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bioRxiv · 10.1101/585273

The land-use dynamics of potato agrobiodiversity in the highlands of central Peru: a case study of spatial-temporal management across farming landscapes

Arce Indacochea, A.·de Haan, S.·Juarez, H.·Plasencia, F.·Burra, D.·Ccanto, R.·Polreich, S.·Scurrah, M.
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Abstract

In the high Andes, environmental and socio-economic drivers are transforming land use and presumably affecting the in situ conservation of potato (Solanum spp.). To monitor the use and conservation of intraspecific diversity, systematic and comparative studies across land-use systems are needed. We investigated the spatial-temporal dynamics of potato in two contrasting landscapes of Perus central Andes: a highland plateau (Huancavelica) vs. an eastern slope (Pasco). We examined household-level areal allocations, altitudinal distribution, sectoral fallowing practices, and the conservation status for three main cultivar groups: (i) bred varieties, (ii) floury landraces, and (iii) bitter landraces. Mixed methods were used to survey 323 households and the 1,101 potato fields they managed in 2012-2013. We compared the contemporary altitudinal distribution of landraces with 1975-1985 altimeter genebank data from the International Potato Center. We show that intensification occurs in each landscape through adaptations of traditional management practices while maintaining high intraspecific diversity. Access to land and production end use (sale vs. consumption) significantly affected smallholder management and differentiated the landscapes. Total areas in Huancavelica and Pasco were allocated to 82.9% vs. 74.2% floury landraces, 9.2% vs. 25.7% bred varieties, and 7.9% vs. 0.1% bitter landraces. In market-oriented Pasco, fields in sectoral fallows between 3,901 m and 4,116 m above sea level consistently contained the highest levels of landrace diversity. The bulk of diversity in subsistence-oriented Huancavelica occurred between 3,909 m and 4,324 m outside sectoral fallows. Most of the unique landraces documented were scarce across households: 45.4% and 61.7% respectively in Huancavelica and Pasco. Bred varieties showed the widest (1,100 m) and bitter landraces the narrowest (400 m) altitudinal distributions. Potato cultivation has moved upward by an average of 306 m since 1975. Landrace diversity is versatile but unevenly distributed across landscapes. This requires adaptive ways to incentivize in situ conservation.

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Arce Indacochea, A., de Haan, S., Juarez, H., Plasencia, F., Burra, D., Ccanto, R., Polreich, S., Scurrah, M.. 2019-03-21. The land-use dynamics of potato agrobiodiversity in the highlands of central Peru: a case study of spatial-temporal management across farming landscapes. https://doi.org/10.1101/585273

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