Olive trees in past desert agriculture in the Negev Highlands

In the Negev Highlands remnants of abandoned and presently maintained Bedouin fruit trees can be found. Most of the older groves were deliberately planted in preexisting agricultural systems that were built in the distant past, mainly during the Byzantine era. In these groves a variety of domesticated fruit trees such as date-palms, pomegranates, almonds, grapevines and olives, can be found. The trees found in these abandoned sites, throughout the Negev Highlands region, have not been artificially irrigated for at least several decades. Despite the lack of water, some of the trees continue to flourish and various trees even persist in bearing fruit to this day. The olive trees growing in the Negev Highlands can be divided into several periods. The oldest trees are the descendants of trees planted in the area during the Byzantine period, and the youngest were planted by the Bedouins recently. The factors affecting the survival of the trees are geological, such as rock types and distribution contributing to the potential runoff water, topographic layouts enhancing runoff water and various land features, such as soil water holding capacity, depth, salinity, and the organic matter content.