Monitoring On The Chlorophyll Fluorescence Change Of Plants Caused By Coal Mining Subsidence In Semi-Arid Area

This experiment site was on the 52302 working face which located in Daliuta coal mining area and used Poplar, Caragana Korshinskii and Artemisia ordosica as the research object. By field monitoring and laboratory analysis, the effect on plant growth in different land type caused by coal mining subsidence and monitoring methods was investigated; Then the plant growth situation after coal mining and the relation with environment factors was researched. Meanwhile, the Caragana Korshinskii and Artemisia ordosicachlorophyll fluorescence response of root injuried plant was investigated and the quantitative relation between chlorophyll fluorescence parameters parameters and injuried root quantities was established. The main results are as follows:.(1) Chlorophyll fluorescence kinetics technique was effective tool for mining area plant monitoring, and more precise than index of photosynthesisto reflect photosynthetic organizationsituation. By using Principal Component Analysis,we got the result that affected degree on plant growth in hard beam area was greater than that in arid sandy area. Soil moisture content and soil respiration were main factors for plnat growth.(2)The fluorescence parameters of Poplar and Caragana korshinskiion May 20 thand Sep 20 th had significant difference to control, but had little differences onAugust6 th. It indicated that poplar and Caragana korshinskii had been recovering on May 20 th. However the Artemisia ordosica fluorescence parameters differences between subsidence and control kept reducing. It indicated that influence of coal mining on Artemisia ordosica was short-term and unsustainable, but on poplar and Caragana korshinskii was long-term and sustainable. By analyzing the relation between fluorescence parameters and environment factors, we found that soil moisture content had most significant influence on three plants growth after coal mining, and Fv/Fm, RC/CS were sensitive to environment changing.(3)In the process of studying on the relation between different damaged root quantities and physiological response, mechanical experiment and root diameter distribution were researched. The results showed that Caragana Korshinskii 48.4% and Artemisia ordosica47.5% of damaged roots respectively were snapped when earth's surface reached the maximum tensile strain. With damaged root increasing, net photosynthesis rate was effected from stomatal limitation to non stomatal limitation, accompanied by an increase in net photosynthesis and the photochemical efficiency decline degree. Artemisia ordosica had stronger resistance than Caragana Korshinskii.