We have spent quite some time studying the role of the walled bedouin gardens in the arid landscape of South Sinai. Having learnt orchard agricultural techniques from the Byzantine monks who flocked to Mt Sinai in the 3rd to 6th century, the Bedu of South Sinai are the only bedouin group to adopt this method of cultivation, siting their gardens where normally unavailable water can be brought to the surface. In normal arid years, the gardens are island-like oases of greenery in a landscape of apparently barren rock, forming a network of vegetated patches that maintain biodiversity at substantially higher levels than would be the case without them: they are the arid-land equivalents of 'run-off agroforests'. All measured ecosystem services benefit: pollination, soil quality and decomposition by the macrofauna. Olivia Norfolk (MRes 2009-2010; PhD 2012-2015) studied the gardens from both economic and biodiversity standpoints. Hilary Gilbert (postdoc, Leverhulme grant 2012-15) studied the contribution the gardens (and flocks) make to household economics and child health.
Rainwater harvesting techniques such as the Bedu use are known to improve crop yields and enhance food security in arid regions, but this is one of the first studies to address the impact upon dependent wildlife. The results show that the irrigated gardens support a much more diverse plant community than the surrounding unmanaged habitat, providing an abundance of floral resources which in turn enhance wildlife abundance and species richness.
Within their gardens the Bedu also grow culturally important but minor crops such as fennel and mint. Our work showed that these elements have a dramatic positive effect upon the structure of plant-pollinator visitation networks: such minority cultivated plants supplement the resources provided by wild flowers, and maintain the pollinator community through the hot summers. In early spring the presence of wildflowers has a positive effect upon pollination services to the primary crop (almond), by attracting higher densities of wild pollinators into the gardens and facilitating enhanced fruit set. The higher abundance of resources within the gardens increases the variety and density of birds in the region, and are particularly important for spring and autumn European migrants, providing an important stop-over for numerous small passerines.
In conclusion, this study provides evidence that irrigated agriculture in arid environments has the potential to increase biodiversity above that found in the unmanaged environment. The implications on a local scale are that traditional Bedouin practices can have a positive influence on wildlife within the Protectorate, and thus initiatives to fund and support gardeners should be encouraged. On a wider scale the results suggest that rainwater harvesting may provide a sustainable mechanism for increasing food security in arid regions, offering a low-cost strategy for increasing agricultural productivity that does not undermine the biodiversity on which it depends.
Norfolk O, Eichhorn M & Gilbert F (2016)
Flowering ground vegetation increases wild pollinator densities and enhances fruit set of an orchard crop.
Insect Conservation & Diversity, in press
de Swaaf K (2015)
Biblische Raststation und Winterresidenz. [Biblical rest-stops and winter residences]
Der Standard 22 April 2015: 16
Norfolk O, Power A, Eichhorn M & Gilbert F (2015b)
Migratory bird species benefit from traditional agricultural gardens in South Sinai.
Journal of Arid Environments 114: 110-115
Norfolk O, Eichhorn M & Gilbert F (2015a)
Contrasting patterns of turnover between plants, pollinators and their interactions.
Diversity & Distributions 21(4): 405-415
Norfolk O, Eichhorn M & Gilbert F (2014)
Culturally valuable minority crops provide a succession of floral resources for flower
visitors in traditional orchard gardens.
Biodiversity & Conservation 23: 3199-3217
Norfolk O & Gilbert F (2014)
Insect visitation rates to wild flowers increase in the presence of arid agriculture in South Sinai, Egypt.
Journal of Arid Environments 109: 83-87
Norfolk O, Eichhorn MP & Gilbert F (2013)
Traditional agricultural gardens conserve wild plants and functional richness in arid South Sinai.
Basic & Applied Ecology 14: 659-669.
Norfolk O & Gilbert F (2012)
Rainwater harvesting and arthropod biodiversity within an arid agro-ecosystem.
Agriculture, Ecosystems & Environment 162: 8-14