Forest restoration

Invasive alien species pose a grave threat to oceanic islands, such as Mauritius.

Non-native or exotic organisms often outcompete and kill native flora and fauna, contributing to their extinction. Whole landscapes can be changed as invasive species can alter fire regimes, exacerbate soil erosion, and reduce water quality. Our strategy is to remove the problem species, animals and plants, and reintroduce endemic species so we can safeguard what little biodiversity remains.

Forest restoration: controlling invasive alien plants and planting native species

While there are more non-native plant species in Mauritius than native, not all are invasive or problematic.

The worst invasive alien trees that our restoration teams battle to control are:

Hiptage benghalensis, liane cerf
Origin: India, Asia

Psidium cattleianum, Chinese guava
Origin: Brazil

Tabebuia pallida, tecoma
Origin: Caribbean Islands

Ravenala madagascariensis, Ravenala
Origin: Madagascar

Syzygium jambos, Jambos
Origin: Malay archipelago

Litsea spp., Bois d’oiseaux
Origin: Asia

Before

• Invaded guava forest
• Low biodiversity
• Low carbon sequestration

After

• Restored forest (after 4 years)
• High biodiversity
• High carbon sequestration

Since the discovery of Mauritius by sailors, the introduction of mammals has devastated the indigenous biodiversity that evolved in their absence.

Introduced herbivores voraciously consume seeds, seedlings, and native vegetation, hindering the natural regeneration of forests, while introduced carnivores prey on vulnerable endemic bird species, causing a sharp decline in their populations by eating the eggs, chicks, and adult birds.

Pigs
Herbivore

Deer
Herbivore

Rats
Omnivore

Cats
Carnivore

Mongoose
Carnivore

Long-tailed macaque
Omnivore

Tenrec
Omnivore

Controlling these introduced species is the only way to let native biodiversity thrive. It is a long-term and sustained effort as our sites are continually re-invaded. But it makes the difference.

Our bird and reptile numbers are increasing and it is helping the forest regenerate naturally.

We manage a 50 ha. predator control grid at Ebony Forest, the largest in the Indian Ocean, and a 40 ha. predator control grid at Vallée De L’Est. By controlling invasive alien plants and animals these sites are ideal for the reintroduction of pollinators and seed-dispersers.

To learn more about our individual species projects see the individual pages.