Bats help recover Colombian forests
UN/DICYT For four years and through a scientific tool based on the ecological role of frugivorous bats, researchers have been working on seed dispersion through guano, thus accelerating the ecological succession of ecosystems.
According to Biological Sciences doctoral candidate and member of the Universidad Nacional de Colombia (UNal) Neotropical Mammal Evolution and Ecology Research Group Diego Casallas–Pabón, Colombia is second only to Indonesia in the amount of bat species in the world, with 200 species of bats.
Casallas–Pabón focused his doctoral study on implementing artificial bat shelters and assess seed rain dispersed by bats during flight, creating new vegetation.
In fact this relationship between plants and bats which for centuries has enabled adaptations and interactions which helps provoke their coevolution is what Casallas–Pabón has been observing in two natural reserves in the Province of Meta.
“My goal was to take advantage of the ‘natural reforesting’ capabilities of bats and stimulate them into flying over selected areas in this region of the country and build an ecosystem recovery scenario. A forest, depending on its origin and impact can take up to 70 years to recover”, said Casallas–Pabón.
The Las Unamas and Rey Zamuro Natural Reserves located in the municipality of San Martín (Province of Meta) has an area close to 7,000 ha (17,300 acres) and great fauna diversity such as porcupines, foxes, oncilla’s, capybaras, coypu’s and bats were the strategic areas to test the shelters developed.
According to Casallas–Pabón forests are selectively felled, starting with the tallest trees which are the ones used by bats, thanks to the natural cracks and holes in the trees.
They built 36, 40 x 40 x 120 cm (15.7 x 15.7 x 47.2 in) shelters to mimick a natural refuge. The artificial shelters were placed in three areas: forests, mountain shrubs and isolated grassland trees to assess their effectiveness in regards to seed rain, moisture and temperature inside in the shelters. Furthermore they installed 468 seed traps and they noticed how the bats colonized these areas, turning them into food and resting areas, as well as increasing the seed rain. They also identified 38 species of bats, 47% of them frugivorous.
The researcher said the shelters were colonized in the following manner: isolated grassland trees 8%; forest shelters 58% and shrubs 25%.
“These results are very promising. We now need to increase shelter colonization in open areas and grasslands, where high temperatures could have hindered access, as deforestation continues, shelters could be a limiting resource for bats in tropical ecosystems,” he said.
Regarding seed dispersion, the study says that plant genera such as Vismia, Solanum and Piper were dispersed by bats in grasslands and mountain shrubs, far from their original source, showing the importance of the task of bats in natural dispersion processes.
Additionally the project showed that the organic matter dispersed by bats in isolated trees and mountain shrubs is equal to the amount deposited naturally in the forest.
The ideal scenario is for these pioneering seeds to reach areas like open grasslands, places they could not reach without the help of bats. Therefore having shelters in isolated trees and mountain shrubs, bats are compelled to feed in the forest and return to these areas and disperse seeds.
Therefore this pilot program headed by Professor Rosario Rojas continues to provide excellent results in mistreated Colombian forests. Also due to the significant biological impact the project was also supported by the NGO Applied Biodiversity Research Foundation and the Colombian Bat Conservation Program (PCMCo, for its Spanish acronym).
In 2013 the Ministry of the Environment and Sustainable Development recorded a total deforestation of 120,933 hectares (299,000 acres) in Colombia. The most impacted area was the Amazon region with 57% followed by the Andean regions with 22%.
The deforestation areas with the greatest loss are forest of the Caquetá–Putumayo and Meta–Guaviare regions as well as the San José del Guaviare–Calamar axis.
The Ministry also adds that during the last 23 years there has been a disconnection between the forest mass of the Amazon and the Eastern Mountain range and alerts of the need to recover the Amazonian and Orinoquía foothills.