The response of Iris pseudacorus to the introduction of earthworms and to a variety of substrates in constructed wetland systems was investigated under greenhouse conditions. The growth of I. pseudacorus was influenced by the presence of earthworms and the type of substrate. Plants grown on a sand substrate had the fewest seedlings and the smallest plant size. Because the sand substrate started with the lowest nutritional value, the addition of earthworms resulted in the largest increase in fresh and dry weights of I. pseudacorus, when compared with the other pairs of substrate treatments, with or without earthworms. The addition of earthworms increased pod production in I. pseudacorus, especially on substrates of mixed sand and soil, and with mixed sand and organic matter. Pod production in I. pseudacorus pots with earthworms varied by substrate.

This paper investigates the differences in the temporal heterogeneity of soil moisture between natural restoration ecosystem without disturbance (named as eco-1), restoration ecosystem with disturbance (named as eco-2) and shrubs ecosystem (named as eco-3) in red soil hillside fields. The probe soil moisture measured at 20 and 40 cm below the soil surface Hydrosense Portable Time Domain Reflectometry (TDR) system. The results showed that: (1) Daily measurements during a growing season showed significantly temporal interactions between vegetation and water. Soils under eco-2 (restoration ecosystem with disturbance) and eco-3 (shrubs ecosystem) were wettest at the start of the growing season but dries at the end; (2) The coefficient of variation of soil moisture content over time during the growing season was significantly higher in eco-2 than in eco-1, and at two depths beneath the soil surface (20 and 40 cm).