Toxic Effects of Serpentine Soils on Plant Growth

Serpentine soils are distributed in a small area in Korea, and generally exhibit high contents of Ni, Cr, Fe, Mn, Co and Mg. We investigated the growth of woody plants and herbs in the Andong serpentine area, Korea. Pinus densiflora and P. rigida growing on serpentine soils have high contents of Fe, Mg, Ni and Co, with contents approximately twice as high as those of non-serpentine plants. Tree species on serpentine soil also had lower ratios of tree height/DBH than trees in a control area. In greenhouse culture experiments on two bodenvag herb species, Setaria viridis and Cymbopogon tortilis, the biomass of the plants was significantly affected by soil type but not by seed origins. After 66 days, the growth of S. viridis and C. tortilis seedlings was significantly inhibited in serpentine soil, and the dry weight of each species showed significant negative correlations with soil heavy metal contents (Ni, Co and Cr). These results suggest that the growth of plants was inhibited by properties of the serpentine soil, and in particular, their high heavy metal concentration, which induced dwarfing in woody plants and reduction of total plant biomass in herbs.