ניר בתי גידול של צומח ומערכות אקולוגיות ויערניות

We studied the root systems of urban sidewalk trees, in relation to soil structure and properties,  and compared them to root systems of trees in Israel’s natural maquis. Understanding the rock-soil-root interactions and hydrodynamics in natural habitats,  can shed light on how trees grow in urban environments, which are difficult to study in situ and explain how urban trees survive the long and dry summers.Natural forests and maquis in Israel grow mainly in rocky environments, with their roots inhibiting soil pockets surrounded by porous chalk which serves as a water reservoir. In summer, stored water diffuses from the chalk's capillary pores towards the soil pockets and into the roots. If the habitat is composed of dolomite, water stored at the bottom of karstic pockets is taken up by the roots. In the coastal plain where the soil is sandy red loam (Hamra),  a deep layer of clay preserves water, is where most root hairs are found.Our excavations for exposing root systems of sidewalk trees in Tel Aviv revealed that roots can extend over 10 m from the trees, and reach depths over 2.75 m, mostly in the clay layer of the Hamra. Our observations resolved a local debate concluding that urban tree growth is predominantly limited by water availability, and not by the lack of aeration.Understanding that urban tree root systems under sidewalks, follow similar principles of roots in natural maquis ecosystems, could be the basis for future planning of tree planting and irrigation design in the cit