In Ibity, located 170 km south of the capital, the endemic biodiversity of the savannah, such as Aloe, Pachypodium, Hypochoeris, Cynorkis (orchid), critically endangered (CR) according to the International Union for Conservation of Nature (IUCN) Red List, is threatened by the spreading phenomenon of invasive plants. Weeds and pine seedlings contribute to endanger these endemic species. Some are proliferating thanks to fertile soil, others under the action of the wind. Misssouri Botanical Garden (MBG), the manager of the protected area, has opted for a rather disruptive method to fight invasive plants: fire.
To better understand the approach, let’s consider this background information on fire:
- Fires often come from human sources, but they may also occur naturally. In Ibity, strikes of lightning ignite bush fires naturally during the rainy seasons (about 5 times a year);
- Fires contribute to the germination of certain seeds. The principle of slash-and-burn and fires for grazing land explains the deforestation process in the country. Thus, before the rainy season (November to April) the land is burned in order to promote young shoots;
- The wind and the dry vegetation are conducive to the extension of the fire.
Ibity protected area has opted for the early fire method by taking advantage of these fire characteristics. Meaning, at the end of the rainy season and the beginning of the dry season, when the temperature begins to drop, the wind is not very strong yet, and the grass is still moist (biomass moisture), conditions are favorable to avoid uncontrolled fire spread. The savannah is then burned but fire extension is kept under control. As a result, pine seedlings and weeds stop growing and native species are preserved. In addition, the fires encourage the dormant Tapia (pyrophyte species), a distinctive feature of Ibity which can regenerate naturally. Finally, these early fires also protect against late fires (October) which cause the most damage, as they prevent the accumulation of biomass that facilitates combustion.
The point here is not to encourage fires, but to understand that in the case of Ibity (savanna), zero fire is not an ideal situation, and neither are too frequent fires. Therefore, a balance must be sought so that biodiversity is protected and the protected area continues to offer ecosystem services to the surrounding populations. Ibity provides drinking water for villages and irrigation for rice fields, thanks to its forests.
A portion of FAPBM funding is dedicated to invasive plant control in the granted protected areas. While predictable threats are financed under the annual grants, unpredictable ones can be the subject of a request for emergency funds, which is open to all protected areas (with permanent or even temporary status).
