Temporal patterns in recruitment from the seed bank during drawdowns in a prairie wetland.
Temporal patterns in seedling recruitment of seven wetland plant species in a Canadian prairie marsh are described. Recruitment occurred during artificial drawdown or drainage. Within a season, most seedlings were recruited during June when soil moisture was high, temperature was moderate, and conductivity was low. Differences between drawdown treatments in first-year recruitment of certain species appear to be due to differences between years in soil moisture and temperature, not differences in densities of seeds in the soil prior to drawdowns. Far fewer emergents but more mud-flat annuals were recruited during the second year of the 2-year drawdown than the first. Considerable mortality occurred during the second year in seedling of emergent species established in the first year of the 2-year drawdown.