How This Delicious Fruit Hampers Reforestation in Madagascar

Explore

IIf you want to spot lemurs in Madagascar, try an area where strawberry guavas bear fruit. Consider especially the mountainous rainforests of Ranomafana National Park, a UNESCO World Heritage Site, where lemurs love to feast on guava fruit. But a recent study published in Biological conservation shows that strawberry guava, while providing juicy food for lemurs and humans, is damaging the park’s ecosystems.

Originally from Brazil, strawberry guava (Psidium Cattleyanum) was introduced to Madagascar by 19th-century settlers, who preferred hard, durable wood for construction. Over time, the plant showed its invasive tendencies, spreading and forming dense understory thickets, particularly in open areas where the rainforest canopy has been damaged by storms or human intervention.

American and Malagasy researchers compared areas invaded by strawberry guava with adjacent, uninvaded areas. They focused on vegetation structure, soil composition and the abundance and diversity of arthropods. The data showed that strawberry guava was changing the native forests of Ranomafana National Park on several levels.

Where guava grows, soils are less nutrient rich, lacking organic matter and essential minerals like nitrogen and ammonia. Understory vegetation is up to 3.5 times denser, crowding out other plant species. Not to mention that the insect fauna of the forest floor is less diverse and distant from decomposer insects. And, although native tree seeds take root beneath thickets of strawberry guava, their development appears to be arrested at the seedling stage, so they never become fully grown canopy trees.

“Our study shows that when strawberry guava becomes established, this natural regeneration process can stop, halting the recovery of native species at an early stage and disrupting the soil, insect and plant communities that support the rest of the forest,” lead author and Rice University biologist Amy Dunham explained in a press release.

Read more: “On the Trail of a New Understanding of Invasive Species”

Recognizing the negative impacts of the invasive strawberry guava on the ecosystem lays the foundation for restoring its native plant flora. But that’s easier said than done, researchers say, for both cultural and structural reasons. “Strawberry guava is extremely difficult to eradicate, useful to the Malagasy people and positively associated with lemurs,” Dunham added.

Strawberry guava is a prolific producer of seeds that can also germinate from roots and stems. Thus, a concerted program of herbicides, cutting and burning would be necessary to eradicate strawberry guava.

While this won’t make Madagascar’s lemurs happy in the short term, it will improve the long-term health of their Malagasy ecosystems.

Enjoy Nautilus? Subscribe for free to our newsletter.

Main image: Amy Dunham / Rice University

• Devin Reese

  Published on February 12, 2026

  Devin Reese is the editor-in-chief of Natural history and a science writer based in Alexandria, Virginia.