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Wherever possible it is PLECserv policy to seek papers based on detailed research, which convey a hopeful message. Sometimes, it is important to deepen the knowledge about less hopeful situations, in order to be able to design improved development strategies. For example, in places where shifting agriculture is practiced, rapid recent shortening of fallow periods is foreclosing possibilities of sustainable use of the system, leading to accelerating degradation and biodiversity loss, and curtailing livelihoods. Often, this is taking place with the full knowledge of the farmers concerned. Such a case, the tavy system in the rainforest belt of eastern Madagascar is analyzed in a recent paper based on two years of fieldwork by Erika Styger, now an independent consultant based in Bamako, Mali, and four other colleagues collaborating closely with Malagasy (Betsimisaraka) farmers.

The study was conducted along the borders of one of the largest remaining contiguous rainforest corridors in mid-eastern Madagascar, with an altitude ranging from 500 to over 1000 m. Tavy is the traditional shifting cultivation system in eastern Madagascar. Primary forest or secondary vegetation is cut, burned and upland rice is cultivated for one season, followed by a root crop and subsequently left to fallow. Tavy rice cultivation is the first farming objective for the Betsimisaraka, who inherited the system from their ancestors. Upland rice fields harbour a wide variety of associated crops contributing substantially to food security.

The tavy system (fallows and upland fields) occupies between 75 and 88% of the communal landscape, in addition to 7% under agroforestry systems, 3% in lowland rice, and between 2 and 15% of forest, depending on the proximity to the forest boundary. Farmers tend to deforest their entire village territory, in order to gain the maximum amount of agricultural land. Despite this extension, fallow periods shortened from 8-15 years in the 1970s to only 3-5 years around 2000. The research team found that currently the land degradation dynamics are 5-12 times faster then previously reported. Within only 20-40 years, or 5-7 cultivation cycles, rainforests are transformed into sterile grasslands or ‘dead’ land in Betsimisaraka terminology.

Styger et al. focus in their land degradation analysis on fallow succession and integrate indigenous knowledge into their analysis. The authors describe the species succession in relation to fallow cycles after deforestation. Tree fallows persist only during the first cycle. They are subsequently replaced by shrubby indigenous and exotic invasive species. Best crop yields are obtained with the first two cycles after deforestation and start to decline significantly with the third cycle. Ferns and Imperata grass begin to invade fallows with the fourth cycle. Once they dominate over the shrubby fallow species in the fifth to sixth fallow cycle, upland rice cultivation is ended. For one or two cycles more, farmers may cultivate some root crops, but when Imperata is replaced by Aristida grass communities, land is abandoned for agriculture.

These results were integrated with the indigenous fallow categories, serving as a powerful identification tool for agricultural productivity. The categories integrate a range of attributes, such as species composition, cycle reference, vegetation appearance and growth rate, fallow height, age and most interestingly agricultural potential. With each fallow type, clear management guidelines go along that would guarantee the fallow system to restore and remain productive. Critical points in fallow management during the succession as well as the point of no return for agriculture are also clearly identified with the Betsimisaraka fallow systems.

Repeated fire use was identified to be the main driver of degradation, rapidly depleting nutrient stocks, killing woody species and replacing the endemic biodiversity with a few invasive and aggressive shrubby and herbaceous species. Farmers have a precise knowledge of degradation dynamics, and seem to be able to predict quite uniformly how many years it will take to lose their agricultural land to degradation. But farmers lack efficient and suitable technical options that would allow them to maintain their uplands in productive condition. This forces them, especially the young, to migrate to the forest boundary and continue deforestation in search of new agricultural land.

Conservation and development organizations spend a lot of money to protect Madagascar’s forests, which are among the most threatened and critical of global biodiversity hotspots. For these organizations, often, the notion of slashing and burning fallows is an acceptable form of farming so long as farmers keep out of the forest. On the other hand, agricultural development has focused on lowland rice cultivation and agroforestry systems. Very little work is done on developing fire-less annual upland cropping systems, which according to the analysis of the authors is critical in order to address the multiple problems in the region. Some encouraging and pioneering work is currently undertaken in Madagascar, but, unfortunately, its impact has not yet reached a landscape-wide scale. This is what is desperately needed.

To communicate with the authors, and/or to request a single electronic copy of the paper, write to Erika Styger at estyger@yahoo.com

E. Styger, H.M. Rakotondramasy, M.J. Pfeffer, E.C.M. Fernandes and D.M. Bates 2007. Influence of slash-and-burn farming practices on fallow succession and land degradation in the rainforest region of Madagascar. Agriculture, Ecosystems and Environment 119: 257-269.