Study On The Effects And Applications Of Phytocoenosium In The Weathering Process Of Serpentine

Serpentine has high chemical activity in the surficial environment as olivine’s metamorphic rocks, characterized by lacking of N&P and high pH with toxic metals (such as Mg, Ni, Fe, etc.) concentration in its weathering crust, which leads to special phytocoenosium in these area. Indepth study was carried out on the effects and of phytocoenosium in the weathering process of serpentine, as well as the selection and culturvation of native hyperaccumulators which can form potential biocenosis for further application with native microorganism. Process through this study can serve as reference for the enhancement of other extreme environments by using phytocoenosium. Supported by investigation analysis and experimental results, the main conclusions are as follows:(1) High rate of rock weathering in serpentine distribution area:The silicate weathering rate reaches 16.89 t/(km2* a) in the exposed area of Xiwan rock mass in Dexingjiangxi, and with the presence of phytocoenosium, the value is effectively improved by 14.1%, to 19.28 t/(km2* a).(2) Mineral phase and elemental concentration are oobviously changed by phytocoenosium in the serpentine weathering crust, which highlighted by the increased carbonate and quartz share of its roots-soil, and with the evolution of phytocoenosium, this increase becomes more prominent.(3) Phytocoenosium in the region can be divided into three types which can coexist in a small area:Moss and tolerant plant phytocoenosium; Avoidance plant phytocoenosium; Woody plant phytocoenosium. The evolution of these phytocoenosium is sequential with its diversity and biomass’ increasing.(4) Herba Sedi Sarmentosi has stronger accumulation ability of characteristic elements such as Mg, Ni than other species most of which belong to avoidance plants. BCF in all samples of Herba Sedi Sarmentosi are more than 1 when refers to in Ni enrichment capacity. The maximum concentration of Ni in samples of Herba Sedi Sarmentosi reaches 1432 ppm, which means Herba Sedi Sarmentosi can be a potential hyperaccumulators in such environment.(5) Compared with Herba Sedi Sarmentosi, Lobularia Desv has a better accumulation ability at the same concentration of the metal element, but the bottleneck is its poor adaptation to environment conditions of this study area, as well as the difficulty to live with native microbial symbiosis, which means Lobularia Desv is not suitable for application in the serpentine distribution area of this study.(6) Although the accumulation ability isn’t outstanding in reported hyperaccumulators, Herba Sedi Sarmentosi has a good adaptability in the serpentine distribution area of our study, who also has a better performance with native fungus Talaromyces flavus, excretion of its roots also promotes the formation of fungus-mineral aggregates. Herba Sedi Sarmentosi has the potential of forming symbiotic community which can be used in the serpentine comprehensive utilization, and a long period needed for a stable community formation of mineral plant-microbe-mineral system, which can participate in the process of element cycling effectively.