The Effect Of Mining Subsidence On Reproductive Characteristics Of 13 Plant Species In Typical Steppe Community

The effects of coal mining subsidence on reproductive characteristics of 13 plant species in shenmu county, Shanxi Province were studied; seed setting,1000-grain weight and seed germination characteristics were compared between coal mining subsidence areas and surrounding control areas. This study aimed to provide the effects of mining subsidence on reproductive characteristics, and to provide basis and the practice exploration for vegetation restoration in coal mining subsidence areas.The results showed that:The setting rate of Astragalus melilotoide is between 30%～50%, Stipa bungeana is between30%～80%, Stipa breviflora is between 15%～50%, Caryopteris mongolica is between 20%～40%, and the setting rate of Dracocephalum moldavica can reach 90%.In general the setting rates of perennial plants are lower.The subsidence made little influence on the plants at the study area. However the habitat condition made large differences on the setting rate.Thousand seed weights of majority plants showed little difference with the influence of coal mining subsidence. But the thousand seed weight of Stipa breviflora decreased significantly. Because of the Stipa breviflora is edificatory at the study area, the decrease of its thousand seed weight could make adverse effects on the reneneration of native grassland vegetation at the study area.The seed germinations of majority plants showed little difference with the influence of subsidence, according to the comparison and analysis of germination potential, germination rate, germination index and vigor index. But the germination potential and germination rate of Caryopteris mongolica were generally greater at non-subsidence areas.