We are also in a Karst area in Puglia (Southern Italy). Our five acre property was planted with olives, some over a hundred years old, walnuts, almonds, figs and a virety of other fruit trees as well as native oaks. Wild asparigus, chickories and many other edible plants grow. Our property has a natural cistern at the top of the property that had water all last summer.Durring the summer, water trucks can be seen driving all around the countryside filling peoples cisterns. We are at about 400 meters and the wells here are about that deep. Stone walls were built over the centuries to terrace the land, and look to me like they are serving a similar purpose to swales. We also have a thin layer of a redish brown clayish top soil varying in depth from about 30cm to 1 meter. The local tradition is to remove all organic matter from the soil. I am fighting this trend and also feel having a lot of mulched organic matter is the best solution for moisture retension. There is a four hundred year old drystacked limestone structure called a trullo with a cone shaped roof. I am slowly renovating this structure, but want to keep it original and off the grid.
Thanks to all for the great information on this site.