Effects of Cadmium and a One-Time Drought Stress on Survival, Growth, and Yield of Native Plant Species1
- L. J. Miles and
- G. R. Parker2
Andropogon scoparius, Monarda fistulosa, and Rudbeckia hirta were grown from seed for 6 weeks in an uncontaminated rural site soil and a heavy metal-contaminated urban site soil. The rural site soil was amended with cadmium chloride. Plants grown in both soils were subjected to a one-time drought stress. Survival, shoot weight, root weight, total weight, height, and weekly growth of Andropogon and Monarda were adversely affected by cadmium (Cd) addition and drought stress. Results were similar for Rudbeckia except that shoot, root, and total weight were not significantly affected by drought stress. Root weights of Monarda and Andropogon were more severely affected by Cd addition than were shoot weights. Root/shoot ratios were not significantly affected by drought stress for any species. Drought stress and Cd addition effects were found to be additive for Monarda and Andropogon.
The effect of soil Cd addition on growth was found to be primarily due to an initial delay in growth rather than a reduction in the overall rate of growth. However, on the heavy metal contamination urban site soil the growth rate was found to be reduced. This was especially true for Andropogon which was found to be most tolerant of Cd addition to the rural site soil for the species tested. The reduction in growth rate of plants on the urban site soil was probably not due to Cd alone.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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