The Hyperspectral Response Of Carex Cinerascens To Pb And Combined Pollution Stress

The speeding up of the industrialization, urbanization and the rapid development of economy, it has led to the increasingly serious heavy mental pollution in Chinese soil and water and has posed a serious threat to human health and the sustainable development of ecological environment. Took the dominant plant Carex cinerascens(C. cinerascens) and the main heavy metal Pb pollutant in the Poyang lake wetland as the research objects in thesis, by means of establishing of field experimental base, monitored the spectral parameters change of C. cinerascens under different single Pb concentrations and combined concentrations of Pb, Cu, Zn during its whole culture period, which are the Location and Depth of Blue Valley, the Location and value of Green Peak, the Location and Depth of Red Valley, the Location and value of Red Edge, the Red Edge Slope, the Normalized Difference Vegetation Index of Red Edge(NDVI705), the Near-Infrared reflection level ground of average reflectance from 750 to 1250 nm(R750-1250), including seeding stage, growing season and flowing season, so as to studied C. cinerascens hyperspectral response under heavy mental pollution, the results showed as follows:1 For single Pb pollution, we designed the 0, 500, 1000, 1500 and 2000 mg/kg treatments:(1) In the range of test concentration for single Pb pollution, C. cinerascens’ wither and death phenomenon doesn’t appear during its whole culture period, so the supreme tolerance concentration for C. cinerascens was more than 2000 mg/kg;(2) With the increased of added Pb concentration, Pb content in the leaf of C. cinerascens and available content of soil raised obviously, while SPAD value, which on behalf of the relative content of chlorophyll, in the leaf of Carex cinerascens reduced obviously;(3)The sensitive spectral bands and characteristic parameters of the leaf Carex cinerascens responded to Pb pollution were the Green Peak value at 550 nm, the depth of Blue Valley at 495 nm, the depth of Red Valley at 675 nm, the peak value of Red Edge and the Red Edge Slope at 725 nm. During the whole culture period, the relationship between the depth of Blue Valley, depth of Red Valley, peak value of Red Edge, Red Edge Slope, NDVI705, R750-1250 and Pb content in the leaf were the negative correlation, but it had a positive correlation with the Green Peak value;(4) During the whole culture period, the changes rule between the SPAD value and spectral characteristic parameters which included the depth of Blue Valley, the depth of Red Edge, the peak value of Red Edge, the Red Edge Slope, NDVI705 and R750-1250 were relatively consistent during growth of Carex cinerascens, which was reduced gradually along with the time;(5)Meanwhile, the spectral parameters in growing stage was found more sensitive than those in two other periods, so growing season was the best monitoring growth period.2 For the combined pollution of Pb and Cu, we designed the 0, Pb400/Cu100, Pb400/Cu200, Pb600/Cu200, Pb800/Cu100 mg/kg treatments:(1) With the increased of added Pb and Cu concentration, Pb and Cu content in the leaf of C. cinerascens and available content of soil raised gradually in general;(2)Stress of Cu predominate the combined pollution of Pb and Cu, because there was little effect between the increase of Pb concentration and the Cu content in the leaf and available content of soil;(3)During the whole culture period, there was no significant correlation among of the content in the leaf, available content of soil, chlorophyll content of leaf, spectral characteristic parameters.3 For the combined pollution of Pb and Zn, we designed the 0, Pb400/Zn400, Pb600/Zn600 mg/kg treatments:(1) Pb and Zn content in the leaf of C. cinerascens and available content of soil raised gradually along with the increased of added Pb and Zn concentration, while SPAD value in the leaf reduced by degrees;(2) The spectral parameters in growing stage was also found more sensitive than those in two other periods, so growing season was the best monitoring growth period for the combined pollution of Pb and Zn. And the value of Red Edge and Red Edge Slope was found more sensitive than other spectral parameters, so they were determinated for monitoring spectral characteristics.4 For the combined pollution of Pb, Cu and Zn, we designed the 0, Pb200/ Cu100/Zn200, Pb200/Cu200/Zn200, Pb200/Cu200/Zn600, Pb400/Cu100/Zn800, Pb400/Cu200/Zn600, Pb600/Cu100/Zn600 mg/kg treatments; the results showed that all the monitoring spectral indices had no significant correlation with the concentration of added compound three metals.