Savannahs

Threats

Invasive alien species:

Acacia mangium and the Paperbark tree Melaleuca quinquenervia were introduced by man to respectively revegetate mining sites and for the timber industry. Characterised as being invasive due to their rapid growth and expansion in the wild, these trees are capable of altering the nature of the soil thus threatening savannas and other open habitats in Guiana.

Habitat destruction:

The accessibility of the dry savannah renders them susceptible to property and agricultural development which is more and more worrying. Their area has declined considerably due to a lack of understanding of their environmental role and lack of management tools. This singular habitat is being transformed into agricultural prairie maintained using fertilizers, into quarries or through speculative development.

Les actions

Control of invasive alien species

Acacia mangium control will be started in order to eradicate the species from all “Conservatoire du Littoral” (Coastal conservancy) sites. Also, two buffer zones will be created in order to prevent its expansion. Both chemical and mechanical control of the Paperbark tree will be tested in order to choose the most efficient solutions with the objective of later employing them over a large area.

Replacing Acacia mangium:

Despite the threat that it presents to the savannahs, local people use the species as firewood, for construction and protection against the wind and sun. The production and planting of Acacia mangium replacement species will be trialled in order to produce a selection of local non-invasive species that can be used as a replacement for the acacia.

The expert

Anna Stier

Project leader with the GEPOG « Groupe d’Etude et de Protection des Oiseaux en Guyane » (Guyana bird protection study group) and an expert of the Guiana dry savannahs

What do the people of Guiana think of this ecosystem?

An anthropological study has shown that this depends on a person’s profession, culture and background. They might be considered as being “empty” spaces that need to be transformed, or as a landscape heritage that singularizes those coastal parishes where they occur.

How have things changed since you arrived?  

7 % of the savannah has been lost between 2001 and 2015 but this tendency has slowed in recent years. Areas are more and more isolated and equally invaded by alien trees that tend to thrive in open spaces. Only 2.4 % of the Guiana savannah is protected whereas 75 % is classified ZNIEFFs « Zone Naturelle d’Intérêt Ecologique Faunistique et Floristique” (similar to SSSIs) – and thus known for their ecological interest. When we consider that they have 16 % of the area’s total flora on just 0.3 % of its area according to the latest information, the stakes are high.

What are the main threats to the savannah?

Mainly the overall loss of the habitat and invasive alien species, especially Acacia mangiun and the Paperbark that are transforming open spaces into mono-specific forests of alien species.

What do you want from the LIFE BIODIV’OM program concerning the conservation of this habitat?

I hope that the project will allow for more consideration and awareness of the savannahs value, be it as a natural, cultural or historic heritage.  In parallel, I hope that the threat posed by alien species for these fragile and not very resilient habitats can be controlled so that we won’t see this landscape disappear from the Guianese coast.