The effect of habitat and erosion on the distribution and development of Pistacia atlantica trees in the central Negev highlands of Israel

Pistacia atlantica trees have a very limited distribution in wadis in the central Negev highlands, and erosive processes may have a negative impact on the recruitment and survival of the trees. We measured the sizes of the trunks of adult trees, the condition of their canopies, fruit density, insect herbivory, and soil parameters - both in eroded and noneroded habitats. This was to determine the habitat soil quality and how it relates to the demographic disposition and vitality of these trees. The results revealed irregular size/age distribution and possible poor recruitment. There were no differences in fruit density between trees in eroded and noneroded habitats. However, analysis on gall density per branch revealed that Slavum wertheimae prefer host plants in relatively uneroded habitats. Analysis of water-holding capacity, soil organic carbon content, and pH revealed significant differences, with better soil quality existing in noneroded areas.