Kolo Yeo

Assessing the Impact of Human Pressure on Biodiversity Conservation in Banco National Park – The Use of Ants as Bioindicators

Ants.

Sensitisation on the park.

Team member digging soil to isolate a monolith.

Ants' identification.

Town/RegionCountryCategoriesDate
Banco National Park, AbidjanCote D'IvoireAfrica, Insects3 Nov 2009

Banco National park is 3000ha of primary forest situated inside Abidjan city. It is one of the rare urban National parks in West Africa. This forest offers many ecosystem services to the city inhabitants (air purification, climate regulation, entertainment opportunities). It also constitutes a refuge for the Guineo-congolean forest biodiversity. Despite its importance, the park is victim of several aggressions (abusive logging of rare species, poaching, searching for firewood and medicinal plants, pollution, and uncontrolled human settlements threatening its limits). These threats are due to people living around the park and also to neighboring industrial units. This situation was worsened by massive arrival at Abidjan of people coming from the inner country during the recent militaro-political crisis. These human pressures give rise to a fundamental question as what is the current conservation state of the park.

My project intends to assess impacts of these pressures on biodiversity, focusing on ant communities that are known to reflect their habitat’s health. Ants play important roles in terrestrial food webs, functioning as predators, herbivores, mutualists and preys. They are essential for the dispersion of several plants and are considered to be ecological engineers because they can influence nutrients availability for other organisms.

I’ll use standard methods for collecting ants, and investigate species richness, diversity and community structure along an anthropogenic gradient. I’ll define two zones according to this gradient: a zone under human influence and an intact zone.

I’ll address ants from 3 strata:

-Leaf litter ants will be collected using Ants of Leaf Litter protocol which combines Winkler bags’ use for extracting ants from sifted litter and pitfall traps for capturing foraging ants. This protocol uses 200m transect, along which 20 litter samples and 20 pitfalls are collected at 10m interval.

-Gound ants will be collected using monoliths method along a 200m transect. 20 soil monoliths (30cmx30cmx15cm) will be dug out at 10m interval and ants sorted by hand in the field.

-Arboreal ants will be collected using tuna baits placed at 1.5m high on 20 tree truncks 10m apart along a 200m transect.

I’ll Chose 3 replicates sampling sites in each zone.

I hope to provide understandable scientific information about the threats on the park. Such information may help persuade the authorities about the need to reinforce the park’s protection. I also aim at promoting ants as a tool in conservation biology in Côte d’Ivoire.

For more information contact koloyeo@yahoo.fr

Project Update: February 2010

During November2009, I gathered all the materials and equipment needed to run the project. In December 2009 the team started the first activity i.e. the anthropogenic gradient determination. We divided the Banco National Park into sectors and scrutinized each of them in search of evidence indices of perturbation due to human impact.

A particular effort was made in the peripheral and central areas. We completed this work at the end of January 2010 as we identified thee zones as degraded and thee others as intact. From February 5th 2010, we have started sampling soil living ants.

Project Update: July 2010

Ant sampling was completed at the end of April 2010. We made a change in the method for sampling arboreal ants. We used leaf beating instead of baiting ants with tuna because the dominant arboreal ant’s species belonging to genus Crematogaster monopolized the tuna baits. The same species often occupied half of the baits along transect. As the objective is to capture as many species occurring in the area as possible, we preferred beating the leaves above a 1m² white cloth using a stick and collecting the ants that fall onto the cloth. We are currently identifying the ant species collected during the whole sampling.

Final Report

Read more about the activities undertaken and findings of this project in the final report below.

File DownloadSize
Final Report691 KB

Other Projects in: