A Tale of Two Highlands Part II: Ankafobe, Madagascar

Leighton Reid, James Aronson, and Chris Birkinshaw all contributed to this post on restoration in one of Missouri Botanical Garden’s community-based conservation sites in Madagascar. They are currently travelling together discussing opportunities for ecological restoration in MBG’s Madagascar Program and more generally for the country as a whole.

Madagascar’s central highlands appear as a grassy sea – an undulating terrain with intermittent red gashes where heavy rain has dramatically eroded the landscape. Driving north along the national highway from the capital, Antananarivo, one sees Eucalpytus trees growing near villages, as fuel and firewood plantations, but there is almost no natural forest. The few natural communities that remain represent vestiges of a former world.

The view across the road from Ankafobe – nearly unbroken grassland.

Our destination today is one such vestige – the Ankafobe reserve. Ankafobe is a tiny (33 hectare) strip of native forest growing near the headwaters of a highland stream. Water-loving Pandanus trees demarcate the stream bed and provide fruits for several lemur species. A Souimanga Sunbird (Cinnyris sovimanga) flitters from tree to tree. Just outside of the forest, highly flammable grassland stretches to every horizon.

Fragmented gallery forest at Ankafobe. Spikey Pandanus demarcate the streambed. Red strips in the background are incipient forest restoration plots, where the soil has been turned over prior to planting nitrogen-fixing shrubs and native trees.

MBG staff and local villagers are working to restore forest on these bare hills, but it is not an easy task. Between clumps of grass is baked, orange laterite – rock hard soil bereft of life and nutrients. Tree seedlings planted in it grow slowly, or not at all. To improve seedling growth, MBG scientists are testing several strategies. One method is to turn over the soil and seed hearty legumes, whose symbiotic bacteria replenish soil nitrogen – a key ingredient in DNA.

Leguminous shrubs, like this Tephrosia, have been planted on turned-over soil to replenish its fertility.

Crotalaria, another green manure species.

Last October, a wildfire jumped the double fire breaks surrounding Ankafobe and burned a piece of the forest. Two hundred people from the local village (with a population of 600) voluntarily and spontaneously fought the fire for three days. Their impressive response minimized damage to this small forest and raised hopes and excitement about working together on conservation going forward.

The wildfire highlighted this forest fragment’s vulnerability, but it also provided a unique opportunity to observe the response to fire by a natural biotic community that has almost disappeared from the world. A number of trees were completely burned up that had been growing in the savannah just outside of the forest. Unexpectedly, several of these resprouted from their base and from superficial roots at some distance from the main stem. Nearby, the burned grassland bloomed an interesting  array of geophytic plants – particularly orchids – that were rarely observed in unburned grassland. These observations seem to support the hypothesis that at least part of the highland flora may be adapted to fire – a controversial idea that complicates the already challenging task of managing Ankafobe.

Ankafobe is a rare gem; a green emerald that stands out from the surrounding countryside and supports at least one species found almost nowhere else. The reserve is also a special opportunity for ecological restoration. Hard-won lessons from this site could eventually be used to restore tens of thousands of square miles of Madagascar’s central highlands.

Chris Birkinshaw (center) and the Ankafobe restoration team after a rainy afternoon in the field.