Permaculture in subtropical Tertsa

The former neighbor to the left liked to have his Olive farm on flat land, so he toke the mountain on his side away. Luckily in dry areas like this such steep drops stay like this. But what should I do to prevent for worse? Planting Mimosa from nature along and on the drop to keep the earth together? And of course planting trees like Citrus and Fig along the drop to prevent the soil from sliding down. Maybe a first perpendicular swale from where you see the more horizontal grass area (left side) changing into a downward going more varied grass area? A swale is a permaculture term for a sinus shape soil area in order for rainwater staying longer in that area.

View to the South from the mid lower part of the land. Height around 200 meter. Some of the tops around are 340 meter in height.  View to the south.  View to the south, from the middle lower part, with natural green.  View to the southwest. Middle part. Natural green and some parts with grasses.  View to the East, with a natural green  'mammoot azalea'. The highest part of the land seen from the middle part of the land, including the top of 3.000 m2. This grass is bordering a 3-4 m deep cut down in the land to the left, where the neighbor has made his land flat for olive trees in rows. From the middle part taken to the top, view Northeast. The high tree being an olive tree. The land has not been watered or cared for for 20-30-40 or more years. All photographs taken at the end of April with temperatures around 24 C.  View for the upper middle part of the land, more land inwards, looking NE. The tree on the right close by will be bearing fruit.