Interactions between mycorrhizal colonization and plant life forms along the successional gradient of coastal sand dunes in the eastern Mediterranean, Turkey

The mycorrhizal status of dune plant species in relation to their plant life forms was surveyed along a successional gradient of sand dune on the southern Mediterranean coast of Turkey. Roots of 64 dune plant species belonging to 30 families were collected from sand dune communities at four different successional stages: embryonic dunes (ED), mobile dunes (MD), fixed dunes (FD), and remnant dunes (RD). Of the plant species surveyed in all successional stages, 54 (84%) had formed mycorrhizal associations. Nonmycorrhizal plants with cryptophyte life forms predominated in the earlier successional stages (ED and MD), whereas the number and percent coverage of mycorrhizal plant species belonging to hemicryptophytes, phanerophytes, and chamaephytes generally increased with the stabilization of sand dunes. Arbuscular mycorrhizal (AM) colonization was found to be the dominant mycorrhizal type in ED, MD, and RD. But phanerophytes with dual colonization, AM and ectomycorrhizal, became the dominant life form with high plant coverage in the FD stage. Total percentage of mycorrhizal root length colonization showed significant positive correlations relating to soil parameters such as organic matter and nitrogen content, while negatively correlating to high soil reaction (pH).