The leaf reflectance spectra of plants polluted with heavy metal copper exhibit abnormal behavior. This paper investigates the spectral changes in copper-polluted leaves using seven spectral signatures and the spectral angle method. Wheat and lettuce were selected as the experimental subjects and were cultured in copper-polluted soil. Leaf spectra reflectance and scanning electron micrograph of ten copper treatment groups were measured in four regular periods. The reflectance spectra of the leaves were obtained using an ASD Field Spectrometer. Results showed that the irregular spectral changes of copper-polluted leaves depend on crop growth stages and crop types. The spectral angle, a simple method of comparing the vector angle of the leaf spectra with the given threshold values, has been justified as an efficient method of describing the spectral differences between copper-polluted leaves and healthy leaves. The method is very sensitive to light and the severity of copper pollution. Results also show that the leaf structural parameter ( N ) of copper-polluted leaves is larger than that of healthy leaves. The linear relationship between N and the reflectance value of the red shoulder was fitted with a correlation coefficient of 0.978. As a result, the deduced N from the leaf reflectance spectra may be used as an indicator to reflect the leaf structure distortion under copper pollution conditions. The significance of this study lies in its provision of data asbasis and theoretical support for the construction of a copper-polluted leaf reflectance spectral model.

重金属铜污染植被的反射光谱特性会发生明显改变。在本研究中，采用不同程度的铜污染土壤作为培养基质，选择春小麦、上海青两种农作物进行铜胁迫实验，获取了4个不同生育期、10个不同铜污染强度下的植被叶片的反射光谱，并采用铜污染叶片7个特征波段和光谱角的方法研究了铜污染叶片的光谱特征。结果表明，铜污染叶片光谱差异与作物时期和作物类型有关，可以采用叶片光谱角描述铜污染叶片与健康叶片的光谱差异。该方法只需与阈值做简单的比较，方法简便易行，而且对轻度及重度铜污染十分敏感。叶片光谱辐射传输模型反演结果表明铜污染叶片内部结构参数N明显变大，这也证明了铜污染使叶片内部结构更加散乱无序。在此基础上进一步建立了N与红肩处反射率值的线性关系，相关系数为0.978。本文为铜污染叶片光谱反射模型的建立提供了初步的数据基础与理论支持。

As one of the most phytotoxic heavy metals, cadmium (Cd) is easily taken up by vegetables. However, more than 0.2 mg/kg Cd content in leafy vegetables will seriously impact human health according to the standard of maximum levels of contaminants in food (GB2762-2012). Thus, it is of great significance to closely monitor the content of Cd content in leaves of the vegetables. Hyperspectral remote sensing (RS) techniques could monitor the content of metal and non-metal in crops, through a rapid and non-destructive way compared with traditional methods. In order to explore a suitable method for monitoring the heavy metal contents in the leaves of Brassica rapa chinesis under different Cd contaminations, hyperspectral remote sensing techniques were adopted for this research. In the mean time, the most sensitive parameter for certain Cd content in the leaves could also be explored. Six treatments including 0 (CK), 0.5 (T1), 1 (T2), 5 (T3), 10 (T4), 20 (T5) mg/kg of Cd in soils (calculated according to dry weight) were applied for growing B. rapa chinesis . ASD portable field spectrometer was utilized to scan the hyperspectral reflective rate of leaf samples, and Flame atomic absorption spectrometer was used to measure the Cd concentrations, on the 15th and 30th day after the beginning of treatments, respectively. After correlation analysis and stepwise regression between original spectral datum, first derivative spectral datum, spectrum parameters and Cd contents, the sensitive parameters were determined. According to these sensitive parameters, fitting models used to estimate the Cd content in vegetable leaves were established. Results showed that: (1) Both near wavelength of 540 nm and near infrared bands, the spectral reflectance of leaves were generally decreased with increasing of Cd concentration, while no significant difference was detected between the graphs of B. rapa chinesis under T1 and CK. (2) Sensitive bands of the original spectrum were mainly distributed from 690 nm through 1300 nm and the correlation coefficient of wavelength 782 nm was the highest. For first derivative spectra, a range of sensitive bands that was correlative with the Cd content located in the yellow edge, infrared, near infrared and far infrared; (3) Sensitive parameters MCARI (Modified Chlorophyll Absorption Reflectance Index), SDy (Yellow Edge Area), WI (Water Index), DCWI (Disease Water Stress Index), SDr (Red Edge Area) and Dr (The Amplitude of the Red Edge), which reflected the changes of pigment, water content and cell structure, could be used to estimate the Cd content of the leaves. The nonlinear inverse fitting models of the 6 sensitive parameters can well predict the Cd contents of leaves of B. rapa chinesis under different Cd stresses; and (4) The nonlinear inverse fitting models of the SDr derived from the data collected on the 15th day was best fitted for the Cd content in B. rapa chinesis leaves on 30 d. This study showed that the red edge area parameters can be used to estimate the Cd content in B. rapa chinesis leaves. Hyperspectral remote sensing technique is suitable for evaluating the edible security of B. rapa chinesis , and can provide fundamental information for the detection of Cd content in vegetables.

为实现利用高光谱技术快速、准确、无损地检测叶类蔬菜叶片重金属镉污染情况,通过采用室内盆栽试验,检测了小白菜在6个不同的镉浓度梯度0 mg/kg (CK)、0.5 mg/kg (T1)、1 mg/kg (T2)、5 mg/kg (T3)、10 mg/kg (T4)和20 mg/kg (T5)下的叶片高光谱反射率及其镉含量。利用相关分析和逐步回归的统计方法对叶片原光谱、一阶导数光谱和光谱参数与镉含量进行统计分析,确定了反演叶片镉含量的敏感光谱参数,并建立了估算叶片镉含量的参数模型。结果表明:(1) 在540 nm附近和红外区域,叶片光谱反射率随着处理浓度的增加呈下降趋势。T1组叶片光谱与对照组的光谱没有明显的变化差异;(2) 原光谱与镉含量的敏感波段主要在690-1300 nm,相关系数最高的波段是782 nm。一阶微分光谱与镉含量的敏感波段在黄边、红外、近红外和远红外范围均有分布;(3) 反映植物色素、水含量和细胞结构的参数MCARI(叶绿素吸收反射修正指数Modified Chlorophyll Absorption Reflectance Index), SDy (黄边面积Yellow Edge Area), WI (水质指数Water Index),DCWI(病态水分胁迫指数Disease Water Stress Index), SDr (红边面积Red Edge Area)和 Dr (红边幅值The Amplitude of the Red Edge)可分别作为反演镉含量的敏感光谱参数,其倒数回归模型能够较好地反演镉污染下小白菜叶片的镉含量;(4) 镉胁迫处理15 d时,建立的 SDr 的倒数模型估算处理30 d时小白菜叶片镉含量的效果最优。研究表明红边面积参数可以用于估算小白菜叶片的镉含量,可为评价小白菜的食用安全提供科学方法。

The paper imitated three (25, 50, 100 mg·kg -1 ) concentration uranium contamination using pot method. The tolerance and enrichment characteristics of pokeweed ( Phytolacca Americana L.) were measured, including the biomass, the plant height, stem diameter, leaf length, leaf width and the content of uranium in plant. The rhizosphere microbial community of pokeweed was studied by biolog technology. The main results showed that there might be a threshold value of uranium contamination affecting the growth of pokeweed. The threshold value might be between 25~50 mg·kg -1 . When uranium contamination was lower than this value, it facilitated pokeweed growth. However, when uranium contamination was higher than this value, it inhibited pokeweed growth. The maximum enrichment amount of uranium in pokeweed's roots, stems and leaves were 131.69 μg, 9.87 μg and 45.33 μg respectively in the mature period. Pokeweed became an ideal plant of repairing uranium tailings. Biolog-Eco test showed that uranium pollution had a negative influence on rhizosphere microbial community of pokeweed. The microbial metabolic activity was delayed. The microorganisms' choice of carbon source was transferred. Rhizosphere microbial significantly reduced the utilization of carbohydrates, carboxylic acids and amines, while they significantly increased the utilization of phenolic acids. Uranium stress caused rhizosphere microbial community functional diversity index, evenness index and dominant microbial species to be decreased. Cluster and principal component analysis of substrate reactions were performed after 96h of incubation. The results indicated that rhizosphere microbial communities of pokeweed under uranium were different from controls. The rhizosphere microbial community of pokeweed adapted to uranium at the cost of reducing the consumption of carbohydrates, carboxylic acids and amines.

在模拟低（25 mg·kg -1 ）、中（50 mg·kg -1 ）、高（100 mg·kg -1 ）剂量铀污染的条件下，采用盆栽试验，研究了美洲商陆富集铀的特点及铀污染对根际微生物群落的影响.结果表明，铀污染对美洲商陆生长的影响可能存在一个阈值，该阈值介于25~50 mg·kg -1 之间，低于该阈值时，铀污染能够促进美洲商陆的生长，反之，则会抑制美洲商陆的生长.美洲商陆成熟时，根、茎和叶的最大铀富集量分别为131.69、9.87和45.33 μg，是一种较为理想的修复铀尾矿的植物.Biolog-Eco测试结果表明，土壤中铀会对美洲商陆根际微生物群落产生负效应，铀胁迫可使根际微生物代谢迟缓，对碳源的选择发生转移，对糖类、羧酸类和胺类碳源的利用显著减少，对酚酸类碳源的利用显著增加；同时，铀胁迫可导致根际微生物群落功能多样性指数、均匀度指数及优势微生物种类降低.最后，利用培养96 h的平均吸光值进行聚类和主成分分析.结果表明，铀胁迫下美洲商陆根际微生物群落异于对照，美洲商陆根际微生物对铀胁迫的适应是以降低对糖类、羧酸类和胺类等碳源的利用为代价的.

The activities ofmining produce great heavymetal pollution which threatens the surrounding ecosystem and human s health, the heavymetals can be transported to the surrounding soi,l river and underground water. The heavy metal s stress to the biology can cause the variation ofplants and community, which is called biogeochemistry effects. The excessive copper mi pedes the growth and developmentofvegetation, such as greenness decreasing, photosynthesi sweakening, and the absorption capacity ofother elements decreasing. The leaves of the vegetation lackwater and getwithered,so the spectral characteristics changewith the influence of the stress.Dexing coppermine is an oversizemulti-metalmine bed in our country. The development ofmining has caused the pollution ofmine environment, such as the ecologic problem inmine vegetation, land, water and the heavy pollution of solid waste and tailingwater, particularly, the pollution ofheavymetals such as copper. These problems have influenced\nthe growth ofvegetation greatly.This paper studies the heavymetal contamination and the biogeochemistry responses ofvegetationRhus chinensisMill inDexing coppermine area. The spectralcharacteristicsofthe responses are systematically extracted and analyzedwith the principles andmethods of remote sensing biogeochemistry.Acid, Cu, Cd are themain environmentalpollution factors, the copper content in the soil ismuchmore than the national environment standard and the pH value of thewater in the lower reaches of the river is about three over the year.The plantRhus chinensisMillhas enriched and translocated responses to copper, thisplant is suitable for the environ-mental recoverywhich is one of themain vegetation and growswell in the area. From spectral processing such as derivative technology, continuum-removed spectra, red edge, vegetation index, we can get that the spectral position effects are notable to the influence ofheavymetals. W ith the increasing of the influence ofheavymetal stress:(1) the spectral reflectance ofRhus chinensisMillincreases obviously, about5%―30%,(2) spectral shape blue-shiftoccurs, about5―15nm,(3) the red edge slope increases, from 4.5534 to 8.9475, the variation is up to five,(4) the chlorophyll absorption depth decreases, the absorption center is near680 nm and blue-shift,(5) thewater absorption depth becomes lower and red-shiftoccurs about10―20nm,(6) vegetation indices alterobviously, the ratioB4/B3is from 18.763 to13.1839, indicating the decrease ofchloro-phyll content in leaves, theWEI( water effect index) changes from 0.098014 to0.226503, indicating the increase of in-tensity ofwater stress effect.Then some predominantcharacteristics are selectedwhich are suitable for the evaluation ofheavymetalpollutionwith the comprehensive analysis of spectral characteristics and the correlation between them and the contents ofheavymetals.

利用遥感生物地球化学的原理和方法,分析了德兴铜矿的重金属污染状况和植物盐肤木的生物地球化学效应,对盐肤木生物地球化学效应的波谱特征进行了系统的提取和分析.研究发现酸、铜、镉等是德兴铜矿地区主要的环境污染因子,野外调查及样品的化验分析表明盐肤木对铜元素呈现一定的富集作用和很强的位移效应,是适合铜矿复垦的植被.利用导数光谱、包络线去除、红边效应、植被指数等光谱信息处理方法对盐肤木的野外波谱分析表明,随着叶片中Cu等金属元素含量的增大,其产生的毒化效应的波谱特征越明显,盐肤木叶片光谱反射率明显升高,波形蓝移,红边陡坡斜率增大,叶绿素吸收深度变浅,吸收中心稍有蓝移,水的吸收深度变浅,吸收中心位置红移,绿度指数变化明显.对波谱特征及其与重金属含量的相关关系综合分析后认为,红边特征、植被指数NDVI、叶绿素吸收深度与叶片铜含量关系显著,可以作为植被铜污染遥感图像特征提取的参考.

Pigments are of great importance in physiological and ecological processes of plants. Revealing the relationships between their characteristic bands in the spectral reflectance and the contents of photosynthetic pigments using hyperspectral data will help to understand the spectral reflectance characteristics of photosynthetic pigments and provide the technical supports for rapid non-destructive monitoring of plant photosynthetic pigments using hyperspectral remote sensing. In this paper, eucalyptus leaf samples collected in field were used to measure the hyperspectral reflectance of the leaves and the corresponding contents of chlorophyll, carotenoid in our laboratory. The spectral data were processed using spectral analysis techniques and analyzed using statistical methods to extract spectral characteristic parameters and subsequently to establish the estimation models of spectral characteristics and both chlorophyll and carotenoid contents. Precision tests proved that the best model is the exponential model using (SDr-SDb)/(SDr+SDb) as a variable, where SDr and SDb are red and blue edge areas, respectively.

色素在植物的生理生态过程中非常重要,利用高光谱数据,揭示光谱反射率上特征波段与光合色素含量间的关系将有助于理解光合色素光谱反射特征的规律,同时为利用高光谱遥感技术快速无损监测植物叶片光合色素提供了技术支持。利用野外采集的桉树叶片样本,在实验室内测定了叶片的高光谱反射率及对应的叶绿素、类胡萝卜素含量。利用光谱分析技术和统计学方法对光谱数据进行处理分析,提取了光谱特征参量,并建立叶绿素、类胡萝卜素含量与光谱特征参量间的估算模型。通过精度检验,研究结果表明以 (SDr-SDb)/(SDr+SDb) 为变量建立的指数模型估算效果最佳。