Extinction of lowland tapir and white-lipped peccary would impair forest diversity

November 04, 2019

According to a team of researchers affiliated with São Paulo State University (UNESP) in Rio Claro, Brazil, the extinction of South America's two largest herbivores - the lowland tapir (Tapirus terrestris) and the white-lipped peccary (Tayassu pecari) - would cause a significant decrease in forest diversity throughout the continent.

The results of experiments that began ten years ago showed that plant communities are more diversified in areas where both species are present and less diversified in forests inhabited by only one species. The two species have complementary ecological functions.

The study, which was supported by São Paulo Research Foundation - FAPESP, is published in the British Ecological Society's Journal of Ecology.

It was conducted as part of the Thematic Project "Ecological consequences of defaunation in the Atlantic Rainforest", led by Professor Mauro Galetti under the auspice of the FAPESP Research Program on Biodiversity Characterization, Conservation, Restoration and Sustainable Use (BIOTA-FAPESP).

Tapirs and peccaries used to be found almost everywhere in South America's forests, but both species are now endangered in many localities owing to poaching and deforestation for agriculture. According to the researchers, the ecological roles of these species and their importance in the ecosystem services of the forests (biodiversity, nutrient cycling, carbon storage and maintenance of water sources, among others) are poorly understood.

Peccaries consume large amounts of seeds and seedlings. They live in large family groups that can exceed one hundred individuals. Their foraging habits and soil trampling help significantly reduce understory growth in tropical forests.

Tapirs, in contrast, are solitary and feed on leaves and fruits of several species, without affecting plant numbers. They defecate some way away from the places where they feed, moving seeds from one part of the forest to another. "While peccaries act as small 'tractors', turning over the forest soil, tapirs are gentle giants that transport seeds in their stomachs. Their ecological roles are very different," Jose Ignacio (Nacho) Villar, first author of the article, told.

Both species travel long distances in the forest, and the disturbance caused by peccaries overlaps with the seed dispersal performed by tapirs.

"Our hypothesis is that the disturbance caused by peccaries increases the likelihood that seeds dispersed by tapirs will become adult trees, favoring forest diversity on a large spatial scale," said Villar, who has a postdoctoral scholarship from FAPESP and is supervised by Galetti.

Previous studies speculated that both tapirs and peccaries were "ecosystem engineers", but this is the first to evaluate field data, which shows that only the combined activities of both species have a substantial positive impact on forest diversity.

"The disappearance of these herbivores from the tropical forests of South America could have significant effects on ecosystem dynamics, possibly equivalent to the eradication of elephants from African and Asian forests, or that of gnus from savannas," Villar said. Peccaries are among the favorite prey of the jaguar (Panthera onca), the apex predator in South America's forests, so their extinction would affect all levels of the food chain.

"We're only just beginning to understand the consequences of mass extinction of large herbivores on tropical forests," Villar said. "It's the tip of the iceberg. We must generate this knowledge before it is too late. Long-term experiments like ours are essential to achieving this goal."
About São Paulo Research Foundation (FAPESP)

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at http://www.fapesp.br/en and visit FAPESP news agency at http://www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

Fundação de Amparo à Pesquisa do Estado de São Paulo

Related Biodiversity Articles from Brightsurf:

Biodiversity hypothesis called into question
How can we explain the fact that no single species predominates?

Using the past to maintain future biodiversity
New research shows that safeguarding species and ecosystems and the benefits they provide for society against future climatic change requires effective solutions which can only be formulated from reliable forecasts.

Changes in farming urgent to rescue biodiversity
Humans depend on farming for their survival but this activity takes up more than one-third of the world's landmass and endangers 62% of all threatened species.

Predicting the biodiversity of rivers
Biodiversity and thus the state of river ecosystems can now be predicted by combining environmental DNA with hydrological methods, researchers from the University of Zurich and Eawag have found.

About the distribution of biodiversity on our planet
Large open-water fish predators such as tunas or sharks hunt for prey more intensively in the temperate zone than near the equator.

Bargain-hunting for biodiversity
The best bargains for conserving some of the world's most vulnerable salamanders and other vertebrate species can be found in Central Texas and the Appalachians, according to new conservation tools developed at the National Institute for Mathematical and Biological Synthesis (NIMBioS) at the University of Tennessee, Knoxville.

Researchers solve old biodiversity mystery
The underlying cause for why some regions are home to an extremely large number of animal species may be found in the evolutionary adaptations of species, and how they limit their dispersion to specific natural habitats.

Biodiversity offsetting is contentious -- here's an alternative
A new approach to compensate for the impact of development may be an effective alternative to biodiversity offsetting -- and help nations achieve international biodiversity targets.

Biodiversity yields financial returns
Farmers could increase their revenues by increasing biodiversity on their land.

Biodiversity and wind energy
The location and operation of wind energy plants are often in direct conflict with the legal protection of endangered species.

Read More: Biodiversity News and Biodiversity Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.