Ibity Mountain, Madagascar: Background and Perspectives for Ecological Restoration

For decades, Madagascar has drawn scientific attention for its unique biodiversity and high levels of endemism. This island nation has long been recognized for its remarkable biota, which has evolved during nearly 100 million yr of tectonic isolation, with a diverse range of climates and substrates, and a varied topography (Kull 2000). Current estimates suggest that the Malagasy flora consists of approximately 13–14,000 species, more than 90% endemic (Phillipson et al. 2006), which occur in a wide range of native vegetation types, many of which have been highly degraded or replaced by secondary formations resulting from human activities (Lowry et al. 1997).

Tapia woodland is a sclerophyllous formation restricted to Madagascar’s central highlands, dominated by the endemic tapia tree (Uapaca bojeri). This formation is adapted and resilient to the region’s natural fire regime and occurs today in scattered, isolated stands that total no more than 132,255 ha. Most other native woody vegetation types of the central highlands have been replaced by grasslands formed during the last 1,500–2,000 yr primarily by a human-caused increase in fire frequency well above that of the natural regime. These grasslands are burned annually to renew livestock pasture, clean fields, or control pests (Kull 2000), and fires encroach well into the interior of the tapia woodland. Today the remaining tapia woodland has an extensive herbaceous layer and an open canopy with many woody representatives of the endemic family Sarcolaenaceae (Lowry et al. 1997, Figure 1). Traditional management practices appear to have spared remnants of tapia woodland because this vegetation plays an important role in the local economy as a source of fuel wood, edible fruits, mushrooms and medicinal plants, and as habitat for wild silk worms (Borocera madagascariensis), whose cocoons are collected by local residents to produce cloth (Gade 1985, Kull 2002). However, the remaining stands are fragmented and structurally-modified by a changing fire regime that hinders woody species regeneration. Tapia woodland was once managed using traditional methods, which allowed sustainable extraction of forest resources for local consumption. Today it is still partly managed using traditional methods, but newer practices have caused degradation through increased cultivation and grazing, illegal exploitation and marketing of natural resources, reforestation with exotic tree species such as swamp mahogany (Eucalyptus robusta), Baguio pine (Pinus kesiya) and silver wattle (Acacia dealbata), and changes in the fire regime.

Figure 1.

Tapia woodland is dominated by the tapia tree (Uapaca bojeri) and includes an extensive herbaceous layer and an open canopy composed largely of woody species in the endemic family Sarcolaenaceae (Photo by Swanni T. Alvarado).

A new protected area (PA) is currently being established at Ibity Massif (classified as type V, Harmonious Landscape, within the IUCN PA classification system). In December 2008, a temporary protection order was issued for Ibity (renewed in December 2010), and definitive establishment of the new PA is pending. A community-based conservation and restoration project is being coordinated by the Missouri Botanical Garden (MBG—Madagascar Program, Antananarivo) in cooperation with key Malagasy institutions and local communities. Ibity Massif is an approximately 6,000-ha quartzitic mountain located on the Malagasy highlands 25 km south of Antsirabe and 200 km south of the capital, Antananarivo. This massif is oriented north-south and ranges in elevation from 1400 to 2240 m. The MBG initiative has involved significant outreach and community education programs focusing on raising awareness of Ibity’s conservation and economic importance, the threats to its biodiversity, and ongoing efforts to reduce fire frequency and implement ecological restoration projects with significant local community participation. This approximately 45-km2 PA contributes to the Madagascar Protected Areas System, which is scheduled to encompass over 6 million ha (about 10% of the country) (Borrini-Feyerabend and Dudley 2005). The Ibity PA will protect most of the massif’s characteristic environments (dense forest, tapia woodland and woody savanna, the latter two restricted to quartzitic substrates) and rare species.

On Ibity, lightening is thought to have...