expensive and rarely a feasible option, and, in general, knowledge on how best to rapidly restore natural vegetation is lacking. “We believe that bats could help in reforestation. They are able to cover large distances during their nightly foraging flights and are willing to enter deforested areas”, says Detlev Kelm from the IZW. Many bats eat fruits or nectar. This makes them a key species for seed dispersal and flower pollination. The team showed that the principal barrier to reforestation - the lack of seed inputs - could be overcome by the deployment of artificial day roosts for bats in deforested areas. The roosts were designed to approximate characteristics of large, hollow tree trunks, the main type of natural bat roost. “Within a few days to weeks the first bats will move in. So far we have found ten bat species using the roosts, and several of these are common and important seed dispersers”, Kelm reports.