Revegetation in abandoned quarries with landfill stabilized waste and gravels: water dynamics and plant growth - a case study.

Large amounts of quarry wastes are produced during quarrying. Though quarry wastes are commonly used in pavement construction and concrete production, in-situ utilization during ecological restoration of abandoned quarries has its advantage of simplicity. In this paper, rock fragments of 2 ~ 3 cm in size were mixed with landfill stabilized waste (LSW) in different proportions (LSW: gravel, RL), which was called LGM. The water content, runoff and plant growth under natural precipitation were monitored for two years using a runoff plot experiment. LGM with a low fraction of LSW was compacted in different degrees to achieve an appropriate porosity; water dynamic and plant growth of compacted LGM were studied in a field experiment. The results showed that, (1) LGM can be used during restoration in abandoned quarries as growing material for plants. (2) RL had a significant effect on infiltration and water holding capacity of LGM, and thus influenced retention of precipitation, water condition and plant growth. LGM with RL ranging from 8 : 1 to 3 : 7 was suitable for plant growth, but the target species grew best when RL was intermediate. (3) Compaction significantly enhanced water content of LGM with a low RL of 2 : 8, but leaf water content of plants was lower or unchanged in the more compacted plots. Moderate compaction was beneficial to the survival and growth of Robinia pseudoacacia. Platycladus orientalis and Medicago sativa were not significantly affected by compaction, and they grew better under high degree of compaction which was disadvantageous for the uppermost layer of vegetation. [ABSTRACT FROM AUTHOR]