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 Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>