Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ants plant tomorrow's rainforest

18.03.2014

Tropical montane rain forests are highly threatened and their remnants are often surrounded by deforested landscapes.

For the regeneration of these degraded areas, seed dispersal of forest trees plays a crucial role but is still poorly understood. Most tree species are dispersed by birds and mammals, but also by ants.


Ants are attracted by the lipid-rich aril of Clusia seeds and move the seeds to safe microsites for germination. Picture: S. Gallegos

A study published today in the Journal of Ecology by a team from the LOEWE Biodiversity and Climate Research Centre and the University of Halle-Wittenberg proves the importance of this hitherto neglected ecosystem function for the restoration of montane rain forests. Ants promote the regeneration of these forests by dispersing seeds to safe sites for tree establishment.

The Yungas, a region on the eastern slopes of the Bolivian Andes near La Paz, are marked by elongated valleys with relicts of the original mountain rain forest. Due to land-use practices like slash-and-burn agriculture and the extension of coca plantations, the forests are highly fragmented. The forest relicts are surrounded by an open, largely degraded cultural landscape.

In this context, the team conducted experiments to find out to what extent ants contribute to the dispersal of a widespread, primarily bird-dispersed tree (Clusia trochiformis) and tested whether this ecosystem function may contribute to the restoration of deforested areas.
The red, lipid-rich aril, a fleshy pulp surrounding the seeds of Clusia, is highly attractive to many animals. Birds are the primary dispersers.

They feed on the nutritious part of the fruits, the fleshy aril, and defecate the seeds. Ants haul seeds, which have fallen to the ground, to their nests or leave them intact on their way. Research has already been conducted on the influence of this so-called secondary seed dispersal, but very little is known about its impact in degraded forest ecosystems. The study reveals that ants reduce seed predation by rodents and increase germination success – which confirms the importance of this ecosystem function for forest regeneration.

The study has been carried out in two 3,000 ha islands of natural mountain rain forest, which are surrounded by coca fields and degraded fallows, covered with fern and shrub vegetation. The microclimate in the deforested areas is characterized by harsh abiotic conditions that limit seed germination and recruitment, and hence inhibit the re-establishment of forest trees. The researchers deposited 1,440 Clusia seeds in 72 depots at six sites. At each site, they studied three habitat types: forest interior, degraded habitat close to the forest and degraded habitat far from the forest edge.

To quantify the effect of rodents in addition to the impact of ants, half of the depots where equipped with wire exclusion cages.

Well-concealed: ants reduce predation and increase germination

"Ants readily approached and hauled away about 60 percent of all seeds," says Silvia Gallegos, lead author of the study and a doctoral student at the Biodiversity and Climate Research Centre (BiK-F) and the University of Halle-Wittenberg. 48 hours and again one month after establishing the depots, the team searched for the seeds within a 2.5 meter radius. More than 80 percent of the seeds transported away could be relocated. In most cases, the ants removed the aril, which is a benefit for the plants, due to a lower risk of fungal infestation and a higher germination rate.

But there are more positive effects of ants: "Especially in the degraded habitats, we found that seeds which had been removed by ants were predated less often and germinated more frequently than the unmoved seeds," explains Dr. Matthias Schleuning, co-author and scientist at BiK-F. Quite often, the ants removed the seed aril only in their nests or on the way there – often leaving the seeds protected by the litter layer.

Under the leaf litter, the seeds were less likely to be detected by rodents or other seed predators and benefited from the humid conditions, favorable for germination. The effect in the deforested habitats was clearly visible: one month after the experiment had started, establishment of seedlings was about five times higher for dispersed than for non-dispersed seeds. Dispersal distance had a positive effect as well: The farther the ants had transported the seeds, the higher was the chance that Clusia seedlings had established.

Even more important services by ants in the future

Ants have a clearly positive impact on the dispersal and establishment of the investigated tree species. This is particularly relevant as other animal and plant species may follow the species that facilitates the establishment of others. "We may use our knowledge to stimulate the establishment of Clusia in degraded habitats and enhance the regeneration of deforested areas" says Silvia Gallegos. Due to the ecosystem service provided by ants in the degraded areas, a faster and sustainable establishment of tree seedlings like Clusia may be expected.

In the medium term, this will enhance living conditions for a number of other animal and plant species and accelerate the regeneration of the mountain rain forest ecosystem. Schleuning concludes: “Drought frequencies in the Andes are likely to increase in the future. Under this scenario, the dispersal function of ants may further increase in importance for the restoration of tropical mountain forests.”

Publication:
Gallegos, S. C., Hensen, I., & M. Schleuning: Secondary dispersal by ants pro-motes forest regeneration after deforestation. - Journal of Ecology, DOI 10.1111/1365-2745.12226

For further information please contact:
Dr. Matthias Schleuning
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Tel. +49 (0)69 7542 1892
Matthias.Schleuning@senckenberg.de

Silvia Gallegos
LOEWE Biodiversity and Climate Research Centre (BiK-F)
Tel. +49 (0)69 7542 1887
silvia.gallegos@senckenberg.de

or

Dr. Julia Krohmer
LOEWE Biodiversity and Climate Research Centre (BiK-F),
Transfer office
Tel. +49 (0)69 7542 1837
julia.krohmer@senckenberg.de

Sabine Wendler | Senckenberg
Further information:
http://www.senckenberg.de

Further reports about: BiK-F Biodiversity Climate Senckenberg ants dispersal ecosystem effect forests germination habitat seeds species

More articles from Ecology, The Environment and Conservation:

nachricht Saving coral reefs depends more on protecting fish than safeguarding locations
03.09.2015 | Wildlife Conservation Society

nachricht Seabird SOS
01.09.2015 | University of California - Santa Barbara

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fraunhofer ISE Develops Highly Compact Inverter for Uninterruptible Power Supplies

Silicon Carbide Components Enable Efficiency of 98.7 percent

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have developed a highly compact and efficient inverter for use in uninterruptible power...

Im Focus: How wind sculpted Earth's largest dust deposit

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...

Im Focus: An engineered surface unsticks sticky water droplets

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.

Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...

Im Focus: Increasingly severe disturbances weaken world's temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Together - Work - Experience

03.09.2015 | Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

 
Latest News

Lighter with Laser Welding

03.09.2015 | Process Engineering

For 2-D boron, it's all about that base

03.09.2015 | Materials Sciences

Phagraphene, a 'relative' of graphene, discovered

03.09.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>